Immature Fasciated tiger-heron
Well, here’s one that I wasn’t expecting, despite the recent fly-over by a Great blue heron (Ardea herodias). Herons are scarce around here. Chalo Porras had already told me that he had seen a heron on Quebrada La Loca at the bridge just below Carlos Luis’s place. It’s the same spot where I have seen the Sunbittern several times. Along all of its length, the Quebrada La Loca is a rushing mountain stream, bouncing over rocks, while at the same time, for much of its course, it is hidden away among thick vegetation. I assumed, from Chalo’s description, that the heron might possibly be an immature night-heron, but such is not the case.
After a hard day at the computer, a slow amble down to the Quebrada was just the ticket for setting the world right. The short walk changes slightly each time I take it. A new cabin has been constructed on a small hillock that had previously been the site of a large bamboo clump. The bamboo harboured many birds each evening but there is also a small forest patch at the side, on a steep slope leading down to the Quebrada. The new owners of the cabin, very nice folks from San Jose, gave me access on a small path through the forest, telling me that they too had seen a heron down there. Their description of a long-necked brown-spotted heron pretty much matched Chalo’s.
First surprise on the way down was a loudly calling Bright-rumped attila (Attila spadiceus), but it evaded my binoculars. I have still not actually seen this large, bull-headed flycatcher in San Antonio. The path gives easy access, via thick forest, to the river bed, and after clambering over the slippery stones I crossed easily to the other side where I immediately caught a glimpse of a streaked immature heron disappearing around the first bend. A silent approach to the bend brought its reward and I was able to view the bird at my leisure for some ten minutes or more. No camera, as usual! A tiger-heron here was a first for San Antonio, but which species was it?
Only after consulting Garrigues, Stiles & Skutch and the Turrialba area bird lists can I be reasonably sure that this was indeed the Fasciated tiger-heron (Tigrisoma fasciatum), a species with which I am quite unfamiliar. The other two tiger-herons, (Bare-throated tiger-heron (Tigrisoma mexicanum) and Rufescent tiger-heron (Tigrisoma lineatum)) are lowland birds. Was the yellow I thought I saw on the throat simply a reflection from the yellow base of the bill? The Bare-throated is rarely found above 500 m and does not have any preference for rocky streams and enclosed forest. Immatures of the other two species are supposedly very difficult to separate in the field, but my bird was very rusty-coloured and had a large black patch on the back, while the Bare-throated immature is supposedly lighter in colour. To decide between the Fasciated and the Rufescent seems to depend on habitat and altitude. The latter is found only rarely as high as 500 m and likes quiet streams and swamps, while the habitat for the Fasciated matches Quebrada La Loca quite exactly. Moreover, the Fasciated is the only tiger-heron to figure on any local list, namely on the Rancho Naturalista list, where it is given as rare but regular in the Tuis River Valley at pretty much the same altitude as here in San Antonio.
I welcome very much any help from any birdwatchers more experienced with this species, but I’m plumping for fasciatum! I will re-explore just as soon as I possibly can.
In other news, noisy squeaks brought my attention to a pair of Sulphur-bellied flycatchers here in the same part of the garden that first attracted them last year. This time I have found them several months earlier, in March instead of in July. The flash of cinnamon in the wings is very noticeable, while the call note is quite distinctive. I now have several different nesting flycatchers in the garden, most conspicuously the Piratic flycatcher, though the Gray-capped flycatcher seems to have dropped out of sight lately.
Many thanks to Richard Garrigues and Karel Straatman for their fine photos.