ML539344231

Age

Not specified

Sex

Not specified

Observation details

A lifer for us, this is an adult, probably a male. Note its thicker bill and bulkier shoulders compared to the similar Shiny Cowbird. Like other cowbirds, Screaming Cowbird is an obligate brood parasite, but unlike other cowbirds it lays its eggs only in the nest of the Grayish Bay-wing (formerly Bay-winged Cowbird). Both the eggs and juvenile plumage of the two are almost identical. The theory was that these two species were closely related and the Baywing was basal to the other cowbirds, an example of a primitive non-parasitic cowbird. This theory offered a compelling "just so story" about the evolution of brood parasitism in cowbirds. However modern molecular analysis found the two are not closely related and the so-called Bay-winged Cowbird is not a Cowbird at all. It has now been moved to its own genus and rebranded with the English name "Grayish Baywing" or just "Baywing" to help make that point.

Technical information

Model

Canon PowerShot SX70 HS

ISO

100

Focal length

247 mm

Flash

Flash did not fire

f-stop

f/6.5

Shutter speed

1/500 sec

Dimensions

1024 pixels x 887 pixels

Original file size

166.07 KB