Another beautiful day of sunshine and clouds, but no rain. I have to solve these wood-pewee problems caused by conflicting voice descriptions in the various bird guides. My bird(s), if they’re always the same species, make a short ‘bubbly trill’ (Garrigues‘ description of the voice of the Tropical pewee seems to fit exactly). Therefore, on the basis of voice, the bird I have seen in my guayabo most evenings this week cannot be the Western that I thought it was. I finally listened to a voice recording of the Western, admittedly not made in Costa Rica, but it is nothing like the little trill I’m hearing.
Presumably, then, it’s the Tropical (Eastern would seem to be excluded if the voice descriptions are any guide at all), but if so why does it fly just a very short sally and then return to the same spot (almost) every time? After all, that’s what the Western is supposed to do, not the Tropical. I have noted tail quivering on this bird only when it trills, not when it alights. Usually I don’t see any trace of yellow, but in good light today the lower belly does look a tad yellowish. The breast is lighter down the centre, almost suggesting an Olive-sided flycatcher, and no bird I have seen has had a completely dark breast as illustrated in Sibley. The crown is definitely darker than the rest of the peaked head. I looked again for the supposedly differentiating ‘white lores’. No sign of them!. The lower mandible is yellow, but I can’t make out the tip with any certainty. The wing bars can be clearly seen, but are a dull buffy colour. Next I have to consider what species all the past pewees have been, both here and in the vicinity. Do we also get the Eastern here? The guide books say yes. For example, some birds over at the Guayabo National Monument had bills that looked all dark and a call note that was not the trill I hear here in my garden.
I have sightings for December through February, and also in late April. According to the literature, these would almost certainly be Tropical, yet the April birds, for example, showed no yellow whatsoever. Oh what fun!
No other notes for today, other than to say that the Red-billed pigeons and Grayish saltators seem to be returning from vacation.
As an update to all this, I listened carefully today (November 28) to all the pewee/wood pewee recordings on Xeno-canto. It’s a fantastic resource and very much confirms that my garden bird (now sadly departed, it seems) must be a Tropical pewee, despite my reservations about field marks and behaviour. Let’s hope all future visiting pewees will speak up when pressed.