Now showing items 1-10 of 1908
Symmetry, change, perturbation, and observing mode in natural communities
Like a kaleidoscope, nature presents continuously fleeting images of natural communities. It has been difficult to discern patterns of community structure in these elusive images. For both theoretical and applied considerations, ...
Coastal food web structure, carbon storage, and nitrogen retention regulated by consumer pressure and nutrient loading
By factorial field experiments we analyzed the relative effects of increased nutrient (N+P) loading and natural grazing pressure on species composition, carbon storage, and nitrogen retention in the Baltic Sea littoral ...
An experimental test of offspring recognition in Western Bluebirds
No abstract available.
Effects of eutrophication, grazing, and algal blooms on rocky shores
Eutrophication can profoundly change rocky shore communities. These changes often cause the replacement of perennial, canopy-forming algae such as Fucus spp. with annual, bloom-forming algae such as Enteromorpha spp. ...
Seasonal and Age-Dependent Dietary Partitioning between the Great Black-Backed and Herring Gulls
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
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
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
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
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 ...
Characteristics of predators and offspring influence nest defense by Arctic and Common Terns
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, ...