Repeated Brood Parasitism by Brown-Headed Cowbirds (Molothrus ater) at Nesting Sites of Eastern Phoebes (Sayornis phoebe) across Non-consecutive Years

2013 ◽  
Vol 125 (2) ◽  
pp. 389-394 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Zachary Aidala ◽  
Rebecca Croston ◽  
Mark E. Hauber
2001 ◽  
Vol 79 (8) ◽  
pp. 1518-1523 ◽  
Author(s):  
Mark E Hauber

The reproductive success of obligate brood parasitic birds depends on their ability to seek out heterospecific nests. Some nests are more suitable for parasitism than others and, for example, parasitic females may benefit from laying eggs preferentially and repeatedly at safer sites. Observations on patterns of Brown-headed Cowbird (Molothrus ater) parasitism on Eastern Phoebes (Sayornis phoebe) across 2 years suggested that parasitism occurred at above chance levels during the first rather than the second nesting attempts and at nests located under eaves rather than bridges. Previously parasitized nests were more likely to be parasitized again in the subsequent breeding season. Sites under eaves and bridges did not differ in whether Brown-headed Cowbirds could be detected in the proximity of the nest. However, nests from first nesting attempts and nests under eaves were less likely to be lost as a result of structural failure of the Eastern Phoebe's mud nest. These data suggest that site discrimination by Brown-headed Cowbirds leads to adaptive patterns of parasitism among available Eastern Phoebe nests.


Western Birds ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 68-75
Author(s):  
Jessie L. Williamson ◽  
Matthew J. Baumann

Brood parasitism is a fascinating natural history phenomenon that provides a window into the coevolution of antagonistic interactions. Many ecological and evolutionary aspects of brood parasitism remain unknown, and new hosts of brood parasites are still being discovered. We document the second instance of brood parasitism of the Olive Warbler (Peucedramus taeniatus) by the Brown-headed Cowbird (Molothrus ater). Apparent lack of habitat and elevation overlap across the ranges of these two species prompted us to examine how frequently they come into contact. We analyzed >3 million Olive Warbler and Brown-headed Cowbird occurrence records from two open-source repositories, eBird and GBIF, to examine both synchronous and asynchronous locality overlap during the breeding season. We found that the two species were documented together simultaneously in only 3.1% of analyzed instances, but that they co-occurred in similar habitat types and/or at similar elevations at 11.8% of localities analyzed across the Olive Warbler’s range. Additional research on aspects of ecology and evolution, such as host selection, the cowbird’s diurnal patterns of movement, and the dynamics of intracellular pathogens infecting brood parasites and their hosts, may shed light more broadly on the ecological interactions and mechanisms underlying brood parasitism.


2011 ◽  
Vol 7 (5) ◽  
pp. 670-673 ◽  
Author(s):  
Brian D. Peer ◽  
Michael J. Kuehn ◽  
Stephen I. Rothstein ◽  
Robert C. Fleischer

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.


2019 ◽  
Vol 374 (1769) ◽  
pp. 20180194 ◽  
Author(s):  
Stephanie C. McClelland ◽  
Gabriel A. Jamie ◽  
Katy Waters ◽  
Lara Caldas ◽  
Claire N. Spottiswoode ◽  
...  

Brood parasitism has evolved independently in several bird lineages, giving rise to strikingly similar behavioural adaptations that suggest convergent evolution. By comparison, convergence of physiological traits that optimize this breeding strategy has received much less attention, yet these species share many similar physiological traits that optimize this breeding strategy. Eggshell structure is important for embryonic development as it controls the flux of metabolic gases, such as O 2 , CO 2 and H 2 O, into and out of the egg; in particular, water vapour conductance ( G H 2 O ) is an essential process for optimal development of the embryo. Previous work has shown that common cuckoos ( Cuculus canorus ) have a lower than expected eggshell G H 2 O compared with their hosts. Here, we sought to test whether this is a trait found in other independently evolved avian brood parasites, and therefore reflects a general adaptation to a parasitic lifestyle. We analysed G H 2 O for seven species of brood parasites from four unique lineages as well as for their hosts, and combined this with species from the literature. We found lower than expected G H 2 O among all our observed brood parasites both compared with hosts (except for brown-headed cowbirds ( Molothrus ater )) and compared with the expected rates given their phylogenetic positions. These findings suggest that a lowered G H 2 O may be a general adaptation for brood parasitism, perhaps helping the parasite nestling to develop greater aerobic fitness. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.


The Auk ◽  
2005 ◽  
Vol 122 (2) ◽  
pp. 648-660 ◽  
Author(s):  
William E. Jensen ◽  
Jack F. Cully

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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