Nest distance mediates the costs of coloniality in Eared Grebes

We examined the behaviors and reproductive characteristics of 4 fared Grebe (Podiceps nigricollis) colonies located at the Malheur National Wildlife Refuge in eastern Oregon that varied in nesting density. In 1993, we studied 2 colonies found on 2 different lakes, whereas in 1994 we conducted a within-lake comparison of 2 subcolonies. During both years, nearest neighbor distances differed significantly between the colonies investigated. Breeding pairs were significantly more aggressive at those colonies with smaller distances among nests. Within each year, there was a greater rate of intraspecific brood parasitism and egg loss at the higher density colony. Infanticide occurred at high rates when nests were very densely packed, whereas a relatively high rate of predation by American Coots (Fulica americana) resulted when nests were quite dispersed. Thus, in spite of the distinct breeding characteristics of fared Grebes, many disadvantages associated with nesting density in seabirds also have an impact on these colonially breeding waterbirds.

Title	Nest distance mediates the costs of coloniality in Eared Grebes
Creator	Hill, Wendy L.
	Browne, M.
	Jones, K. J.
	Hardenbergh, C. L.
Publisher	Colonial Waterbirds
Academic Department	Psychology
Division	Social Sciences
Organization	Lafayette College
Date Issued	1997
Date Available	2013-10-10T18:02:46Z
Type	Article
Language	English
Keyword	aggression
	Eared Grebe
	brood parasitism
	coloniality
	nest density
	infanticide
	Podiceps nigricollis
	predation
Bibliographic Citation	Hill, W. L., et al. (1997) " Nest distance mediates the costs of coloniality in Eared Grebes." Colonial Waterbirds 20 (3): 470-477.
Standard Identifier	Handle 10385/1320
Standard Identifier	DOI 10.2307/1521597
Permalink	http://hdl.handle.net/10385/1320
Rights Statement	In Copyright
Rights Holders	Waterbird Society