Some Adaptations of Marsh-Nesting Blackbirds. (MPB-14), Volume 14

by Gordon H. Orians

Overview

The variety of social systems among the New World blackbirds (Family Icteridae) and the structural simplicity of their foraging environment provide excellent opportunities for testing theorics about the adaptive significance of their behavior. Here Gordon Orians presents the results of his many years of research on how blackbirds utilize their marsh environments during the breeding season. These results stem from information he gathered on three species during ten breeding seasons in the Pacific Northwest, on Red-winged blackbirds during two breeding seasons in Costa Rica, and on three species during one breeding season in Argentina.


The author uses models derived from Darwin's theory of natural selection to predict the behavior and morphology of individuals as well as the statistical properties of their populations. First he tests models that predict habitat selection, foraging behavior, territoriality, and mate selection. Then he considers some population patterns, especially range of use of environmental resources and overlap among species, that may result from those individual attributes. Professor Orianns concludes with an overview of the structure of bird communities in marshes of the world and the relation of these patterns to overall source availability in these simple but productive habitats.

Product Details

ISBN-13:	9780691082370
Publisher:	Princeton University Press
Publication date:	04/21/1980
Series:	Monographs in Population Biology , #14
Pages:	312
Product dimensions:	5.50(w) x 8.50(h) x (d)

Table of Contents

	Preface	vii
1.	The Approach and the Subjects	3
1.1.	The Players	3
1.2.	The Theater	8
1.3.	Materials and Methods	18
2.	Marshes as Providers of Resources for Blackbirds	25
2.1.	Quantity of Emergence	26
2.2.	Temporal Pattern of Emergence	34
2.3.	Abundance of Insects on the Uplands	42
3.	The Adaptations: Selection of Habitats, Territories and Mates	48
3.1.	Habitat Selection by Males	50
3.2.	Habitat Selection by Females	53
3.3.	Predictions and Tests about Habitat and Mate Selection	56
3.4.	Sizes of Territories	73
3.5.	The Cues Used by Blackbirds in Selecting Their Territories	80
3.6.	Conclusions	86
4.	The Adaptations: Foraging Behavior	90
4.1.	Theory	91
4.2.	Tests of Foraging Theory	102
4.3.	Tests of CPF Theory	131
4.4.	Conclusions	138
5.	The Patterns: Variability in Use of Resources	141
5.1.	Range of Lake Productivity Occupied	141
5.2.	Range of Nest Sites Occupied	149
5.3.	Breeding Seasons	153
5.4.	Clutch Sizes	155
5.5.	Variability in Foods and Foraging	159
5.6.	Conclusions	171
6.	The Patterns: Competition, Overlap and Community Structure	173
6.1.	Short-Term Effects of Competition	174
6.2.	Long-Term Effects of Competition	186
6.3.	Competition and Size	189
7.	Adaptations Among Argentine Marsh-nesting Blackbirds	194
7.1.	The Species of Blackbirds Breeding in Argentine Marshes	195
7.2.	Foods and Foraging	210
7.3.	Patch Utilization While Foraging	216
7.4.	Dietary Breadths	222
7.5.	Competition and Overlap	222
8.	Of Birds and Marshes	226
8.1.	Significance of Marsh Structural Simplicity	226
8.2.	Nonpasserine Birds in Marshes	239
8.3.	Avian Social Systems in Marshes	241
8.4.	Island Biogeography of Marshes	242
8.5.	Effects of Blackbird Predation on Odonate Populations	244
8.6.	Conclusions	251
	General Conclusions	253
	Appendixes	255
	References	275
	Index	291