A Common Bird Census survey of Lavernock Point Nature Reserve Carried out by Thomas Simcock for the Wildlife Trust of South and West Wales 26th March 19 th June 2011 Introduction Breeding bird surveys have been carried out at Lavernock Point for the Wildlife Trust of South and West Wales annually since 2002 to determine the species present and to estimate the number of territories or breeding pairs. There are several habitats on the reserve including scrub, open grassland, woodland, stands of dense herbaceous vegetation and tall hedges. The reserve is currently being managed primarily for its limestone grassland and this survey will help to determine how the reduction in the amount of scrub on the site affects the bird populations. The results of the survey can be taken into account when undertaking management work on the site in the future. Method The survey was carried out using the British Trust for Ornithology (BTO) Common Bird Census (CBC) method. A set transect route was walked through the reserve, with a different direction being taken on each alternate visit. Nine visits were made to the site between 26 th March and the 19 th June 2011. Bird species were identified visually, by call or by song and this information was marked on a map of the site using the appropriate BTO symbols. A separate map was used for each visit, producing nine visit maps. These maps were then used to produce species maps, by transferring all the information for a particular species from the nine visit maps onto one species map, replacing the species code with a visit letter. This enables territories to be determined. The CBC guidelines require that a minimum of three registrations be used to indicate a territory if nine or more visits were made or two registrations if there were eight or fewer visits. Rooks, Feral Pigeons and all gulls are recorded on the visit and species maps only if they are nesting, when a count or estimate of active nests is made and recorded. Woodpigeon, Magpie, Carrion Crow, House Sparrow, Starling, Swift, Swallow and House Martin populations are normally assessed by
using a combination of active nests and other registrations, such as birds in song or displaying birds. These species can be assessed by recording active nests only and omitting all other registrations, but it should be stated clearly if this is being done. The surveys were carried out by Thomas Simcock. Visit Dates A B C D E F G H I 26 th March 2 nd April 9 th April 16 th April 29th April 15 th May 21 st May 11 th June 19 th June Each visit lasted between two and a half and three hours. Results The results for 2011 show that at least 36 species were present at, or flying over, Lavernock Point during the survey period, with 13 or 14 of these species holding territories or nesting, and therefore breeding, on site. There is doubt over the total number of species that held territories on the reserve, because it is not certain whether or not the Goldcrest held a territory (see later in the discussion for the reasons for this). There may have been a Skylark territory in the fields surrounding the reserve. No singing Skylarks were recorded there, however. The results are summarised in Table 1. In the table, P indicates that the species is present on site, but did not appear to hold any territories. Table 1 SPECIES TERRITORIES COMMENTS Mallard P Seen on two visits (D and E). One flew onto the pond on visit D and three were seen on the pond on visit E. Sparrowhawk P Seen on three visits (visits B, D and H). A pair was seen flying over on visit B. Pheasant P Heard and/or seen on seven of the nine visits. Associated with cultivated country near to the woodland. Wood Pigeon P Seen on every visit in wooded areas of the site. May have bred on or near to the site, but no nests were found.
Collared Dove P Seen on one visit (visit E). Normally found in towns and villages. Swift P Seen on two visits (visits F and I). Great Spotted Woodpecker Green Woodpecker P P Heard drumming in the small wood to the north of the reserve on visit A. Heard calling on 3 visits, in the woodland, mostly in the main part of the reserve, but also once in the small woodland to the north of the reserve (on visit I). Swallow P Seen flying over the reserve on six visits, from visit B. House Martin P Seen flying over the reserve once, on visit I. Wren 6 An abundant species, seen on every visit. Found in both woodland and scrub. Dunnock 6 Also common. Seen on every visit, most commonly in the scrub and hedges, but also in the woodland. Robin 5 Seen on every visit. Seen in the woodland and scrub, throughout most of the reserve. Blackbird 3 Very abundant and seen or heard on every visit. Seen throughout the woodland and scrub and along the hedges. Song Thrush 2 Singing males heard on 6 visits and a pair seen going to a nest with nesting material on visit B, in the hedge to the north of the Old Hayfield. Lesser Whitethroat P Seen/heard on two visits (visits E and H), in the scrub Whitethroat 2 First seen and heard on visit C and then on all subsequent visits. Seen and heard over most of the reserve, in the hedges, tall vegetation and scrub. Garden Warbler P Only heard on two visits (C and D). One was heard in the scrub just below the gun emplacements on visit C and two different birds were heard there and in the hedge at the top of the Old Hayfield on visit D. There was no evidence of a territory having been established. Blackcap 7 First seen and heard on visit B and then on all subsequent visits. Seen and heard in both the woodland and scrub throughout the reserve. Willow Warbler P Only heard on two visits (C and D), in the small woodland to the north of the reserve (on both visits) and in the scrub and woodland around the gun emplacements (only on visit D). There was no evidence of a territory
having been established. Chiffchaff 8 Heard from visit A, on every visit, in the woodland and scrub, throughout the reserve. Goldcrest 1? Seen/heard on six visits, although singing males were only heard on visits A, B, D and E, mainly in the woodland in the southern end of the reserve. The species may have held 1 territory there. Singing males were also heard in the north of the reserve on visits D and E. Blue Tit 4 Seen on every visit, throughout the reserve, mainly in the woodland, but also in the scrub and hedgerows. Singing males were heard on six visits in total, but most of them were heard in April. Different birds were seen entering two different nest boxes on the same visit (visit G), in the woodland just beyond the Old Hayfield. A family was seen on visit I, in the woodland to the south of the reserve. Coal Tit P One seen and heard singing on visit C, in the scrub and the woodland in the centre of the reserve. Great Tit 3 + 1 edge Seen or heard on every visit, mainly in the woodland, but also in the scrub and hedgerows, throughout most of the reserve. A bird was seen using a nest box on two separate visits (visits F and G), in the woodland near to the Old Hayfield. Long-tailed Tit P Seen on five visits, mainly in the woodland, but also in the scrub and hedgerows. Jay P Seen on three visits, in the woodland. No evidence of nesting was observed. Magpie P Seen on every visit, throughout the reserve. No evidence of nesting was observed. Jackdaw P Seen on two visits (visits D and F). No evidence of nesting was seen. Carrion Crow P Seen on 6 visits throughout the reserve. No evidence of nesting was observed. House Sparrow P Seen on 8 visits, in the hedgerows close to the caravan park, except on visit A, when one was seen in the scrub not far from the Old Hayfield. Four were seen fighting in a hedgerow close to the caravan park on visit B. No other evidence of territories being held was observed. Chaffinch 3 Seen on six visits, mainly in the scrub, but also in the woodland and hedges in the main reserve, south of the Old Hayfield. The species was seen in the small wood to the north of the reserve on three visits, but no singing males were heard there. The
Chaffinch was less abundant in 2011 than in previous years. Goldfinch P 5 seen calling and then flying off in the scrub to the south of the reserve on visit C. Greenfinch 3 Seen on every visit, mainly in the hedgerows around the Old Hayfield, but also in the scrub south of the Old Hayfield and the small woodland to the north of the reserve. Bullfinch P Seen on two visits (G and I), in the scrub. A pair was seen on visit I, in the scrub just south of the gun emplacements. The Bullfinch was less abundant in 2011 than in previous years. Linnet 1 Seen on 3 visits, flying over areas of scrub and hedges throughout the reserve.
Discussion and Conclusions The Willow Warbler didn t hold a territory on the reserve again in 2011, although it was heard on two visits (C and D), there being two singing males recorded (one in the main reserve and one in the small woodland to the north of the reserve). There had been no observations of Willow Warbler at all in the 2010 or 2008 survey seasons, however and there was just one singing male heard in the 2009 season. The records made in 2011 represent a slight increase in numbers compared to previous years, therefore. The decline in numbers of the Willow Warbler started in 2007, when the species held just 1 territory on the reserve. The species had held between 4 and 6 territories in all seasons prior to 2007. The reasons behind the decline are not obvious. The work to clear scrub on a rotational basis and to clear small parts of the woodland continued up to the start of the 2011 survey season, but there still should have been enough scrub and woodland left on the site to enable the species to hold territories. There was an increase in the number of territories held by the Chiffchaff in 2011 and this species uses similar habitats to the Willow Warbler (i.e., woodland and scrub). The Willow Warbler does show a stronger preference for scrub than the Chiffchaff does, however and the continuing programme of scrub clearance at Lavernock Point will have the affect of reducing the favoured breeding habitat of the Willow Warbler. Some scrub will always be left on the reserve for the birds to breed in, though and the majority of the woodland remains untouched by the management work. The Whitethroat is another species that commonly uses scrub during the breeding season and this species held the same number of territories on the reserve in 2011 (2), as it did between 2004 and 2008 and in 2010. BTO data (taken from Breeding Bird Survey results) shows that the Willow Warbler population in Wales declined by 10% overall between 1995 and 2009. This doesn t explain the Willow Warblers disappearance as a breeding species from Lavernock Point, either, though, especially since the results also show a slight increase in the Welsh population of the species between 2005 and 2010. It seems logical to conclude, therefore, that the Willow Warbler cannot have suffered such a severe decline in the numbers of territories it has held on Lavernock Point as a result of any change in or loss of their habitat due to the management work that has been carried out there. The reason for the disappearance of the Willow Warbler as a breeding species at Lavernock Point could be connected with a general reduction in habitat quality on the species breeding grounds throughout Britain and pressure during migration and in the winter. The bird species found at Lavernock Point are typical of the habitats and accompanying ecological niches available. Many of the bird species recorded are familiar woodland species such as Robin, Blackbird, Wren, Chaffinch, Great Tit and Blue Tit. The Great Spotted Woodpecker and Green Woodpecker are also commonly found in deciduous woodland, while the Song Thrush is found in deciduous woodland and scrub. Some of the summer migrant species (such as Blackcap and Chiffchaff) are also species that mainly breed in woodland. The Greenfinch is most often found around man in gardens and parks and in arable and pasture farmland, but it can also use woodland edges and tall hedges, or anywhere with tall, dense trees that are fairly open (at Lavernock Point, this species mainly breeds in the tall scrub). The Linnet is
a bird of lowland farmland and open, rough ground, with small to medium weed species and scrub (such as gorse or blackthorn), suitable hedges (especially hawthorn) or low trees. The species breeds mainly in the hedges in the Old Hayfield at Lavernock Point. Of the summer migrant species, the Lesser Whitethroat and Whitethroat also breed in more open habitats, such as scrub and hedges. The Goldcrest and the Coal Tit are normally found in coniferous woodland, although both can, much less frequently, be found in deciduous woodland and scrub. 36 species were recorded as being present on site in the 2011 survey (compared to 31 in 2010) with 13 or 14 of those species holding territories or nesting on the reserve. This means that the number of bird species holding territories or nesting on the reserve has declined between 2010 and 2011 by 2 or 3 (from 16 to 13 or 14). It was decided that the Skylark should not be included in the species list from the 2005 breeding season onwards, as the species territories are held in the fields outside the reserve. The total number of species recorded on the reserve increased by five between 2010 and 2011, from 31 to 36. This is the largest number of species that has been recorded on the reserve since the surveys began, the next highest total being 35, which was recorded in 2003 and 2004. Mallards were seen on the pond on the reserve for the first time (on visits D and E). Three were seen flying over the reserve in 2009, but they didn t land. The pond is probably too small for aquatic birds to use regularly or to breed on, but species such as Mallards may well continue to be seen irregularly on it. A Sparrowhawk has only been seen three times before on the reserve, in the 2004, 2009 and 2010 seasons. The species has now been seen in three consecutive years, however. The species was seen flying over the reserve on three occasions in 2011. A pair was seen on visit B. There is no clear reason why Sparrowhawks shouldn t be regularly seen hunting over the reserve, because the habitat on the reserve (and surrounding it) is good for that species (the species most commonly uses deciduous woodland and fields during the breeding season). The fact that the species was seen three times in the 2011 season, in April and June, suggests that it may have been breeding on or near the reserve. The species was also seen on three visits in 2009, although it was only seen on visits in April then. House Martins were seen flying over the reserve for the first time in 2011. This species is seen over open country feeding on insects. They are often seen near to human habitation, where they nest, although Penarth isn t too far away from Lavernock Point. There are other buildings near to the reserve that the birds could be nesting in, however, such as the farm buildings. They were seen once, on visit I. There is no reason why the species shouldn t been seen again over the open parts of the reserve in the summer, although the amount of open space available to them on the reserve is limited, which means that they won t be seen here very frequently. The Garden Warbler was heard for only the second time on the reserve (the first time being in 2002). It was heard twice, on visits C and D. The species is found in scrub and deciduous woodland with open areas. Scrub is still plentifully available on the reserve, but the woodland on the reserve isn t very open. Despite that, there is no reason why the Garden Warbler shouldn t have regularly held territories in the scrub in previous years, or shouldn t do so regularly in the future.
The Goldcrest was seen on the reserve for only the fourth time, the previous occasions being in 2004, 2007 and 2008. The species is usually found in coniferous woodland, especially pine forests, but can, much less frequently, be found in deciduous woodland. It is surprising, therefore, to find them on the reserve. There is coniferous woodland not far along the coast from the reserve, however. It is also surprising that the species was found on six visits in 2011. Singing males were heard on four visits altogether (visits A, B, D and E) and so it is possible that the species was holding a territory on the reserve, given the number of registrations. This seems unlikely, however, given that the right habitat is not present. A Coal Tit was heard on the reserve for only the fourth time, the previous records being in 2002, 2003 and 2010. One bird was heard singing on visit C. The Coal Tit is normally found in coniferous woodland, but can, much less frequently, be found in deciduous woodland. There is some coniferous woodland not very far from the reserve, where Coal Tits are likely to be found, but none on the reserve itself, so it s not surprising that this species isn t found on the reserve very frequently. The number of territories held by each of the species breeding on the reserve increased, decreased or remained the same between 2010 and 2011, according to the species in question. Seven species have increased their number of territories between 2010 and 2011. These can be seen in the table below. Species Number of territories held 2010 2011 Wren 5 6 Dunnock 5 6 Song Thrush 0 2 Blackcap 6 7 Chiff Chaff 5 8 Goldcrest 0 1? Blue Tit 2 or 3 4 None of these increases appear to be significant, except for the possible exceptions of the Song Thrush and Chiff Chaff. The Song Thrush increased its number of territories by two to two (having not held a territory in 2010); whereas the Chiff Chaff increased it s number of territories from 5 to 8. The Song Thrush is most frequently found in deciduous woodland, although it also found in scrub. The management work that is being carried out on the reserve involves the clearance of scrub on a rotational basis and the occasional clearance or thinning of small patches of woodland. Any reduction in the amount of suitable habitat available could reduce the number of territories that the Song Thrush is capable of holding on the reserve. The species has clearly not been affected by the management work carried out so far, though. This work has only resulted in small losses of scrub and woodland from the reserve and there is still plenty of habitat for the Song Thrush to breed in. This suggests that the fact that this species held no territories on the reserve in 2010 was simply a consequence of natural fluctuations in the local population.
The Chiff Chaff is also most frequently found in deciduous woodland, although it is found in scrub, as well. The management work carried out on the reserve so far has left plenty of these habitats for the Chiff Chaff to breed in, but hasn t led to an increase in the habitat available (and may have resulted in a small decrease). The increase in the number of territories held by the Chiff Chaff on the reserve can t have been caused by the effect of the management work on the habitat, therefore. Eight is the highest number of territories that the Chiff Chaff has held on the reserve since 2004, when it held nine. There is no obvious reason for this. The UK Chiff Chaff population as a whole has been increasing steadily since the mid-1980s, but the species consistently held five or six territories throughout the period 2005-2010, so this trend hasn t been reflected at Lavernock Point. The increase in the number of territories held in 2011 may simply be due to local population fluctuations. The Goldcrest was recorded on six visits in 2011 and the species could, in theory, have held a territory on the reserve, as enough singing males were registered during the season. There has to be some doubt, however, about whether this was actually the case, because this species is usually found in coniferous woodland and is only infrequently found in broadleaf woodland. There are conifer plantations not far from the reserve, however. The species could have been breeding in the coniferous woodland and just feeding in the deciduous woodland on the reserve. It was recorded as having held one territory on the reserve in 2007, but the same doubt must also apply to this record. As in 2010, most of the singing male Blue Tits in 2011 were heard in April, although 1 was heard on visit G (21 st May) and 1 on visit H (11 th June). There is no obvious reason why singing male Blue Tits shouldn t have been heard consistently throughout the breeding season. Changes in the species preferred breeding habitat is unlikely be the cause, because the woodland has been so little affected by the habitat management. Five species have not shown any change in the number of territories they held on the reserve between 2010 and 2011, these being the Whitethroat, Willow Warbler, Chaffinch, Greenfinch and Linnet. The Whitethroat is frequently found in scrub and the Willow Warbler and Chaffinch are frequently found in scrub and woodland. The Greenfinch is found in the mature scrub and hedges at Lavernock Point and the Linnet is found in the open areas with scrub and hedges. Clearly, the management work that had been carried out in the woodland and scrub areas up to the start of the 2011 season hasn t affected these species ability to successfully establish territories. There hasn t been any management work carried out on the hedges, so far. Five species held fewer territories in 2011 than in 2010. These can be seen in the table below. Species Number of territories held 2010 2011 Robin 7 5 Blackbird 5 3 Lesser Whitethroat 1 0 Great Tit 4 3 + 1 edge Long-tailed Tit 1 0
Bullfinch 1 0 Of those species that showed decreases in the number of territories held on the reserve, the Robin and Blackbird have shown possible significant declines. The Robin held 7 territories in 2010, but only 5 in 2011. The Blackbird held 5 territories in 2010, but only 3 in 2011. Both the Robin and Blackbird are species of woodland and scrub at Lavernock Point. The fact that these species held fewer territories in 2011 than in 2010 cannot be attributable to a decline in the amount of breeding habitat available to them on the reserve. Most of the deciduous woodland on the reserve had remained unaffected by the management work up until the start of the 2011 breeding season and there was still plenty of scrub available for the Robin and Blackbird to breed in. The habitat available should have been capable of supporting the same number of Robin and Blackbird territories as in previous years. The decreases may be due to local population fluctuations. The Lesser Whitethroat didn t hold a territory at Lavernock Point in 2011, for the first time since 2007. This is only the third time since the surveys began in 2002 that this has been the case. The fact that the Lesser Whitethroat didn t hold a territory on the reserve in 2011 can t have been caused by a corresponding decrease in the amount of breeding habitat available. The species breeds in the scrub and hedges on the reserve and the amount of scrub available hadn t decreased significantly up to the start of the 2011 breeding season, while the hedges hadn t been touched at all. The Lesser Whitethroat held 1 territory in 2010 and 3 in 2009, so it was clearly able to breed successfully in those years and there was a similar amount of suitable habitat available in those years as there was in 2011. Any decline in breeding success in 2011 may, therefore, simply be due to natural variations in the population. The Long-tailed Tit didn t hold a territory on the reserve in 2011, whereas it had held 1 in 2010. This species is mainly found in deciduous woodland in the breeding season, although it is also found in scrub and hedges. Since the amount of deciduous woodland, scrub and hedgerows on the site has not changed significantly over the years that these surveys have been carried out, there is no reason, in terms of breeding habitat available, why this bird shouldn t be a regular breeder on the reserve, or why it shouldn t hold territories on the reserve in the future. The Bullfinch didn t hold a territory on the reserve in 2011, whereas it held 1 in 2010. This species mainly uses deciduous woodland and scrub in the breeding season. The amount of deciduous woodland and scrub at Lavernock Point has not declined significantly during the last ten years and there is no reason, in terms of breeding habitat available, why this species shouldn t have held a territory on the reserve in 2011, or why it shouldn t hold territories on the reserve in the future. The Bullfinch was also less abundant in terms of the number of visits it was seen on during the course of the survey season than in previous years (it was only seen on two visits in 2011). Again, there is no reason, in terms of breeding habitat available, why this should be the case. The Bullfinch population has been declining in Wales (by 18% between 1995 and 2009), according to Breeding Bird Survey data analysed by the BTO. It is possible that the decline of the Bullfinch population at Lavernock Point could be linked to this wider decline.
There is interest to be drawn from comparing the number of territories held per species throughout all ten survey seasons. The most striking observation is that the Willow Warbler had been fairly consistent in the number of territories it had held on the reserve up to and including 2006 (the number held ranging from four to six territories), before this number fell to 1 in 2007, then 0 in 2008, 2009, 2010 and 2011. As has been stated already (at the beginning of the discussion), it is not clear what the cause of this decline is. The Chaffinch held significantly more territories in 2003 than in any of the other years, but, even if it is assumed that the number of territories held in 2003 was an anomaly, this species seems to have suffered a moderate decline in the number of territories held on the reserve. The species consistently held 5 or 6 territories each year between 2002 and 2006 (apart from 2003). After this, however, the number of territories held has remained stable at 2 or 3 each year between 2008 and 2011. It is unlikely that the number of territories held by the Chaffinch declined from the earlier higher numbers to the later lower numbers as a consequence of a corresponding decline in the amount of breeding habitat available to it on the reserve. The Chaffinch most regularly occupies deciduous woodland and scrub in the breeding season and there were still plenty of both of these types of habitats available at the start of the 2011 season (and throughout the later period). Across the UK, there has been a downturn in Chaffinch numbers since 2006, linked to a widespread and severe outbreak of trichomonosis (an infectious disease caused by a parasite) that began in 2005, the downturn being greatest in areas with a high incidence of the disease. Whether the downturn in the numbers of territories held by the Chaffinch at Lavernock Point is related to this issue is not known. There also seems to have been a similar decline in the number of territories held on the reserve by the Greenfinch, the number held falling to 3 in 2009 and staying at that level in 2010 and 2011. The species had consistently held more territories than that in previous survey years. Again, the habitat management that had been carried out up until the start of the 2011 breeding season can t really have affected the breeding success of this species. The Greenfinch breeds in the hedges and scrub on the reserve. The hedges have not been affected by the habitat management carried out and there was still plenty of scrub left for the species to breed in. Greenfinches have also been badly affected in the UK by the trichomonosis outbreak. Again, whether the downturn in numbers of territories held by the Greenfinch at Lavernock Point is related to this issue is not known. BTO data (taken from Breeding Bird Survey results) shows that the Wales population of the Chaffinch decreased by 8% between 1995 and 2009. The same data also shows that the Greenfinch population in Wales increased by 9% in the same period (although there has been a decrease in the population between 2005 and 2010). Neither of these trends involves large increases or decreases in population, though and can t explain why the two species should have experienced a decrease in the number of territories held at Lavernock Point over the last 3 or 4 years. The Wren held twice as many territories between 2003 and 2005 than it did in 2002 or between 2006 and 2011. The species held 6 territories in 2002, consistently 6 between 2006 and 2009, 5 in 2010 and 6 in 2011. The Robin held almost twice as many territories in 2003 than in any other year and held more territories in 2004 and
2005 (8 and 9) than the average, but since then, has been more consistent in the number of territories it has held, with minor fluctuations. The Blackbird similarly held almost twice as many territories in 2003 than in any other year, but has since been fairly consistent in the number of territories it has held, with fluctuations. The Blackbird did hold the joint lowest number of territories on the reserve in 2011 (3) since the surveys began (it also held 3 territories in 2008), but this is not too far outside of the average. The Chiffchaff held significantly more territories in 2003 and 2004 (11 and 9) than it has in any other year, although it did hold 8 territories in 2011, which is more territories than it has held since 2005. The species held either 5 or 6 territories every survey year between 2005 and 2010. The habitat management work that had been carried out on the reserve up to the start of the 2003 season or since is unlikely to have caused any of these anomalies and trends. The Wren, Robin, Blackbird and Chiffchaff all mainly use woodland and scrub in the breeding season, but, although some scrub has been cleared and some of the woodland thinned, this management has left a substantial amount of scrub still standing and hasn t touched most of the woodland. The management work, therefore, shouldn t have significantly affected the breeding success of these four species. The Song Thrush has been consistent in the number of territories it has held on the reserve during the ten survey seasons. It has most commonly held 2 territories (having done so 5 times), but has held 1 territory twice and not held a territory twice. There is no reason why the habitat management work carried out at Lavernock Point over the last ten years should have had much, if any, effect on the number of territories held by the Song Thrush. The species is found in broadleaf woodland and scrub during the breeding season. Although some scrub has been removed to increase the area of grassland on the reserve and a small area of woodland has been cleared, the total area of these habitats hasn t decreased by much and there is still plenty of habitat left for the Song Thrush to breed in. Both the Whitethroat and Lesser Whitethroat are found in the scrub on the reserve, with the Lesser Whitethroat also being found in the hedges. They have both been very consistent in the number of territories they have held on the reserve. The Whitethroat has typically held two territories in most years, while the Lesser Whitethroat has most frequently held 1 (which it has 6 times). These two species have clearly not been affected much, if at all, by the habitat management work carried out on the reserve. Plenty of scrub has been left on the reserve and the hedges have not been affected by any management, so there is still plenty of habitat left for these species to breed in. Even though the Lesser Whitethroat didn t hold any territories in 2011, this has been the case before (in 2007) and the species went on to hold territories in subsequent years. The Blackcap held more territories in 2005 (8 in total) than in any of the other years. There does seem to have been a decline in the number of territories held by this species between 2005 and 2008 (from 8 territories in 2005 to 3 in 2008), but the numbers of territories then increased again (to 7 in 2011). This species is mainly found in deciduous woodland, so the habitat management work should not have affected it very much and this may be natural fluctuation in the population. The Dunnock is a species that breeds in scrub and undergrowth. It could, in theory, have been affected by the management work that had been carried out to reduce the
amount of scrub on the reserve, but has remained unaffected, holding roughly the same number of territories throughout the period 2002-2011 (between 4 and 7 territories, although most frequently 5 or 6 territories). The Blue Tit consistently held 6 or 7 territories between 2002 and 2004, whereas between 2005 and 2011, it has consistently held either 3 or 4 territories. It is very unlikely that this trend is linked to any habitat management work that has been carried out at the site over the years, as this has mainly involved the clearing of scrub and the Blue Tit chiefly utilises deciduous woodland in the breeding season. The Great Tit had held a consistent number of territories throughout the period 2003 2010, but held the lowest number of territories in 2011 (3 plus 1 edge territory) since 2002 (when it held 1), representing a possible decline from a high of 6 in 2007. This species breeds mainly in deciduous woodland, but also in scrub at Lavernock Point, so it shouldn t have been affected very much by the management work that has been carried out, as a large proportion of both these habitats have been left unaffected by the management work. The Welsh population of the Great Tit has increased by 51% between 1995 and 2009, so this decline in the number of territories held on the reserve can t be linked to any decline in the wider population. The Bullfinch has consistently held 1 or 2 territories on the reserve since 2003 (although most frequently 1), apart from 2002, 2005 and 2011 when it didn t hold a territory. This species breeds mainly in scrub, but also in deciduous woodland at Lavernock Point, so it shouldn t have been affected very much by the management work that has been carried out there over the last ten survey years. The Linnet wasn t recorded as having held a territory on the reserve between 2002 and 2005, but, after that, it has consistently held either 1 or 2 territories (apart from 2006, when it held 3). The Linnet, at Lavernock Point, breeds mainly in the hedges in the Old Hayfield, which have been unaffected by the habitat management. This management cannot account for the Linnet not holding any territories in the first four survey seasons, therefore. 51 species have been recorded from the reserve over the course of all 10 survey years, with 17 or 18 species recorded as having bred on the reserve at least once in that period. The exact number of breeding species depends on whether it is accepted that the Goldcrest held a territory at Lavernock Point or not. The conclusions from the survey are essentially the same for 2011 as they were for 2010. Six species were seen in 2011, that weren t in 2010 (Mallard, Great Spotted Woodpecker, House Martin, Garden Warbler, Goldcrest and Goldfinch). Two species weren t seen in 2011, that were in 2010, the Starling and the Raven. The Starling is usually found around towns and villages and there is not much habitation near to the reserve, although the species may use the caravan park. It isn t surprising that they aren t found every year, though. The Raven was a surprising record, though and will probably always be a species that is seen only very occasionally at Lavernock Point. Although the reserve is being managed primarily for its limestone grassland and its floral and insectivorous interest, the mosaic of open, grassy areas with tall stands of herbaceous vegetation, scrub and woodland provides birds with a lot of suitable
habitat. The management work that had been carried out up until the start of the 2011 survey season does not seem to have significantly affected the abundance of the bird species present. Even though the number of Willow Warbler territories declined to zero between 2006 and 2008 and then stayed at zero up to and including the 2011 survey season and the number of territories held by the Chaffinch and Greenfinch declined to lower levels between 2008 and 2011 than had been the case between 2002 and 2007, it seems unlikely that this was due to any changes in habitat caused by the management work. If the current management work continues, however, it may affect the abundance of some of the species that need bushy vegetation to nest in. However, this type of vegetation is not going to be removed completely, and so the reserve should still be able to cater for these species (the Whitethroat, for example) to some degree. Furthermore, it is important that this work is carried out to enhance the value of the site for its limestone grassland and associated wild flowers and insects. Increasing the amount of grassland in the reserve may benefit some bird species, such as the Skylark and Meadow Pipit and the thrushes. Management Considerations Even seemingly common species are suffering from population declines. The publication Birds of Conservation Concern 3 (2009), places several species, found at Lavernock Point, on a Red list. This includes those species whose UK breeding population has declined severely (i.e., by more than 50%). This could be over the last 25 years, or over the longer term, which means the entire period used for assessments since the first Birds of Conservation Concern review, starting in 1969. Several species recorded at Lavernock Point are also on the Amber list, their breeding populations having declined moderately (by more than 25%, but less than 50%). This could also be over the last 25 years or over the longer term, as for the Red List criteria. The species found at Lavernock Point that are on the Red and Amber lists are shown below. Red list species Song Thrush House Sparrow Linnet Amber list species Mallard Swift Green Woodpecker Swallow House Martin Dunnock Whitethroat Willow Warbler Bullfinch The House Sparrow and Linnet have been placed on the Red list for their Species of European Conservation Concern status, as well as for declines in their breeding populations.
The Willow Warbler has been placed on the Amber list because of moderate declines in its breeding population over the last 25 years and over the longer term. However, another migrant species, the Whitethroat, has also been placed on the Amber list because of declines in its breeding population and this species has not suffered any declines in the number of territories it has held at Lavernock Point over the last 10 years. The Mallard is on the Amber list because of moderate declines in the non-breeding population of the species. The Green Woodpecker and Swallow are on the Amber list because they are categorised as Species of European Conservation Concern, not because of declines in their breeding populations in the UK. The House Martin is on the Amber list because of declines in its breeding population and because it is a Species of European Conservation Concern. All the long distance migrants on the Amber list, i.e., the Swift, Swallow, House Martin, Whitethroat and Willow Warbler may be affected by potential issues on their migration routes and in their wintering grounds, as well as in their breeding grounds. Linnet is on the Red list largely because it has suffered as a result of the impacts of intensive agriculture, which has resulted in there being less food available to it, in the form of arable weed seeds. The other species on the lists are also in decline largely because of loss of suitable habitat caused, in many instances, by changes in farming practices. The Dunnock, Song Thrush, House Sparrow, Linnet and Bullfinch are all also included in the UK Biodiversity Action Plan (UK BAP) priority species list. The Song Thrush, House Sparrow and Linnet are on both the Red List and The UK BAP priority species list. If the reserve is managed so that it continues to provide a mixture of habitats, including open areas, scrub and woodland, it should cater for the existing bird populations. While several of the species recorded are of conservation concern, none have conservation management needs that go beyond the sensible management of their habitat. Some thought should go into how much scrub is going to be cleared altogether, because if a lot is cleared, then this may start affecting the abundance of some species. The Willow Warbler has disappeared from Lavernock Point as a breeding species, the Lesser Whitethroat and Bullfinch didn t hold any territories on the reserve in 2011 and the Chaffinch and Greenfinch have held consistently fewer territories on the reserve since 2008/2009, in comparison to earlier years. While it is unlikely that any of these declines are due to some of the scrub on the reserve having been cleared as part of the habitat management, a good amount of the scrub habitat should be left in place, so that these species still, potentially, have plenty to breed in. This may enable them to start breeding, or breeding in healthier numbers, on the reserve again in the future. The diversity of the scrub could be improved by introducing grazing, or by using a combination of grazing and cutting. If cutting is used, a small proportion of the scrub should be cut each year, on a rotational basis, ideally in late winter. This would maintain patches of scrub of different ages and improve structural diversity. The woodland may need more management to open it up and give it a more varied structure. This could be achieved by selectively thinning or coppicing parts of the
woodland to allow natural regeneration to occur. The hedges may benefit from being re-laid once every few years, to ensure that they don t become too dense and die inside. The tall, herbaceous vegetation in the Old Hayfield in the north of the site and in other areas should be prevented from scrubbing over. Open areas of grassland, in the Old Hayfield and elsewhere on the reserve, should continue to be maintained either by regular cutting or by introducing grazing. There may be benefit in observing the flight patterns and behaviour of the Swallows and Swifts recorded around the reserve, as the wetter and muddier areas on the reserve may be a source of nest building materials, for birds nesting in near by buildings. If so, some consideration should be given to the future of such areas in the reserve.
References Svensson, L., 2009, Collins Bird Guide, HarperCollins Publishers Ltd, London. Royal Society for the Protection of Birds et al, 2009, Birds of Conservation Concern 3. Royal Society for the Protection of Birds et al, 2011, The State of the UK s Birds 2011. Information was also taken from the web site of the BTO and additional pages of the RSPB web site.