1 Appendix. Ecological factors influencing vigilance among species
advertisement
1 Appendix. Ecological factors influencing vigilance among species of foraging birds. Data are sorted by year of study. Species Body mass (g) Sample size Maximum group Diet size Vigilance alone Asymptotic % time spent in (%) vigilance (%) agonistic References activities Anser albifrons 2075 100 vegetation Sturnus vulgaris 87.6 10 seeds Branta leucopsis 1550 200 vegetation Branta leucopsis 1788 28 2000 vegetation 33.00 6.00 Drent and Swiestra 1977 Anser albifrons 2075 42 1061 vegetation 65.00 5 Lazarus and Inglis 1978 Anser brachyrhynchus 2770 2235 33 vegetation 5.00 0 Lazarus 1978 Branta bernicla 1370 43 600 vegetation 25.00 10.00 Inglis and Isaacson 1978 Junco phaeonotus 20.4 97 10 seeds 28.10 10.00 Caraco 1979 Numenius arquata 742 42 28 invertebrates 16.20 3.00 Abramson 1979 236 47.00 3 Owen 1972 12 Powell 1974 10.10 0.3 Ebbinge et al. 1975 2 Junco phaeonotus 20.4 267 7 seeds 66.00 34 Passer domesticus 28 98 50 seeds Passer domesticus 28 37 4 seeds 62.00 47 McVean and Haddlesey 1980 Struthio camelus 111000 70 4 vegetation 34.90 14 Bertram 1980 Sturnus vulgaris 87.6 39 225 invertebrates 27.30 2 Jennings and Evans 1980 Branta bernicla 1370 64 1800 vegetation 25.00 9 Inglis and Lazarus 1981 Corvus frugilegus 489 139 30 invertebrates 56.00 12 Waite 1981 Chionis minor 625 75 30 invertebrates 8.00 3 Burger 1982 Anas platyrhynchos 1082 1000 seeds Passer domesticus 28 5 6 seeds Passer domesticus 28 57 4 seeds Anas strepera 968 100 vegetation 10 9 Caraco et al. 1980 6 Barnard 1980 1 Jorde et al. 1983 Elcavage and Caraco 1983 80.67 38.00 1.4 Studd et al. 1983 11.1 0.5 Paulus 1984 3 Eudocimus albus 1036 39 78 invertebrates 5.7 Passer domesticus 28 541 4 seeds Picoides pubescens 27.5 160 4 invertebrates Streptopelia risoria 152 22 6 seeds Cyanistes caeruleus 11.1 10 5 seeds 12.00 Haliaeetus leucocephalus 4130 110 14 carrion 40 Anas americana 792 15 vegetation 4 Carduelis carduelis 16 1 seeds Corcorax melanorhamphos 364 62 33 seeds Eudocimus albus 1036 25 15 invertebrates Fringilla coelebs 21.9 196 11 seeds 60 Grus americana 7300 7 invertebrates 6.30 Bildstein 1983 Elgar et al. 1984 11.10 Sullivan 1984 Lendrem 1984 68.00 75.00 Hegner 1985 Knight and Knight 1986 0.9 Turnbull and Baldassare 1987 Glück 1987 7.00 Heinsohn 1987 18.00 Petit and Bildstein 1987 Beveridge and Deag 1987 Hunt 1987 4 Passer domesticus 28 75 4 seeds 52.00 Passer domesticus 28 281 10 seeds 39.00 Beveridge and Deag 1987 Plocepasser mahali 44 49 4 mixed 16.5 Ferguson 1987 Poecile montana 11.1 2064 4 seeds Sturnus vulgaris 87.6 55 14 seeds 25 Anas fulvigula 1043 1061 10 vegetation 4.9 Calidris alpina 55.4 91 7 invertebrates Chen caerulescens 2744 14500 seeds Eolophus roseicapilla 354 199 50 seeds 49.00 Grus canadensis 3350 128 1000 mixed 1.58 Poecile montana 11.1 451 4 mixed Psephotus haematonotus 61.4 159 30 seeds 41.00 30.00 25.00 34.00 1 0.7 0 Paulus 1988 Gauthier et al. 1988 Westcott and Cockburn 1988 0.4 11 Ekman 1987 Redpath 1988 12 28.00 Lima 1987 Beveridge and Deag 1987 5 10.3 56.00 1 2 Tacha 1989 Hogstad 1988 Westcott and Cockburn 1988 5 Struthio camelus 111000 159 10 vegetation 43.00 40 Burger and Gochfeld 1988 Calidris melanotus 97.8 5 invertebrates 14.8 7.3 Young 1989 Calidris pusilla 27.5 15 invertebrates 2.70 2.4 Young 1989 Limnodromus scolopaceus 100 9 invertebrates 1.88 1.1 Young 1989 Tringa flavipes 77.5 8 invertebrates 9.20 2.6 Young 1989 Chenonetta jubata 815 25 280 vegetation 13 Ciconia ciconia 3571 64 40 invertebrates 57 117 11 invertebrates Cyanistes caeruleus 10.1 14 1 seeds Larus atricilla 327 279 300 invertebrates Lophophanes cristatus 11.4 29 1 seeds 38.00 Moreno and Carrascal 1991 Parus major 18.9 37 1 seeds 30.30 Moreno and Carrascal 1991 Calidris alba 40.00 Briggs 1990 15.00 0.2 Carrascal et al. 1990 3.50 0.2 Burger and Gochfeld 1991a 31.30 Moreno and Carrascal 1991 2.8 1 Burger and Gochfeld 1991b 6 Periparus ater 9.2 31 1 seeds 29.50 Moreno and Carrascal 1991 Pica pica 221 113 3 mixed 32.80 Sitta europaea 22.6 49 1 seeds 28.20 Anser albifrons 2393 163 100 vegetation 29.70 Branta bernicla 1760 33 1000 vegetation 5 1 Black et al. 1992 Calidris alpina 55.4 300 100 invertebrates <1% 1 Mouritsen 1992 Chen caerulescens 2744 360 7117 vegetation 5 1 Bélanger and Bédard 1992 Lophophanes cristatus 11.4 27 1 seeds 34.30 Carrascal and Moreno 1992 Periparus ater 9.2 27 1 seeds 27.80 Carrascal and Moreno 1992 Phasianus colchicus 1317 47 10 seeds 97.30 Phoenicopterus ruber ruber 3540 887 3500 vegetation Sitta europaea 22.6 28 1 seeds 22.9 Moreno and Carrascal 1991 Ely 1992 79.30 1.1 34.80 Diaz and Asensio 1991 Milligan and Brigham 1992 4.9 Schmitz and Baldassarre 1992 Carrascal and Moreno 1992 7 Anser anser 3509 6 140 seeds 5.00 Grus grus 5500 394 10 seeds 18.00 Pica pica 189 91 12 carrion 32.00 71.00 Anas crecca crecca 320 157 8 vegetation 37.00 30 Ciconia ciconia 3571 167 26 invertebrates Corvus corone corone 570 1203 17 seeds Grus canadensis 3350 1250 5 mixed 16.5 Arenaria interpres 134 9 4 invertebrates 6.46 Barbosa 1995 Calidris alba 57 23 59 invertebrates 0.90 Barbosa 1995 Calidris alpina 55.4 96 215 invertebrates 2.73 Barbosa 1995 Calidris minuta 21.1 26 46 invertebrates 1.48 Barbosa 1995 Charadrius alexandrinus 42.3 23 28 invertebrates 6.53 Barbosa 1995 20.00 Kotrschal et al. 1993 0.5 Alonso and Alonso 1993 McKinstry and Knight 1993 Pöysä 1994 17.5 Alonso et al. 1994 3.70 Saino 1994 0.2 Sparling and Krapu 1994 8 Charadrius hiaticula 63.3 5 14 invertebrates 3.33 Barbosa 1995 Coccothraustes vespertinus 55.7 1472 10 seeds 15 Bekoff 1995 Gallinago gallinago 97 5 9 invertebrates 13.7 Barbosa 1995 Haematopus ostralegus 526 8 19 invertebrates 8.8 Barbosa 1995 Himantopus himantopus 161 24 13 invertebrates 3.55 Barbosa 1995 Junco hyemalis 19.3 117 6 seeds Limosa lapponica 309 10 173 invertebrates 3.45 Barbosa 1995 Limosa limosa 252 47 178 invertebrates 3.9 Barbosa 1995 Philomachus pugnax 170 22 165 invertebrates 2.49 Barbosa 1995 Pluvialis squatarola 250 33 17 invertebrates 1.33 Barbosa 1995 Recurvirostra avosetta 304 48 146 invertebrates 4.38 Barbosa 1995 23000 33 8 vegetation Rhea americana 37.00 Lima 1995 34.00 13 Martella et al. 1995 9 Tringa totanus 129 23 169 invertebrates 5.16 Barbosa 1995 Vanellus vanellus 211 38 34 invertebrates 1.94 Barbosa 1995 Anser albifrons 2700 122 vegetation 14 0.5 Gawlik and Slack 1996 Branta canadensis 2180 38 1000 vegetation 11.00 0.5 Gawlik and Slack 1996 Chen caerulescens 2744 65 10000 vegetation 14.00 0.5 Gawlik and Slack 1996 Junco hyemalis 19.3 26 7 seeds Calidris alpina 55.4 77 189 invertebrates 1.7 Barbosa 1997 Corvus brachyrhynchos 538 23 7 invertebrates 9.50 Ward and Low 1997 Gallus gallus 844 52 1 seeds 12.70 Lonchura punctulata 13.6 6 5 seeds 62.00 Loxia leucoptera 26 511 5 seeds Rhea americana 23000 65 26 vegetation Lima and Zollner1996 Burger 1997 35.00 Beauchamp and Livoreil 1997 Benkman 1997 16.00 5 Reboreda and Fernandez 1997 10 Calidris mauri 26.6 232 22 288 Dromaius novaehollandiae 31500 136 18 seeds Limnodromus scolopaceus 100 472 20 invertebrates 4.2 0 Molothrus ater 48.7 30 7 mixed 7.3 3.3 Parus major 18.9 15 1 seeds 98.00 Streptopelia chinensis 159 73 10 seeds 41.00 111000 9 3 53.8 133 22 Calidris pusilla Haematopus ostralegus Calidris minutilla Struthio camelus Calidris himantopus Calidris minutilla 200 invertebrates 5 1 Davis and Smith 1998 invertebrates 7 0.2 Davis and Smith 1998 47.00 47 Hough et al. 1998 Davis and Smith 1998 Morris and Thompson 1998 Krams 1998 13 Sadedin and Elgar 1998 seeds 29.00 Ross and Deeming 1998 10 invertebrates 2 de Leon and Smith 1999 358 6 invertebrates 10.00 de Leon and Smith 1999 27.5 159 8 invertebrates 8 de Leon and Smith 1999 526 159 5 invertebrates 17.00 Goss-Custard et al. 1999 11 Serinus serinus 11.2 35 30 seeds 63.00 Domènech and Senar 1999 Anser albifrons 2700 211 142 vegetation 15.5 Kristiansen et al. 2000 Emberiza citrinella 29.7 226 100 seeds 25.00 van der Veen 2000 Myiopsitta monachus 120 79 31 seeds 68.00 20 Numenius americanus 640 17 1 invertebrates 1.10 1.10 3.4 Somateria mollissima 2218 117 22 invertebrates 25.3 1 Anas clypeata 620 33 65 mixed 12 Guillemain et al. 2001 Anas crecca crecca 320 47 23 seeds 21.00 Guillemain et al. 2001 Corvus caurinus 415 571 80 invertebrates 50.00 20 Robinette and Ha 2001 Junco hyemalis 19.3 625 35 seeds 58.00 15 Boysen et al. 2001 Anas clypeata 620 32 13 mixed 8 Guillemain et al. 2002 Anas penelope 680 45 50 vegetation 14 Guillemain et al. 2002 South and Pruett-Jones 2000 Mathis 2000 Beauchamp 2000 12 Anas platyrhynchos 1082 12 12 seeds 8.30 Emberiza elegans 17 43 10 seeds 32.00 24 Limosa limosa 252 535 30 invertebrates 20.00 10.00 Dominguez 2002 Somateria mollissima 2218 233 3 invertebrates 57.00 40.00 Ost et al. 2002 Anser albifrons 2700 58 6790 seeds Anser cynoides 3575 34 120 vegetation Branta leucopsis 1788 172 3374 Bubulcus ibis 372 69 Colinus virgianus 178 7.20 Yamaguchi and Yahara 2002 0.2 Shimada and Shimada 2003 15.00 Randler 2003 vegetation 3.00 Carbone et al. 2003 40 invertebrates 6.40 Wahungu et al. 2003 25 20 seeds 15.00 Williams et al. 2003 31500 17 41 seeds 73.70 9.50 Boland 2003 Fringilla coelebs 21.9 39 1 seeds 70.00 Grus grus 5500 203 10 mixed Dromaius novaehollandiae 15.00 Fritz et al. 2002 Cresswell et al. 2003 19.00 Aviles 2003 13 Fernàndez-Juricic and Schroeder Patagioenas maculosa 309 30 20 seeds 66.00 37.00 2003 Phoenicopterus ruber ruber 3540 26 100 vegetation 43.40 10.40 Beauchamp and McNeil 2003 Rhea americana 23000 40 12 vegetation 12.00 2.00 Fernandez et al. 2003 Fernàndez-Juricic and Schroeder Zenaida auriculata 131 30 20 seeds 46.00 19.00 2003 Fulica atra 902 25 80 vegetation 11.10 Randler 2004 Arenaria interpres 134 15 16 invertebrates 5 Vahl et al. 2005 Calidris canutus 148 10 16 invertebrates 3 Vahl et al. 2005 Cygnus columbianus 7200 214 100 vegetation 16.90 0.7 Badzinski 2005 Nettapus pulchellus 310 207 2 vegetation 6.50 1 Anser albifrons 2700 53 3700 seeds 25.11 1.11 3.7 Columbina squamata 52.9 142 19 seeds 6.67 1.00 Nye and Dickman 2005 Amano et al. 2006 Dias 2006 14 Acridotheres tristis 120 310 23 invertebrates Grus grus 5500 485 564 mixed Molothrus ater 48.7 126 7 seeds 15.20 5.70 Newey 2007 Aviles and Bednekoff 2007 88.00 65.00 Fernàndez-Juricic et al. 2007 Morgan and Fernàndez-Juricic Molothrus ater 48.7 56 8 seeds 71.00 45.00 2007 Perdix perdix 418 122 13 seeds 54.30 12.70 Watson et al. 2007 Phoenicopterus ruber roseus 3540 117 350 vegetation 18.00 30.00 Boukhriss et al. 2007b Phoenicopterus ruber roseus 3540 21 31 vegetation 25.79 4.48 Turdoides bicolor 78.3 84 11 invertebrates 14.00 Radford and Ridley 2007 Miliaria calandra 53.6 137 60 seeds 36.40 Smart et al. 2008 Spizella wortheni 13 41 30 mixed 54.20 Canales-Delgadillo et al. 2008 Tringa totanus 129 296 65 invertebrates 20.00 Sansom et al. 2008 40.00 1 Boukhriss et al. 2007a 15 References ABRAMSON, M. 1979. Vigilance as a factor influencing flock formation among curlews Numenius arquata. -Ibis, 121: 213-216. ALONSO, J. A. and ALONSO, J. C. 1993. Age-related differences in time budgets and parental care in wintering common cranes. -Auk, 110: 78-88. ALONSO, J. A., ALONSO, J. C., CARRASCAL, L. M. and MUNOZPULIDO, R. 1994. Flock size and foraging decisions in central place foraging white storks, Ciconia ciconia. Behaviour, 129: 279-292. AMANO, T., USHIYAMA, K., FUJITA, G. and HIGUCHI, H. 2006. Costs and benefits of flocking in foraging white-fronted geese (Anser albifrons): effects of resource depletion. J. Zool., 269: 111-115. AVILES, J. M. 2003. Time budget and habitat use of the Common Crane wintering in dehesas of southwestern Spain. -Can. J. Zool., 81: 1233-1238. AVILES, J. M. and BEDNEKOFF, P. A. 2007. How do vigilance and feeding by common cranes Grus grus depend on age, habitat, and flock size? -J. Avian Biol., 38: 690-697. BADZINSKI, S. S. 2005. Social influences on Tundra Swan activities during migration. Waterbirds, 28: 316-325. BARBOSA, A. 1995. Foraging strategies and their influence on scanning and flocking behaviour of waders. -J. Avian Biol., 26: 182-186. BARBOSA, A. 1997. The effects of predation risk on scanning and flocking behavior in dunlin. J. Field Ornithol., 68: 607-612. BARNARD, C. J. 1980. Flock feeding and time budgets in the house sparrow (Passer domesticus L.). -Anim. Behav., 28: 295-309. BEAUCHAMP, G. 2000. Parental behaviour and brood integrity in amalgamated broods of the Common Eider. -Wildfowl, 51: 169-179. 16 BEAUCHAMP, G. and LIVOREIL, B. 1997. The effect of group size on vigilance and feeding rate in spice finches (Lonchura punctulata). -Can. J. Zool., 75: 1526-1531. BEAUCHAMP, G. and MCNEIL, R. 2003. Vigilance in Greater Flamingos foraging at night. Ethology, 109: 511-520. BEKOFF, M. 1995. Vigilance, flock size, and flock geometry - Information gathering by western evening grosbeaks (Aves, Fringillidae). -Ethology, 99: 150-161. BÉLANGER, L. and BÉDARD, J. 1992. Flock composition and foraging behaviour of gretaer snow geese (Chen caerulescens atlantica). -Can. J. Zool., 70: 2410-2415. BENKMAN, C. W. 1997. Feeding behavior, flock-size dynamics, and variation in sexual selection in crossbills. - Auk, 114: 163-178. BERTRAM, B. C. R. 1980. Vigilance and group size in ostriches. -Anim. Behav., 28: 278-286. BEVERIDGE, F. M. and DEAG, J. M. 1987. The effects of sex, temperature and companions on looking up and feeding in single and mixed species flocks of house sparrows (Passer domesticus), chaffinches (Fringilla coelebs) and starlings (Sturnus vulgaris). -Behaviour, 100: 303-320. BILDSTEIN, K. L. 1983. Age-related differences in the flocking and foraging behavior of white ibises in a South Carolina salt marsh. -Col. Waterbirds, 6: 45-53. BLACK, J. M., CARBONE, C., WELLS, R. L. and OWEN, M. 1992. Foraging dynamics in goose flocks: the cost of living on the edge. -Anim. Behav., 44: 41-50. BOLAND, C. R. J. 2003. An experimental test of predator detection rates using groups of freeliving emus. -Ethology, 109: 209-222. BOUKHRISS, J., SELMI, S., BECHET, A. and NOUIRA, S. 2007a. Vigilance in Greater Flamingos wintering in southern Tunisia: Age-dependent flock size effect. -Ethology, 113: 377-385. 17 BOUKHRISS, J., SELMI, S. and NOUIRA, S. 2007b. Time allocation and vigilance behaviour of Greater Flamingos (Phoenicopterus roseus) wintering in the Gulf of Gabes, Tunisia. Ostrich, 78: 459-461. BOYSEN, A. F., LIMA, S. L. and BAKKEN, G. S. 2001. Does the thermal environment influence vigilance behavior in dark-eyed juncos (Junco hyemalis)? An approach using standard operative temperature. -Journal of Thermal Biology, 26: 605-612. BRIGGS, S. G. 1990. Sexual and annual differences in activity budgets of maned ducks Chenonetta jubata. -Emu, 90: 190-194. BURGER, A. E. 1982. Foraging behaviour of lesser sheathbills Chionis minor exploiting invertebrates on a sub-antarctic island. -Oecologia, 52: 236-245. BURGER, J. 1997. Vigilance behavior and chickens: Differences among status and location. Appl. Anim. Behav. Sci., 54: 345-350. BURGER, J. and GOCHFELD, M. 1988. Effects of group size and sex on vigilance in ostriches (Struthio camelus): antipredator strategy or mate competition? -Ostrich, 59: 14-20. BURGER, J. and GOCHFELD, M. 1991a. Human activity influence and diurnal and nocturnal foraging of sanderlings (Calidris alba). -Condor, 93: 259-265. BURGER, J. and GOCHFELD, M. 1991b. Vigilance and feeding behaviour in large feeding flocks of laughing gulls, Larus atricilla, on Delaware Bay. -Estuarine, Coastal and Shelf Science, 32: 207-212. CANALES-DELGADILLO, J. C., SCOTT-MORALES, L. M., CORREA, M. C. and MORENO, M. P. 2008. Observations on flocking behavior of Worthen's Sparrow (Spizella wortheni) and occurrence in mixed-species flocks. -Wilson J. Ornithol, 120: 569-574. CARACO, T. 1979. Time budgeting and group size: a test of theory. -Ecology, 60: 618-627. CARACO, T., MARTINDALE, S. and PULLIAM, H. R. 1980. Avian time budgets and distance from cover. -Auk, 97: 872-875. 18 CARBONE, C., THOMPSON, W. A., ZADORINA, L. and ROWCLIFFE, J. M. 2003. Competition, predation risk and patterns of flock expansion in barnacle geese (Branta leucopsis). -J. Zool., 259: 301-308. CARRASCAL, L. M., ALONSO, J. C. and ALONSO, J. A. 1990. Aggregation size and foraging behaviour of white storks Ciconia ciconia during the breeding season. -Ardea, 78: 399404. CARRASCAL, L. M. and MORENO, E. 1992. Scanning behaviour and spatial niche. -J. Ornithol., 133: 73-77. CRESSWELL, W., QUINN, J. L., WHITTINGHAM, M. J. and BUTLER, S. 2003. Good foragers can also be good at detecting predators. -Proc. R. Soc. Lond. Ser. B-Biol. Sci, 270: 1069-1076. DAVIS, C. A. and SMITH, L. M. 1998. Behavior of migrant shorebirds in Playas of the southern high plains, Texas. -Condor, 100: 266-276. DE LEON, M. T. and SMITH, L. M. 1999. Behavior of migrating shorebirds at North Dakota Prairie Potholes. -Condor, 101: 645-654. DIAS, R. I. 2006. Effects of position and flock size on vigilance and foraging behaviour of the scaled dove Columbina squammata. -Behav. Proc., 73: 248-252. DIAZ, J. A. and ASENSIO, B. 1991. Effects of group size and distance to protective cover on the vigilance behaviour of black-billed magpies (Pica pica). -Bird Study, 38: 38-41. DOMÈNECH, J. and SENAR, J. C. 1999. Are foraging serin Serinus serinus females more vigilant than males?: The effect of sex ratio. -Ardea, 87: 277-284. DOMINGUEZ, J. 2002. Biotic and abiotic factors affecting the feeding behavior of the Blacktailed Godwit. -Waterbirds, 25: 393-400. DRENT, R. and SWIESTRA, P. 1977. Goose flocks and food finding: field experiments with barnacle geese in winter. -Wildfowl, 28: 15-20. 19 EBBINGE, B., CANTERS, K. and DRENT, R. H. 1975. Foraging routines and estimated daily food intake in barnacle geese wintering in the northern Netherlands. -Wildfowl, 26: 5-19. EKMAN, J. 1987. Exposure and time use in willow tit flocks: the cost of subordination. -Anim. Behav., 35: 508-514. ELCAVAGE, P. and CARACO, T. 1983. Vigilance behaviour in house sparrow flocks. -Anim. Behav., 31: 303-304. ELGAR, M. A., BURREN, P. J. and POSEN, M. 1984. Vigilance and perception of flock size in foraging house sparrows Passer domesticus L. -Behaviour, 90: 215-223. ELY, C. R. 1992. Time allocation by greater white-fronted geese: influence of diet, energy reserves and predation. -Condor, 94: 857-870. FERGUSON, J. W. H. 1987. Vigilance behaviour in white-browed sparrow-weavers Plocepasser mahali. -Ethology, 76: 223-235. FERNÀNDEZ-JURICIC, E., BEAUCHAMP, G. and BASTAIN, B. 2007. Group-size and distance-to-neighbour effects on feeding and vigilance in brown-headed cowbirds. -Anim. Behav., 73: 771-778. FERNÀNDEZ-JURICIC, E. and SCHROEDER, N. 2003. Do variations in scanning behavior affect tolerance to human disturbance? -Appl. Anim. Behav. Sci., 84: 219-234. FERNANDEZ, G. J., CAPURRO, A. F. and REBOREDA, J. C. 2003. Effect of group size on individual and collective vigilance in greater rheas. -Ethology, 109: 413-425. FRITZ, H., GUILLEMAIN, M. and DURANT, D. 2002. The cost of vigilance for intake rate in the mallard (Anas platyrhynchos): An approach through foraging experiments. -Ethol. Ecol. Evol., 14: 91-97. GAUTHIER, G., BÉDARD, Y. and BÉDARD, J. 1988. Habitat use and activity budgets of greater snow geese in spring. -Journal of Wildlife Management, 52: 191-201. 20 GAWLIK, D. E. and SLACK, R. D. 1996. Comparative foraging behavior of sympatric snow geese, greater white-fronted geese, and Canada geese during the non-breeding season. Wilson Bull., 108: 154-159. GLÜCK, E. 1987. An experimental study of feeding, vigilance and predator avoidance in a single bird. -Oecologia, 71: 268-272. GOSS-CUSTARD, J. D., CAYFORD, J. T. and LEA, S. G. 1999. Vigilance during food handling by oystercatchers Haematopus ostralegus reduces the chances of losing prey to kleptoparasites. -Ibis, 141: 368-376. GUILLEMAIN, M., DUNCAN, P. and FRITZ, H. 2001. Switching to a feeding method that obstructs vision increases head-up vigilance in dabbling ducks. -J. Avian Biol., 32: 345350. GUILLEMAIN, M., MARTIN, G. R. and FRITZ, H. 2002. Feeding methods, visual fields and vigilance in dabbling ducks (Anatidae). -Func. Ecol., 16: 522-529. HEGNER, R. E. 1985. Dominance and anti-predator behaviour in blue tits (Parus caeruleus). Anim. Behav., 33: 762-768. HEINSOHN, R. G. 1987. Age-dependent vigilance in winter aggregations of cooperatively breeding white-winged choughs (Corcorax melanorhamphos). -Behav. Ecol. & Sociobiol., 20: 303-306. HOGSTAD, O. 1988. Advantages of social foraging of willow tits Parus montanus. -Ibis, 130: 275-283. HOUGH, D., WONG, B., BENNETT, G., BRETTSCHNEIDER, K., SPINNOCHIA, M., MANION, N. and HEINSOHN, R. 1998. Vigilance and group size in emus. -Emu, 98: 324-327. HUNT, H. E. 1987. The effects of burning and grazing on habitat use by Whooping Cranes and Sandhill Cranes on the Aransas National Wildlife Refuge. Texas A&M University. 21 INGLIS, I. R. and ISAACSON, A. J. 1978. The responses of dark-bellied brent geese (Branta bernicla bernicla) to models of geese in various postures. -Anim. Behav., 26: 953-958. INGLIS, I. R. and LAZARUS, J. 1981. Vigilance and flock size in brent geese: the edge effect. Zeitschrift fur Tierpsychologie, 57: 193-200. JENNINGS, T. and EVANS, S. M. 1980. Influence of position in the flock and flock size on vigilance in the starling, Sturnus vulgaris. -Anim. Behav., 28: 634-635. JORDE, D. G., KRAPU, G. L. and CRAWFORD, R. D. 1983. Feeding ecology of Mallards wintering in Nebraska. -Journal of Wildlife Management, 47: 1044-1053. KNIGHT, S. K. and KNIGHT, R. L. 1986. Vigilance patterns in bald eagles feeding in groups. Auk, 103: 263-272. KOTRSCHAL, K., HEMETSBERGER, J. and DITTAMI, J. 1993. Food exploitation by a winter flock of greylag geese: behavioral dynamics, competition and social status. -Behav. Ecol. & Sociobiol., 33: 289-295. KRAMS, I. 1998. Dominance-specific vigilance in the great tit. -J. Avian Biol., 29: 55-60. KRISTIANSEN, J. N., FOX, A. D., BOYD, H. and STROUD, D. A. 2000. Greenland whitefronted geese Anser albifrons flavivostris benefit from feeding in mixed-species flocks. Ibis, 142: 142-144. LAZARUS, J. 1978. Vigilance, flock size and domain of danger in the white-fronted goose. Wildfowl, 29: 135-145. LAZARUS, J. and INGLIS, I. R. 1978. The breeding behaviour of the pink-footed goose: parental care and vigilant behaviour during the feeding period. -Behaviour, 65: 62-88. LENDREM, D. W. 1984. Flocking, feeding and predation risk: absolute and instantaneous feeding rates. -Anim. Behav., 32: 298-299. LIMA, S. L. 1987. Distance to cover, visual obstructions, and vigilance in house sparrows. Behaviour, 102: 231-238. 22 LIMA, S. L. 1995. Back to the basics of anti-predatory vigilance: the group-size effect. -Anim. Behav., 49: 11-20. MARTELLA, M. B., RENISON, D. and NAVARRO, J. L. 1995. Vigilance in the greater rhea: effect of vegetation height and group size. -J. Field Ornithol., 66: 215-220. MATHIS, R. L. 2000. Analysis of Long-billed Curlews (Numenius americanus) distributions at three special scales. Humboldt State University, Arcata. MCKINSTRY, M. C. and KNIGHT, R. L. 1993. Foraging ecology of wintering black-billed magpies. -Auk, 110: 632-635. MCVEAN, A. and HADDLESEY, P. 1980. Vigilance schedules among house sparrows Passer domesticus. -Ibis, 122: 533-536. MILLIGAN, B. N. and BRIGHAM, R. M. 1992. The influence of group size on vigilance in captive-raised ring-necked pheasants. -Condor, 94: 787-790. MORENO, E. and CARRASCAL, M. 1991. Patch residence time and vigilance in birds foraging at feeders: implications of bill shape. -Ethol. Ecol. Evol., 3: 345-350. MORGAN, T. and FERNÀNDEZ-JURICIC, E. 2007. The effects of predation risk, food abundance, and population size on group size of brown-headed cowbirds (Molothrus ater). -Ethology, 113: 1173-1184. MORRIS, D. L. and THOMPSON, F. R. 1998. Effects of habitat and invertebrate density on abundance and foraging behavior of brown-headed cowbirds. -Auk, 115: 376-385. MOURITSEN, K. N. 1992. Predator avoidance in night feeding dunlins Calidris alpina: a matter of concealment. -Ornis Scand., 23: 195-198. NEWEY, P. 2007. Foraging behaviour of the Common Myna (Acridotheres tristis) in relation to vigilance and group size. -Emu, 107: 315-320. 23 NYE, E. R. and DICKMAN, C. R. 2005. Activity budgets and habitat use of the green pygmygoose (Nettapus pulchellus) on dry-season refuges in Kakadu National Park, Northern Territory. -Emu, 105: 217-222. OST, M., MANTILA, L. and KILPI, M. 2002. Shared care provides time-budgeting advantages for female eiders. -Anim. Behav., 64: 223-231. OWEN, M. 1972. Some factors affecting food intake and selection in white-fronted geese. -J. Anim. Ecol., 41: 79-92. PAULUS, S. L. 1984. Activity budgets of non-breeding gadwalls in Louisiana. -Journal of Wildlife Management, 48: 371-380. PAULUS, S. L. 1988. Time-activity budgets of mottled ducks in Louisiana in winter. -Journal of Wildlife Management, 52: 711-718. PETIT, D. R. and BILDSTEIN, K. L. 1987. Effect of group size and location within the group on the foraging behavior of white ibises. -Condor, 89: 602-609. POWELL, G. V. N. 1974. Experimental analysis of the social value of flocking by starlings (Sturnus vulgaris) in relation to predation and foraging. -Anim. Behav., 22: 501-505. PÖYSÄ, H. 1994. Group foraging, distance to cover and vigilance in the teal, Anas crecca. Anim. Behav., 48: 921-928. RADFORD, A. N. and RIDLEY, A. R. 2007. Individuals in foraging groups may use vocal cues when assessing their need for anti-predator vigilance. -Biol. Lett, 3: 249-252. RANDLER, C. 2003. Vigilance in urban Swan Geese and their hybrids. -Waterbirds, 26: 257260. RANDLER, C. 2004. Coot benefit from feeding in close proximity to geese. -Waterbirds, 27: 240-244. 24 REBOREDA, J. C. and FERNANDEZ, G. J. 1997. Sexual, seasonal and group size differences in the allocation of time between vigilance and feeding in the greater rhea, Rhea americana. -Ethology, 103: 198-207. REDPATH, S. 1988. Vigilance levels in preening dunlin Calidris alpina. -Ibis, 130: 213-216. ROBINETTE, R. L. and HA, J. C. 2001. Social and ecological factors influencing vigilance by northwestern crows, Corvus caurinus. -Anim. Behav., 62: 447-452. ROSS, E. J. and DEEMING, D. C. 1998. Feeding and vigilance behaviour of breeding ostriches (Struthio camelus) in a farming environment in Britain. -British Poultry Science, 39: 173177. SADEDIN, S. R. and ELGAR, M. A. 1998. The influence of flock size and geometry on the scanning behaviour of spotted turtle doves, Streptopelia chinensis. -Australian Journal of Ecology, 23: 177-180. SAINO, N. 1994. Time budget variation in relation to flock size in carrion crows, Corvus corone corone. -Anim. Behav., 47: 1189-1196. SANSOM, A., CRESSWELL, W., MINDERMAN, J. and LIND, J. 2008. Vigilance benefits and competition costs in groups: do individual redshanks gain an overall foraging benefit? Anim. Behav., 75: 1869-1875. SCHMITZ, R. A. and BALDASSARRE, G. A. 1992. Correlates of flock size and behavior of foraging American flamingos following hurricane Gilbert in Yucatan, Mexico. -Condor, 94: 260-264. SHIMADA, T. and SHIMADA, K. 2003. Factors affecting vigilance in greater white-fronted geese Anser albifrons. -Wildfowl, 54: 201-218. SMART, S. L., STILLMAN, R. A. and NORRIS, K. J. 2008. Measuring the functional responses of farmland birds: an example for a declining seed-feeding bunting. -J. Anim. Ecol., 77: 687-695. 25 SOUTH, J. M. and PRUETT-JONES, S. 2000. Patterns of flock size, diet, and vigilance of naturalized monk parakeets in Hyde Park, Chicago. -Condor, 102: 848-854. SPARLING, D. W. and KRAPU, G. L. 1994. Communal roosting and foraging behavior of staging sandhill cranes. -Wilson Bull., 106: 62-77. STUDD, M., MONTGOMERIE, R. D. and ROBERTSON, R. J. 1983. Group size and predator surveillance in foraging house sparrows (Passer domesticus). -Can. J. Zool., 61: 226-231. SULLIVAN, K. A. 1984. The advantages of social foraging in downy woodpeckers. -Anim. Behav., 32: 16-22. TACHA, T. C. 1989. Social organization of Sandhill cranes from midcontinental North America. -Wildl. Monogr., 99. TURNBULL, R. E. and BALDASSARE, G. A. 1987. Activity budgets of mallards and American wigeons wintering in east-central Alabama. -Wilson Bull., 99: 457-464. VAHL, W. K., VAN DER MEER, J., WEISSING, F. J., VAN DULLEMEN, D. and PIERSMA, T. 2005. The mechanisms of interference competition: two experiments on foraging waders. -Behav. Ecol., 16: 845-855. VAN DER VEEN, I. T. 2000. Daily routines and predator encounters in Yellowhammers Emberiza citrinella in the field during winter. -Ibis, 142: 413-420. WAHUNGU, G. M., MUMIA, E. N. and MANOA, D. 2003. The effects of flock size, habitat type and cattle herd sizes on feeding and vigilance in cattle egrets (Ardeola ibis). -Afr. J. Ecol., 41: 287-288. WAITE, R. K. 1981. Local enhancement for food finding by rooks (Corvus frugilegus) foraging on grassland. -Z. Tierpsychol., 57: 15-36. WARD, C. and LOW, B. S. 1997. Predictors of vigilance for American crows foraging in an urban environment. -Wilson Bull., 109: 481-489. 26 WATSON, M., AEBISCHER, N. J. and CRESSWELL, W. 2007. Vigilance and fitness in grey partridges Perdix perdix: the effects of group size and foraging-vigilance trade-offs on predation mortality. -J. Anim. Ecol., 76: 211-221. WESTCOTT, D. A. and COCKBURN, A. 1988. Flock size and vigilance in parrots. -Australian J. Zool., 36: 335-349. WILLIAMS, C. K., LUTZ, R. S. and APPLEGATE, R. D. 2003. Optimal group size and northern bobwhite coveys. -Anim. Behav., 66: 377-387. YAMAGUCHI, N. and YAHARA, T. 2002. Factors causing variation in flock size: Decision making to join a foraging flock. -Ecological Research, 17: 361-371. YOUNG, A. D. 1989. Spacing behaviour of visual- and tactile-feeding shorebirds in mixedspecies groups. -Can. J. Zool., 67: 2026-2028.
