Nest dispersion in the Red-winged Blackbird

Article Abstract:

A study was conducted to examine the nest dispersion characteristics of Red-winged Blackbirds (Agelaius phoeniceus). The nearest-neighbor distances for Blackbird nests were measured in southern Rock County, WI, from 1984 to 1986. A high incidence of dispersion of primary nests supported the hypothesis about male territoriality among Blackbirds. Since active nests were either found clumped together or unevenly dispersed, no clear evidence of female territorial behavior was available. Primary females were, however, more aggressive in guarding their subterritories within the male territory than females who nested later.

Ornithological research, Nest building, Wisconsin

---

The effect of aggregated nesting on Red-winged Blackbird nest success and brood parasitism by Brown-headed Cowbirds

Article Abstract:

There is no effect of spatial or temporal nesting aggregations on nest success in Red-winged Blackbirds, according to research focusing on the effects of aggregated nesting on blackbird nest success and brood parasitism by Brown-headed Cowbirds. The findings of this research were in line with the view that marsh-nesting populations of Red-winged Blackbirds are less vulnerable to parasitism than upland-nesting populations as high nest density allows cooperative vigilance and deterrence. However, the findings go against many studies indicating that predation is negatively correlated with nest density.

Predation (Biology)

---

Impact of brood parasitism by brown-headed cowbirds on red-winged blackbird reproductive success

Article Abstract:

The reduction in reproductive success in red-winged blackbirds (Agelaius phoenicus) as a result of parasitism by brown-headed cowbirds (Molothrus ater) has been investigated. A prarie-nesting population of blackbirds was studied from 1984 to 1997. The results showed that 2%-32% of redwing nests were parasitized each year, with the proportion of nests parasitized and the number of cowbird eggs laid significantly increasing over the year. The success of unparasitized nesting was found to be negatively related to the intensity of cowbird parasitism.

Cowbirds

Similar abstracts:

• Abstracts: The unfolding tale of the unfolded protein response. XBP1 mRNA is induced by ATF6 and spliced by IRE1 in response to ER stress to produce a highly active transcription factor
• Abstracts: Unfounded assumptions about diet of the Cooper's Hawk. Prey of Peregrine Falcons breeding in West Greenland. Lifetime nesting area fidelity in male Cooper's hawks in Wisconsin
• Abstracts: Correlates of hunting range size in breeding merlins. Assortative mating in urban-breeding Merlins. Hunting ranges and habitat use and selection of urban-breeding Merlins

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.