Aggressive Responses of Red-Winged Blackbirds (Agelaius phoeniceus) Toward Brown-Headed Cowbirds (Molothrus ater) in Areas of Recent and Long-Term Sympatry

Bird Behavior ◽  
1999 ◽  
Vol 13 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J.W. Prather ◽  
C.P. Ortega ◽  
A. Cruz
Keyword(s):  
Molothrus Ater ◽  
Agelaius Phoeniceus

The time of day of egg laying by the Brown-headed Cowbird and other icterines

1991 ◽  
Vol 69 (8) ◽  
pp. 2093-2099 ◽  
Author(s):  
David M. Scott
Keyword(s):  
Molothrus Ater ◽  
Time Of Day ◽  
Egg Laying ◽  
Agelaius Phoeniceus ◽  
Brood Parasite ◽  
Dendroica Petechia ◽  
Cardinalis Cardinalis ◽  
Vireo Olivaceus ◽  
Molothrus Bonariensis ◽  
Dumetella Carolinensis

I present data on the time of day of oviposition for 16 species of icterines to evaluate the idea that laying exceptionally early in the morning by the brood parasite, the Brown-headed Cowbird (Molothrus ater), is a specialization for parasitism. This cowbird, the earliest known layer among icterines, typically lays before sunrise (sunrise −9.14 ± 2.52 (SE) min, n = 36). Another brood parasite, the Shiny Cowbird (Molothrus bonariensis), also sometimes lays before sunrise. The best-known nonparasitic icterines, the Red-winged Blackbird (Agelaius phoeniceus) and the Common Grackle (Quisacalus quiscula), lay shortly after sunrise. Fragmentary records show that several other icterines lay within an hour or so after sunrise. Data are inadequate to conclude that early laying by Brown-headed Cowbirds has arisen as an adaptation for parasitism. The Brown-headed Cowbird at London, Ontario, lays earlier than most local passerines, as is shown by new data on oviposition by seven host species arranged in order of increasing lateness of oviposition: Agelaius phoeniceus, Dendroica petechia, Melospiza melodia, Cardinalis cardinalis, Vireo olivaceus, Dumetella carolinensis, and Turdus migratorius.

Reactions of Four Passerine Species To Threats of Predation and Cowbird Parasitism: Enemy Recognition or Generalized Responses?

Behaviour ◽  
1992 ◽  
Vol 123 (1-2) ◽  
pp. 84-105 ◽  
Author(s):  
Spencer G. Sealy ◽  
Diane L. Neudorf
Keyword(s):  
Host Species ◽  
Molothrus Ater ◽  
Egg Laying ◽  
Agelaius Phoeniceus ◽  
Bombycilla Cedrorum ◽  
Cowbird Parasitism ◽  
Dumetella Carolinensis ◽  
Passerella Iliaca ◽  
Enemy Recognition ◽  
Defensive Behaviours

AbstractFour host species of the parasitic brown-headed cowbird (Molothrus ater) were exposed to taxidermic mounts of a female cowbird, fox sparrow (Passerella iliaca), and common grackle (Quiscalus quiscula) at their nests during their egg-laying or nestling stage. Red-winged blackbirds (Agelaius phoeniceus), a species that accepts cowbird eggs laid in their nests, responded more aggressively to cowbird models early in their nesting cycle, indicating that they recognized the unique threat the cowbird posed. Gray catbirds (Dumetella carolinensis), northern orioles (Icterus galbula), and cedar waxwings (Bombycilla cedrorum) can remove cowbird eggs from their nests and for the most part they responded similarly to cowbird models and the "nonthreatening control," i.e. a fox sparrow. Cedar waxwings were nonaggressive to all the models and may rely on concealment to protect their nests from enemies. Removal of cowbird eggs by puncture ejection is more risky than grasp ejection. Despite this, orioles and waxwings (puncture ejectors) were not significantly more aggressive to cowbird models at egg laying than catbirds (grasp ejectors). Responses of the three rejector species toward the cowbird model did not change over the nesting cycle, indicating further that they do not recognize cowbirds as a unique threat. Rejector species may not recognize cowbirds because they have little experience with them. With the exception of waxwings, all of the hosts recognized the grackle as an enemy and increased their levels of defence from the laying to nestling stages. Three of the host-species did not simply respond in a generalized manner to any intruder at their nests but indeed recognized specific enemies. Considerable interspecific variability exists amongst the four species in defensive behaviours, which may reflect their different nesting habitats.

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.

Variation in weight and composition of Red-winged Blackbird eggs

1987 ◽  
Vol 65 (3) ◽  
pp. 605-607 ◽  
Author(s):  
Katherine E. Muma ◽  
C. Davison Ankney
Keyword(s):  
Total Energy ◽  
Breeding Season ◽  
Good Predictor ◽  
Molothrus Ater ◽  
Agelaius Phoeniceus ◽  
Egg Weight ◽  
Highly Correlated

To investigate variation in egg weight and composition we collected and analyzed 38 Red-winged Blackbird (Agelaius phoeniceus) eggs. The composition of Red-winged Blackbird eggs was very similar to that reported for Brown-headed Cowbird (Molothrus ater) eggs. Egg weight is a good predictor of total energy (kJ) in blackbird eggs as those two variables were highly correlated (r2 = 0.66). Weight of Red-winged Blackbird eggs did not change over the breeding season.

scholarly journals Eavesdropping on Referential Yellow Warbler Alarm Calls by Red-Winged Blackbirds Is Mediated by Brood Parasitism Risk

2021 ◽  
Vol 9 ◽  
Author(s):  
Shelby L. Lawson ◽  
Janice K. Enos ◽  
Sharon A. Gill ◽  
Mark E. Hauber
Keyword(s):  
Brood Parasitism ◽  
Molothrus Ater ◽  
Agelaius Phoeniceus ◽  
Alarm Calls ◽  
Playback Experiments ◽  
Yellow Warbler ◽  
Incubation Stage ◽  
Yellow Warblers ◽  
Current Risk ◽  
Setophaga Petechia

Referential alarm calls that denote specific types of dangers are common across diverse vertebrate lineages. Different alarm calls can indicate a variety of threats, which often require specific actions to evade. Thus, to benefit from the call, listeners of referential alarm calls must be able to decode the signaled threat and respond to it in an appropriate manner. Yellow warblers (Setophaga petechia) produce referential “seet” calls that signal to conspecifics the presence of nearby obligate brood parasitic brown-headed cowbirds (Molothrus ater), which lay their eggs in the nests of other species, including yellow warblers. Our previous playback experiments have found that red-winged blackbirds (Agelaius phoeniceus), a species also parasitized by brown-headed cowbirds, eavesdrop upon and respond strongly to yellow warbler seet calls during the incubation stage of breeding with aggression similar to responses to both cowbird chatters and predator calls. To assess whether red-winged blackbird responses to seet calls vary with their own risk of brood parasitism, we presented the same playbacks during the nestling stage of breeding (when the risk of brood parasitism is lower than during incubation). As predicted, we found that blackbirds mediated their aggression toward both cowbird chatter calls and the warblers’ anti-parasitic referential alarm calls in parallel with the low current risk of brood parasitism during the nestling stage. These results further support that red-winged blackbirds flexibly respond to yellow warbler antiparasitic referential calls as a frontline defense against brood parasitism at their own nests.

Sign in / Sign up

Export Citation Format

Share Document