Abstract
Shorebird populations have been declining globally due to human disturbances. One such affected site is the Mumbai Metropolitan Region (MMR), particularly Thane Creek, India. Thane Creek has been under grave threat from urbanisation. Though a critical shorebird wintering site on the west coast of India and Central Asian Flyway (CAF), it has been neglected. Hence, we undertook this study to examine the site fidelity, annual return rate, site switching, and movement of wintering shorebirds in Thane Creek to understand their migration ecology and suggest conservation management actions. We ringed 10,575 shorebirds belonging to 49 species from five high-tide roosting sites around Thane Creek during 2014–15 and 2018–21. A total of 1,013 recaptures and re-sightings of 196 individuals belonging to 19 species were recorded. Site fidelity estimates ranged between 10.22% (n=274) for Terek Sandpiper Xenus cinereus to 0.41% (n=245) for Little Stint Calidris minuta. Annual return rates were highest for Common Redshank Tringa totanus (16.71%, n=383) and Common Sandpiper Actitis hypoleucos (10%, n=30), whereas lowest for Little Stint (0.12%, n=1606). We found that site fidelity was usually higher than site switching (less than 2% for most species) reflecting the strong site fidelity. The roost site fidelity variation seemed more likely to be driven by the roosting site’s quality, age or sex of species, capturing efforts, and human and predator disturbances. Our findings suggested that TSC (Training Ship Chanakya), Panje wetlands, and BPS (Bhandup Pumping Station) saltpans and mangrove were critical sites for shorebird conservation in Thane Creek. Currently, these sites are facing threats from landfilling, excavation, blocking tidal water movement, mangrove incursion, fishing, recreational and commercial development, electric power transmission lines, and bird watching and photography. We recommend the following measures should be taken at high-tide roosting sites to improve shorebird conservation: Regulating blocking of tidal water, water level, fishing, and birdwatching and photography; active management of mangrove incursion; prohibiting mangrove and tree plantation, landfilling, excavation, recreational and commercial development; and the roosting sites should be included in or made legally associated with Thane Creek Flamingo Sanctuary.
References
Aarif, K.M. & K. Musammilu (2018): Pivotal reasons for the decline of the shorebirds in Kadalundi-Vallikkunnu Community Reserve, a key stop-over site in the west coast of India. Asian Journal of Conservation Biology 7: 46–50.
Aarif, K.M. & P.K. Prasadan (2015): Silent shores: population trend of migrant shorebirds & conservation issues of habitat. Partridge Publishing, India, p. 108.
Aarif, K.M., P.K. Prasadan & S. Babu (2011): Conservation signi?cance of the Kadalundi-Vallikkunnu Community Reserve. Current Science 101(6): 717–718.
Aarif, K.M., N. Aymen, M. Nasser, P.K. Prasadan, T.R. Athira & S.B. Muzaffar (2021): Multiple environmental factors and prey depletion determine declines in abundance and timing of departure in migratory shorebirds in the west coast of India. Global Ecology and Conservation 26: e01518. https://doi.org/10.1016/j. gecco.2021.e01518.
Almende, B.V., B. Thieurmel & T. Robert (2019): visNetwork: Network Visualization using ‘vis.js’ Library. R package version 2.0.9. https://CRAN.R-project.org/package=visNetwork.
Apte, D. & V. Rasal (2017): Mangrove enumeration study of proposed 400kV Talegaon-Vikhroli/Kalwa-Vikhroli transmission line by the Tata Power Company Limited. Report. Bombay Natural History Society, 60 pp.
Apte, D., R. Khot, S. Bajaru, M. Prabhu, R. Pitale, S. Jain, A. Lokhande, S. Sankpal, P. Noronha, T. Mundra, P. Chogale, K. Chandel & P. Sail (2019): Monitoring and mitigating the impacts of Mumbai Trans-Harbour Link on flamingos and other avifauna and formulating a conservation blueprint for the Sewri–Nhava seascape. Report. Bombay Natural History Society. Pp. 48.
Azeez, A.S., L. Gnanappazham, K.R. Muraleedharan, C. Revichandran, S. John, G. Seena & J. Thomas (2022): Multidecadal changes of mangrove forest and its response to the tidal dynamics of thane creek, Mumbai. Journal of Sea Research 180: 102162. https://doi.org/10.1016/j.seares.2021.102162.
Bailiss, C. (2020): pivottabler: Create Pivot Tables. R package version 1.5.0. https://CRAN.R-project.org/package=pivottabler. Accessed on October 20, 2021.
Baker, A.J., P.M. González, T. Piersma, L.J. Niles, I. De L. S. Do Nascimento, P.W. Atkinson, N.A. Clark, C.D.T. Minton, M.K. Peck & G. Aarts (2004): Rapid population decline in Red Knots: Fitness consequences of decreased refuelling rates and late arrival in Delaware Bay. Proceedings of the Royal Society of London, Series B 271: 875–882. http://doi.org/10.1098/ rspb.2003.2663.
Balachandran, S. (1995): Shore birds of the Marine National Park in the Gulf of Mannar, Tamil Nadu. J. Bombay Nat. Hist. Soc. 92(3): 303–313.
Balachandran, S. (1998a): Population, moult, biometrics and subspecies of Large Sandplover Charadrius leschenaultii wintering in southeast India. J. Bombay Nat. Hist. Soc. 95(3): 426–430.
Balachandran, S. (1998b): Population status, moult, measurements & subspecies of Knot Calidris canutus wintering in south India. Wader Study Group Bulletin 86: 44–47.
Balachandran, S. (2002): Indian Bird Banding Manual. Bombay Natural History Society. Pp. 80.
Balachandran, S. (2006): The decline in wader populations along the east coast of India with special reference to Point Calimere, south-east India. Pp. 296–301. In: Boere, G.C., C.A. Galbraith & D.A. Stroud (Eds): Waterbirds around the world. The Stationery Office, Edinburgh.
Balachandran, S. (2007): Decline of coastal birds along the south-east coast of India. In: Editor-Director (Eds): National Symposium on Conservation and Valuation of Marine Biodiversity. Zoological Survey of India, Kolkata.
Balachandran, S. (2012): Avian diversity in coastal wetlands of India and their conservation needs. Uttar Pradesh State Biodiversity Board. Pp. 155–163.
Balachandran, S. & P. Sathiyaselvam (2007): Further records of Great Knot (Calidris tenuirostris) and Red Knot (Calidris canutus) from the north-east coast of India. J. Bombay Nat. Hist. Soc. 104(3): 350–351.
Balachandran, S. & S.A. Hussain (1994): Longest longevity record for the Lesser Sandplover Charadrius mongolus pallas. J. Bombay Nat. Hist. Soc. 91(1): 140–141.
Balachandran, S. & S.A. Hussain (1998): Moult, age structure, biometrics and subspecies of Lesser Sand Plover Charadrius mongolus wintering along the south-east coast of India. The Stilt 33: 3–9.
Balachandran, S., T. Katti & R. Manakadan (2018): Indian Bird Migration Atlas. Bombay Natural History Society and Oxford University Press, India. 216 pp.
Balachandran, S. & V. Natarajan (1992): Possible occurrence of four subspecies of Lesser Sand Plover Charadrius mongolus at Pt. Calimere Wildlife Sanctuary, Tamil Nadu. J. Bombay Nat. Hist. Soc. 89(1): 118–119.
Balachandran, S. & V. Natarajan (1997): Biometrics, moult, age structure and subspecies of Broad-billed Sandpiper Limicola falcinellus wintering at Great Vedaranyam Swamp, in south-east India. The Stilt 31: 23–25.
Bibby, C.J., N.D. Burgess, D.A. Hill & S.H. Mustoe (2000): Bird Census Techniques. 2nd Edn. Academic Press, London. Pp. 302.
Bobika, V.K., K. Mohamed Dhaya EL Hak, R. Renila, K. Manjusha & K.M. Aarif (2021): Does substrate quality influence diversity and habitat use of waterbirds?: A case study from wetlands in Southern India. Ekológia (Bratislava) 40: 70–79. https://doi.org/10.2478/eko-2021-0009.
Bocher, P., F. Robin, J. Kojadinovic, P. Delaporte, P. Rousseau, C. Dupuy & P. Bustamante (2014): Trophic resource partitioning within a shorebird community feeding on intertidal mudflat habitats. Journal of Sea Research 92: 115–124.
Burger, J., C. Jeitner, K. Clark, & L.J. Niles (2004): The effect of human activities on migrant shorebirds: Successful adaptive management. Environmental Conservation 31(4): 283–288.
Burton, N.H.K. (2000): Winter site-?delity and survival of Redshank Tringa totanus at Cardiff, South Wales. Bird Study 47(1): 102–112. https://doi.org/10.1080/00063650009461164.
Burton, N.H.K., M.M. Rehfisch & N.A. Clark (2002): Impacts of disturbance from construction work on the densities and feeding behavior of waterbirds using the intertidal mud?ats of Cardiff Bay, U.K. Environmental Management 30(6): 865–871. doi:10.1007/s00267-002-2733-4
Burton, N.H.K., M.M. Rehfisch, N.A. Clark & S.G. Dodd (2006): Impacts of sudden winter habitat loss on the body condition and survival of redshanks Tringa totanus. Journal of Applied Ecology 43(3): 464–473. https://doi.org/10.1111/j.1365-2664.2006.01156.x
Burton, N.H.K. & P.R. Evans (1997): Survival and winter site ?delity of Turnstones Arenaria interpres and Purple Sandpipers Calidris maritima in northeast England. Bird Study 44(1): 35–44. https://doi.org/10.1080/00063659709461036.
Burton, N.H.K., P.R. Evans & M.A. Robinson (1996): Effects on shorebird numbers of disturbance, the loss of a roost site and its replacement by an arti?cial island at Hartlepool, Cleveland. Biological Conservation 77: 193–201.
Chatterjee, B. (2020): Path clear for Navi Mumbai golf course. Hindustan Times dated, February 20, 2020. https://www.hindustantimes.com/mumbai-news/path-clear-for-navi-mumbaigolf-course/story-0fvDrop1v0DSvEHdN66oZJ.html. Accessed on November 15, 2021.
Colwell, M.A. (2010): Shorebird Ecology, Conservation, and Management. University of California Press Berkeley and Los Angeles. Pp. 344.
Conklin, J.R. & M.A. Colwell (2007): Diurnal and nocturnal roost site ?delity of Dunlin (Calidris alpina pacifica) at Humboldt Bay, California. The Auk 124(2): 677–689. doi:10.1093/auk/124.2.677
Conklin, J.R., M.A. Colwell & N.W. Fox- Fernandez (2008): High variation in roost use by Dunlin wintering in California: Implications for habitat limitation. Bird Conservation International 18: 275–291. doi: 10.1017/S0959270908000270
Cresswell, W. (1994): Flocking is an effective anti-predation strategy in redshanks, Tringa totanus. Animal Behaviour 47(2): 433–442.
Dierschke, V. (1998): Site fidelity and survival of Purple Sandpipers Calidris maritima at Helgoland (SE North Sea). Ringing & Migration 19(1): 41–47. https://doi.org/10.1080/03078698.199 8.9674162
Durell, S.E.A. Le V. Dit, J.D. Goss-Custard & R.W.G. Caldow (1993): Sex-related differences in diet and feeding method in the Oystercatcher Haematopus ostralegus. Journal of Animal Ecology 62(1): 205–215. https://doi.org/10.2307/5495
Evans, P.R. & M.W. Pienkowski (1984): Population dynamics of shorebirds. Pp. 83–123. In: Burger, J. & B.L. Olla (Eds): Shorebirds: breeding behavior and populations. Behavior of Marine Animals: Current Perspectives in Research, 5. Plenum Press, New York.
Foster, C.R., A.F. Amos & L.A. Fuiman (2009): Trends in abundance of coastal birds and human activity on a Texas Barrier Island over three decades. Estuaries and Coasts 32(6): 1079–1089.
Gadgil, M. (2019): Navi Mumbai SEZ: Committee stops all work on wetland in Uran and Panje. Mumbai Mirror dated December 21, 2019. https://mumbaimirror.indiatimes.com/mumbai/other/navi-mumbai-sez-committee-stops-all-work-on-wetland/articleshow/72910283.cms. Accessed on November 15, 2021.
Gerstenberg, R.H. & W.H. Stanley (1976): Trapping and marking of shorebirds at Humboldt Bay, California. Bird Banding 47: 1–7.
Goss-Custard, J.D. (1985): Foraging behaviour of wading birds and the carrying capacity of estuaries. Pp. 169–188. In: Sibly, R.M. & R.H. Smith (Eds): Behavioural Ecology: Ecological Consequences of Adaptive Behaviour. Blackwell, Oxford.
Goss-Custard, J.D. & N. Verboven (1993): Disturbance and feeding shorebirds on the Exe estuary. Wader study group bulletin 68: 59–66.
Goss-Custard, J.D., S.E.A. Le V. Dit. Durell, H.P. Sitters & R. Swinfen (1982): Age-structure and survival of a wintering population of Oystercatchers. Bird Study 29(2): 83–98. https://doi.org/10.1080/00063658209476743
Hockin, D., M. Ounsted, M. Gorman, D. Hill, V. Keller & M.A. Barker (1992): Examination of the effects of disturbance on birds with reference to its importance in ecological assessments. Journal of Environment Management 36: 253–286.
Huang, S.C., S. Shih, Y. Ho, C. Chen & H. Hsieh (2010): Restoration of shorebird–roosting mudflats by partial removal of estuarine mangroves in Northern Taiwan. Restoration Ecology 20: 76–84. https://doi.org/10.1111/j.1526-100X.2010.00744.x.
Iwajomo, S.B., M. Stervander, A. Helseth & U. Ottosson (2013): Population trends and migration strategy of the Wood Sandpiper Tringa glareola at Ottenby, SE Sweden. Ringing Migration 28(1): 6–15. doi: 10.1080/03078698.2013.811157
Jahn, A.E., V.R. Cueto, M.C. Sagario, A.M. Mamani, J.Q. Vidoz, J.L. Casenave & A.G. Giacomo (2009): Breeding and winter site fidelity among eleven neotropical austral migrant bird species. Ornitologia Neotropical 20(2): 275–284.
Johnson, O.W., P.L. Bruner, J.J. Rotella, P.M. Johnson & A.E. Bruner (2001): Long-term study of apparent survival in Pacific Golden Plovers at a wintering ground on Oahu, Hawaiian Islands. The Auk 118(2): 342–351.
Kannan, V. & J. Pandiyan (2012): Shorebirds (Charadriidae) of Pulicat Lake, India with special reference to conservation. The World Journal of Zoology 7(3): 178–191.
Kannan, V., R. Manakadan, R.A. Prakash, K.K. Mohapatra, S. Sivakumar & V. Santharam (2008): The waterbirds of Pulicat Lake, Andhra Pradesh-Tamil Nadu, India, including those of the adjoining wetlands and heronries. J. Bombay Nat. Hist. Soc. 105(2): 162–180.
Koch, S.L. & P.W. Paton (2014): Assessing anthropogenic disturbances to develop buffer zones for shorebirds using a stopover site. The Journal of Wildlife Management 78(1): 58–67. https://doi.org/10.1002/jwmg.631
Kulavmode, A.R., S. Bajaru, M.V. Prabhu, R. Khot & D. Apte (2021): Urbanisation and its drivers in the Mumbai Metropolitan Region (MMR), India: Spatio-temporal analysis of land-use and land-cover change from 1973 to 2018 [Unpublished manuscript]. Bombay Natural History Society, India.
Latta, S.C., H.L. Cueva & A.B. Harper (2012): Abundance and site fidelity of migratory birds wintering in riparian habitat of Baja, California. Western Birds 43: 90–101.
Latta, S.C. & J. Faaborg (2001): Winter site fidelity of Prairie Warblers in the Dominican Republic. Condor 103: 455–468.
Lourenço, P., C. Serra Gonçalves, J. Ferreira, T. Catry & J. Granadeiro (2017): Plastic and other microfibers in sediments, macroinvertebrates and shorebirds from three intertidal wetlands of southern Europe and west Africa. Environmental Pollution 231: 123–133.
Manakadan, R. & V. Kannan (2007): An ecological account of the waterbirds of Pulicat Lake with special reference to conservation. Final Report. Bombay Natural History Society.
Manikannan, R., S. Asokan, S.A. Mohamed & A. Hameed (2012): Abundance and factors affecting population characteristics of waders (Charadriiformes) in Great Vedaranyam Swamp of Point Calimere Wildlife Sanctuary, south-east coast of India. International Journal of Ecosystem 2(1): 6–14.
Matthew, J.G., J.C. Michael, A.B. David & B.S. William (2013): Wetland wildlife monitoring and assessment. Pp. 265–312. In: Anderson, J.T. & C.A. Davis (Eds): Wetland techniques: Volume 2: Organisms. Springer, Dordrecht. https://doi.org /10.1007/978- 94-007-6931-1_7.
Mclusky, D.S., D.M. Bryant & M. Elliott (1992): The impact of landclaim on macrobenthos, fish and shorebirds on the Forth estuary, eastern Scotland. Aquatic Conservation: Marine and Freshwater Ecosystems 2: 211–222.
Mohanraj, S. & J. Pandiyan (2014): Invasion of shorebirds into inland wetlands of Periyakulam lake, Tiruchirappalli, Southern India. Scientific Transaction in Environmental and Technovation 7: 113–117.
Morrison, R.I.G., B.J. Mccaffery, R.E. Gill, JR., S.K. Skagen, S.L. Jones, G.W. Page, C.L. Gratto-Trevor & B.A. Andres (2007): Population estimates of North American shorebirds. Wader study group Bulletin 111: 66–84.
Mundkur, T., T. Langendoen & D. Watkins (eds) (2017): The Asian waterbird census 2008–2015 - results of coordinated counts in Asia and Australasia. Wetlands International, Ede.
Nagarajan, R. & K. Thiyagesan (1996): Waterbirds and substrate quality of the Pichavaram wetlands, southern India. Ibis 138(4): 710–721.
Newton, I. (2007): The Migration Ecology of Birds. Academic Press, London. Pp. 984.
Page, G. & D.P. Whitacre (1975): Raptor predation on wintering shorebirds. Condor 77: 73–83.
Pandiyan, J. & S. Asokan (2016): Habitat use pattern of tidal mud and sand flats by shorebirds (Charadriiformes) wintering in southern India. Journal of Coastal Conservation Planning and Management 20:1–11. https://doi.org/10.1007/s11852-015-0413-9.
Pandiyan, J., S. Mahboob, R. Jagadheesan, K. Elumalai, K. Krishnappa, F. AL-Misned, Z.A. Kaimkhani & M. Govindarajan (2020): A novel approach to assess the heavy metal content in the feathers of shorebirds: A perspective of environmental research. Journal of King Saud University Science 32(7): 3065– 3071. https://doi.org/10.1016/j.jksus.2020.08.014.
Parr N., S. Bearhop, D.C. Douglas, J.Y. Takekawa, D.J. Prosser, S.H. Newman, W.M. Perry, S. Balachandran, M.J. Witt, Y. Hou, Z. Luo & L.A. Hawkes (2017): High altitude flights by ruddy shelduck Tadorna ferruginea during trans-Himalayan migrations. Journal of Avian Biology 48(10): 1310–1315. doi: https://doi.org/10.1111/jav.01443
R CORE TEAM (2020): R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/.
Rahmani, A., Z. Islam & R. Kasambe (2016): Important Bird and Biodiversity Areas in India: Priority Sites for Conservation. (Revised and updated). Bombay Natural History Society, Indian Bird Conservation Network, Royal Society for the Protection of Birds and BirdLife International (UK). Pp. 1992.
Rao, G.B., S. Babu, G. Quadros & V. Anoop (2019): Bird diversity in the coastal talukas of Sindhudurg District, Maharashtra, India. Journal of Threatened Taxa 11: 14166–14186.
Rehfisch, M., H. Insley & R. Swann (2003): Fidelity of overwintering shorebirds to roosts on the Moray Basin, Scotland: implications for predicting impacts of habitat loss. Ardea 91: 53–70.
Rehfisch, M.M., N.A. Clark, R.H.W. Langston & J.J.D. Greenwood (1996): A guide to the provision of refuges for waders: an analysis of 30 years of ringing data from the Wash, England. Journal of Applied Ecology 33: 673–687.
Robertson, G. & F. Cooke (1999): Winter philopatry in migratory waterfowl. The Auk 116: 20–34.
Rogers, D.I., P.F. Battley, T. Piersma, J.A. Van Gils & K.G. Rogers (2006): High-tide habitat choice: insights from modeling roost selection by shorebirds around a tropical bay. Animal Behaviour 72: 563–575.
Rogers, D.I., T. Piersma & C.J. Hassell (2007): Roost availability may constrain shorebird distributions: exploring the energetic costs of roosting and disturbance around a tropical bay. Biological Conservation 133: 225–235.
Sampath, K. & K. Krishnamurthy (1990): Shorebirds (Charadriiformes) of the Pichavaram mangroves, Tamil Nadu, India. Wader Study Group Bulletin 58: 24–27.
Silvy, N.J. & R.J. Robel (1968): Mist nets and cannon nets compared for capturing Prairie Chickens on booming grounds. The Journal of Wildlife Management 32: 175–178.
Smith, K.W., J.M. Reed & B.E. Trevis (1992): Habitat use and site fidelity of Green Sandpipers Tringa ochropus wintering in southern England. Bird Study 39: 155–164.
SoIB (2020): State of India’s Birds, 2020: Range, trends and conservation status. The SoIB Partnership. https://www.thehinducentre.com/ resources/article30921926.ece 12 June 2021
Sutherland, W.J., José A. Alves, Tatsuya Amano, Charlotte H. Chang, Nicholas C. Davidson, C. Max Finlayson, Jennifer A. Gill, Robert E. Gill JR, Patricia M. González, Tómas Grétar Gunnarsson, David Kleijn, Chris J. Spray, Tamás Székely, Des B.A. Thompson (2012): A horizon scanning assessment of current and potential future threats to migratory shorebirds. Ibis 154: 663–679.
Swennen, C. (1984): Differences in quality of roosting flocks of oystercatchers. Pp. 160– 176. In: Evans, P.R., J.D. Goss-Custard & W.G. Hale (Eds): Coastal waders and wildfowl in winter. Cambridge University Press, Cambridge.
Symonds, F.L. & D.R. Langslow (1986): The distribution and local movements of shorebirds within the Moray Firth. Proceedings of the Royal Society Edinburgh. Section B. Biological Sciences. 91: 143–167. doi: 10.1017/S0269727000009283
Thomas, G.H., R.B. Lanctot & T. Székely (2006): Can intrinsic factors explain population declines in North American breeding shorebirds? A comparative analysis. Animal Conservation 9(3): 252–258. doi: 10.1111/j.1469-1795.2006.00029.x
Tomkovich, P.J. & M.Y. Soloviev (1994): Site fidelity in high arctic breeding waders. Ostrich 65(2): 174–180. doi: https://doi.org/10.1080/00306525.1994.9639680
Van Gils, J.A., B. Spaans, A. Dekinga & T. Piersma (2006): Foraging in a tidally structured environment by Red Knots (Calidris canutus): Ideal, but not free. Ecology 87(5): 1189–1202.
Warkentin, I.G. & D. Harnandez (1996): The conservation implications of site fidelity: a case study involving near cticneotropical migrant songbirds wintering in a costarican mangrove. Biological Conservation 77(2–3): 143–150.
Warnock, N. & S.E. Schwarzbach (1995): Incidental kill of Dunlin and killdeer by strychnine. Journal of Wildlife Diseases 31(4): 566–569. doi: 10.7589/0090-3558-31.4.566
Warnock, S.E. & J.Y. Takekawa (1995): Habitat preferences by wintering shorebirds in a temporally changing environment: Western Sandpipers in the San Francisco Bay estuary. The Auk 112(4): 920–930.
White, D.H., C.A. Mitchell & T.E. Kaiser (1983): Temporal accumulation of organochlorine pesticides in shorebirds wintering on the south Texas coast, 1979–80. Archives of Environmental Contamination and Toxicology 12: 241–245. doi: https://doi.org/10.1007/BF01059587
Zhang, M., Y. Hong, F. Zou, Q. Zhang, H. Fan, S. Chan, K. Cheong, & K. Leong (2019): Response of shorebird habitat selection to coastal reclamation and urbanization in an extensively developed delta: A case study in Macao, China. Ocean & Coastal Management 179: 104–871. doi: https://doi.org/10.1016/j.ocecoaman.2019.104871
Zöckler, C., S. Balachandran, G. Bunting, M. Fanck, M. Kashiwagi, E. Lappo, G. Maheswaran, A. Sharma, E. Syroechkovski & K. Webb (2005): The Indian Sunderbans: an important wintering site for Siberian waders. Wader Study Group Bulletin 108: 42–46.
Zöckler, C., S. Delany & W. Hagemeijer (2003): Wader populations are declining—how will we elucidate the reasons? Wader Study Group Bulletin 100: 202–211.