Molothrus aeneus: BirdLife International

2016 ◽  
Author(s):  
Keyword(s):  
Molothrus Aeneus

scholarly journals Sarcocystis sp. parasites in the Mexican Great-tailed Grackle (Quiscalus mexicanus), Bronzed Cowbird (Molothrus aeneus), and Stripe-headed Sparrow (Aimophila ruficauda)

2014 ◽  
Vol 1 (2) ◽  
Author(s):  
Félix Domingo Sánchez-Godoy ◽  
Fernando Chávez-Maya ◽  
Adriana Méndez-Bernal ◽  
Gary García-Espinosa ◽  
Cristina Guerrero-Molina ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Internal Transcribed Spacer ◽  
Sequence Similarity ◽  
Bird Species ◽  
The United States ◽  
Histopathological Analysis ◽  
Biological Studies ◽  
Pcr Rflp ◽  
Molothrus Aeneus ◽  
Specific Fragment

The objective of this study was to describe the morphological and ultraestructural characteristics, the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) results, the sequences and the phylogenetic analysis of a specific fragment of internal transcribed spacer 1 (ITS-1), amplified using the 25/396 primers, of the Sarcocystis sp. parasites identified in the muscles of wild great-tailed grackles, bronzed cowbirds, and stripe-headed sparrows in Mexico. Fifteen birds with sarcocystosis in their skeletal muscles were studied: 7 great-tailed grackles (Quiscalus mexicanus), 6 bronzed cowbirds (Molothrus aeneus), and 2 stripe-headed sparrows (Aimophila ruficauda). Histopathological analysis revealed thin-walled mature parasite cysts. Ultrastructurally, the cyst wall consisted of a granular layer with villar protrusions and numerous microtubules. The bradyzoites measured 4.1 × 1.6 µm, and micronemes appeared in the anterior third of the conoid. For molecular identification, PCR-RFLP was performed using sequences of a specific fragment of internal transcribed spacer 1 (ITS-1) using the primers 25/396 and Hinf I. Hind III did not cut this fragment. The sequencing results indicated a 100% similarity among the Sarcocystis parasites from the three bird species, and a BLAST search revealed 96% sequence similarity with S. neurona. The phylogenetic analysis shows that the sequences studied are topologically distant to those sequences reported for S. neurona in the United States and in South America and are not related to any group previously reported. Although our morphological and molecular analysis data provide strong evidence that S. neurona uses these bird species as intermediate hosts, future molecular studies with additional DNA fragments, combined with biological studies, will ultimately allow us to convincingly identify these parasites. This is the first report of a Sarcocystis sp. parasite in wild birds in Mexico that may be S. neurona.

scholarly journals Geographic Variation and Dialects in Songs of the Bronzed Cowbird (Molothrus Aeneus)

The Auk ◽  
2002 ◽  
Vol 119 (2) ◽  
pp. 349-361 ◽  
Author(s):  
Paige S. Warren
Keyword(s):  
Quantitative Analysis ◽  
Geographic Variation ◽  
Discriminant Function Analysis ◽  
Large Scale ◽  
Major Element ◽  
Function Analysis ◽  
Song Type ◽  
Acoustic Characteristics ◽  
Initial Element ◽  
Molothrus Aeneus

Abstract Vocal dialects have presented a puzzle for evolutionary biologists for nearly 50 years. However, there is still a dearth of detailed description of variation in species with dialects, especially regarding acoustic characteristics that discriminate among dialects. In this study, I show that dialects occur in the “flight whistle” song type of the Bronzed Cowbird (Molothrus aeneus). Dialects in this species occur at a very large scale, spanning hundreds of kilometers. A discriminant function analysis revealed that the initial element of the song shows greater differences among dialects than a major element in the final portion of the song. This quantitative analysis of the dialect system provides the basis for understanding how Bronzed Cowbirds recognize songs from different dialects.

First record of non-migratory Blue-gray Gnatcatcher (Polioptila caerulea) as a host to the Bronzed Cowbird (Molothrus aeneus) in Mexico

10.1676/20-96 ◽  
2021 ◽  
Vol 132 (3) ◽  
Author(s):  
Fernando González-García ◽  
Aurelio Molina Hernández ◽  
Diego Santiago-Alarcon
Keyword(s):  
First Record ◽  
Molothrus Aeneus ◽  
Polioptila Caerulea

scholarly journals Nuevos registros de aves con anormalidad pigmentaria en México y propuesta de clave dicotómica para la identificación de casos

2017 ◽  
Vol 18 (1) ◽  
Author(s):  
Erick R. Rodríguez-Ruíz ◽  
Wilberth A. Poot-Poot ◽  
Régulo Ruíz-Salazar ◽  
Jacinto Treviño-Carreón
Keyword(s):  
Molothrus Aeneus

Las anormalidades pigmentarias en aves han adquirido mayor importancia e interés entre la comunidad ornitológica; sin em- bargo, resulta necesario contar con una herramienta de diagnóstico apropiada que brinde los criterios para lograr un sistema de identificación entre los distintos tipos de anormalidades. Para ello, proponemos una clave dicotómica para su identificación en campo con base en terminología obtenida de literatura especializada y una asociación de caracteres fenotípicos de aves. También, reportamos la presencia de anormalidades pigmentarias en la coloración corporal y de plumaje de cinco especies de aves que han sido observadas de forma ocasional en áreas perturbadas por impacto antropogénico en Tamaulipas, México: melanismo en la tortolita mexicana (Columbina inca), aberración ino en la paloma turca (Streptopelia decaocto), aberración ino en el correcaminos norteño (Geococcyx californianus), leucismo parcial en el pijuy (Crotophaga sulcirostris) y leucismo parcial en el tordo de ojo rojo (Molothrus aeneus). Las evidencias de casos actuales sugieren un aparente aumento de especies en vida libre con variación en la pigmentación. Las causas que lo provocan aún son discutibles, por lo cual, relacionar qué factores naturales o artificiales están involucrados en estos padecimientos podrá contribuir a determinar su origen y detectar problemas a nivel de poblaciones. La clave dicotómica propuesta en la identificación de anormalidades pigmentarias puede ser una herramienta continua en contextos modernos, si se unifica la terminología empleada.

scholarly journals Intermediate Frequencies of Egg Ejection by Northern Mockingbirds (Mimus polyglottos) Sympatric with Two Cowbird Species

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 855-858 ◽  
Author(s):  
Brian D. Peer ◽  
Kevin S. Ellison ◽  
Spencer G. Sealy
Keyword(s):  
High Frequency ◽  
Previous Evidence ◽  
Mimus Polyglottos ◽  
Egg Ejection ◽  
Molothrus Aeneus ◽  
Study Sites ◽  
Northern Mockingbirds

Abstract We experimentally parasitized Northern Mockingbird (Mimus polyglottos) nests to determine whether that species is more likely to eject immaculate eggs of the Bronzed Cowbird (Molothrus aeneus) or the spotted eggs of the Brown-headed Cowbird (M. ater); the latter species lays eggs that more closely resemble mockingbird eggs. Mockingbirds ejected 69% of model Bronzed Cowbird eggs, indicating that contrary to previous evidence Northern Mockingbirds eject Bronzed Cowbirds eggs at a high frequency. Mockingbirds also ejected 60% of model and real Brown-headed Cowbird eggs. Bronzed Cowbird eggs were ejected faster than Brown-headed Cowbird eggs (1.3 and 2.1 days, respectively). Ejection by mockingbirds may account for the lack of observed parasitism at our study sites in southern Texas, but it is more likely that cowbirds did not parasitize mockingbirds.

scholarly journals Fate of Grackle (Quiscalus SPP.) Defenses in the Absence of Brood Parasitism: Implications for Long-Term Parasite-Host Coevolution

The Auk ◽  
2004 ◽  
Vol 121 (4) ◽  
pp. 1172-1186 ◽  
Author(s):  
Brian D. Peer ◽  
Spencer G. Sealy
Keyword(s):  
Host Species ◽  
Brood Parasitism ◽  
Selection Pressure ◽  
Egg Rejection ◽  
Allopatric Population ◽  
Brood Parasites ◽  
Cowbird Parasitism ◽  
The Common ◽  
Molothrus Aeneus

Abstract We tested grackles (Quiscalus spp.) to determine whether they retain egg rejection behavior in the absence of the selection pressure of brood parasitism. Neither Bronzed Cowbird (Molothrus aeneus) nor Brown-headed Cowbird (M. ater) parasitism was recorded in 797 Great-tailed Grackle (Q. mexicanus) nests. Cross-fostered Bronzed Cowbird nestlings, but not Brown-headed Cowbird nestlings, fledged from Great-tailed Grackle nests, indicating that Brown-headed Cowbird parasitism does not select for rejection in these grackles. Great-tailed Grackle populations sympatric and allopatric with Bronzed Cowbirds rejected 100% of model cowbird eggs. An allopatric population of Boat-tailed Grackle (Q. major), a sister species of the Great-tailed Grackle, also rejected 100% of model eggs. Egg rejection in the Boat-tailed Grackle has apparently been retained in the absence of parasitism for as long as 800,000 years since it split from the Great-tailed Grackle. The Common Grackle (Q. quiscula), which lays the most variable eggs among the grackles, also has the lowest level of egg rejection—which is consistent with the argument that it may have lost most of its rejection behavior in the absence of parasitism. With extreme intraclutch egg-variation, Common Grackles may be more likely to reject their own oddly colored eggs, which would select against rejection behavior in the absence of parasitism. Those results have significant implications for long-term parasite-host coevolution, because they suggest that egg rejection has been retained in most species of Quiscalus in the absence of parasitism. If typical of the world's avifauna, such retention may force brood parasites to specialize on a few host species and to rarely return to using old hosts, which would readily reject their eggs.

First record of brood parasitism between Bronzed Cowbird (Molothrus aeneus) and Golden-crowned Warbler (Basileuterus culicivorus)

2021 ◽  
Vol 133 (2) ◽  
Author(s):  
Macario Fernández-Popo ◽  
Fernando González-García ◽  
Diego Santiago-Alarcon
Keyword(s):  
Brood Parasitism ◽  
First Record ◽  
Molothrus Aeneus

Genetic elucidation of host use by individual sympatric bronzed cowbirds (Molothrus aeneus) and brown-headed cowbirds (M. ater)

2006 ◽  
Vol 84 (9) ◽  
pp. 1269-1280 ◽  
Author(s):  
K. Ellison ◽  
S.G. Sealy ◽  
H.L. Gibbs
Keyword(s):  
Dna Markers ◽  
Host Species ◽  
Microsatellite Dna ◽  
Molothrus Ater ◽  
Host Use ◽  
Suitable Host ◽  
Brood Parasites ◽  
Potential Host ◽  
Microsatellite Dna Markers ◽  
Molothrus Aeneus

Species of avian brood parasites that use one or several species of hosts are called host specialists and generalists, respectively. To determine host use of individual bronzed cowbirds, Molothrus aeneus (Wagler, 1829), and brown-headed cowbirds, Molothrus ater (Boddaert, 1783), we assigned maternity to eggs using microsatellite DNA markers. We measured patterns of host use by individual sympatric cowbirds. This allowed us to determine whether these species competed for host nests and the number of females laying at nests that were already parasitized by conspecifics. We monitored 1447 nests of 42 potential host species and found that each species of cowbird used primarily four host species, with minimal overlap in the species used, yet at least some individuals acted as generalists. Individual cowbirds tended to avoid laying again at nests each had already parasitized, and multiple parasitism was frequently due to same-day laying by more than one female (19% and 44% of 27 and 39 cases for brown-headed and bronzed cowbirds, respectively). Our results suggest that both cowbirds can differentially parasitize host species; however, host use does not appear to be refined, as many eggs were laid in already-parasitized nests when unparasitized nests of other suitable host species were available.

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