AVIS-IBIS

Birds of Indian Subcontinent

Habitat Selection and Breeding Success in the Reed Warbler (Acrocephalus scirpaceus)

Publication Type:Journal Article
Year of Publication:1974
Authors:Catchpole, CK
Journal:Journal of Animal Ecology
Volume:43
Issue:2
Date Published:1974
ISBN Number:00218790
Keywords:Acrocephalidae, Acrocephalus, Acrocephalus scirpaceus
Abstract:(1) Ornithological literature has always emphasized the relationship between the reed warbler (Acrocephalus scirpaceus) and reed beds of Phragmites communis. In a breeding population at the Attenborough Nature Reserve, Nottinghamshire, only 47% of territories and 54% of nests were located in Phragmites, and the remainder in a variety of other vegetation including some in dry land habitats. (2) Birds breeding in Phragmites were compared with those breeding in other vegetation, and no significant differences were found in dates of first arrival, rates of occupation or habitat fidelity. Some birds clearly selected other vegetation in preference to almost empty Phragmites reed beds, and were not necessarily those forced into `sub-optimal' habitats by population pressure. There was no correlation between natal habitat and habitat selection for first breeding, but early post-fledging experience as well as later site tenacity and habitat fidelity, appear to be important additional factors effecting habitat selection. (3) Phragmites was found to be structurally optimal for nesting, the stem being more rigid, having a higher density per unit area, and persisting for several years. Mean nest height was lower in Phragmites than in other vegetation, but unlike the latter, increased significantly with season. Old Phragmites stems were used in 82% of nests, and its importance for early nesting was demonstrated in burning experiments. (4) Phragmites was not found to be optimal in terms of breeding success, and there were no significant differences in breeding activity or clutch size between birds breeding in Phragmites and other vegetation. Excluding predation there was no significant difference in breeding success, but including predation, breeding success in Phragmites (35%) was significantly lower than in other vegetation (51%). In other vegetation, high nests were preyed upon significantly less than low nests, but in Phragmites both high and low nests were preyed upon at the same high rate. (5) Other evidence is advanced which suggests that low breeding success in Phragmites, and large numbers breeding successfully in other vegetation, are not peculiar to the present situation at Attenborough. A recent ecological expansion into drier habitats is therefore considered unlikely. It seems more probable that, though undoubtedly specialized to colonize Phragmites, the reed warbler has not overspecialized to depend completely upon a rather unstable habitat, but has retained a greater degree of flexibility in habitat selection than the literature suggests.
URL:http://www.jstor.org/stable/3370
Short Title:Journal of Animal Ecology
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith