Bonaparte's Gull in Paitilla, MacGillivray's Warbler in Tocumen
Jay Carlisle, Sarah Hamilton, Larry Barnes and Robin Garwood found a first-winter Bonaparte's Gull flying over the Matasnillo River at Paitilla.
Here is the information on the Bonaparte's Gull seen in Panama City on Dec. 23:
Observers: Jay Carlisle, Sarah Hamilton, Larry Barnes, Robin Garwood
Location: at water outflow near intersection of Via Italia and Ave Balboa (Punta Patilla area)
All four of us have seen hundreds and/or thousands of Bonaparte's Gulls in the United States in all plumages and are also experienced at differentiating them from other of the "Black-headed gulls" that could potentially occur. We saw the bird at approximately 1400 (2pm) and observed it clearly in good light at a distance of 50-400 feet for about ten minutes (it was still present when we left for the airport). It was flying up and down stream on the south side of Balboa Ave among numerous laughing gulls. It was in first-winter plumage and we clearly observed the black bill, fleshy legs, dark ear patch, light underwings, tail bar, and wing markings distinctive of this species.
If you need any more information on this bird, feel free to ask and I hope you all get to see it.
Also, yesterday (Dec. 29th) we went to Tocumen Marsh (w/ permission) before going to the airport. Notable birds included a MacGillivray's Warbler and about 40 Dickcissels. Both were in the area near the first ponds (as described in Ridgeley), the Dickcissels in the field edge as you head towards the next dike from the ponds. I'll give some details on the MacGillivray's since it seems to be a rarity in the canal area.
I (Jay) was the only person to see this bird as the others were looking elsewhere. I saw it 2x for about 10 seconds each time at about 0710 (AM) and we could not find it again (although since this is one the commoner warblers in Idaho and there were plenty of new birds to see, we didn't try too hard). It was in the shrubs on the right side of the road as you bend the corner towards the open-water pond on the right.
I clearly saw the yellow underparts, grayish-brown upperparts and throat/chest area, and fleshy legs indicating an Oporornis species. I also saw its hopping behavior in the understory of shrubs, counting out Connecticut Warbler. Lastly, I saw the distinct, broken eye-ring (crescents above and below the eye) found on MacGillivray's. Although this is a skulker, I did have unobstructed views of these characteristics for seconds at a time. I have extensive experience with MacGillivray's warblers from birding in the western US for the last 6 years and also have captured and banded hundreds at our fall banding station in Idaho. Additionally, before this sighting I had seen at least 15-20 Mourning Warblers throughout Panama in the last two weeks in plumages ranging from hatch-year females to adult males and feel very comfortable with this identification. The MacGillivray's seemed to be a female or hatch-year male. Again, feel free to ask any questions.