Nestling diets of coexisting salt marsh sparrows: Opportunism in a food-rich environment

@article{Post2006NestlingDO,
  title={Nestling diets of coexisting salt marsh sparrows: Opportunism in a food-rich environment},
  author={William C. Post and Jon S. Greenlaw},
  journal={Estuaries and Coasts},
  year={2006},
  volume={29},
  pages={765-775}
}
The saltmarsh sharp-tailed sparrow (Ammodramus caudacutus) and the morphologically similar seaside sparrow (Ammodramus maritimus) occur together in Atlantic coast salt marshes. Over 2 yr we examined food exploitation patterns to gain an understanding of how these species coexist and to characterize the trophic conditions that allow the maintenance of different mating systems within the same habitat. In the promiscuous saltmarsh sharp-tailed sparrow, only females feed the young, while the young… 
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References

SHOWING 1-10 OF 39 REFERENCES
Ecotope Differentiation in a Guild of Sap-Feeding Insects on the Salt Marsh Grass, Spartina Patens
TLDR
Niche and habitat differentiation are studied in seven sap-feeding insects (mostly leaf- hoppers and planthoppers) that inhabit the salt marsh grass Spartina patens and one species, the leafhopper, is the only species that fully retains the ability to fly.
DIETARY RELATIONSHIPS AMONG SHRUBSTEPPE PASSERINE BIRDS: COMPETITION OR OPPORTUNISM IN A VARIABLE ENVIRONMENT?
TLDR
Several aspects of this study indicate that shrubsteppe passerines are largely opportunistic in their foraging and diet selection, and that the apparent absence of fine tuning to their competitive milieu is most likely a function of the variable environment in which they coexist.
Niche Relationships Among Six Species of Shorebirds on Their Wintering and Breeding Ranges
TLDR
The dynamics of the organization of a community of six species of migrant predatory shorebirds was appraised by studying foraging behavior and habitat utilization under winter conditions in southern Florida and under summer conditions in the eastern Canadian Arctic.
High overlap in diets of sympatric dabbling ducks — an effect of food abundance?
TLDR
It is proposed that the high level of diet overlap was promoted by abundant food resources, which are quite typical for habitats where many species of dabbling ducks coexist.
Effects of Tide Cycles on Habitat Selection and Habitat Partitioning by Migrating Shorebirds
-We studied assemblages of feeding shorebirds in three intertidal habitats on the coast of New Jersey during August to document how species segregate spatially both among and within habitats and to
Distributions of Galapagos Ground Finches Along An Altitudinal Gradient: The Importance of Food Supply
TLDR
Investigating the abundance, diet and food supply of ground finch species (Geospiza Gould) at different altitudes over a calendar year on Isla Pinta, Galapagos suggests that while competition may be occurring between species, variation in food supply is currently a far more important determinant of distributions on PintA.
Overlap in Foods and Foraging of Four Species of Blackbirds in the Potholes of Central Washington
TLDR
Overlap in foods and foraging of four species of breeding blackbirds in the Potholes of central Washington was estimated from samples of food delivered to the nestings obtained by the pipe—cleaner technique, and the total overlap values are very similar to the theoretical maximum values derived from competition theory by MacArthur and Levins.
Nesting season food habits of 4 species of Herons and Egrets at Lake Okeechobee, Florida
TLDR
Pronounced interannual and intercolony variation in diet composition suggested that Great Egrets and Little Blue Herons switched prey types as hydrologic conditions and habitat availability changed, and have implications for managing the Lake Okeechobee ecosystem.
Diet niche relationships among North American grassland and shrubsteppe birds
TLDR
The findings seem generally most consistent with the suggestion that food is not normally limiting to bird populations in these systems, and individuals and populations are exploiting the food resources in an opportunistic fashion, which leads to considerable individual, between-year, and between-location variation in diet compositions and interspecific overlaps.
...
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