Age-related differences in diet and foraging behavior of the critically endangered Mariana Crow (Corvus kubaryi), with notes on the predation of Coenobita hermit crabs
Tóm tắt
Knowledge of foraging behavior across life stages of endangered species is important for identifying potential drivers of age-dependent mortality. Juvenile mortality is a primary threat to the persistence of the single remaining Mariana Crow (Corvus kubaryi) population, which is found on Rota, Commonwealth of the Northern Mariana Islands. Therefore, variation in foraging behavior among fledglings, sub-adults and adults may highlight different needs or susceptibilities that could inform age-specific management strategies. During observations of 36 Mariana Crows, we found that of all food captures, 14% were plant-based, 56% were insects or their larvae and eggs and 30% were non-insect animal prey. Two food categories, fruits/seeds/plants and ants/termites/larvae, which were procured and processed with simple behaviors, were taken more frequently by fledglings. Crabs, which were processed using complex behaviors, were captured more frequently by adults. Adults acquired more food items from the ground than did fledglings and sub-adult birds, a result that was driven by the former’s high level of crab predation. We did not detect differences in foraging behavior between wet and dry seasons, suggesting that Mariana Crows maintain a similar diet year-round. Overall, our results highlight age-related differences in foraging behavior; however, future studies should identify whether these differences drive age-dependent variation in survivorship. Finally, we suggest that complex trophic interactions between non-native snails and Coenobita hermit crabs may have modified Mariana Crow foraging behavior, increasing their vulnerability to feral cat predation.
Tài liệu tham khảo
Banko PC, Camp RJ, Farmer C, Brinck KW, Leonard DL, Stephens RM (2013) Response of Palila and other subalpine Hawaiian forest bird species to prolonged drought and habitat degradation by feral ungulates. Biol Conserv 157:70–77
Beaty JJ (1967) Guam’s remarkable birds. South Pacific. Bulletin 17:37–40
Bluff LA, Troscianko J, Weir AA, Kacelnik A, Rutz C (2010) Tool use by wild New Caledonian crows Corvus moneduloides at natural foraging sites. Proc R Soc B 277:1377–1385
Blumstein DT (2002) Moving to suburbia: ontogenetic and evolutionary consequences of life on predator-free islands. J Biogeogr 29:685–692
Blumstein DT, Daniel JC, Springett BP (2004) A test of the multi-predator hypothesis: rapid loss of antipredator behavior after 130 years of isolation. Ethology 110:919–934
Brook BW, Sodhi NS, Bradshaw CJ (2008) Synergies among extinction drivers under global change. Trends Ecol Evol 23:453–460
Brumm H, Teschke I (2012) Juvenile Galápagos Pelicans increase their foraging success by copying adult behaviour. PLoS One 7:e51881
Camp RJ, Brinck KW, Gorresen PM, Amidon FA, Radley PM, Berkowitz SP, Banko PC (2015) Current land bird distribution and trends in population abundance between 1982 and 2012 on Rota, Mariana Islands. J Fish Wildl Manag 6:511–540
Cristol DA, Switzer PV (1999) Avian prey-dropping behavior. II. American Crows and walnuts. Behav Ecol 10:220–226
Dukas R, Kamil AC (2000) The cost of limited attention in Blue Jays. Behav Ecol 11:502–506
Engen S, Stenseth NC (1989) Age-specific optimal diets and optimal foraging tactics: a life-historic approach. Theor Popul Biol 36:281–295
Enoksson B (1988) Age-related and sex-related differences in dominance and foraging behaviour of nuthatches Sitta europaea. Anim Behav 36:231–238
Faegre SK, Nietmann L, Hubl D, Ha JC, Ha RR (2018) Spatial ecology of the Mariana Crow (Corvus kubaryi): Implications for management strategies. Bird Conserv Int. https://doi.org/10.1017/S0959270918000394
Fritz J, Kotrschal K (1999) Social learning in Common Ravens, Corvus corax. Anim Behav 57:785–793
George AD, O’Connell TJ, Hickman KR, Leslie DM Jr (2013) Food availability in exotic grasslands: a potential mechanism for depauperate breeding assemblages. Wilson J Ornithol 125:526–533
Ha JC, Butler A, Ha RR (2010) Reduction of first-year survival threatens the viability of the Mariana Crow Corvus kubaryi population on Rota, CNMI. Bird Conserv Int 20:335–342
Hazlett BA (1981) The behavioral ecology of hermit crabs. Annu Rev Ecol Syst 12:1–22
Heinsohn RG (1991) Slow learning of foraging skills and extended parental care in cooperatively breeding White-winged Choughs. Am Nat 137:864–881
Heinsohn RG, Cockbu A, Cunningham RB (1988) Foraging, delayed maturation, and advantages of cooperative breeding in White-winged Choughs, Corcorax melanorhamphos. Ethology 77:177–186
Heise CD, Moore FR (2003) Age-related differences in foraging efficiency, molt, and fat deposition of Gray Catbirds prior to autumn migration. Condor 105:496–504
Holzhaider JC, Hunt GR, Gray RD (2010a) The development of pandanus tool manufacture in wild New Caledonian crows. Behaviour 147:553–586
Holzhaider JC, Hunt GR, Gray RD (2010b) Social learning in New Caledonian crows. Learn Behav 38:206–219
Hunt GR, Sakuma F, Shibata Y (2002) New Caledonian crows drop candle-nuts onto rock from communally-used forks on branches. Emu 102:283–290
IBM Corp. (2010) IBM SPSS statistics for Windows, version 19.0. IBM Corp., Armonk
Jahn AE, Levey DJ, Mamani AM, Saldias M, Alcoba A, Ledezma MJ, Flores B, Vidoz JQ, Hilarion F (2010) Seasonal differences in rainfall, food availability, and the foraging behavior of Tropical Kingbirds in the southern Amazon Basin. J Field Ornithol 81:340–348
Jenkins JM (1983) The native forest birds of Guam. Ornithol Monogr 31:1–61
Lack D (1954) The natural regulation of animal numbers. Clarendon Press, Oxford
Lander MA, Guard CP (2003) Creation of a 50-year rainfall database, annual rainfall climatology, and annual rainfall distribution map for Guam. Water and Environmental Research Institute of the Western Pacific, University of Guam, Technical Report No. 102
Lawrence JM (1976) Organic composition and energy content of the hepatopancreas of hermit crabs (Coenobita) from Eniwetok Atoll, Marshall Islands (Decapoda, Paguridea). Crustaceana 31:113–118
Lawrence ES (1985) Vigilance during “easy” and “difficult” foraging tasks. Anim Behav 33:1373–1375
MacLean AA (1986) Age-specific foraging ability and the evolution of deferred breeding in three species of gulls. Wilson Bull 98:267–279
Marchetti K, Price T (1989) Differences in the foraging of juvenile and adult birds: the importance of developmental constraints. Biol Rev 64:51–70
Martin K (1995) Patterns and mechanisms for age-dependent reproduction and survival in birds. Am Zool 35:340–348
Michael GA (1987) Notes on the breeding biology and ecology of the Mariana or Guam Crow. Avic Mag 93:73–82
Morton JM, Plentovich S, Sharp T (1999) Reproduction and juvenile dispersal of Mariana Crows (Corvus kubaryi) on Rota, 1996–1999. U.S. Fish and Wildlife Service, Pacific Islands Ecoregion, Honolulu
Nafus D, Schreiner I (1989) Biological control activities in the Mariana Islands from 1911 to 1988. Micronesica 22:65–106
Nietmann L, Ha RR (2018) Variation in age-dependent nest predation between island and continental Rufous Fantail (Rhipidura rufifrons) subspecies. Auk 135:1064–1075
Olson SL, Rauzon MJ (2011) The extinct Wake Island Rail Gallirallus wakensis: a comprehensive species account based on museum specimens and archival records. Wilson J Ornithol 123:663–689
Partridge L, Greene P (1984) Intraspecific feeding specializations and population dynamics. In: Sibly RM, Smith RH (eds) Behavioral ecology: ecological consequences of adaptive behavior. Blackwell Scientific Publications, Oxford, pp 207–226
Pemberton CE (1954) Invertebrate Consultants Committee for the Pacific, Report for 1949–1954. National Research Council (U.S.), Pacific Science Board. National Academies Press, Washington DC
Penteriani V, Ferrer M, Delgado MDM (2011) Floater strategies and dynamics in birds, and their importance in conservation biology: towards an understanding of nonbreeders in avian populations. Anim Conserv 14:233–241
Price MR, Hayes WK (2017) Diverse habitat use during two life stages of the critically endangered Bahama Oriole (Icterus northropi): community structure, foraging, and social interactions. PeerJ. https://doi.org/10.7717/peerj.3500
Pyke GH, Pulliam HR, Charnov EL (1977) Optimal foraging: a selective review of theory and tests. Q Rev Biol 52:137–154
Rutz C, St Clair JJH (2012) The evolutionary origins and ecological context of tool use in New Caledonian Crows. Behav Proc 89:153–165
Rutz C, Bluff LA, Weir AAS, Kacelnik A (2007) Video cameras on wild birds. Science 318:765
Slagsvold T, Wiebe KL (2011) Social learning in birds and its role in shaping a foraging niche. Philos Trans R Soc B 366:969–977
Smith-Hicks KN, Newnam JC, Colon MR, Long AM, Morrison ML (2016) Golden-cheeked Warbler behavior in relation to vegetation characteristics across their breeding range. Am Midl Nat 176:81–94
Steadman DW (2006) Exctinction and biogeography of Tropical Pacific birds. University of Chicago Press, Chicago
Sullivan KA (1988) Ontogeny of time budgets in Yellow-eyed Juncos: adaptation to ecological constraints. Ecology 69:118–124
Sussman AF, Ha RR, Henry H (2015) Attitudes, knowledge, and practices affecting the critically endangered Mariana Crow Corvus kubaryi and its conservation on Rota, Mariana Islands. Oryx 49:542–549
Szabo JK, Khwaja N, Garnett ST, Butchart SH (2012) Global patterns and drivers of avian extinctions at the species and subspecies level. PLoS One 7:e47080
Tebbich S, Taborsky M, Fessl B, Blomqvist D (2001) Do woodpecker finches acquire tool-use by social learning? Proc R Soc B 268:2189–2193
Tomback DF (1986) Observations on the behavior and ecology of the Mariana Crow. Condor 88:398–401
Vanderhoff EN, Eason PK (2008) Influence of environmental variables on foraging by juvenile American Robins. J Field Ornithol 79:186–192
Wanless RM, Hokey PAR (2009) Natural history and behavior of the Aldabra Rail (Dryolimnas [cuvieri] aldabranus). Wilson J. Ornithol 120:50–61
Wunderle JM (1991) Age-specific foraging proficiency in birds. Curr Ornithol 8:273–324
Yoerg SI (1994) Development of foraging behaviour in the Eurasian Dipper, Cinclus cinclus, from fledging until dispersal. Anim Behav 47:577–588
Yoerg SI (1998) Foraging behavior predicts age at independence in juvenile Eurasian Dippers (Cinclus cinclus). Behav Ecol 9:471–477