Category: Icteridae

Spatial responses of bobolinks (dolichonyx oryzivorus)near different types of edges in northern iowa

Bobolink (Dolichonyx oryzivorus) Science Article 2 abstract Habitat edges are well-studied components of fragmented landscapes, yet factorsmediating edge effects remain unclear. We report how different types of edges surroundingpatches may affect spatial distributions of Bobolink (Dolichonyx oryzivorus), a declining, area-sensitive songbird that breeds in grasslands. We expected Bobolinks to be less abundant near edges, and […]

Preliminary Study in whether land management affects dialect formation in Bobolinks

Bobolink (Dolichonyx oryzivorus) Science Article 4 abstract Song dialects occur when individuals share similarity in song phrases at the group level. Most hypotheses regarding formation and maintenance of dialects attempt to explain how females select mates through preferences for local song types (Payne et al. 1981; Baker & Cunningham 1985; Rothstein & Fleischer 1987). Anastasia […]

Natural and induced magnetization in the bobolink, dolichonyx oryzivorus (aves: icteridae)

Bobolink (Dolichonyx oryzivorus) Science Article 1 abstract The magnetic characteristics of the heads from 28 bobolinks [Icteridae:Dolichonyx oryzivorus (L.)] were analysed using remanence magnetometers. Thenatural remanent magnetization of 12 freshly preserved heads averaged 3-20xl0~7electromagnetic units (e.m.u.) (le.m.u. = 103Am~’) and was oriented horizontallyfrom side to side. An electromagnet was used to induce magnetization with externalfield […]

Male and Female Reproductive Strategies in the Polygynous Bobolink

Bobolink (Dolichonyx oryzivorus) Science Article 6 abstract Most species of birds are socially monogamous, however approximately 8% of bird species are polygynous. By mating polygynously,females lose paternal care, but might gain access to a superior territory or male. We examined five factors that affect polygyny inbobolinks: territory size, perching sites, predation rate, insect abundance, and […]

Coloniality in the yellow-rumped cacique as a defense against nest predators

Yellow-rumped Cacique (Cacicus cela) Science Article 1 abstract Individuals of the colonial Yellow-rumped Cacique (Cacicus cela) in Amazonian Peru can defend their nests against predators in three ways. First, by nesting on islandsand around wasp nests, caciques are safe from arboreal mammals such as primates, whichdestroy many more-accessible colonies. Caimans and otters that live in […]

Red-winged and Yellow-headed Blackbird Nesting Habitat in a Wisconsin Marsh

Yellow-headed Blackbird (Xanthocephalus xanthocephalus) Science Article 1 abstract Competitive interactions between Red-winged (Agelaius phoeniceus) and Yellow-headedblackbirds (Xanthocephalus xathocephalus) have been reported by a number of workers(e.g., Orians and Willson 1964, Willson 1966, Miller 1968). Most studies concerned withboth species occurring together have been conductedin western regions of North America;however, see Weller and Spatcher (1965), Burt […]

Nestling Diets of Red-Winged and Yellow-Headed Blackbirds on Playa Lakes of West Texas

Yellow-headed Blackbird (Xanthocephalus xanthocephalus) Science Article 3 abstract Red-winged blackbirds (Agelaius phoeniceus) and yellow-headed blackbirds (Xanthocephalus xanthocephalus) are abundant breeding birds on the playa lakes of the Panhandle of Texas. Earlier studies have described the foods of nestling icterids in areas supporting wetlands undisturbed by agriculture (Willson 1966, Robertson 1973, Orians and Hom 1969), but […]