Recent Submissions

  • Characteristics of predators and offspring influence nest defense by Arctic and Common Terns 

    Whittam, RM, and ML Leonard. 2000. "Characteristics of predators and offspring influence nest defense by Arctic and Common Terns." Condor 102(2): 301-306.
    Nest defense is a critical aspect of parental care that entails both costs and benefits. The purpose of this study was to examine patterns of nest defense in a colony of Arctic and Common Terns (Sterna paradisaea and S, ...
  • Seasonal and Age-Dependent Dietary Partitioning between the Great Black-Backed and Herring Gulls 

    Steenweg, Rolanda J., Robert A. Ronconi, and Marty L. Leonard. 2011. "Seasonal and Age-Dependent Dietary Partitioning between the Great Black-Backed and Herring Gulls." Condor 113(4): 795-805.
    Studies of seabird diets may reveal subtle ways in which sympatric species partition resources to facilitate co-existence. We studied the variability and partitioning of diets between the Herring (Larus argentatus) and ...
  • Spatiotemporal Patterns in Nest Box Occupancy by Tree Swallows Across North America 

    Shutler, Dave, David J. T. Hussell, D. R. Norris, David W. Winkler, et al. 2012. "Spatiotemporal Patterns in Nest Box Occupancy by Tree Swallows Across North America." Avian Conservation and Ecology 7(1): 3-3.
    Data from the North American Breeding Bird Survey (BBS) suggest that populations of aerial insectivorous birds are declining, particularly in northeastern regions of the continent, and particularly since the mid-1980s. ...
  • Aggressive nest intrusions by male Humboldt Penguins 

    Taylor, Sabrina S., Marty L. Leonard, and Daryl J. Boness. 2001. "Aggressive nest intrusions by male Humboldt Penguins." Condor 103(1): 162-165.
    During observations at a breeding colony of Humboldt Penguins (Spheniscus humboldti), we noted five male penguins enter nests occupied by breeding pairs and engage in aggressive interactions with the resident adult. These ...
  • Mitochondrial DNA variation, species limits, and rapid evolution of plumage coloration and size in the Savannah Sparrow 

    Zink, RM, JD Rising, S. Mockford, AG Horn, et al. 2005. "Mitochondrial DNA variation, species limits, and rapid evolution of plumage coloration and size in the Savannah Sparrow." Condor 107(1): 21-28.
    We compared sequences from two mitochondrial DNA (mtDNA) genes (ND2, ND3) in Savannah Sparrows (Passerculus sandwichensis; n = 112) sampled from Baja California (five sites), coastal Sonora and the continental range (eight ...
  • The role of development, parental behavior, and nestmate competition in fledging of nestling Tree Swallows 

    Michaud, T., and M. Leonard. 2000. "The role of development, parental behavior, and nestmate competition in fledging of nestling Tree Swallows." Auk 117(4): 996-1002.
    Fledging (i.e. leaving the nest) in altricial birds is a major step toward independence. The timing of this important event may be influenced by nestling development, parental behavior, and sibling interactions. In this ...
  • An experimental test of offspring recognition in Western Bluebirds 

    Leonard, ML, JL Dickinson, AG Horn, and W. Koenig. 1995. "An experimental test of offspring recognition in Western Bluebirds." Auk 112(4): 1062-1064.
    No abstract available.
  • Sex-specific, seasonal foraging tactics of adult grey seals (Halichoerus grypus) revealed by state-space analysis 

    Breed, Greg A., Ian D. Jonsen, Ransom A. Myers, W. Don Bowen, et al. 2009. "Sex-specific, seasonal foraging tactics of adult grey seals (Halichoerus grypus) revealed by state-space analysis." Ecology 90(11): 3209-3221. Copyright by the Ecological Society of America.
    In many large pelagic animals, observing behavior is limited to observation by radio or satellite telemetry. In many cases, discriminating different behaviors from telemetry data has been a key, but often elusive, goal. ...
  • Observer Effects and Avian-Call-Count Survey Quality: Rare-Species Biases and Overconfidence 

    Farmer, Robert G., Marty L. Leonard, and Andrew G. Horn. 2012. "Observer Effects and Avian-Call-Count Survey Quality: Rare-Species Biases and Overconfidence." Auk 129(1): 76-86.
    Wildlife monitoring surveys are prone to nondetection errors and false positives. To determine factors that affect the incidence of these errors, we built an Internet-based survey that simulated avian point counts, and ...