A study of suburban bird-life at Dollis Hill. By Eric Simms. (Plates 1-2)

Transcription

1 ritish irds Vol. 55 No. i JNURY 1962 study of suburban birdlif at Dollis Hill y Eric Simms (Plats 12) INTRODUCTION UNTIL THE PRESENT TIME no thorough or systmatic survy of th distribution and bhaviour of th birds of a suburban ara has appard sinc F. D. Powr's Ornithological Nots from a South "London Suburb, , publishd in This papr sts out th rsults obtaind by th author from th study of Dollis Hill, a suburban ara in northwst London. It is basd on dtaild obsrvations carrid out ovr a priod of mor than tn yars from January 1951 to th summr of 1961, whn I livd in th district, as wll as on spasmodic obsrvations from ugust 1943 to Dcmbr 1950, whn I was a frqunt visitor. Th ara chosn for study lis within 1,250 yards or lss of my hom and can b comfortably managd by on obsrvr; it contains fiv major habitats forming a fascinating, almost xclusivly manmad, cological unit. DESCRIPTION ND HISTORY OF THE RE Th study ara lis som fiv mils northwst of Marbl rch. It consists of approximatly 546 acrs (or fivsixths of a squar mil) and is containd in a rctangl formd to th north by th North Circular Road, to th wst by Duddn Hill Lan, to th ast by th Edgwar Road and to th south by th Midland Rgion railway, lin of ritish Railways (formrly part of th Midland and SouthWstrn Junction Railway). This rctangl of land is just ovr a mil across from wst to ast and slightly mor than thrquartrs of a mil from north to south (s Fig. 1). Th ara has th form of a shallow con on th London clay. Th land riss from btwn 115 and.172 ft abov salvl on th priphry to th highst point of 2 51 ft immdiatly to th ast of th Post Offic Rsarch Station. 1

2 RITISH IRDS FIG. I. Mapof th ara studid at DolsHiU, London, during , showing th major buildings, rsidntial parts, factoris, parkland and allotmnts Immdiatly to th north lis th rnt Rsrvoir and, although it has som ffct on th birdlif of th slctd ara, it was dlibratly xcludd so that undu wight would not b givn to any birds occurring in this rathr spcialisd habitat. Th ways in which th rsrvoir has any clar influnc on th birds of Dollis Hill will b xamind at various points in this papr. n arial photograph of th study ara and th rsrvoir is rproducd on plat 1. t th tim of th Enclosur ward of 1816, th study ara consistd of a 16th cntury farm at Oxgat (still in 1961 th oldst building in th orough of Willsdn), anothr farm at th top of Dollis Hill, a mansion known as Nasdn Hous and som 75 filds rsulting from th nclosur. Th rgion was typical opn farming country and th only road across th ara was Dollis Hill Lan which travrsd it from ast to wst. Dollis Hill Hous was built in 1825 and th railway which provids th southrn boundary to th ara in y 1895 th southwstrn cornr had bcom occupid by a golfcours. 2

3 SUURN IRDLIFE T DOLLIS HILL FIG. 2. Th study ara at Dollis Hill, London, at intrvals from 1875 to 1961, with th builtup parts in black Rsidntial building rally startd in th southast from , with a fw houss as wll in th southwst cornr. t this tim brding birds of th ara includd such spcis as Sparrowhawk,* Partridg, Corncrak, Cuckoo, Wrynck, Skylark, Swallow, Magpi, Trcrpr, lackcap, Gardn Warblr, Whitthroat, Lssr Whitthroat, ullfinch and Yllowhammr (Dixon 1909 and Kndall 1907). Of th major landmarks constructd in th first quartr of th cntury, th two most notworthy ar St. ndrw's Hospital, built in 1913, and th Post Offic Rsarch Station which ros in 1923 on th sit of th old Dollis Hill Farm. In th mid1920's Edgwar Road was dvlopd and thr was som smallscal building in th middl of th ara. So far a larg part of th study ara still rtaind much of its rural charactr, but a grat transformation took plac btwn 1928 and *Th scintific nams of all birds mntiond in th txt can b found in th summary appndix on pags 3536; othrwis thy ar givn only in th tabls. 3

4 RITISH IRDS 1930 whn 29 nw strts wr laid out in th cntr and thr was furthr dvlopmnt in th two southrn cornrs; this was also th priod in which th North Circular Road was built. From 1950 to 1932 furthr building pushd into th wstrn nd and into th factoryara of th northast. Within th nxt thr yars th total dvlopmnt of th wstrn sid of th ara was compltd. Sinc thn thr hav bn som xtnsions to factory prmiss, and a fw houss and small blocks of flats wr built aftr th war. Th John Klly Schools wnt up in 1958 on opn land north of th Rsarch Station. Fig. 2 shows th dramatic changs that took plac in th ara btwn 1928 and HITT Today th study ara can b convnintly dividd into fiv main habitats and ths will b dscribd in ordr of siz. /. Rsidntial ara This compriss privat houss and thir gardns, roads and a fw small blocks of flats, and rprsnts som 60% of th total ara. In all, thr ar slightly mor than 3,600 houss in th 330 acrs of th rsidntial district. Most of ths houss ar ithr trracd or smidtachd with small front gardns typically bordrd by low walls, railings, fncs or privt hdgs. Many hav som grass in th front, oftn with hydrangas, ross and prnnials, but incrasing numbrs of front gardns hav bn concrtd in. This has gnrally bn to sav labour or, during th last dcad, in th cas of trracd houss, to giv parking spac for th cars that hav com with incrasd afflunc. Th ffct of this is to concntrat birds in fding aras; it has crtainly not yt rsultd in a dcras in numbrs. Plat 2 shows a typical road and front gardn in th rsidntial ara. Th avrag back gardn is som 20 ft wid and varis from 50 to 100 ft in lngth. Excptionally, a fw smidtachd and dtachd houss hav back gardns of 200 ft in lngth. Most of th back gardns ar sparatd from ach othr by woodn fncs or palings, chainlink or walls, and thr has bn a slow but stady raction against th privt hdgs so popular 25 yars ago. Th most striking thing about th majority of ths gardns is that th top layr of tr or shrub growth is only about 20 ft high and in many gardns is far lowr than this. Many I hav sn, although thy ar 30 yars old, hav no vgtational growth abov six ft; on had a black currant bush as th tallst plant within it! Th highr growth to 20 ft or so is largly accountd for by ashtrs, flowring chrris, laburnums, lilacs, sycamors and by fruittrs such as appls, pars, 4

5 SUURN IRDLIFE T DOLLIS HILL plums and damsons. small numbr of ancint oaks, mostly staghadd, wr incorporatd in th stat whn it was laid out; ths rais thir strang archaic forms abov th rdtild rooftops and provid occasional prchs for Carrion Crows, Common Gulls, lackhadd Gulls and Starlings. Thr ar also a fw lms and Lombard^ poplars in th gardn aras. Quit a numbr of th roads in th rsidntial ara hav trs plantd on both sids. Th stat buildrs who bgan this wr rsponsibl for som not rally suitabl spcis that wr includd. Th commonst trs in th roads ar two spcis of lm (including th Jrsy lm), thr varitis of mountain ash, th London plan, th hors chstnut, th trofhavn, th sycamor, two spcis of acacia and four varitis of Norway mapl. Othr trs includ th silvr mapl, th nativ silvr birch, svn spcis of Cratagus, th laburnum, th whit and ncklac poplars, thr spcis of Prtmus, th whit bam, th crab appl, th whit willow, th broadlavd lim and a varity of ashs. fw, ancint indignous lms surviv along Dollis Hill Lan, th prstat road north of Gladston Park. Th gratr part of th rsidntial ara, as will b sn in Fig. i, lis in th cntr and wst of th district. Th typical brding birds hr ar th Hous Sparrow, Starling, lackbird and Dunnock. fw pairs of Woodpigons brd in roadsid trs, spcially lms and hors chstnuts, and in gardn trs of sufficint hight. Tits, Wrns and Robins cannot usually find nsting sits in ths gardns, and th Song Thrush no mor than an occasional wintr visitor to som of thm will only rarly attmpt to nst, sinc thr ar fw vrgrns or shrubs of sufficint hight or dnsity to giv it th protction it nds. 2. Factory ara Th scond habitat is mad up of th northrn block of factoris along th North Circular and th Edgwar Road, as wll as th Post Offic Rsarch Station which I hav includd hr bcaus of its massiv and xtnsiv natur. Ths and thir surrounds rprsnt som 15 % of th total ara. Most of th factory structurs ar slablik and up to 60 ft in hight; thy usually hav mown or unmown grass or rough ground in thir immdiat nighbourhood. Th rsarch station is an agglomration of buildings; som of concrt or brick ar of grat hight and dominat th top of Dollis Hill whil othr buildings ar lowr and of a lss prmannt natur. Thr is a small lak in th grounds frquntd by Mallard. Th typical nsting spcis of this ara ar th Fral Pigon, Hous Sparrow, Starling and Pid Wagtail. Carrion Crows us all ths high buildings as prchs or mting placs; on of thir favourit assmbly 5

6 RITISH IRDS points is on th radiomasts of th rsarch station. lackbirds will occasionally sing from factory rooftops and a pair onc brd in a workshop, }. Parkland Includd in this sction ar som 70 acrs of Gladston Park (north of th railway lin) and a small part of th grounds of St. ndrw's Hospital with tall trs, som hollis and grass; ths togthr rprsnt 13% of th total ara. Gladston Park is most plasantly sitd on th southrn slops of Dollis Hill. Th park incorporats Dollis Hill Hous a favourit rsort of W. E. Gladston as th gust of Lord brdn as wll as a swimming pool, a small lak nar th hous, tnnis courts, playing filds, a bowling grn and a formal walld gardn. For som yars aftr th last war much of th lowr part of th park was undr cultivation and a pair of Skylarks brd thr vry yar from 1946 to Th land was thn rhabilitatd and th larks disappard. Today most of th park consists of grass, intrsctd by svral fin avnus of London plans up to 70 ft in hight. numbr of th original oaks and lms, dating from th priod of th privat hous and including som magnificnt trs, ar scattrd ovr th grass. Thr ar also black poplars, hors chstnuts, and a fw chrris, almonds, hawthorns, Lombardy poplars, willows and othr trs. Shrubbris ar fw and asily pntratd by childrn. Only on shrubbry has any ral covr and this is mad up of laburnums, chrris, laurustinus and tamarisk growing through a thickr layr of brbris, flowring currant and Cydonia japonica. This is an important roost for thrushs. Th typical nsting spcis of this habitat ar Mallard, Woodpigon, Tawny Owl, Carrion Crow, Grat Tit, lu Tit, Wrn, Mistl Thrush, Song Thrush, lackbird, Robin, Spottd Flycatchr, Dunnock, Starling, Grnfinch, Chaffinch and Hous Sparrow. singl pair of Stock Dovs hld on until 1952, brd in 1954 and may hav don in 1953, 1956 and 1957 as wll. Sinc 1957 I hav not sn a singl bird in th park. Th shooting of Woodpigons from i960 onwards would prhaps hav providd too much disturbanc for thm had thy stayd. 4. llotmnts Thr ar fiv aras of allotmnts in th district. On is too small to hav any significanc and anothr has rvrtd to rough grassland. Th othr thr ar of considrabl importanc and can b sn in Fig. 1. Th largst is in th astrn cornr btwn Dollis Hill Lan and th railway lin: th scond lis on two sids of St. ndrw's Hospital and th third is immdiatly to th north of th Post Offic Rsarch Station. Ths allotmnts mak up 10% of th total ara. 6

7 SUURN IRDLIFE T DOLLIS HILL Th allotmnts in varying stags of cultivation, with thir occasional dns hawthorn, ldr and brambl bushs ar important fding aras for many birds spcially thrushs, Woodpigons, Wrns, Robins, finchs and sparrows. Mallard brd in som of th grass tussocks, Song Thrushs and lackbirds in th bushs, Wrns and Robins in low covr and against woodn fncs. In th migration sasons, warblrs of svral spcis ar rgular visitors. small shallow pond on th allotmnts immdiatly to th wst of th hospital, still with Iris psudacorus and Typha latifolia growing in it, is oftn visitd by Mallard and provids a drinking plac in all wintrs and som summrs for many diffrnt spcis. /. Spcial ara This, th fifth habitat, compriss only 2% of th study ara and yt it is on of th most important. It consists of thr parts: th first is a blt of sycamors, lms, lims, ashs, hors chstnuts and ancint oaks, with a ground covr of cow parsly, blublls, nttls and ivy and a tangld mass of hawthorn, privt, ldr and willow at on nd; th scond is an orchard with rough grass; and th third consists of working or disusd chicknruns. This spcial ara with its rural qualitis is a vritabl bird sanctuary. Th brding spcis includ Woodpigon, Carrion Crow, Grat and lu Tit, Wrn, Song Thrush, lackbird, Robin, Dunnock, Starling, Grnfinch, Goldfinch, Chaffinch, Tr Sparrow and Hous Sparrow. Hr th lackcap and th Willow Warblr hav also nstd. NUMER OF SPECIES RECORDED IN STUDY RE Sinc obsrvations first bgan I hav rcordd 70 diffrnt birds in th ara, and it is intrsting to not that 52 of ths hav occurrd in or ovr my own gardn in rook Road. Th total of 70 spcis can b subdividd in th following way: Rgular brdrs 21 Formr or occasional brdrs 4 Prsnt in summr but not brding 3 Wintr visitors 6 Passag migrants 21 Occasionally flying ovr 3 Vagrants 12 This figur ovr a priod of narly lvn yars compars favourably with th total of 63 spcis that I rcordd in Ladbrok Squar, Knsington (wst London), ovr thirtn yars. 7

8 RITISH IRDS SUMMER POPULTION Tabl i shows th spcis brding or prsnt in th brding sason during ach yar from It can b sn that th losss in this priod hav bn th Stock Dov and th Skylark. Th Jay has only rcntly com into th district: I hav always wondrd at th prvious absnc of this bird sinc it has for so long frquntd th cntral London parks and squars, Paddington Cmtry and th northrn bank of th rnt Rsrvoir. TLE I SPECIES REEDING OR PRESENT IN REEDING SESON T DOLLIS HILL, LONDON, indicats brding and p prsnt but not brding i Mallard {nas platyrhynchas) Kstrl (Fako tinnumulus) Stock Doy {Columba anas) Fral Pigon (C. livid) Woodpigon {C. palumbus) Tawny Owl (Strix aluco) Swift {pus apus) Skylark {tauda arvnsis) Carrion Crow {Corvus coron) Jay {Garrulus glandarim) Grat Tit {Parus major) lu Tit (P. caruhus) Wrn (Troglodyts troglodyts} Mistl Thrush {Turdus viscivorus) Song Thrush (T. pbilomtlos) lackbird (T. mruld) Robin {Eritbacus rubcula) lackcap {Sylvia atricapilla) Willow Warblr {Phylloscopus trochilus) Spottd Flycatchr {Muscicapa striata) Dunnock {Prunlla nodularis) Pid Wagtail {Motacilla alba) Starling {Sturnus vulgaris) Grnfinch {Chhris Moris) Goldfinch {Cardulis cardmtis) Chaffinch {Frmgilla olbs) Hous Sparrow {Passr dotmsiicus) Tr Sparrow (P. montanus) P P P P P P? i > P P *?? > P P P P???? i ' P?5 > P P P P P P P P P P From Tabl 1 it will b sn that th avrag numbr of brding spcis during was 21, with a minimum of 20 and a maximum in 1954 of?}. Ths figurs may b compard with th total of 22 nsting spcis discovrd by E. C. Rowbrry in 1956 during a cnsus 8

9 SUURN IRDLIFE T DOLLIS HILL ofa builtup ara in southwst London (Homs ta/. 1957). Similarly, during th avrag brding figur for Rgnt's Park and Primros Hill was 25 spcis (Wallac 1961), and for Hyd Park and Knsington Gardns 19 spcis, whil th avrag for St. Jams's and th Grn Parks during was 16 (Rp. Comm. Royal Parks, , , ). Th inclusion of th rnt Rsrvoir, which adjoins th study ara, would hav addd only fiv mor. It is clar, too, that th numbr of spcis is fairly static from yar to yar. NUMERS OF REEDING PIRS ND SELECTION OF NESTING SITES In 1951 only two pairs of Mallard brd in th ara; by 1961 th total had risn to svn or ight pairs. bout 90% of all thir nsts hav bn in rough grass on allotmnts, in gardns or in th grounds of th Post Offic Rsarch Station. Th rmaining 10% hav bn in hols in lmtrs som 1520 ft abov th ground. Whn th ducklings hatch, th adults usually tak thm down to th rnt Rsrvoir, somtims aftr journys of mor than 1,000 yards. vry diffrnt bird which ovrlaps th brding habitats of th Mallard is th Tawny Owl. From 1951 to 1956 two pairs nstd in Gladston Park and on pair in th hospital grounds. Thr was a fourth pair in th park from 1957 to 1959, but by i960 th total brding population in th ara was rducd to two pairs. ll th nsts hav bn in hols in lms 2025 ft abov th ground. Of th dovs, som 1415 pairs of Fral Pigons brd (a ris sinc 1951 of 78 pairs), and about 3640 pairs of Woodpigons (narly thr tims th numbr in 1951). Th formr spcis nsts in roofvntilators on th rsarch station and on high ldgs on a factory facad nar Stapls Cornr; thr ar fw availabl nsting sits in a comparativly modrn stat. Woodpigons hav built in acacias, lms, London plans, ashs, hors chstnuts and svral spcis of Prtmus, but I hav no rcords of buildings bing usd for brding sits. Of 187 nsts xamind, on was six ft abov th ground, ight wr 1015 f t > 132 wr 1520 ft and 46 abov 20 ft. Woodpigons somtims nst in such dns foliag that accss is difficult. Nsts hav somtims bn startd in midmarch and I hav known unfldgd young in arly Octobr. singl pair of Carrion Crows brd in Gladston Park from 1943 to 1961, and a scond pair in 1953 and nothr pair also nstd in th grounds of St. ndrw's Hospital during and Of th 29 nsts sn, 20 hav bn in lms, ight in sycamors and on in a black poplar. Crows forag ovr a wid ara and it would sm unlikly that th status of this spcis will altr much in th immdiat futur. 9

10 RITISH IRDS Only two spcis of tit nst rgularly. Th annual brding population of Grat Tits varis from fiv to six pairs; most of th nsts ar in stackpips, hollow trs and old walls. Th numbr of brding pairs of lu Tits rmains fairly constant at about nin pairs. Nsting sits ar similar to thos of th Grat Tit, but th lu Tit will mor radily us nstboxs in privat gardns, and for this rason th largr spcis is almost ntirly absnt from ths aras in th summr. Th Wrn is confind in th brding sason to Gladston Park, St. ndrw's Hospital and th adjoining allotmnts. Hr som svn pairs nst ach yar amongst crprs and ivy on fncs and shds, and in hols in old walls. t Dollis Hill th Mistl Thrush is a marginal spcis. Its main stronghold is in th park whr two pairs brd from 1951 to 1:954 and on pair only from 1955 to Thr has bn on attmpt to xtnd this rang and that was whn a pair nstd succssfully som 2 5 ft up in a tall Lombardy poplar in a privat gardn nar my hom; this tr was flld th following wintr. ll th nsts hav bn built btwn 18 and 30 ft abov th ground, usually in London plans, but somtims in lms, oaks and hawthorns. Th Song Thrush, on th othr hand, is rprsntd by six to ight brding pairs. Th chif limiting factor on its distribution is its consrvativ choic of nsting sits; all th nsts xamind hav bn fiv to 15 ft abov th ground and, with on xcption, in hollis or hawthorns. Dixon (1909) calld th Song Thrush "th commonst thrush" in northwst London, but now th lackbird asily outnumbrs it by 26 or 27 to on. During and btwn 185 and 195 pairs of lackbirds brd at last onc ach yar in th ara, and in th vry wt summr of 1958, whn insct food was plntiful, th total ros to mor than 200 pairs. With th lackbird, two broods ar rgular and thr not uncommon; in 1958 a pair that had built on top of a partially finishd Hous Sparrow's nst on a rainpip bnath th guttr of a nighbour's hous succssfully raisd four broods in th sam nst. t on stag th mal of this pair was simultanously fding th fldgd young of th third brood and th nwly hatchd nstlings of th fourth. Most of th nsts hav bn in trs and bushs, spcially ashs, London plans, pars, plums, ornamntal chrris, hors chstnuts, hawthorns, ldrs, almonds, syringas, wping willows, and ross on stumps and fncs. 'pair onc built on top of a clock in a workshop at th Post Offic Rsarch Station. Tabl 2 summariss th hights abov ground and th situations of all th lackbird nsts found in th ara. Th Robin is confind in th brding sason to Gladston Park, th grounds of St, ndrw's Hospital and som allotmnts. Svn to ight pairs nst ach yar in wall cavitis or dns crpr, or in grassy 10

11 SUURN IRDLIFE T DOLLIS HILL TLE 2 HEIGHTS ND SITUTIONS OF 611 LCKIRD (Turdus mmla) NESTS T DOLLIS HlLL, LONDON, I ft 510 ft 1015 f t 1520 ft 2025 f t 2550 ft In trs and bushs In crpr on walls On pips on walls On ldgs of fncs On stackd laddrs In shds and buildings banks on th allotmnts. Robins avoid th privat gardns in th summr as thr ar no suitabl nsting sits for thm. In 1958 a pair of lackcaps built six ft up in an ldr and in 1957 a pair of Willow Warblrs brought off a brood in a nst in rough grass. Th Spottd Flycatchr, howvr, has changd its status littl sinc Kndall (1907) rportd two pairs at Dollis Hill. During a pair has com ach yar and usually nstd about six ft up against a wall in th northastrn cornr of Gladston Park; a scond pair brd in th grounds of th rsarch station in Two pairs of Pid Wagtails, sparatd by about half a mil, nst at th rsarch station and at on of th factoris along th North Circular Road; ths dpnd on th rnt Rsrvoir and a small lak by th rsarch station for accss to watr. Th nxt two brding spcis ar closly associatd with man. Th Dunnock is widly distributd, with th annual numbr of brding pairs varying from 45 to 50. It is ssntially th bird of th privt and 99.5% of all th nsts hav bn in hdgs of this kind; tn othr nsting sits hav bn in hawthorn and lilac. Of th 214 nsts I hav found, 84.6% hav bn btwn thr and fiv ft off ground lvl and th rmaining 15.4% btwn fiv and ight ft. Th Starling is also a common rsidnt and from 250 to 275 pairs nst ach yar in th study ara; this givs a dnsity of about 50 nsts pr 100 acrs. Howvr, as Nicholson (1951) pointd out, dnsitis of 120 nsts pr 100 acrs ar known. Of th Starling nsts at Dollis Hill, 92% hav bn in houss and buildings and only 8% in hols in trs. From 1952 to i960 Starlings ntrd my own loft through a small gap undr th lad covring to a bay window; it was ncssary for th birds to squz and struggl for som fiv to ight sconds bfor thy could gt through, but ach yar a brood was succssfully rard in this sit. Thr spcis of finch brd in vry small numbrs ach yar and ar strictly confind to th ara of th park and th hospital. Thr, somtims four, pairs of Grnfinchs nst in ovrgrown hdgs or 11

12 RITISH IRDS shrubbris. On pair of Goldfinchs has brd in vry yar sinc 1953 and may wll hav don so in th two prcding yars; in 1956 and 1959 a scond pair ajso nstd. ll th nsts hav bn in hawthorns or appltrs. Two pairs of Chaffinchs brd in almonds or hawthorns in Gladston Park and on pair in an appltr nar th hospital. Th finchs ar ntirly dpndnt on th conditions availabl in ths two aras and any changs in thm could advrsly affct th status of all thr. bout 900 pairs of Hous Sparrows brd vry yar in th ara, which givs a brding dnsity of 3.3 birds pr acr. This figur can b compard with th dnsity of 4.3 birds pr acr found by S. Cramp in 43 acrs of loomsbury in 1950 and with th 4.0 birds pr acr countd in Lambth by W. G. Tagl (Homs t al. 1957); howvr, in a suburb of StocktononTs, Co. Durham, SummrsSmith (1959) found a dnsity of only on bird pr acr. Th total numbr of Hous Sparrows at Dollis Hill has rmaind constant throughout th dcad, although S. Cramp has rcordd a slow dclin in cntral London. Narly all th nsts hav bn built in hols in roofs, vntilators and pips. I also hav rcords of fiv nsts in hawthorns in Gladston Park, of svn nsts among crprs on walls and of on nst which was constructd in th opn, rsting on a rainpip whr it curvd towards th wall from th shltring guttr abov. Nsts in my own loft hav somtims bn built on th floor with opn cups or suspndd from th undrsid of a til with th classical domd form. Th chif matrials usd hav bn drid grass, spcially common couch and annual madow grass, roots and, from my own gardn, th dry stringy lavs of th lilyofthvally. Fathrs ar oftn usd for nstlinings and Hous Sparrows may travl as much as 400 yards to bring fathrs from th hospital chicknruns. Dog hairs ar also collctd. rding has takn plac in vry month of th yar at Dollis Hill and two or thr broods ar usual. I hav rcords of 153 broods bing fd in Octobr, 52 in Novmbr, 24 in Dcmbr, 20 in January, 12 in Fbruary and 316 in March. Dad fathrlss nstlings ar oftn found lying in th strt. Tr Sparrows wr prsnt in th summrs of 1951 and 1952 in th spcial habitat ara (pag 7), but brding was not provd until Sinc thn two pairs hav crtainly nstd in vry yar up to Th nsts hav invariably bn in hols in old oaks som 1620 ft abov th ground. In th sam priod Tr Sparrows hav nstd at arn Hill, Mill Hill and th rnt Rsrvoir, but th tiny Dollis Hill colony is th narst to th cntr of London in this dirction. Th birds ar sdntary all th yar round and fd rgularly on th allotmnts. 12

13 SUURN IRDLIFE T DOLLIS HILL SIZE OF REEDING POPULTION Many cnsuss wr rgularly and systmatically carrid out ach yar to chck and rchck th siz of th brding population, most bing undrtakn in th vnings or arly mornings. In fact, mor than 2,000 such counts wr mad during , in ordr to arriv at as clos as possibl an stimat of th annual brding population. In 1951 th total numbr of brding pairs of all spcis was btwn 1,445 an< i i>5, giving a dnsity of 5253 birds pr tn acrs. Th i960 total was slightly highr from 1,480 to 1,525 pairs but this also gav a dnsity of 5253 birds pr tn acrs. This dnsity figur can b compard with 1922 birds pr tn acrs in Rgnt's Park (Wallac 1961), and my own rcords of 48 birds pr tn acrs in an ara of north Oxford gardns in 1946 and 98 birds pr tn acrs in th Ladbrok Squar district of Knsington bfor th last war. Som of th national avrags for brding dnsitis of birds pr tn acrs ar as follows: Rough grazing Prmannt grass Dciduous woodland Mixd woodland uiltup aras Parks Th figurs for Dollis Hill ar thrfor comparabl to thos for mixd woodland and builtup aras. It would b most valuabl to hav a wid sris of figurs availabl for diffrnt kinds of ara of houss and gardns. Th high figur for Knsington suggsts that mor dnsly builtup aras with som opn spacs may b mor attractiv to birds than suburban districts. Wallac's low figur is du largly to th prsnc of many opn grass swards in Rgnt's Park. n xampl of th kind of dnsity that xists in Dollis Hill is as follows. In i960 thr wr within 180 ft of my own hous 17 lackbird nsts, 15 TLE 3 FIGURES SHOWING THE TENDENCY FOR COMMUNITIES TO CONSIST OF UNRELTED SPECIES uthor Locality % of gnra with only vrag numbr of on spcis prsnt spcis pr gnus Elton (1946) Cramp (1949) Wallac (1961) Simms Simms Simms Svral communitis Rgnt's Park (1947) Rgnt's Park (1959) Ladbrok Squar (1937) Dollis Hill (1951) Dollis Hill (i960) i37 i

14 RITISH IRDS Hous Sparrow nsts, four Starling nsts, two Dunnock nsts and on Woodpigon nst. Cramp (1949) and Wallac (1961), in thir studis of th birds of Rgnt's Park, corrlatd thir data with thos of Elton (1946) who, in a wid survy of cological communitis, found a high and fairly constant prcntag of gnra with only on spcis prsnt. Tabl 3 compars thir figurs and Elton's with min for Ladbrok Squar (1957) and Dollis Hill (1951 and i960). HEIGHTS OF NESTS Rcords wr also kpt of th hights of 4,266 nsts of 23 diffrnt spcis. This part of th survy covrd all natural and manmad sits in ordr to find out whr th altitudinal wight of th brding population was to b found. Tabl 4 givs th prcntag distribution of nsts according to hight. It will b sn that two layrs thos of 510 and 2025 f t account for mor than 89% of all th nsts rcordd. Th lowr layr is largly occupid by th lackbird/ Dunnock community and th highr layr by th Starling/Hous Sparrow on. TLE 4 PERCENTGE HEIGHTS OF 4,266 NESTS OF 23 SPECIES T DOLLIS HILL, LONDON, Ground 05 ft 510 ft 1015 ft 15zo ft 2025 ft Ovr 25 ft '5 /o 3* Z /O 136% 23% 37% 758% o.9% SONG ND DISPLY Full rcords wr kpt of song sasons and any displays that wr sn. Th paragraphs which follow summaris th mor intrsting aspcts of ths obsrvations. ginning with th dovs, song from th mal Stock Dov oftn prsnt in Gladston Park during was vry infrqunt, as might b xpctd, sinc thr wr no adjoining trritoris of othr birds of this spcis. Fral Pigons sing and display in vry month of th yar, and I hav also hard song from Woodpigons in vry month, though it is most rgular from midfbruary to midsptmbr. Th only othr nonpassrin that should b mntiond hr is th Tawny Owl: hooting is at its hight in lat Sptmbr and Octobr whn trritoris ar st up. Grat Tit song normally bgins towards middcmbr and arly January, and lasts until July; thr is thn a partial rsumption in arly autumn. Similarly, lu Tits oftn sing from Dcmbr to July with a rsumption in Sptmbr. I hav hard song from Coal Tits in 14

15 SUURN IRDLIFE T DOLLIS HILL March, pril and ugust. Wrns sing in vry month of th yar, but most strongly from Fbruary to July; th song givs a clar indication of th autumn sprad of this spcis into privat gardns away from th brding trritoris. Turning now to th thrushs, I hav hard subsong from Mistl Thrushs from Dcmbr to March and full song from Dcmbr to May. In th cas of th Song Thrush, my arlist autumn dat for full song is 6th Octobr and this is thn maintaind through until arly July; subsong is frqunt in Sptmbr and Octobr. lackbirds may bgin in Dcmbr, but thy normally start up in midfbruary and go on until July. For thr conscutiv Fbruaris a mal bgan his subsong on th ground undr som dns rhododndrons in my front gardn; thn aftr a day of full song in this strang location h movd up to th guttrs and chimny of my hous and ths bcam his rgular songposts for th rst of th sason. y making xtnsiv tap rcordings of this individual I was abl to trac th dvlopmnt of his song. Subsong in his third yar was comparabl, for xampl, to full song in his scond yar; it was not until his third sason that his song assumd its fullst rang, varity and bauty. Th autumn song of th Robin bgins ach yar btwn 10th and 20th ugust. I hav hard full song from Dunnocks in vry month of th yar; display is at its hight in March and I hav svral spring rcords of th curious cloacapcking which was first dscribd in 1933 by Edmund Slous. In th cas of th Starling, song is rgular in vry month of th yar but most frqunt from midjuly to arly Jun. Indirct vidnc of Continntal immigration cam from on which gav prfct imitations of th fluting song of th Goldn Oriol in my gardn in Fbruary 1952; Starlings in th ara hav also producd imitations of uzzard and Littl Owl which thy must hav hard lswhr. In addition, I hav rcords of Starlings mimicking th song and low alarm of a lackbird, th song of a Song Thrush and th calls of Chaffinch, Carrion Crow, Grnfinch, Mallard and Tawny Owl. Othr imitations hav includd th miaows of Cats, th squals of braks and, on on occasion, a dut with a crying baby which was so good that it was almost impossibl to sparat th two prformrs. Turning to th finchs, Grnfinch song lasts from lat Fbruary to arly ugust, whil full Goldfinch song bgins in midmarch and continus until midjuly. Th first Chaffinchs in full song can b hard ach yar btwn 6th and 17th Fbruary, with th 14th as th avrag. For th Hous Sparrow I hav rcords of song and communal display in vry month of th yar, but th lattr, occurring strongly in January, rachs a pak in pril and thn bcoms lss frqunt ach month until Dcmbr. 15

16 TLE 5 SONG POSTS USED T DOLLIS HILL, LONDON, = 100 and ovr c= 25 and ovr =Two and ovr = 50 and ovr d= 10 and ovr (=Ononly Houss Gardns Strts On ground Window sills Guttrs Stack pips Roof ridgs and gabl nds Chimny stacks Chimny pots TV arials Factory roofs Fncs and posts Walls Low hdgs and bushs Tall bushs Trs Gardn shds Strt trs Lamp standards Tlgraph pols Stock Dov (Columba onas) Fral Pigon (C. livid) Woodpigon (C. palumbus) Tawny Owl {Strix alucd) Grat Tit (Parus major) lu Tit (P. carulus) Wrn troglodyts troglodyts) Mistl Thrush (Turdus viscivorus) Song Thrush (T. philomlos) lackbird (T. mrula) Robin (Erithacus rubcula) lackcap {Sylvia atricapilla) Willow Warblr {Phylloscopus trocbilus) Chiffchaff(P,&. collybita) Dunnock {Prunlla /nodularis) Pid Wagtail (Motacilla alba) Starling {Sturnus vulgaris) Grnfinch (Chloris Moris) Goldfinch (Cardulis cardulis) Chaffinch (Fringilla colbs) Hous Sparrow (Passr domstkus) Tr Sparrow (P. montanus) _ c c ē i c ē _ d c c c _ d d i c i d c d d c c ē c c Ā _ c d d d c c ē d c c d c c d ē t / ē

17 TLE 6 NUMERS OF OSERVTIONS OF DIFFERENT TYPES OF TELEVISION ERILS S SONG POSTS, DOLUS HLLL, LONDON, I95I Yagi array (cross mmbr) Woodpigon (Columba palumbus) lu Tit (Parus cturultus) Song Thrush (Tardus pbilomlos) lackbird (T. mrula) Willow Warblr (Phylloscopm trochilus) Dunnock (Prunlla modularis) Dipol 4 Dipol brackt Htyp (upright) 1 1 Htyp (cross mmbr) Xtyp (diagonal) i 15 1 Xtyp (intrsction) Yagi array (singl upright) i Yagi array (doubl upright) Starling (Sturnus vulgaris) , Grnfinch (Chloris Moris) Hous Sparrow (Passr donasticus) ,

18 RITISH IRDS SONG POSTS Vry littl has bn publishd to dat about th choic of song posts in builtup aras, though Fittr (1949) dscribd lackbirds and Song Thrushs as occasionally singing from rooftops in London and Hulm (1955) rportd ight diffrnt spcis using buildings as song posts in on builtup part of th Midlands; in th London ara, too, th Woodpigon has bn rgularly notd as using buildings for singing and displaying (Homs t al, 1957). t Dollis Hill th lackbirds quit rgularly, and th Song Thrushs not infrquntly, us buildings as song posts and I hav notd 14 othr spcis taking advantag of som part of a prmannt building (including radio and tlvision arials) as a point of vantag for singing. Tabl 5 summariss my rcords of song posts ovr a priod of tn yars. bird had to sing at last on full phras of song to qualify for inclusion. Tlvision arials crtainly rprsnt idal song posts for such spcis as lackbird, Starling and Hous Sparrow and thy ar, on occasion, usd by much lss likly birds (Tabl 6). In 1951 tlvision arials wr infrqunt at Dollis Hill and it has bn most intrsting to trac, with th growth in thir numbr, thir incrasd us as vantag points for singrs. (Incidntally, in 1961 I saw a Corn unting bgin to us a tlvision arial on a nw housing stat at Ptrhad, brdnshir, shortly aftr it was rctd.) Of th nin chif prching placs associatd with arials, only th Starling has so far bn abl to us all of thm as song posts. Th Hous Sparrow has usd svn and th lackbird six. Of cours, in th London ara th tlvision arials ar normally vrtically polarisd. WINTER POPULTIONS With th coming of wintr thr is a chang in numbrs of som of th rsidnt spcis, as wll as th arrival of svral wintr visitors. Sinc th bginning of th prsnt cntury th Mallard has incrasd normously at this sason in th London ara. In th wintr of 1951 it was not unusual to s a handful of ths birds by th small lak in Gladston Park, but thr wr nvr mor than 20. y th wintr of 1952 th maximum had risn to 33, by 1956 to 52, by 1957 to 67 and by 1961 to 71. It should b addd, howvr, that this local incras can to som xtnt b dirctly corrlatd with th incras in human visitors fding thm. Mallard flight twic a day btwn th park and th rnt Rsrvoir and pass ovr my hous whil doing so, a habit which has nabld m to watch th stady ris in numbrs throughout th dcad in addition to making rgular counts in th park itslf. In lat wintr it is also intrsting to watch th disprsal of Mallard into gardns and allotmnts, and throughout th park, in thir sarch for 18

19 SUURN IRDLIFE T DOLLIS HILL brding sits; I hav sn up to 21 birds at a tim sitting in lms, oaks and plan trs in Gladston Park in th arly morning. Thr is also a disprsal of som of th othr brding spcis into parts of th study ara whr thy ar rar or unknown in th summr. From Sptmbr to Fbruary ach wintr up to fiv Grat Tits will visit my gardn and birdtabl, and forays into othr privat gardns ar frqunt during this priod. lu Tits ar also rgular visitors; in Dcmbr 1957 mor than a dozn wr prsnt in my gardn and by 3rd Fbruary 1958 th party had grown to 20. During this tim incrasd numbrs of lu Tits wr rportd from Innr London survivors of th autumn irruption of 1957 but it is intrsting to not that thr wr no attacks on milkbottls, papr or putty at Dollis Hill, such as thos which occurrd in cntral London, Hampstad and alham. Grnfinchs, Goldfinchs and Chaffinchs com in wintr to quit small gardns in sarch of plant sds and thr is also a disprsal of Wrns and Song Thrushs. In addition, Robins will appar in gardns to tak up wintr trritoris. singl Robin arrivs in my own gardn ach yar btwn 23rd July and 3rd ugust; it sings rgularly, visits th birdtabl, fights off intrudrs and rmains until midmarch. In wintr, too, rsidnt birds ar oftn concntratd in aras whr th covr is good. For xampl, in any fivminut priod from dawn to dusk on 20th January 1958 thr wr nvr lss than 16 individuals of four spcis in my own gardn; at on tim th numbr ros to 39 individuals of ight spcis. On 21st January 1958 thr wr nvr lss than 14 Hous Sparrows in my gardn (20 ft by 180 ft) at any on tim from 8 a.m. to 4.15 p.m. and for mor than twnty minuts in th aftrnoon thr wr ovr 200. Th six rgular wintr visitors to Dollis Hill ar th Madow Pipit, which at this sason can b flushd from th grass in Gladston Park or on th allotmnts, and fiv spcis of gull. Until th wintr of th lackhadd Gull was th commonst of ths. Evn fifty yars ago Kndall (1907) dscribd it as "of frqunt occurrnc" and so it would sm to hav bn a rgular wintr visitor for th last half cntury. Th lackhadd Gulls hav drivd bnfit from th incrasing numbr of popl who fd thm rgularly, but thy ar much harassd by Common Gulls. lackhadd Gulls normally appar in numbrs in th study ara in lat ugust and arly Sptmbr and rmain until arly pril, but in 1952 and 1961 advanc arrivals cam in strngth in July. I hav watchd as many as 70 in th air at on tim, and svral daily watchs of 10 hours' duration ach in January 1958 showd that at last on and somtims as many as 24 wr in sight from my hous in vry fivminut priod. lackhadd Gulls also rgularly us oaks, rooftops and chimnypots as T 9

20 RITISH IRDS rsting placs. Thy covr th privat gardns most diligntly in thir sarch for scraps and oftn assmbl on th grass in Gladston Park to hunt for worms. Th Common Gull occurs in wintr on th rnt Rsrvoir but during I had only a singl isolatd rcord of on at Dollis Hill (1st Novmbr 1947). Thn a fw appard in th wintr of and by th numbr had risn to 20. Ths Common Gulls wr shy and always obtaind thir food indirctly by harrying lackhadd Gulls which had pickd up scraps from th ground. y Common Gulls outnumbrd th smallr spcis and, bsids parasitising th lattr, thy also obtaind thir own food dirct. In it was not unusual to s up to 30 Common Gulls sitting on staghadd oaks, rooftops and chimnypots. Thy arriv in Sptmbr or Octobr and rmain until March. Sinc Fbruary 1958 quit larg congrgations hav appard tmporarily on th grass in Gladston Park, for xampl on 2nd Fbruary 1958 (300), roth Fbruary 1959 (163, and on this day thr wr also 830 on th rnt Rsrvoir), 13th Fbruary i960 (180) and 21st Fbruary 1961 (85). Sag (i960) has shown that "thr must b a larg influx of Common Gulls into th London ra during th priod Fbruary to pril to augmnt th wintr population". Lik th Hrring Gull, this spcis has addd anothr nw habitat that of suburban builtup aras to thos of frshwatr and grassland. Its adaptation took littl tim and was most succssfully accomplishd. Until th wintr of th Hrring Gull was a July migrant flying across th survy ara. From that tim small numbrs (up to 14) hav wintrd and othrs hav appard in May, Jun and ugust. Thr hav oftn bn Hrring Gulls on th rnt Rsrvoir, but it is only in th last thr yars that thy hav bcom rgular visitors to th builtup ara, sarching for food in gardns, chicknruns and othr opn spacs, and occasionally prching on rooftops. This is crtainly a movmnt into a nw habitat. Th wintring birds arriv in Sptmbr and lav again in midmarch. I hav svral tims hard thir massd trumpting displays ovr Dollis Hill in arly March. Th Lssr lackbackd Gull is bst known in th ara as a lat summr and autumn migrant with movmnts bginning in th last wk of May or arly Jun and lasting until Sptmbr. Sinc th wintr of a fw hav appard ach Dcmbr and ths can b sn quartring gardns until March or pril. I hav sn svral hundrds by th rnt Rsrvoir btwn July and Novmbr, but thy stay in th immdiat vicinity of this pic of watr. It is intrsting to not that Harting (1866) dscribd this gull as "a rar bird in Middlsx" and Kndall (1907) usd th sam trms for its status in northwst London at th bginning of th cntury. n individual 20

21 SUURN IRDLIFE T DOLLIS HILL of th Scandinavian form {h. f. fuscus) usd a flagpol nar th hospital as a prch in Sptmbr 1951 and During th Grat lackbackd Gull incrasd gratly in th London ara, but at Dollis Hill only rar individuals appard in th wintr months up to Octobr i960 whn thr was a dfinit incras. Som wr thn prsnt until Fbruary 1961 and, with othr spcis of gull, visitd th chicknruns at th top of th hill. t last fourfifths of th birds of this spcis hav bn adults. ROOSTS Most of th roosts in th study ara ar faturs of th wintr months, but som ar stablishd or maintaind during th summr as wll. Fral Pigons roost on th Post Offic Rsarch Station and on or two of th factoris. Woodpigons almost invariably choos th tallr lms and London plans in Gladston Park and hr I hav sn as many as a hundrd. Th only Tawny Owl roosting placs I hav found hav bn in lms. Th most important communal wintr roosts for Song Thrushs and lackbirds ar a clump of bushs in th park and a hdg nar th hospital, but I know many smallr lackbird roosts of from thr to twlv birds and ths ar, in fact, mor typical of th district. I hav found ths small roosts in tall ovrgrown privt hdgs, almonds and hawthorns. Evry wintr thr is a small lackbird roost of thr to fiv birds in a tall syringa in my own gardn. Dunnocks I hav only found roosting in privt and snowbrry hdgs, from which bursts of nocturnal song ar thn not uncommon. Dollis Hill lis wll within th catchmnt zon of th cntral London Starling roosts. Crtainly a numbr of birds from th ara and also from th northwst as far out as Stanmor and Edgwar fly into th cntr of th Mtropolis. For at last nintn yars on of th flightlins has passd southast ovr th Post Offic Rsarch Station and anothr has followd roughly th cours of th Edgwar Road, just insid th study ara. Howvr, som 3,500 Starlings from th lattr flightlin onc st up a subsidiary roost in som Lombardy poplars in th factory ara, instad of going on into cntral London. Th roost was startd in ugust 1951 and lastd until th lavs bgan to fall from th trs in Octobr of that yar. It was intrsting to s that a numbr of Starlings from th Edgwar district flw stadfastly on ovr th nw roost on thir way to cntral London, though from tim to tim th whistls and chattrs of th birds in th poplars blow would ntic a fw down from th passing flocks. No othr communal Starling roost has appard in th study ara, but som Starlings roost in thir nsting hols during th wintr months. On pair rgularlyspnt thir nights in th roof of my hous, aftr brding thr, for 21

22 RITISH IRDS thr conscutiv wintrs. It has bn suggstd that it is unlikly that many adults bgin to roost in thir nsting hols as arlv as Novmbr, but my own pair cam in vry night summr and wintr without a brak; thr was crtainly not vn any qustion of th mal roosting lswhr during incubation. Thr ar many small Hous Sparrow roosts in th district, chifly in crprs on houss, and numbrs may rach as high as 50. largr roost of up to 100 occurrd in hawthorns in th grounds of St. ndrw's Hospital during th wintrs of and During th priod undr rviw, howvr, th rally grat Hous Sparrow roosts hav bn outsid th study ara. Th first was in som plan trs in th Edgwar Road about 400 yards south of th railway lin and this drw to itslf th gratr part of th wintr population of Hous Sparrows in Dollis Hill. In th wintrs of to th roost movd to dns hawthorns by th far sid of th Edgwar Road nar Dollis Hill Lan and only fiv yards outsid th study ara. This group of thorns also drw most of th Dollis Hill birds ovr a radius of just ovr a thousand yards. Counts showd a maximum of 750 sparrows at this roost in January and Fbruary, but smallr numbrs us it in vry month of th yar. In th wintr of thr was an ovrspill across th Edgwar Road into two or thr thorns in som front gardns just insid th study ara, but in Sptmbr 1961 th whol roost movd back to its original sit 400 yards outsid th survy ara. curious phnomnon is th stting up of shorttrm summr roosts by Hous Sparrows. It first cam to my notic at th bginning of May i960 whn som 3040 adults bgan to roost in th syringa in my gardn; this lastd for just ovr thr wks and was usd vry night. Th sam thing happnd again on th vning of 29th pril 1961, with a dozn birds assmbling, and lastd for a fortnight. PSSGE MOVEMENTS Systmatic obsrvations hav also bn mad of th various migrants which appar in th study ara. Th total of migrant spcis notd is 21, of which nin hav bn rprsntd by only singl rcords. Th rmaining 12 spcis hav bn of mor or lss rgular occurrnc. Som of th spcis listd prviously as summr or wintr visitors may also appar as migrants, spcially gulls and Starlings. Th first tru migrants of th yar pass in Fbruary; ths ar nightflying Rdwings (whos movmnts continu until th first wk of pril) and dayflying Rooks and Jackdaws. ll th Rooks I hav sn'hav bn going ast or southast, but th Jackdaws mak for points btwn north and ast. Chaffinchs in small numbrs mov north in th arly morning in pril; and Swallows and Hous Martins 22

23 SUURN IRDLIFE T DOLLIS HILL gnrally appar from th first wk of th month, though thy do not turn up vry yar. n occasional Cuckoo and a rgular sprinkling of Willow Warblrs occur in pril, but I hav only on spring rcord of a Chiffchaff. In lat pril and arly May th summr population of Swifts and Spottd Flycatchrs arrivs. Th avrag dat for th Swift is 2nd May (though it may b as arly as 25 th pril or as lat as 6th May), whil th Spottd Fhxatchr rturns btwn 6th and 10th May. In May and arly Jun thr ar somtims northrly movmnts of Hirundins and larg influxs of Swifts. In som yars Lssr lackbackd Gulls can b sn on th mov in May, but thir tru migration normally starts in lat Jun. Thr ar two spcis which rval midsummr movmnts. Firstly, I hav rcords of partis of 11 Lapwings on th mov on 1 2th July 1956, six on 24th Jun 1959 and four on 29th May i960; it is possibl that ths originatd on th Continnt. Scondly, in thundry and disturbd wathr in lat Jun and July th numbrs of Swifts may tmporarily ris in a spctacular mannr, and I hav somtims sn as many as 400 undr ths conditions. July and ugust ar usually markd by passags of Lssr lackbackd Gulls, Willow Warblrs and a Cuckoo or two. Th autumn movmnts of th Willow Warblr tak plac btwn 17th July and 29th ugust, oftn with two paks about 6th and 25th29th ugust; birds not only appar in th park, on th allotmnts and in th hospital grounds, but in privat gardns and vn in trs in th strts. Th sason of th Chiffchaff's autumn passag is latr and lasts from 1st ugust to 20th Sptmbr. ChifFchaffs spcially favour th brambls and black currant bushs of th allotmnts; hr on Sptmbr morning thr wr mor than 100, about tn of thm bing in song. Linnts and Whitthroats may also appar and th Swifts hav usually lft Dollis Hill by about 24th ugust (dats rang from 15 th ugust to 2nd Sptmbr). In Sptmbr and Octobr I hav sn movmnts of Lapwings, Stock Dovs, Woodpigons, Rooks and Jackdaws, Pid and Gry Wagtails, Grnfinchs, Siskins and Tr Sparrows. Th Swallow is rgular on autumn passag; movmnts bgin about nth Sptmbr and continu into Octobr with a pak about 20th Sptmbr; my latst rcord is 5 th Octobr. Ths Swallow passags ar almost invariably into th wind and th birds fly low and in a narrow lin across th top of th hill. Thy occur most frquntly from on to thr hours aftr dawn, but in xcptional instancs, for xampl on 20th Sptmbr 1952, may last until th aftrnoon. Th movmnts of th Hous Martin bgin in lat Sptmbr andrach thir pak in arly Octobr; on 4th Octobr 1952 as many as 700 passd through. 2 3

24 RITISH IRDS ll th passags of this spcis hav bn into winds of light or modrat strngth. lackbirds can somtims b hard calling at night as thy pass ovr th ara in Octobr and I onc saw 13 flying SW in daylight on 22nd Octobr Most rcords of th Fildfar ar in Octobr and Novmbr; typical xampls ar of partis flying SW (with small numbrs dropping down to fd) on 9th and nth Novmbr 1951 and groups flying NW on 16th Octobr 1955, th lattr bing part of a widsprad movmnt which was also notd in Essx, Knt and Surry. Th autumn migration of th Rdwing lasts from th first wk of Octobr to th first wk of Novmbr. Th thr havist Rdwing nights of th many on which I carrid out counts wr 20th Octobr 1952, 16th Octobr 1955 and 17th Octobr On th last of ths I hard mor than 2,000 calls btwn 6.30 p.m. and p.m. and similar rports cam in from ddington in Surry and from two placs within th City of London. Diurnal movmnts of Rdwings somtims tak plac in Octobr and ths can, of cours, b watchd. Quit havy ons occurrd on 16th Octobr 1955, 14th Octobr 1957 and 16th Octobr i960. On th last dat 472 passd ovr btwn 7.45 a.m. and a.m., all travlling btwn NW and north from 50 to 150 ft abov th ground. Skylark movmnts bgin in midsptmbr and go on until th nd of Octobr; most of thm ar in dirctions btwn SW and NW and would sm to b of Continntal origin. Thr was a considrabl NW passag of ths birds ovr Dollis Hill on 27th Octobr 1956 and similar flights wr sn that day at Stains rsrvoirs in Middlsx and at thr placs in Essx. nothr autumn passag migrant is th Madow Pipit; this can b sn on th mov from 14th Sptmbr to 4th Octobr, with a pak gnrally about 21st Sptmbr. Most Madow Pipit movmnts tak plac in th arly morning and I hav many rcords of birds passing ovr ithr singly or in flocks of from two to nin in siz. 81.5% of migrating Madow Pipits hav bn flying btwn SW and wst, 11.1% btwn NW and north, and 7.4% btwn NE and SE. I hav no obsrvations of migration continuing throughout th day, as not infrquntly happns along th Cotswolds in autumn. Of th many Starlings in vidnc in th autumn it is possibl to sparat th tru migrants from th birds flying from thir roosts by th tims of movmnt. For xampl, on 4th Novmbr 1951 ovr a hundrd flw SW ovr Dollis Hill som 11 hours aftr th last ons had arrivd from th cntral London roost. Th havist passag I hav rcordd was on 16th Octobr i960 whn 3,290 birds passd ovr btwn NW and north from 7.15 a.m. to n. 15 a.m. Th pak lay btwn 8.0 and 8.15 a.m. whn 1,100 flw ovr; partis varid in 24

25 SUURN IRDLIFE T DOLUS HILL siz from 20 to 600. Th cloud bas was at 100 ft, lifting at 9.07 a.m., and thr was a light brz from NNE to NNW. Th Chaffinch is undoubtdly on of th most rgular of th diurnal autumn migrants. Th priod of autumn passag lasts from 19th Sptmbr to 27th Octobr and in such yars as 1955, 1956 and i960 th paks hav bn quit imprssiv. On 27th Octobr 1956 mor than 500 Chaffinchs flw NW btwn 8.55 a.m. and a.m., at th sam tim as big movmnts wr also rportd from Harold Wood and Swardston in Essx. On 16th Octobr i960 1,517 Chaffinchs flw btwn NW and north ovr my hous from 7.45 a.m. to a.m.; partis varid in siz from singl birds up to 35 and as thy passd by 50 ft or so abov th ground my wif and I had no difficulty in counting thm. Th movmnt was crtainly on a broad front and it was likly that mor than 30,000 Chaffinchs passd ovr th whol ara that morning. In vry yar thr is always a crtain amount of broadfront migration to b sn and somtims, as on 16th Octobr i960, it may b vry havy indd. On that day, from 7.15 a.m. to a.m., w countd 5,889 birds of svn spcis flying north or northwst ovr Dollis Hill. Ths sasons of migration ar always of outstanding intrst and Dollis Hill can, in fact, somtims offr xampls of visibl migration comparabl in wight to thos that occur along hillscarpmnts or rivrvallys. On 5th Novmbr 1961, for xampl, whn a hug immigration of lackbirds and Fildfars was notd on th ast coast, mor than 1,000 Fildfars flw NNW ovr my hous btwn 8.10 a.m. and 3.52 p.m. During th arly yars of my migration watchs at Dollis Hill 1 was rasonably crtain that all th movmnts I saw wr on a broad front and this has bn largly confirmd by paralll obsrvations in th London ara. Yt it would now sm that Swallows and Hous Martins in th autumn and Rooks, Jackdaws and Chaffinchs in th spring us th conspicuous top of th hill as a landmark, sinc th partis ar always sn flying ovr th summit and not th lowr slops. ll fiv spcis travl ovr th highst point in a narrow stram. SPECIES OCCSIONLLY FLYING OVER THE RE part from th Swift and Kstrl, which nst outsid but nar to th ara, thr ar thr spcis in this catgory Hron, Mut Swan and Lapwing. Hrons and Lapwings pass ovr at many diffrnt tims of th yar. ny Mut Swans flying ovr com invariably from th rnt Rsrvoir. VGRNTS ND RRE PSSGE MIGRNTS This group includs such spcis as th Whitfrontd Goos, Sparrow 25

26 RITISH IRDS hawk, Hobby, Prgrin, Phasant, Curlw, Whimbrl, artaild Godwit, Grnshank, Glaucous Gull, Turtl Dov, Littl Owl, Kingfishr, Grat Spottd Woodpckr, Sand Martin, Coal Tit, Rdstart, Gry Wagtail, Crossbill, Yllowhammr and Srin. Th Srin may hav bn an scap lik th 12 udgrigars, on Lovbird and on frican Gry Parrot which hav visitd my gardn ovr a priod of tn yars. HRDWETHER MOVEMENTS Th coming of cold wathr oftn brings about an incras in th numbrs of som spcis and it is also possibl to watch movmnts of birds across th district. spll of svr wathr may rsult in a tmporary incras in Grnfinchs, Goldfinchs, tits and gulls. During th cold wathr of January 1955 two Fildfars appard in my gardn for on day; and on 20th Fbruary 1955 anothr, on its own and vry hungry, arrivd and fd for fiv hours on som of th appls I had put out in th snow for th lackbirds. This individual rmaind until 1 ;th March 1955; it fd and roostd in my gardn and spnt many hours chasing lackbirds up to distancs of 150 yards from th gardn bfor rturning to fd again. On 24th January Fildfars flw SSE ovr my hous on a day whn othrs wr rcordd at Dulwich Park and Sutton in Surry and St. Jams's Park in Innr London. In th cold conditions of January 1958 a party of 40 Rdpolls visitd my gardn; this visit could not b xplaind by th prsnc of any food sourc and it would sm that ths tird birds wr tmporarily attractd to th shltr of my wlldvlopd fruittrs. Of visibl wathr movmnts, th most important hav all bn in th month of January in 1955, 1958 and i960. In a short cold snap in 1958 from 22nd to 27th January thr wr movmnts of Lapwings, Chaffinchs, Fildfars, Stock Dovs and Whitfrontd Gs. Mor striking, howvr, wr th vnts of January i960. Th wathr of 10th January that yar was vry cold indd and th skis wr clar. t 3.25 p.m. a party of 40 Lapwings flw SSW som thirty minuts in advanc of a snowstorm which soon brought visibility down to lss than a hundrd yards. Two days latr I watchd Rdwings flying by day ovr Willsdn and th 3..C. Tlvision Cntr in Wood Lan and thr wr mor on th following day. Thn on th 14th a strong movmnt took plac from 8.50 a.m. Rdwings wr passing ovr at th rat of 600 an hour until 1.30 p.m. and with thm wr scors of Fildfars, Skylarks, Lapwings, Grnfinchs and Linnts, all moving SW. This was th pak day for hardwathr movmnts in England and larg numbrs of ths spcis wr sn passing through in Sussx and Hampshir whr th total 26

27 SUURN IRDLIFE T DOLLIS HILL was dscribd as "trrific". This priod of cold wathr may wll hav accountd for th prsnc at Dollis Hill of th Glaucous Gull I saw on 23rd January i960. FREDTION oth avian and mammalian prdators hav som ffct on th birdlif of th survy ara. Th mammalian prdators hav bn introducd by man rown Rats (Rattus norvgicus) and Cats (JFlis catus). rown Rats hav somtims dcimatd th ducklings hatchd on th allotmnts and I hav also known thm to tak th young of lackbirds and th ggs of Dunnocks, but thir total ffct is small sinc thir numbrs ar svrly controlld. Th Cat is by far th mor important nmy of birds in th district. Fittr (1949) stimatd that th total Cat population of London was of th ordr of 550,000. In th study ara at Dollis Hill it has bn impossibl to arriv at an xact figur, but a wid sris of sampl counts in diffrnt parts in 1951 suggstd that thr wr thn about 700. y 1961 th figur had falln to around 300 and thr is littl doubt that at Dollis Hill th Cat has stadily lost ground as a houshold pt. I know of many homs which hav lost a Cat in th last dcad and nvr rplacd it. Th prsnt figur of 300 mans that thr is on Cat to vry 12 houss; in 1951 thr would hav bn on to vry 5 houss. This dcras is not rflctd in any changs in th avian brding population, howvr, sinc th limiting factor on th total numbr of brding birds is clarly th availability of nsting sits. It would sm that Cats in th ara fill th cological nich occupid in th country by ddrs (Vipra hr us) and our nativ carnivors and squirrls. Thr ar, of cours, no Gry Squirrls (Sciurus carolinnsis) in th ara although thy occur at Hampstad and Goldrs Grn. I hav rcords of Cats in th survy ara taking adults of Fral Pigon, lu Tit, Song Thrush, Mistl Thrush, lackbird, Starling, Chaffinch and Hous Sparrow as wll as th young of Mallard, Woodpigon, lackbird, Dunnock, Starling and Hous Sparrow. On occasions I hav watchd Cats stalking adult Dunnocks and Wrns, but timly intrvntion on my part has prvntd ths two spcis from bing addd to th list. In connction with Cats, it is intrsting to not that adult Starlings striv valiantly to ncourag thir nwly fldgd young from th lawns and flowrbds back to th safty of th guttrs and rooftops. This I hav nvr sn Hous Sparrows attmpt and it would sm that this is a cas of adaptation in th Starling for th practic is rgular in Dollis Hill but not so in country districts. Th avian prdators ar th Tawny Owl, th Carrion Crow and onc 27

28 RITISH IRDS a Prgrin. Owls hav oftn takn Hous Sparrows, and Carrion Crows hav fd on th ggs and young of lackbirds, th ggs of Woodpigons and th young of Hous Sparrows. Th Prgrin was a tircl chasing Fral Pigons around th Post Offic Rsarch Station. Sinc th Jays arrivd in th district I hav not yt sn thrn at work; this is also tru for th occasional Sparrowhawks and Kstrls that appar from tim to tim. Parasitism among birds is quit common, of cours, and many spcis will chas and rob othrs of thir food. Th bst xampl in Dollis Hill is that of th Common Gulls which rgularly chas lackhadd Gulls, forcing thm to giv up thir food by shr spd and prsistnc of pursuit. Tabl 7 summariss my obsrvations on birds chasing, attacking and robbing othr spcis of food. Parasit TLE 7 FOODPRSITISM MONG IRDS T DOLLIS HILL, LONDON, Victim Mallard (mu platyrhymhos) Common Gull (Juarus canus) lackhadd Gull (L. ridibunius) Woodpigon (Columba palumbus) lu Tit (Parus carulus) Fildfar (Tardus pilaris) lackbird (7*. mrula) Robin (Erithacus rubcula) Starling (Sturnus vulgaris) Hous Sparrow (Passr domstkus) Fral Pigon, Woodpigon, lackbird, Hous Sparrow lackhadd Gull Mallard, Fral Pigon, Woodpigon lackbird, Hous Sparrow Grat Tit, Hous Sparrow lackbird Dunnock, Hous Sparrow Dunnock, Hous Sparrow lackbird, Dunnock, Hous Sparrow lackbird, Grnfinch, Chaffinch THE EFFECTS OF MN Som human activitis rprsnt an intrvntion by man in favour of th birds; othrs may hav ithr dirct or indirct, but nvrthlss advrs, ffcts upon birdhf. In th broadst sns, all birds which brd, roost or fd in and around buildings and gardns rciv indirct but valuabl bnfits from man's way of lif. Thr ar, howvr, crtain aspcts in an urban ara which can b studid quit closly. uildings provid convnint prching and rsting sits, song posts and, for som spcis, saf placs in which to nst. Poor maintnanc of proprtis oftn allows birds to gain accss to roofs and lofts. Starlings and Hous Sparrows may gt in undr loos tils, undr th lad covring ovr bay windows and through hols undr th roofridgs whr mortar has bcom loosnd or has disappard. Thr is also a suprabundanc of matrial lft about by man which 28

29 SUURN IRDLIFE T DOLLIS HILL birds may us in th construction of thir nsts, I hav sn transparnt cllophan wrappings from cigartt packts, swt paprs, pics of nwspapr, bits of rag and wood shavings in th nsts of Starling, lackbird and Hous Sparrow, whil pics of string, somtims of phnomnal lngth, hav bn usd by Starling, Mistl Thrush, Song Thrush, lackbird and Hous Sparrow. Thr ar now only a fw chicknruns in th ara, but ths supply fathrs for Starlings and Hous Sparrows. I hav watchd a fmal Dunnock assiduously collcting up th whit hairs blowing about on my lawn whil I was still grooming my dog; and in May 1961 I saw Hous Sparrows prforming th sam function in a nighbour's gardn. Onc a lu Tit spnt tn minuts xtracting whit hairs from my dog's blankt which had bn put out for brushing and airing. With mor nlightnd and intrstd attituds to birds thr has bn som incras in th provision of nstboxs as wll as an incrasd dsir not to disturb nsting birds. Tnr ar always voluntrs at hand to scort a duck Mallard and hr brood across th stat and ovr th dangrous North Circular Road to th safty of th rnt Rsrvoir. Th cultivation of gardns and allotmnts in which th soil is rgularly kpt opn bnfits such birds as Song and Mistl Thrushs, Starlings, Robins and Dunnocks, which ar primarily insctatrs. Th rgular cutting of grass provids th short turf which is an important fding ara for thrushs, Starlings, Mallard, crows, pigons, Pid Wagtails, Dunnocks, Hous Sparrows and gulls. Fral Pigons and Woodpigons rgularly fd on th shoots and sds of grasss and also tak th sds of plantains, clovr and knotgrass. I hav sn a Skylark in pril fding on th closcut grass of th bowling grn in Gladston Park. Hous Sparrows in th summr tak many diffrnt kinds of flis, aphids, swarming ants, moths such as th Yllow Undrwing (Tripbana pronuba), and buttrflis such as th Larg, Small and Grnvind Whits (JPiris brassica, rapa and napi) and Small Tortoisshll {glais urticai). On th othr hand, Hous Sparrows can b vry dstructiv and thy hav rippd up th flowrs of yllow crocuss, wild primross and thrift in my own gardn. Starlings in th brding sason tak many inscts and othr invrtbrats and, unlik Hous Sparrows, largly ignor brad at this tim. On warm days in lat summr it is oftn possibl to watch scors of Starlings, oftn with Hous Sparrows, rising from rooftops to hights of ft to catch flis and ants; thir mthods ar cumbrsom but vry succssful. Thy also tak advantag of man's planting of fruittrs and will fd on black currants, raspbrris, loganbrris, plums, pars and appls. Thy ar particularly pron to attack par 29

30 RITISH IRDS trs in long dry sasons, and in 1955 and 1959 strippd on in my gardn of all its fruit, laving just th cors still attachd to th tr. Th rvrtd allotmnts and th mor poorly tndd gardns attract many birds, for hr th commonst wds ar groundsl, broadlavd plantain, chickwd, dandlion, sowthistl, crping thistl, crping buttrcup, couch grass, whit dad nttl and shphrd's purs. Goldfinchs favour th sds of thistl, groundsl, Oxford ragwort and Michalmas daisy, Dunnocks tak chickwd and plantain sds and Hous Sparrows will tak all. Thr has bn a markd incras in th dlibrat fding of birds in Dollis Hill in th last dcad and, as alrady mntiond, th grat ris in th wintr population of Mallard in th district is dirctly du to rgular fding in Gladston Park. It would also sm to b a contributory factor in th incrasd numbrs of Common Gulls. Th gratr part of th food givn to birds consists of brad and I hav sn this takn by th following 20 spcis in th survy ara: Mallard, Hrring Gull, Common Gull, lackhadd Gull, Lssr lackbackd Gull, Fral Pigon, Woodpigon, Carrion Crow, Jay, Grat Tit, lu Tit, Song Thrush, lackbird, Robin, Dunnock, Starling, Grnfinch, Chaffinch, Hous Sparrow and Tr Sparrow. I hav on rcord of polynuritis through Vitamin dficincy in th Fral Pigon. ons and fat attract th two commonr spcis of tit, as wll as Starlings and Robins. singl Fildfar cam to my gardn, attractd by th appls I had put out for th lackbirds in svr wathr. Man's advrs ffcts upon th birdlif of Dollis Hill ar small in rlation to th bnfits. Numbrs of Woodpigons ar systmatically shot in Gladston Park in wintr, but apart from ths control masurs I prsonally know of only thr dirct actions against birds in tn yars. Th first was a boy who took a potshot at a Hous Sparrow with a catapult, th scond was anothr boy who raggd a lackbird's nst and th third was a youth who fird at a Starling in Gladston Park with an airpistol. Nts, muslin, black cotton, frblowing mtal strips, rotating propllrs and skltal scarcrows may b usd to protct fruittrs and bushs, pas and othr crops from th dprdations of birds. llotmnt holdrs hav had many occasions to complain of attacks by Woodpigons on pas and rassica crops. Th havy pruning of strt trs oftn rstricts th numbr of brding sits, but som spcis, such as th lackbird and Woodpigon, may tak advantag of th pollardd condition of London plans. On th othr hand, Woodpigons also fd widly on th buds and flowrs of lm, ash and plan, and th young lavs of ash and hawthorn, as wll as on acorns and haws, and th priodic cutting of trs may rduc ths sourcs of food. Rhabilitation of cultivatd ground in Gladston Park forcd th Skylark from on brding 3

31 SUURN IRDLIFE T DOLUS HILL ground and th building of th John Klly Schools dstroyd its last nsting sit in th survy ara. Th flling of a small group of Lombardy poplars nar my hous also rmovd on saf brding sit for th Mistl Thrush. Thr has bn som grubbing up of privt hdgs to b rplacd by walls and fncs, but not yt on such a scal as matrially to rduc th numbrs of brding Dunnocks. Th priodic trimming of hdgs causs som disturbanc to brding birds, spcially lackbirds and Dunnocks, but th lattr spcis is surprisingly tolrant of this kind of activity providd th nst is not compltly xposd to th air. Incidntally, I hav no rcords of birds bing killd on th roads by vhicls; this must surly b du to th rang of vision availabl to a flying bird in th Dollis Hill ara, whr most roads ar wid and fw front gardns hav much high covr, as wll as to th town bird habit of rising up abov an approaching car and oftn bing carrid ovr it by th slipstram. It is th bird crossing th narrow country road with high hdgs which so oftn divs down low abov th road surfac and is struck by a vhicl. NOTES ON SELECTED SPECIES Hron Thr wr two Hrons on 26th July 1950 and singl birds on 2nd pril 1956, 18th Octobr 1957, 26th May 1958, 28th January 1961 and 3rd pril Mrs. Irn Ruthrford rportd to m that a Hron onc droppd out of a tr in hr gardn in Dollis Hill Lan. Hrons ar not infrqunt visitors to th rnt Rsrvoir and som must cross th ara on thir foraging xpditions. Whitfrontd Goos This is th gry goos most oftn rportd in southast England. t a.m. on 23rd January 1958 a flock of about 40 Whitfrontd Gs flw ovr th top of Dollis Hill in a NNW dirction som two hours in advanc of a snowstorm. In addition, R. E. Jons rportd 8 gry grs nar Nasdn on 4th January 1952 and I saw 16 flying NW ovr th ara on 29th March 1958; ths flocks wr probably also of this spcis. Sparrowhawk Kndall (1907) rcordd that th Sparrowhawk still brd in this part of London and Dixon (1909) said that it could b sn "frquntly in th vicinity of Nasdn and Dollis Hill". This is a lost brding spcis and I hav only two rcords of singl birds on 2nd Fbruary 1953 and 9th Octobr i

32 RITISH IRDS Prgrin Th Prgrin is primarily a rar wintr visitor. singl bird ovr Stapls Cornr on 7th January 1958 and ovr my gardn on 8th, 20th and 22nd January 1958 was somtims havily mobbd by lackhadd Gulls. Othrs flw ovr my hous on 13th Novmbr i960 and 5 th Novmbr Thr ar also two lat summr rcords of a falcon flying ast on 21st July 1961 and of a tircl chasing Fral Pigons ovr th Post Offic Rsarch Station on 9th ugust Kstrl Kstrls hav not brd in th ara during th priod of th survy. Ths falcons hav crtainly nstd at Hampstad and Harrow during this tim, howvr, and it may wll b that th singl birds or pairs that ar sn ovr Dollis Hill com from on or othr of ths districts. Most of th rcords ar from January to pril and from July to Sptmbr. lthough Kstrls can occasionally b sn hovring ovr factory surrounds, allotmnts and gardns, most of thm cross th ara fairly quickly. Cuckoo Som 60 yars ago th Cuckoo usd to appar ach summr at Knsal Ris and Kilburn, both of which ar narr to th cntr of London than Dollis Hill. In th priod undr rviw, howvr, thr hav bn only singl birds in six of th yars from 1951 to My own rcords includ on in th grounds of St. ndrw's Hospital for th first two wks of May 1952; on calling in rook Road on 19th pril 1953; on flying ast ovr my hous on 4th July 1958 and anothr on 9th ugust 1959; and on calling nar th hospital on 6th May i960. In Th Willsdn Chronicl of 19th May 1961 Miss E. C. Hodg rportd that sh hard a Cuckoo in Gladston Park on 20th pril and 13th May Swift Th Swift is prsnt vry summr, but dos not brd in th ara through lack of suitabl nsting sits (it will b rmmbrd that most of th houss hav bn built within th last thirty yars or so). Swifts crtainly nst in adjacnt Cricklwood and rondsbury, howvr, for thr ar many Victorian villas thr, and ths birds com on daily forags ovr Dollis Hill. Th most favourd fding aras ar th southrn slops of Gladston Park, th top of th hill and, as on might xpct, that part of th ara which is closst to th rnt Rsrvoir; this last district is frquntd by many Swifts in May and ugust whn migration is undr way. 32

33 SUURN IRDLIFE T DOLLIS HILL Grat Spottd Woodpckr Grat Spottd Woodpckrs wr prsnt only in Thr wr singl ons in Gladston Park on 13 th July and 24th ugust, and a pair in th sam plac on 5 th ugust. I also saw on nar th hospital on 14th ugust. J<9 for i960 thr was only on rcord of this spcis and that was of a bird found dad in a watrbutt in a rook Road gardn on 2nd Sptmbr On 14th Sptmbr i960, howvr, I discovrd a liv Jay in Gladston Park; this travlld widly round th ara and was joind in th arly part of 1961 by a scond. Th pair spnt much of th nsuing summr in gardns nar th park, but thr was no vidnc of brding. lackcap Singing mal lackcaps wr rgularly hard in on ara in 1952, 1955 and 1956; a hn was also occasionally sn, but thr was no proof of brding, pair nstd in an ldr in 1958, howvr. POSTSCRIPT t th tim of going to prss thr would sm to b som uncrtainty about th futur of on group of allotmnts and part of th spcial habitat ara, both of which may b built ovr. If this happns th pattrn of birdlif at Dollis Hill will b vry much affctd. CKNOWLEDGEMENTS I would lik to thank Mr. J. T. Gilltt, th orough Librarian of Willsdn, for undrtaking numrous pics of rsarch on my bhalf and for th loan of manuscripts and maps. I am also indbtd to Mr. J. G. Grn, Public Rlations Officr to th orough of "Willsdn, for his assistanc in my invstigations. Th ditors of ritish irds hav also mad many valuabl suggstions during th prparation of this papr. SUMMRY (1) Dtaild obsrvations wr carrid out on th bird lif of th London suburban ara of Dollis Hill from 1951 to (2) Th rsulting account opns with a history of th land dvlopmnt from (3) Th fiv main habitats in th study ara ar thn dscribd, with summaris of th spcis that occur within thm. 33

34 RITISH IRDS (4) It is shown that th avrag numbr of brding spcis ach yar from 1951 to 1961 was 21; and that th total population of brding pairs of all spcis in 1961 was about 1,500, a dnsity of 5253 birds pr tn acrs. (5) Th numbrs of brding pairs of ach spcis ar givn, togthr with a dscription of th nsting sits. (6) It is shown that 89% of th nsts xamind wr in two layrs, 510 ft and 2025 f ct abov th ground. (7) Dtails of song and display ar givn, with a dscription of th songposts usd by 22 spcis. Th spcialisd us of tlvision arials as songposts is also discussd. (8) Wintr populations, roosts, migration and hardwathr movmnts ar dscribd. (9) Th chif prdators of birds ar considrd to b Cats (which hav dcrasd in numbrs during th priod), Carrion Crows and Tawny Owls. (10) Th influnc of man on th birds of Dollis Hill is xamind: in rcnt yars it has bn almost wholly bnficial and thr has bn a markd incras in th numbr of popl fding thm. (11) dditional nots ar givn for tn slctd spcis, (12) ltogthr 70 spcis hav bn rcordd in th ara; ths arc listd in broad catgoris in an appndix. REFERENCES CRMP, S. (1949): "Th birds of Knsington Gardns and Rgnt's Park". 'London ird Rport, 15: (i960): "Th irruption of tits and othr spcis in th London ara, ". London ird Rport, 23: and TEGLE, W. G. (1950): " rpat bird cnsus of Knsington Gardns". London ird Rport, 14: 418. (1952): " bird cnsus of St. Jams's Park and th Grn Park", London ird Rport, 15: DIXON, C. (1909): Th ird Lif of London. London. ELTON, C. (1946): "Comptition and th structur of cological communitis". /. nim. EtoJ., 15: FITTER, R. S. R. (1949): London's irds. London. GOODWIN, D. (i960): "Comparativ cology of pigons in innr London". rit. irds, 53: HRTING, J. E. (1866): Th irds of Middlsx. London. HOMES, R. C, t ah (1957): Th irds of th London ra sinc London. HULME, D. C. (1955): "uildings as songposts". rit. irds, 48: KENDLL, W.. (1907): "Th birds of Willsdn" Unpublishd MS. in Willsdn Public Library. NICHOLSON, E. M. (1951): irds and Mn. London. SGE,. L. (i960): "Th spring migration of th Common Gull through th London ara". London ird Rport, 23: SELOUS, E. (1933): Th Evolution of Habit in irds. London. SIMMS, E. (1952): ird Miff ants. London.. (1956): " cntury of birdwatching in northwst London". Willsdn Chronicl (thr articls). SUMMERSSMITH, D. (1959): "Th Hous Sparrow Passr domsticus: population problms". Ibis, 101: "WLLCE, D. I. M. (1961): "Th birds of Rgnt's Park and Primros Hill, 1959". London ird Rport, 24:

35 SUURN IRDLIFE T DOLUS HILL PPENDIX SPECIES RECORDED T DOLLIS HILL, LONDON, DURING 195 I61 irds which stay th summr rgular brdr O formr or occasional brdr P nonbrdr but prsnt Mallard (nas plaiyrhynchos) Kstrl {Falco tinnunculus) P Stock Dov (Columba onas) O Fral Pigon {Columba livid) Woodpigon (Columbus palumbus) Tawny Owl (Strix alum) Swift (pus apus) P Skylark (lauda anmnsis) O Carrion Crow (Corpus coram) Jay (Garrulus glandarius) P Grat Tit {Varus major) lu Tit (Parus carukus) Wrn (Troglodyts troglodyts) Mistl Thrush {Turdus viscivorns) Song Thrush (Turdus phihmlos) lackbird (Turdus mrula) Robin (Eritbams rubculd) lackcap (Sylvia atrkapilld) O Willow Warblr {Phylloscopus trochilus) O Spottd Flycatchr (Muscicapa stria/a) Dunnock (Prunlla nodularis) Pid Wagtail (Motmilla alba) Starling (Sturnus vulgaris) Grnfinch (Chloris Moris) Goldfinch (Cardulis cardwlis) Chaffinch (Fringilla tmlbs) Hous Sparrow (Passr domsticus) Tr Sparrow (Passr montanus) Wintr visitors and passag migrants W wintr visitor M passag migrant I lobby (Falco subbuto) M Prgrin (Falco prgrinus) M W Curlw (Numnius arquatd) M Whimbrl (Numnius phaopus) M artaild Godwit (Limosa lapponicd) M Grcnshank (Tringa nbularia) M Grat lackbackd Gull (}..arus marinus) W Lssr lackbackd Gull (Tarns fusau) M W Hrring Gull (Lams argntatus) M W Common Gull (Larus canus) W lackhadd Gull (Torus ridibimdus) W Turtl Dov (Strptoplia turtur) M Cuckoo (Ctmdus canorus) M Swallow (Hirundo rustica) M Hous Martin (Dlichon urbica) M Sand Martin (SJparia riparid) M Rook (Corvus frugilgus) M Jackdaw (Corvus monduld) M Fildfar (Turdus pilaris) M Rdwing (Turdus musicus) M Rdstart (Phonkurus phonkurus) M Whitthroat (Sylvia communis) M Chiffchaff (Phylloscopus collybila) M Madow Pipit (nthus pratnsis) M W Gry Wagtail (Motacilla cinra) M Siskin (Cardulis spinus) M Linnt (Cardulis catmabina) M Vagrants Hron (rda cinra) Whitfrontd Goos (nsr albifrons) Mut Swan (Cygnus olor) Sparrowhawk (ccipitr nisus) Phasant (Phasianus cokhkus) Lapwing (Vanllus vanllus) Glaucous Gull (Larus hyprborus) Littl Owl (thn noctim) Kingfishr (lcdo atthis) Grat Spottd Woodpckr (Dndrocopos major) Coal Tit (Parus atr) Rdpoll {Cardulis flammd) Srin (Srinus camrius) Crossbill (Loxia curvirostrd) Yllowhammr (Embri^a citrinlld) 35

36 uzzard (uto buto) Partridg (Prdix prdix) Corncrak {Crx crx) frican Gry Parrot (Psittacus rithacus) Rosyfacd Lovbird (gapornis rosicollis) udgrigar (Mlopsittacus tmdulatus) Wrynck (Jytix torquilld) RITISH IRDS Othr birds mntiond in th txt Goldn Oriol (Oriolus oriolus) Magpi {Pica pica) Trcrpr (Crthia jamiliaris) Gardn Warblr (Sylvia borin) Lssr Whitthroat {Sylvia curruca) ullfinch (Pyrrbula pyrrhuld) Corn unting (Embri%a calandra) 36

37 PLTE I. rial photograph showing Dollis Hill and th rnt Rsrvoir, Middlsx, Th width of this rproduction covrs about ij mils. Th limits of th ara dscribd in th papr on pags 136 can b sn from Fig. 1 on pag 2. Th allotmnts in Gladston Park, now rclaimd, and thos on th sit of th John Klly School ar distinctly shown {photo: rofilm and ro Pictorial Ltd.)

38 PLTE 2. typical road and gardn in Dollis Hill, Middlsx, illustrating th rsidntial part of th survy ara (pags 45). bov, a viw north along rook Road towards th rnt Rsrvoir, Sptmbr 1960; th majority of th houss ar smidtachd. low, a front gardn in rook Road, Jun i960 {photos:..c.)