Sunday, October 28, 2001

Antswarms at Calle Maipo, Cerro Azul, a report by Bill Adsett

The were antswarms - quite possibly the same one twice - on Calle Maipo on October 21 and again today. Apart from the usual trio of antbirds (Spotted, Bicolored and Ocellated) both were accompanied by a bit of a strange - but at times exciting - mixture of birds.
The one last week had 4 species of woodcreeper - Barred, Spotted, Plain Brown and Ruddy. I have noticed before that whenever the latter two species are together, the Ruddies bully the Plain Browns, diving on them and taking over their tree trunk (possibly also their prey). Also, the Ruddies always keep their head feathers raised in such situations. The swarm was also attended by Swainson's Thrushes, a Nightingale Wren and a Kentucky Warbler. There was an immature Barred Forest-Falcon. It bore all the standard fieldmarks, and the collar was plain to see, but the underparts were quite different to those described in any book (though I have still to check Wetmore) being virtually immaculate pale creamy white except for some dark spots on the sides of the breast. Before anyone asks, it was definitely NOT a Collared Forest-Falcon. Why so different from the "normal" immature plumage of the Barred?
Also - something I never seen before on an antswarm - there was a Rufous Motmot behaving for all the world like a ground-cuckoo. It was not there by accident - I saw it come in to the swarm and go down on the ground to catch insects. But I was disappointed at finding no real ground-cuckoo.
The antswarm today was weirder still but pure gold. Again the trio of antbirds, plus the woodcreepers. The forest-falcon - I presume the same one - was there. About 8 Black-eared Wood-Quail seemed to be in attendance rather than just turning up accidentally, but flew off (yes, FLEW off) before I could really be sure. Then the Tawny-faced Quail started calling and I had stunning views of two females who just walked in by accident and stood there for several minutes not knowing quite what to do - eventually they just turned round and walked back where they came from. No wonder those birds are so difficult to see - when standing still they look just like little round dead leaves (and when walking they are not much better)!
Then the ground-cuckoo turned up and got to within about 15 feet of me at one point. I was able to observe it well for at least 30 minutes. I have noticed before that when given the choice they will always stay on a fallen tree trunk or similar from which presumably they have a better view of whats going on. They leap off it to go after prey (or, quite often, steal it from someone else), then get back up on another good vantage point. Contrary to Dodge´s theory, Ocellated antbirds were the ones closest to the ground cuckoo, which was pretty stupid of them since the larger bird kept jumping at them and stealing the biggest insects from them. On the other hand, the Bicoloreds kept away from it and preferred my company; one sat on my boot for a couple of minutes.
Looking at my notes, I realise that I forgot to report a flock of 15 or so Blue-fronted Parrotlets flying in Altos del Torreón on August 8. We had been hearing them flying past in the area for several weekends, but not seen them. At present, however, we never hear them, although there are many more of the large parrots around now than at other times of the year.

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