Reserva Ecológica Costanera Sur

Sitio realizado por aficionados a la observación de aves desde 10 de enero 2006

Greyish Baywing - Agelaioides badius

Order: Passeriformes (Oscines) - Family: Icteridae Status: Resident - Frequent - Breeder. Habitat: Bushland, grassland and embankments Previously called Bay-winged Cowbird. The name has been changed so as not to be associated to Molothrus cowbirds which are brood parasites and the Baywing is not. What is more, the Baywing itself is parasitized by Molothrus cowbirds.

All records since January 2014
Tordo músico/Bay-winged Cowbird© Diego Caiafa Tordo músico/Bay-winged Cowbird© José L. Merlo Tordo músico/Bay-winged Cowbird© José L. Merlo
Tordo músico/Bay-winged Coebird© Jorge García Vicente
Dorsally greyish brown. Lighter underparts. Black loral. Dark brown tail. Rufous remiges
Tordo músico/Bay-winged Cowbird© J. Simón Tagtachian
Tordo músico/Bay-winged Cowbird© Carlos González Ledo
Tordo músico J/Bay-winged Cowbird J© Bea Grasso Tordo músicoR/Bay-winged CowbirdB© J. Simón Tagtachian
Parasitism by Screaming Cowbird
TordosP/CowbirdsP© Milano-Muszkats
A juvenile of Screaming Cowbird on top and a Bay-winged Cowbird, below. The Screaming Cowbird parasitizes almost exclusively the Bay-winged Cowbird. The juveniles of these two species are quite alike and similar to the adult Bay-winged Cowbird. The two features that allow telling them apart are the black in lores and around the eyes (not seen in Screaming Cowbird) and black underwing coverts (not black in Bay-winged Cowbird), the latter being difficult to be spotted on the field. That is the Bay-winged Cowbird will not undergo too many changes as aspect is concerned, whereas the Screaming Cowbird has still to change into the adult black plumage, which appears in 45 days approximately and by that time it is no longer fed by the host. With time it gets covered in black spots till it finishes the moult.
Tordo músicoR/Bay-winged CowbirdR© Carlos Gonzalez Ledo
A young without black lores and black around the eye
Parasitism by Shiny Cowbird
Parasitismo/Parasitism© Silvia Vitale
Parasitismo/Parasitism© Silvia Vitale
Parasitismo/Parasitism© Silvia Vitale
Parasitismo/Parasitism© Silvia Vitale
Parasitismo/Parasitism© Silvia Vitale
These photos were taken durante a bird survey. We were walking along the sidewalk when we saw a juvenile Shiny Cowbird soliciting food near a Hornero's nest. We stopped to see who the victim had been. A Bay-winged Cowbird appeared appeared with food to be delivered. But to our surprise the little shiny cowbird got nothing and the bird flew straight to the nest opening and gave the food to the chicks inside - there were two. The Bay-winged Cowbird went away and a second individual (we ignore whether it was the same) appeared. The little cowbird flapped its wings vigorously and screamed to be seen, but again it received nothing. The action repeated several times and no matter how hard he tried he did not succeed. So, what did he do? He got into the nest. Unluckily he had to go on with our task and left.
Above we mentioned that the Bay-winged Cowbird is also parasitized by the Screaming Cowbird and may be by both at the same time. In this case we could not see whether it had been doubly parasitized. Nevertheless, the Bay-winged Cowbird does no longer feed the juvenile Shiny Cowbird when the juvenile leaves the nest. This suggests that the Bay-winged Cowbird recognizes its chicks by the body feathers and not the lores. That is why it keeps feeding the Screaming Cowbird till it changes into the adult plumage
Tordo músico/Bay-winged Cowbird© Hugo Hulsberg
Tordo-músico/Grayish Baywing© Mirta Ragonesi
Tordo músico/Bay-winged Cowbird© J. Simón Tagtachian
The Bay-winged cowbird reuses the nests of other species to breed. Here we have records of reutilization of Rufous Hornero's, Great Kiskadee's and Green-barred Woodpecker's nests.
More photographic records since January 2013