, Volume 184, Issue 4, pp 787–798 | Cite as

Behavioral mechanisms leading to improved fitness in a subsidized predator

  • Elena H. West
  • M. Zachariah Peery
Behavioral ecology – original research


General mechanisms underlying the distribution and fitness of synanthropic predators in human-influenced landscapes remain unclear. Under the consumer resource-matching hypothesis, synanthropes are expected to distribute themselves among habitats according to resource availability, such that densities are greater in human-subsidized habitats, but mean individual fitness is equal among habitats because of negative density dependence. However, “under-matching” to human food resources can occur, because dominant individuals exclude subordinates from subsidized habitats and realize relatively high fitness. We integrated physiological, behavioral, and demographic information to test resource-matching hypotheses in Steller’s jays (Cyanocitta stelleri), a synanthropic nest predator, to understand how behavior and social systems can influence how synanthropes respond to food subsidies. Jays consumed more human foods at subsidized (park campground) sites than jays at unsubsidized (interior forest) sites based on stable isotope analyses. Jays that occurred at higher densities were in better body condition (based on feather growth bars and lipid analyses), and had greater reproductive output at subsidized than unsubsidized sites. Jays with breeding territories in subsidized sites maintained relatively small home ranges that overlapped with multiple conspecifics, and exhibited a social system where dominant individuals typically won contests over food. Thus, jays appeared to be under-matched to prevalent resource subsidies despite high densities and behaviors expected to lead to resource matching. Our results also indicate that local resource subsidies within protected areas can result in source habitats for synanthropes, potentially impacting sensitive species over broader spatial scales.


Resource matching Synanthropic predators Protected areas Resource subsidies 



Funding was provided by Save the Redwoods League, the College of Agriculture and Life Sciences (UW-Madison), the Department of Forest and Wildlife Ecology (UW-Madison), the Office of the Vice Chancellor for Research and Graduate Education (UW-Madison), the U.S. Fish and Wildlife Service, and the California Department of Fish and Wildlife. We thank numerous field and laboratory technicians for their dedicated efforts and California State Parks staff for logistical assistance.

Author contribution statement

EHW and MZP conceived the idea, design, and experiment. EHW performed the experiment. EHW and MZP analyzed the data and wrote the manuscript.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Animal ethics

All applicable institutional and national guidelines for the care and use of animals were followed. The research was conducted under animal ethics permit A01424-0-01-10 and scientific collection permit SC-011200.

Data availability

The data sets analyzed during the current study are available from the corresponding author on reasonable request.

Supplementary material

442_2017_3898_MOESM1_ESM.docx (206 kb)
Supplementary material 1 (DOCX 206 kb)


  1. Bearhop S, Waldron S, Votier SC, Furness RW (2002) Factors that influence assimilation rates and fractionation of nitrogen and carbon stable isotopes in avian blood and feathers. Physiol Biochem Zool 75:451–458CrossRefPubMedGoogle Scholar
  2. Beckmann JP, Berger J (2003) Using black bears to test ideal-free distribution models experimentally. J Mammal 84:594–606CrossRefGoogle Scholar
  3. Beyer HL (2012) Geospatial Modelling Environment (version (software). Accessed 9 Mar 2016
  4. Brown JL (1963) Aggressiveness, dominance and social organization in the Steller Jay. Condor 65:460–484CrossRefGoogle Scholar
  5. Buehler DA, Fraser JD, Fuller MR et al (1995) Captive and field-tested radio transmitter attachments for bald eagles. J Field Ornithol 66:173–180Google Scholar
  6. Calenge C (2006) The package “adehabitat” for the R software: a tool for the analysis of space and habitat use by animals. Ecol Model 197:516–519CrossRefGoogle Scholar
  7. Cornell HN, Marzluff JM, Pecoraro S (2012) Social learning spreads knowledge about dangerous humans among American crows. Proc R Soc Lond B Biol Sci 279:499–508CrossRefGoogle Scholar
  8. Duhem C, Roche P, Vidal E, Tatoni T (2008) Effects of anthropogenic food resources on yellow-legged gull colony size on Mediterranean islands. Popul Ecol 50:91–100CrossRefGoogle Scholar
  9. Emery NJ, Seed AM, von Bayern AMP, Clayton NS (2007) Cognitive adaptations of social bonding in birds. Philos Trans R Soc B Biol Sci 362:489–505CrossRefGoogle Scholar
  10. Evans BS, Ryder TB, Reitsma R et al (2015) Characterizing avian survival along a rural-to-urban land use gradient. Ecology 96:1631–1640. doi: 10.1890/14-0171.1 CrossRefGoogle Scholar
  11. Fagen R (1987) A generalized habitat matching rule. Evol Ecol 1:5–10CrossRefGoogle Scholar
  12. Fedriani JM, Fuller TK, Sauvajot RM (2001) Does availability of anthropogenic food enhance densities of omnivorous mammals? An example with coyotes in southern California. Ecography 24:325–331CrossRefGoogle Scholar
  13. Fieberg J, Kochanny CO (2005) Quantifying home-range overlap: the importance of the utilization distribution. J Wildl Manag 69:1346–1359CrossRefGoogle Scholar
  14. Fretwell SD (1972) Populations in a seasonal environment. Princeton University Press, PrincetonGoogle Scholar
  15. Fretwell SD, Lucas JS (1970) On territorial behavior and other factors influencing habitat distribution in birds. Theor Dev Acta Biotheor 19:16–36CrossRefGoogle Scholar
  16. Gitzen RA, Millspaugh JJ, Kernohan BJ (2006) Bandwidth selection for fixed-kernel analysis of animal utilization distributions. J Wildl Manag 70:1334–1344CrossRefGoogle Scholar
  17. Griffiths R, Double MC, Orr K, Dawson RJG (1998) A DNA test to sex most birds. Mol Ecol 7:1071–1075CrossRefPubMedGoogle Scholar
  18. Grubb JTC (2006) Ptilochronology: feather time and the biology of birds. Oxford University Press, OxfordGoogle Scholar
  19. Haché S, Villard M-A, Bayne EM (2013) Experimental evidence for an ideal free distribution in a breeding population of a territorial songbird. Ecology 94:861–869CrossRefGoogle Scholar
  20. Hopkins JB, Koch PL, Ferguson JM, Kalinowski ST (2014) The changing anthropogenic diets of American black bears over the past century in Yosemite National Park. Front Ecol Environ 12:107–114CrossRefGoogle Scholar
  21. Horak P, Lebreton J-D (1998) Survival of adult Great Tits Parus major in relation to sex and habitat; a comparison of urban and rural populations. Ibis 140:205–209CrossRefGoogle Scholar
  22. Johnston RF (2001) Synanthropic birds of North America. In: Marzluff JM, Bowman R, Donnelly R (eds) Avian ecology and conservation in an urbanizing world. Kluwer Academic Publishers, Boston, pp 49–67CrossRefGoogle Scholar
  23. Kennedy M, Gray RD (1993) Can ecological theory predict the distribution of foraging animals? A critical analysis of experiments on the ideal free distribution. Oikos 68:158–166CrossRefGoogle Scholar
  24. Kernohan BJ, Gitzen RA, Millspaugh JJ (2001) Analysis of animal space use and movements. In: Marzluff JM, Millspaugh JJ (eds) Radio tracking and animal populations. Academic Press, San Diego, pp 125–166CrossRefGoogle Scholar
  25. Loss SR, Will T, Loss SS, Marra PP (2014) Bird–building collisions in the United States: estimates of annual mortality and species vulnerability. Condor 116:8–23. doi: 10.1650/CONDOR-13-090.1 CrossRefGoogle Scholar
  26. Luginbuhl JM, Marzluff JM, Bradley JE et al (2001) Corvid survey techniques and the relationship between corvid relative abundance and nest predation. J Field Ornithol 72:556–572CrossRefGoogle Scholar
  27. Marzluff JM, Neatherlin E (2006) Corvid response to human settlements and campgrounds: causes, consequences, and challenges for conservation. Biol Conserv 130:301–314CrossRefGoogle Scholar
  28. McGowan KJ (2001) Demographic and behavioral comparisons of suburban and rural American Crows. In: Marzluff JM, Bowman R, Donnelly R (eds) Avian ecology and conservation in an urbanizing world. Kluwer Academic Publishers, Norwell, MAGoogle Scholar
  29. Newsome SD, Garbe HM, Wilson EC, Gehrt SD (2015) Individual variation in anthropogenic resource use in an urban carnivore. Oecologia 178(1):115–128CrossRefPubMedGoogle Scholar
  30. Pearson SF, Levey DJ, Greenberg CH, del Rio CM (2003) Effects of elemental composition on the incorporation of dietary nitrogen and carbon isotopic signatures in an omnivorous songbird. Oecologia 135:516–523CrossRefPubMedGoogle Scholar
  31. Peery MZ, Beissinger SR, Newman SH et al (2004) Applying the declining population paradigm: diagnosing causes of poor reproduction in the marbled murrelet. Conserv Biol 18:1088–1098. doi: 10.1111/j.1523-1739.2004.00134.x CrossRefGoogle Scholar
  32. Peery MZ, Becker BH, Beissinger SR, Burger AE (2007) Age ratios as estimators of productivity: testing assumptions on a threatened seabird, the marbled murrelet (Brachyramphus marmoratus). Auk 124:224–240CrossRefGoogle Scholar
  33. Powell LA (2007) Approximating variance of demographic parameters using the delta method: a reference for avian biologists. The Condor 109:949–954CrossRefGoogle Scholar
  34. Pyle P, Howell SNG, Yunick RP, DeSante DF (1997) Identification guide to North American passerines. Slate Creek Press, Bolinas, CaliforniaGoogle Scholar
  35. R Development Core Team (2014) R: a language and environment for statistical computing. R Foundation for Statistical ComputingGoogle Scholar
  36. Ralph CJ, Droege S, Sauer JR (1995) Managing and monitoring birds using point counts: Standards and applications. U.S. Forest Service, Pacific Southwest Research Station, Albany, CaliforniaGoogle Scholar
  37. Ridley J, Komdeaur J, Sutherland W (2004) Incorporating territory compression into population models. Oikos 105:101–108CrossRefGoogle Scholar
  38. Rodewald AD, Shustack DP (2008) Consumer resource matching in urbanizing landscapes: are synanthropic species over-matching. Ecology 89:515–521CrossRefPubMedGoogle Scholar
  39. Sauer JR, Hines JE, Fallon JE, et al (2014) Breeding Bird Survey Summary and Analysis 1966–2013. Version 01.30.2015. In: USGS Patuxent Wildl. Res. Cent. Laurel MD. Accessed 28 May 2015
  40. Shochat E (2004) Credit or debit? Resource input changes population dynamics of city-slicker birds. Oikos 106:622–626CrossRefGoogle Scholar
  41. Shochat E, Warren P, Faeth S et al (2006) From patterns to emerging processes in mechanistic urban ecology. Trends Ecol Evol 21:186–191. doi: 10.1016/j.tree.2005.11.019 CrossRefPubMedGoogle Scholar
  42. Sibly RM, Jones PJ, Houston DC (1987) The use of body dimensions of lesser black-backed gulls larus fuscus to indicate size and to estimate body reserves. Funct Ecol 1:275–279CrossRefGoogle Scholar
  43. Sih A, Ferrari MCO, Harris DJ (2011) Evolution and behavioural responses to human-induced rapid environmental change. Evol Appl 4:367–387CrossRefPubMedPubMedCentralGoogle Scholar
  44. Swihart RK, Slade NA (1985) Testing for independence of observations in animal movements. Ecology 66(4):1176–1184CrossRefGoogle Scholar
  45. Thomas L, Laake JL, Strindberg S et al (2004) Distance 4.1 Release 2. Research unit for wildlife population assessment. (online) Google Scholar
  46. Vigallon SM, Marzluff JM (2005) Is nest predation by Steller’s jays (Cyanocitta stelleri) incidental or the result of a specialized search strategy? Auk 122:36–49CrossRefGoogle Scholar
  47. Walker LE, Marzluff JM (2015) Recreation changes the use of a wild landscape by corvids. Condor 117:262–283CrossRefGoogle Scholar
  48. Webb WC, Marzluff JM, Hepinstall-Cymerman J (2011) Linking resource use with demography in a synanthropic population of common ravens. Bio Conserv 144(9):2264–2273CrossRefGoogle Scholar
  49. West EH, Henry WR, Goldenberg W, Peery MZ (2016) Influence of food subsidies on the foraging ecology of a synanthropic species in protected areas. Ecosphere 7(10):e01532CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  1. 1.Department of ZoologyUniversity of Wisconsin-MadisonMadisonUSA
  2. 2.Department of Forest and Wildlife EcologyUniversity of Wisconsin-MadisonMadisonUSA

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