scholarly journals Conventional oil and natural gas infrastructure increases brown-headed cowbird ( Molothrus ater ) relative abundance and parasitism in mixed-grass prairie

2017 ◽  
Vol 4 (7) ◽  
pp. 170036 ◽  
Author(s):  
Jacy Bernath-Plaisted ◽  
Heather Nenninger ◽  
Nicola Koper
Keyword(s):  
Natural Gas ◽  
Great Plains ◽  
Relative Abundance ◽  
Brood Parasitism ◽  
Molothrus Ater ◽  
Rapid Expansion ◽  
Northern Great Plains ◽  
Brood Parasite ◽  
Parasitism Rates ◽  
Oil And Natural Gas

The rapid expansion of oil and natural gas development across the Northern Great Plains has contributed to habitat fragmentation, which may facilitate brood parasitism of ground-nesting grassland songbird nests by brown-headed cowbirds ( Molothrus ater ), an obligate brood parasite, through the introduction of perches and anthropogenic edges. We tested this hypothesis by measuring brown-headed cowbird relative abundance and brood parasitism rates of Savannah sparrow ( Passerculus sandwichensis ) nests in relation to the presence of infrastructure features and proximity to potential perches and edge habitat. The presence of oil and natural gas infrastructure increased brown-headed cowbird relative abundance by a magnitude of four times, which resulted in four times greater brood parasitism rates at infrastructure sites. While the presence of infrastructure and the proximity to roads were influential in predicting brood parasitism rates, the proximity of perch sites was not. This suggests that brood parasitism associated with oil and natural gas infrastructure may result in additional pressures that reduce productivity of this declining grassland songbird.

scholarly journals Brown-headed Cowbird, Molothrus ater, Parasitism and Abundance in the Northern Great Plains

2007 ◽  
Vol 121 (3) ◽  
pp. 239 ◽  
Author(s):  
Lawrence D. Igl ◽  
Douglas H. Johnson
Keyword(s):  
Great Plains ◽  
Molothrus Ater ◽  
Bird Community ◽  
Northern Great Plains ◽  
Breeding Bird ◽  
Host Parasite Interactions ◽  
Parasitism Rates ◽  
Cowbird Parasitism ◽  
The Mean ◽  
Host Parasite

The Brown-headed Cowbird (Molothrus ater) reaches its highest abundance in the northern Great Plains, but much of our understanding of cowbird ecology and host-parasite interactions comes from areas outside of this region. We examine cowbird brood parasitism and densities during two studies of breeding birds in the northern Great Plains during 1990–2006. We found 2649 active nests of 75 species, including 746 nonpasserine nests and 1902 passerine nests. Overall, <1% of nonpasserine nests and 25% of passerine nests were parasitized by Brown-headed Cowbirds. Although the overall frequency of cowbird parasitism in passerine nests in these two studies is considered moderate, the frequency of multiple parasitism among parasitized nests was heavy (nearly 50%). The mean number of cowbird eggs per parasitized passerine nest was 1.9 ± 1.2 (SD; range = 1–8 cowbird eggs). The parasitism rates were 9.5% for passerines that typically nest in habitats characterized by woody vegetation, 16.4% for grassland-nesting passerines, 4.7% for passerines known to consistently eject cowbird eggs, and 28.2% for passerines that usually accept cowbird eggs. The Red-winged Blackbird (Agelaius phoeniceus) was the most commonly parasitized species (43.1% parasitism, 49.6% multiple parasitism, 71.2% of all cases of parasitism). Passerine nests found within areas of higher female cowbird abundance experienced higher frequencies of cowbird parasitism than those found in areas of lower female cowbird abundance. Densities of female cowbirds were positively related to densities and richness of other birds in the breeding bird community.

Culture Chronology in the Central Great Plains

1947 ◽  
Vol 12 (3Part1) ◽  
pp. 148-156 ◽  
Author(s):  
Waldo R. Wedel
Keyword(s):  
Great Plains ◽  
Armed Forces ◽  
Rapid Expansion ◽  
Northern Great Plains ◽  
Vanishing Point ◽  
Field Investigations ◽  
Laboratory Workers

Archaeology in the central and northern Great Plains stands today on the threshold of what may be its outstanding opportunity for sustained achievement. The intensive field investigations so auspiciously launched in Nebraska, Kansas, and the Dakotas in the decade before the war, have been at a virtual standstill since 1940; and with the rapid expansion of the nation's armed forces and defense industries, the number of students and laboratory workers available for study of the accumulated data and collections, dwindled nearly or quite to the vanishing point. Here and there, a few individuals found it possible, intermittently and subsidiary to war-connected activities, to carry on limited researches.

scholarly journals Persistence of host defence behaviour in the absence of avian brood parasitism

2011 ◽  
Vol 7 (5) ◽  
pp. 670-673 ◽  
Author(s):  
Brian D. Peer ◽  
Michael J. Kuehn ◽  
Stephen I. Rothstein ◽  
Robert C. Fleischer
Keyword(s):  
Brood Parasitism ◽  
New World ◽  
Molothrus Ater ◽  
Egg Rejection ◽  
Brood Parasite ◽  
Bombycilla Cedrorum ◽  
Defence Behaviour ◽  
Cedar Waxwing ◽  
Host Parasite

The fate of host defensive behaviour in the absence of selection from brood parasitism is critical to long-term host–parasite coevolution. We investigated whether New World Bohemian waxwings Bombycilla garrulus that are allopatric from brown-headed cowbird Molothrus ater and common cuckoo Cuculus canorus parasitism have retained egg rejection behaviour. We found that egg rejection was expressed by 100 per cent of Bohemian waxwings. Our phylogeny revealed that Bohemian and Japanese waxwings Bombycilla japonica were sister taxa, and this clade was sister to the cedar waxwing Bombycilla cedrorum . In addition, there was support for a split between Old and New World Bohemian waxwings. Our molecular clock estimates suggest that egg rejection may have been retained for 2.8–3.0 Myr since New World Bohemian waxwings inherited it from their common ancestor with the rejecter cedar waxwings. These results support the ‘single trajectory’ model of host–brood parasite coevolution that once hosts evolve defences, they are retained, forcing parasites to become more specialized over time.

scholarly journals Geographic Variation in Brown-Headed Cowbird (Molothrus Ater) Parasitism on Dickcissels (Spiza Americana) in Great Plains Tallgrass Prairie

The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 648-660 ◽  
Author(s):  
William E. Jensen ◽  
Jack F. Cully
Keyword(s):  
Geographic Variation ◽  
Great Plains ◽  
Tallgrass Prairie ◽  
Brood Parasitism ◽  
Molothrus Ater ◽  
Grassland Birds ◽  
Spiza Americana ◽  
Flint Hills ◽  
Cowbird Parasitism ◽  
Study Sites

Abstract The incidence of brood parasitism by Brown-headed Cowbirds (Molothrus ater; hereafter “cowbirds“) within host species typically reflects the continental pattern in cowbird abundance across North America, where parasitism is heaviest in the Great Plains. However, we found considerable variation in cowbird parasitism on Dickcissel (Spiza americana) nests within a subregion of the Great Plains (the Flint Hills), where the highest levels of cowbird parasitism on grassland bird nests had been previously reported. Local parasitism frequencies on Dickcissel nests varied latitudinally across the Flint Hills, ranging from 0% to 92% of nests parasitized. Interestingly, we found no obvious patterns in habitat or host attributes that were associated with this steep geographic gradient in brood parasitism. Cowbird parasitism on Dickcissel nests was not correlated with the vertical density of local prairie vegetation, mean nest distance to edge, proportion of forest to grassland habitat surrounding study sites (≤5 to 10 km), geographic variation in host abundance, or Dickcissel density or nest initiation dates. Parasitism frequencies and intensities (number of cowbird eggs per parasitized nest) on Dickissel nests were only significantly related to variation in local female cowbird density. Dickcissel clutch size and apparent fledging success were negatively correlated with local cowbird parasitism levels. Geographic patterns in cowbird abundance within and among regions should be considered when establishing conservation areas for grassland birds or other cowbird hosts of concern.

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