Hello Ontbirders: Given the potential for confusion in the identification of first basic (first winter) Rose-breasted Grosbeak and Black-headed Grosbeak, observers should carefully note the upper and lower mandible colours, and the colour of the underwing coverts (wing linings) on the bird in Pakenham. Documentation of these and other points of distinction should be included in reports of this bird, which I hope will be submitted to the Ontario Bird Records Committee. More information is required than can be gleaned from the photographs posted to date on the OFO website, in my opinion. After discussion with fellow OBRC member Ron Pittaway, I would note the following. The upper mandible is dark in Black-headed, contrasting with the paler lower mandible. In Rose-breasted, the upper mandible is pale, being the same colour as the lower mandible. The wing linings are yellow in all ages and sexes of Black-headed. Note that female Rose-breasted also has yellow wing linings, but male Rose-breasted has diagnostic pink wing linings. The Pakenham bird appears to be a male, from the photos posted on the OFO website. In females, yellow wing linings would not be diagnostic of either species.
Perhaps these features have already been recorded by observers who have seen the Pakenham bird. If not, future documentation of these marks would certainly assist the OBRC in its deliberations. The photographs posted do not show the important wing linings, and a detailed written description of the mandibles would assist in evaluating the photographs. Ron Tozer [EMAIL PROTECTED] Ron Tozer <[EMAIL PROTECTED]> Visit http://www.ofo.ca/ontbirdsguide.htm for information on leaving and joining the list. As well as general information and content guidelines.
