A couple of choice South American waterbirds have shown up in Panama and Costa Rica within the past few months. Both are common species in the llanos of Venezuela and Colombia and that’s about the closest they normally come to Central America. Oh yeah, and both also happen to be new records for each country as well as North America! The heron was found by three guides and a friend who frequently show birds to people in Costa Rica and elsewhere. It sounds like they were the only people who got to see it but they also got photos and picked up a Gray-hooded Gull near Panama City at the start of their trip. Check out Kevin Easley’s report.
That was back in July. Fast forward to September and we have another bird that shares much of its habitat and range with the Whistling Heron, but this time, the North American first showed up in Costa Rica. While visiting the shorebird hotspot of Chomes on September 16th, Victor Leiton, Jim Zook, and other local birders noted a large, strange stork. It wasn’t a Wood Stork and it wasn’t a Jabiru so they knew it had to be something good. Not long after, they realized that they had found a Maguari Stork! Several other people chased it the next day but came home empty handed (although most picked up Clapper Rail- an excellent species for Costa Rica). I would have gone too but was guiding in the foothill rainforests near Lands in Love (good day with nice mixed flocks and great looks for the client at niceties such as Blue and gold Tanager, White-throated Shrike Tanger, Black and yellow Tanager, lots of Emerald Tanagers, Black-throated Wren, and so on).
I hope the stork sticks around and won’t be too surprised if it is re-found in Palo Verde or other wetland sites in Guanacaste. I plan on looking for it when I get the chance even though that might not be for another two weeks. Although both of these vagrants turned up a few months apart, since they occur in the same habitat and region, I can’t help but wonder if they wandered for similar reasons. Waterbirds are prone to doing some post-breeding wandering so perhaps they have turned up on very rare occasions in the past but no one was there to see them? This is very possible given the much lower coverage of various birding sites compared to Great Britain and many parts of the USA and southern Canada. Or, perhaps poor feeding conditions urged these hungry birds to wander far and wide? Whatever the case, it’s a reminder to know what might be waiting out there in the field and to be ready for rarities. By definition, vagrant bird species aren’t likely to be encountered but knowing what might show up will help you identify those choice birds if you get lucky enough to see or hear them.
Both of these birds were wake up calls because neither of them had made it onto my list of possible vagrants. I suppose I will have to edit the list to include such possibilities as White-faced Whistling Duck and Whispering Ibis. I should also mention that another bird from the llanos, Large-billed Tern, also showed up in Nicaragua in August and thus likely flew over Costa Rica! It’s also ready on the CR list but would still be a fantastic record. That said, these are my top candidates for additions to the Costa Rica bird list in no particular order:
1. Gadwall: Nearly every other duck has shown up and given the large population and a wintering range that reaches southern Mexico, it seems like this one is due.
2. Double-crested Cormorant: Waterbirds wander and it seems like this one should show up sometime on the Caribbean coast.
3. Lesser Black-backed Gull and Black-tailed Gull: Just two of a few gulls that could certainly turn up in Costa Rica.
4. Black-chinned Hummingbird: I bet that this species has overshot and wandered down to Costa Rica and even if one or two did so every year, what’s the chance that someone would happen to find that one bird and realize that it wasn’t the very similar and common Ruby-throated Hummingbird? Other hummingbirds that could also turn up are Calliope and Lucifer Hummingbirds.
5. Hammond’s Flycatcher: This little flycatcher is pretty much at the top of my list. Like such warblers as Towsend’s and Hermit, it normally winters to northern Nicaragua. Unlike them, it would be very easy to overlook unless you knew what to look for and could just as easily pass the winter months in patches of non-native evergreens that receive very little coverage.
6. Blue-gray Gnatcatcher: Seems like this common bird could overshoot and fly further south than Honduras, the typical limit of its wintering range.
7. Cassin’s Vireo: Although this vireo normally only winters to Oaxaca, Mexico, it seems like it could head further south. In fact, the one possible Blue-headed Vireo that I saw in Costa Rica could have very well been a Cassin’s. I got pretty good looks at it and unfortunately, it was one of those individuals that could have been a Blue-headed or a Cassin’s due to little contrast between the gray on its head and white on its throat. In fact, the lack of contrast, drab colors, and experience with both species made me actually lean towards Cassin’s then and I still do but without very good photos, I can’t say for sure what it was!
Those are just some of the birds that could make it onto the list. There are others and it will be interesting to see what turns up next.