Two main facts to establish in introduction: Woodcock is a wader and a partial migrant.

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2 Two main facts to establish in introduction: Woodcock is a wader and a partial migrant. 2

3 Woodcock refers to any member of the genus Scolopax, of which there are 8 members ours is the Eurasian (S. rusticola) Taxonomically these are waders, in the sandpiper family along with the more typical coastal waders (see pictures on next slide). 3

4 Woodcock retains features of this wading body plan, despite rarely wading (although picture shows wading woodcock). The legs are shorter and stouter than most waders but the long bill is preserved. This adaptation as useful for foraging for worms on dry land as it is marine invertebrates in a tidal estuary. 4

5 Partial migrant a species in which some individuals migrate and others are sedentary. This may be between population i.e. some distinct populations migrate and other populations do not Or it may be witihin population where within a single breeding population certain individuals migrate and others do not In Europe, it is more common than is often appreciated. Many species show a latitudinal variation in their tendency to migrate. Northern populations are more likely to be migratory weather meaning winter conditions are intolerable. 5

6 Woodcock are migratory in the northern parts of their range. These birds move south into more temperate wintering grounds. Here they overlap with sedentary breeding populations. The resident and the migratory populations overlap (click to reveal overlap) Britain is part of the range edge it s breeding population is tiny compared to Baltic states, Russia and Scandinavia 6

7 Reasons for studying migration are covered on next slide General fascination with migration woodcock is the opposite of the typical swallow story i.e. winters in UK, rather than breeding in UK Lots of folklore regarding woodcock migration spending summer months on the moon, the woodcock moon, the goldcrest etc 7

8 More than just curiosity practical understanding of migration is necessary relevant to the species conservation Climate change, habitat degradation, hunting pressure can all affect migratory species understanding the specifics of migration informs us how. 8

9 Value of ringing must not be under estimated. Many benefits but dependent upon recaptures which in the case of woodcock means a lot of work. Lord William Percy ringed woodcock chicks on the Duke of Northumberland s estate in the 1890s the first large scale ringing project in the UK. Now woodcock ringing takes place as part of a national ringing scheme for all bird species co-ordinated by the BTO. Annually, around 1,400 are ringed each year (since 2009 prior to this, far fewer). 9

10 Despite the advent of modern tracking technology, there s still a lot we can learn from ringing. Work of Owen Williams who captures and re-captures hundreds of birds in Wales each year. We conduct similar exercises in Cornwall and Hampshire. Learn about woodcock survival via successive recaptures. Learn about movements if and when birds are recaught (or shot) elsewhere in the world. 10

11 Ringing also demonstrates site fidelity in Woodcock recapture the same bird year after year in the same place. 11

12 ISOTOPEs are variants of an element in which number of NEUTRONS DIFFERS, number of PROTONS remains the SAME. The ratios in which hydrogen isotopes occurs vary geographically (see map). Most biological molecules are made up of the same six elements (Carbon, Nitrogen, Oxygen, Phosphorus, Sulfur and Hydrogen). Hydrogen in the body comes from the environment. Hydrogen from rain becomes part of the woodcock s body via the worms it eats which take water from the soil. Hydrogen from the breeding ground is locked into the feathers during moult and remain with the bird for a year. Chemical analysis of the isotopes in the feather allow us to trace the bird to a rough geographic location. 12

13 Shading shows the likelihood of a bird being from a specific region. 13

14 A rough geographic pattern in origins. Appears that Scottish birds are more likely to be from Scandinavia than those elsewhere in UK. Resolution associated with this technique are not particularly fine-scale. 14

15 Weighs about two grams. Positives light, relatively cheap, long-lasting. Negatives hard to recover data. Spatial resolution is relatively broad. 15

16 Speed of migration. Can cover 1200 km in 36 hours. Typically 30 km/h but can reach 93 km/h. 16

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18 Weight 9 g Several advantages over geolocators namely the accuracy granted and the live return of data via satellite. (number of tags we have done on next slide) 18

19 Deploying many tags is important not just repeating the same exercise. About building a sample large enough to tease out regional variation or variations as the result of age or year of study. 19

20 This is 2015 s birds. Destinations so far: Norway, Sweden, Denmark, Finland, Russia, Estonia, Latvia, Belarus, Poland. If you included UK that makes 10 breeding locations. 20

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23 Much more mixing on the wintering ground than expected not the neat pattern suggested by isotope analysis. It is not necessarily so that Scottish winterers are Scandinavian, Welsh winterers are Baltic etc. However in the long run it has been observed that Scottish birds are slightly more likely to hail from Scandinavia. Isotope analysis results are supported but in actuality the pattern is noisy. 23

24 Monkey covered a distance just over 6000 km on his outward journey. He used the same breeding site two years running. Surprisingly two other birds made journeys of a similar length Crugith (also from Cornwall) and Woody II from Norfolk. 24

25 Did not come back to UK despite having been caught in Norfolk. Generally we see a high degree of site fidelity but not always. Also mention outward route via Latvia and Estonia not all Finish birds do that but they do avoid cross the Baltic Sea 25

26 To date four birds tagged in the County Durham / Northumberland region (technically two in each, but all four on the border). Rose went to Poland, Derwent to Sweden. Quill and Ariel were residents. Appears this may suggest a high proportion of residents in these areas of Britain. (Which leads into next slide ) 26

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28 Do not give popn size, there is a slide dedicated to this later on Briefly mention winter movements of residents infrequent and weather related NOT territorial behaviour explanation on next slide 28

29 Grey roding grounds were not covered in their entirety every night. Varied from one night to the next. Males circuits overlap not territorial behaviour. Aerial lek i.e. males compete for female attention Average approx. 88 ha. Video next 29

30 Little known about breeding pop so survey of residents deemed necessary Collaboration with BTO Shows importance of dedicated survey method because species is difficult to see / nocturnal. 30

31 Repeat in 2013 but we already expected a decline because of Atlas (shown). 31

32 Decline in occupancy. These are raw survey data (extrapolated on next page) 32

33 Most of these declines in the South and West but also areas like southern Scotland. 33

34 Northern Scotland only declines very slightly. Accounts for over 40% of the population estimate in

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36 Note that decline in occupancy in the 2003 to 2013 survey is greater than would be expected based upon the Atlas. Annual counts reveal large proportion of the ten year decline can be accounted for by just one year (2008/2009). Ten year decline may be worsened by weather but this does not take away from the fact it is part of a longer term decline. 36

37 Woodcock are not the only declining woodland bird there are many. But there is not one unifying theory behind all woodland bird declines Many declining woodland species are associated with old, undisturbed forest (pied fly, Capercaillie) Some, such as woodlark/nightjar are reliant on particular types of management. 37

38 Additionally, woodcock are a quarry species. We believe habitat is the primary driver of decline but we are unsure of the impact of shooting at this point in time. Currently migrant populations, which are also hunted, show stable or increasing populations. But resident birds may respond differently to the same shooting pressure. Wide range of opinions within the shooting community many people do not shoot woodcock in the early part of the season or impose their own limits We need to look at the effectiveness of these measure Much of our work involves working with landowners, farmers and gamekeepers the Trust s advice is respected amongst the shooting community. 38

39 What do we still need to know about breeding woodcock? Specifics of habitat use are of greatest interest Knowing more about the habits of brood-rearing females would be desirable but difficulty in obtaining this data. Productivity hard to measure as broods / nest are hard to find and there is a risk of dessertion Studying males can provide important data: Feeding and habitat use Specifics of the breeding display The latter is important as it feeds into our interpretation of the national survey 39

40 Before describing map, describe tag and the data we get Day-time Night-time Dusk (via logger) Feeding after roding, and during. Importance of open areas within woodland? One bird, one evening. No circuits apparently random 40

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