From the still almost frozen wastes of northern Minnesota, friend Larry Waddell has sent great shots of 12 species of migrant warblers that until recently were at my patch near Turrialba, Costa Rica. Amazingly, this does not by any means exhaust the list of species that commute between the two places, although several of the species below are very hard to find around Turrialba.
The American Redstart (Setophaga ruticilla) is generally found at slightly lower elevations in our area. In Costa Rica I have seen it from very late August up until the second week of April. The flashing tail, which is constantly fanned, makes both males and females easy to identify.
The strikingly pretty Black-and-white Warbler (Mniotilta varia)arrives in Costa Rica in August and departs for points north in April. It is frequently seen in gardens in our area throughout the northern winter.
The Black-throated Green Warbler (Setophaga virens) is a fairly common migrant in Costa Rica. I have found it locally each of the last ten years, with the strange exception of 2012. It can be confused here with the much scarcer Townsend’s Warbler (Setophaga townsendi), but not in Minnesota, where the latter, a western species, is absent.
For North American birders the Yellow-rumped Warbler (Setophaga coronata) is a very common, or even abundant, species. This is not the case in Costa Rica. In our area there are very few sightings reported in the eBird data base; this year, for example, there were only two. In 2017 John and Milena Beer photographed one at CATIE, Turrialba, but to date I have still not identified any Yellow-rumped Warbler in Costa Rica. Costa Rica’s Yellow-rumped Warblers are of the white-throated eastern sub-species, formerly called Myrtle Warbler.
By contrast the Yellow Warbler (Setophaga petechia) is found in Costa Rica in large numbers during migration season. Most individuals do not sport the breast stripes of the adult male’s breeding plumage and must be examined carefully to distinguish from the Wilson’s Warbler (seen below).
Wilson’s Warbler (Cardellina pusilla) is a smartly attired, mostly yellow warbler. The male’s black cap is its distinguishing mark and safely separates it from the slightly larger Yellow Warbler females and immatures. Both species are common migrants in most of Costa Rica. In the Turrialba area Wilson’s prefers higher elevations where it is often the only migrant warbler to appear on our birding excursions.
Ah, just another Chestnut-sided! We hear and say this with some regularity because during the northern winter the beautiful Chestnut-sided Warbler (Setophaga pensylvanica) is often the commonest warbler of any kind to be seen in our part of Costa Rica. Most birds in Costa Rica have little, if any, trace of chestnut on the sides and develop this plumage only towards the end of their stay in our area, in March/April.
The Magnolia Warbler (Setophaga magnolia) is an infrequent visitor to our area but certainly not impossible to find. Its black lace breast and throat are distinctive. I was fortunate enough to see one in consecutive months at CATIE, Turrialba, in 2010 and then twice, very close to home in 2017. More recent local sightings (February 2018) have been recorded by Steven Aguilar Montenegro and others, also at CATIE.
The Cape May Warbler (Setophaga tigrina) is a rarity in Costa Rica. Its appearance in my garden always draws interest from twitchers around the country. Most of the individuals that have turned up have not been males in full plumage but the striped breast helps in identification. I have not found it in Turrialba these last two years.
A warbler moving through low undergrowth is most frequently the Mourning Warbler (Geothlypis philadelphia), which visits my garden regularly each year. The male’s grey hood makes it fairly easy to identify because the very similar MacGillivray’s Warbler (Geothlypis tolmiei) is extremely rare in Costa Rica. In Minnesota only the Mourning Warbler is present since MacGillivray’s is a western species in North America.
The next two species that Larry was able to photograph this year in Minnesota are quite rare finds in Costa Rica:
I have not yet identified a Nashville Warbler (Oreothlypis ruficapilla) in Costa Rica at all. The species is quite rare and the last sighting close to us was at Ujarrás in 2012. I live in hope! Many thanks to Larry for this photo, which clearly shows the grey head with prominent eye ring.
Equally hard to find in Costa Rica is the Palm Warbler (Setophaga palmarum). It has not been seen in our area since January 2016 when one appeared at Guayabo Lodge and was seen by numerous observers, myself included. A Palm Warbler at CATIE, Turrialba, the next month, was perhaps the same individual, but neither details of the sighting nor a photo were submitted.
As mentioned, there are several other migrant warblers that shuttle between North America and Costa Rica. But thanks to Larry’s fine photographs I’m able to document the travels of the 12 species above and to enjoy making this post while I’m still away from home. I return very soon but will probably have to wait until September before these beautiful butterflies of the bird world reappear on the slopes of the Turrialba Volcano.