Here today, gone tomorrow

The male Klaas's cuckoo is a dapper fellow, metallic forest green above and mainly white below. That green and white pattern camouflages him perfectly when he's high in a full-foliaged tree (which is where he prefers to hang out). Usually the only thing that gives his presence away is his distinctive and oft-repeated whistling call, one of the characteristic sounds of woodland in this part of Africa. The other day I heard this signature sound up in a tree beside the road I was on; didn't see the bird, but was glad to get a call from him, so to speak. It's been a number of months since I've heard one, and in the few days since then I haven't heard one calling again. He may have been just passing through.

Speaking of birds that are sometimes here and sometimes not, the grey-capped warbler is another one. These tend to be much harder to observe than Klaas's cuckoo, not only because of their grey and green coloration but also because they normally stay well within dense thicket or undergrowth. I tried for many months to get a glimpse of this bird that regales the neighborhood with an extraordinarily loud and varied series of call notes before I finally laid eyes on one. For some reason, though, since returning to Uganda in October, I had not heard a grey-capped warbler sing until early in January. For a couple of weeks, then, I heard their calls several times, but not again since then. They have either moved on, perhaps according to some local migration pattern, or they are skulking in the hedges without vocally advertising their presence.
I'll mention one more that fits in the category of "here today, gone tomorrow"--the African black-headed oriole. For the past several weeks, beginning in December I think, I've been hearing one calling in the early part of the mornings of several days. About three times I've been treated to a sighting--most recently yesterday when one flew between trees not far above my head half a mile or so from our house. These encounters have reminded me that I also saw and heard these orioles several times in December 2005 and January 2006. I would guess that they may be in our area seasonally as intra-African migrants; or alternatively that they simply find it convenient to be here at this time because of the temporary availability of some particular type of food that they favor. The African black-headed oriole is extremely similar to the less widespread western black-headed oriole (which also occurs in our area, according to my field guide). One of my challenges is to observe these birds closely enough with binoculars at some point to be sure which of the two I've been seeing. Sometimes one arrives at a firm identification of a species only after months of peering and researching. Which I think makes reaching that conclusion all the more rewarding.