Aggression by red-winged blackbirds towards marsh wrens

Abstract

PICMAN, J. 1983. Aggression by red-winged blackbirds towards marsh wrens. Can. J. 2001Can. J. . 61: 1896Can. J. -1899 Marshes are simple, two-dimensional habitats that provide little opportunity for ecological specialization. This situation has most likely favored the evolution of interspecific aggression between red-winged blackbirds and marsh wrens. Redwings of both sexes are aggressive towards marsh wrens; however, the rate of redwing-wren agonistic interactions is determined by at least three factors: (i) sex of redwings (most interactions involved males); (ii) time of day (the rate of interactions is determined by territorial and foraging activities of these birds); and (iii) density of marsh wrens in an area (the rate of interactions increased with increasing density of marsh wrens in different areas). Since a consequence of this redwing aggression towards marsh wrens is partial interspecific territoriality, this behavior has presumably evolved as a mechanism reducing interference competition with marsh wrens. PICMAN, J. 1983. Aggression by red-winged blackbirds towards marsh wrens. Can. J. 2001. 61: 1896-1899.Les marais constituent des habitats a deux dimensions, simples, qui donnent lieu a peu de spicialisation Ccologique. Cette situation a vraisemblablement favorisi I'ivolution d'une agressiviti interspicifique entre les carouges a ipaulettes et les troglodytes des marais. Les carouges des deux sexes sont agressifs a l'igard des troglodytes des marais; cependant, le taux d'interactions agonistiques entre les deux especes est ditermini par au moins trois facteurs: (i) le sexe des carouges (la plupart des interactions sont l'apanage des miles); (ii) le moment de la journie (le taux d'interactions est ditermini par les activitis territoriales et alimentaires de ces oiseaux) et (iii) la densiti des troglodytes dans une rigion (le taux d'interactions augmente en fonction de la densiti des troglodytes en diffirentes rigions). I1 dicoule de cette agressiviti une territorialiti interspicifique partielle; ce comportement s'est donc probablement diveloppi comme micanisme propre a riduire les interferences compititives avec les troglodytes.[Traduit par le journal]

Temporal Changes in the Breeding Bird Community at Four Hudson River Tidal Marshes

“…Studies conducted in the late 1970s and early 1980s point to another possible contributing factor to our observed decline of Marsh Wrens at Iona Marsh. PICMAN (1980PICMAN ( , 1982PICMAN ( , 1983 studied the interaction between breeding Red-winged Blackbirds and Marsh Wrens. Marsh Wrens are a highly aggressive species and are known to attack the eggs and nestling of other birds nesting nearby (PICMAN and PICMAN, 1980).…”

Distribution and Abundance of Submerged Aquatic Vegetation and Trapa natans in the Hudson River Estuary**

“…PICMAN (1980PICMAN ( , 1982PICMAN ( , 1983 studied the interaction between breeding Red-winged Blackbirds and Marsh Wrens. Marsh Wrens are a highly aggressive species and are known to attack the eggs and nestling of other birds nesting nearby .…”

“…Red-winged Blackbirds have been demonstrated to counter this threat by acting aggressively toward adult Marsh Wrens and even seek out wren nests in search of adult Marsh Wrens. PICMAN (1980PICMAN ( , 1983 believed that examination by Red-winged Blackbirds of wren nests and aggression toward adults reduced the nesting success of the wren. In addition, PICMAN (1982) found that wrens prefer to sing from the tops of Typha spp.…”

Nest-Defense Behavior in the Red-Winged Blackbird

“…It is surprising, therefore, that one of their conspicuous behaviors, i.e., nest defense, is not well described. Nest-defense behavior has been examined indirectly in the context of parental investment theory (D' Arms 1978, Robertson and Biermann 1979, Biermann and Robertson 1981, Weatherhead 1982) mate choice theory (Searcy 1979, Eckert and Weatherhead 1987, Yasukawa et al 1987 and more directly as an antipredator (Picman 1983) and antinest-parasitism strategy (Folkers and Lowther 1985). Recently, blackbird nest-defense behavior was also used to critically assess results and assumptions of studies dealing with nest-defense behavior of altricial birds Temple 1986a, 1986b).…”