When we were out merrily dipping on the Peterborough Northern Hawk Owl recently we chanced upon this interesting accipiter along Meadowview Road. We were watching a flock of Bohemian Waxwings when this medium-sized accipiter swept in and landed in a nearby tree. Thinking it was simply a Cooper’s Hawk I didn’t even look at it, but MK did and noticed it appeared very pale on the underparts. A short while later the bird took off and flew right over us whereby we all agreed this was not a typical Cooper’s and changed our mind to a small male Northern Goshawk. We thought the wing shape looked good for the latter, though this is not really evident in the photos. Anyway, there were a number of interesting things about the bird so below are a few photos – not great ones I’m afraid!
First of all this was not a big bird and even for a male Northern Goshawk it would be at the dinky end of the scale. It showed some immature primaries and primary coverts (obvious on the upperwing) so was not an adult – maybe a second winter bird? As far as the shape goes we thought the hand part of the wing was rather pointed like a Northern Goshawk. However, the secondaries were perhaps not as bulging as one might expect for this species. The tail was rather broad and certainly not rounded like a typical Cooper’s Hawk. One of the features that made it look like a Northern Goshawk was the fine dense barring on the underparts and lesser underwing coverts. The barring was greyish-buff in colour with none of the rusty tones one would normally expect on a Cooper’s Hawk. Having said that it didn’t look silvery on the underparts like an adult (or near-adult) Northern Goshawk and showed a slight buffy wash. In addition there was little or no contrast between the crown and the rest of the slate grey upperparts. The bird did show a white supercilium or sorts, but it was short and ended rather abruptly just behind the eye. The eye was ruby red, rather like an adult Cooper’s Hawk. On a sub-adult Northern Goshawk I personally would have expected the eyes to be yellowish or amber coloured, but I’m far from expert in this field. The tail bands were somewhat wavy, but otherwise were rather bold and Cooper’s-like.
So, is this just an odd Cooper’s Hawk or Northern Goshawk or a hybrid Cooper’s Hawk/Northern Goshawk? We don’t know. MK found the following to be of interest as the bird featured looks similar to the individual we saw: http://terriermandotcom.blogspot.ca/2010/11/wild-caught-goopers-hawk.html
Please feel free to comment if you have any suggestions…