Olive-sided Flycatcher Contopus borealis
Updates and corrections:
A misleading presentation in the Sibley Guides leads some observers to the conclusion that the white patches on the back are shown only by juveniles. The fluffy white patches sometimes shown by this species have nothing to do with age.
read more here: Olive-sided Flycatcher – white patches and age in fall
Hello. In the Sibley gide, the olive sided flycatcher is presented as having paler underwing coverts than the primaries and secondaries. Are you sure about this? I find the opposite in this picture (if the identification is correct) : https://www.flickr.com/photos/nabok/42890992185/in/datetaken/
it’s true in this one as well: https://www.flickr.com/photos/nabok/42890992185/in/datetaken/). Can you confirm?
Hi Olivier, Good question. I’m guessing that you are using a first edition of the guide (Red-tailed Hawk on the cover), where the underwing coverts were shown paler than the flight feathers. They should be about the same color and this was corrected in the second edition. In the two photos you link, only the leading edge of the underwing is visible (which is the darkest part) and it is in deep shadow so we’re not really seeing the true color. A great resource for questions like this is the Wing Image collection at the Slater Museum, and an example here: http://digitalcollections.pugetsound.edu/cdm/singleitem/collection/slaterwing/id/11694/rec/4 shows the underwing coverts about the same color as the flight feathers.