In Costa Rica, sometimes highland species take these “vacations” to lower elevations. This regular and well documented behavior of the local avifauna is most commonly exhibited by the frugivores. Sometimes White-crowned Manakins are all over the place at Quebrada Gonzalez, a quetzal or two makes it into the foothills, and Three-wattled Bellbirds give their bonking calls from the tall canopy of the humid Pacific lowlands before heading back upslope into the mossy cloud forests for breeding.
To be more specific, these “vacations” are gastronomic trips not taken by choice but are downslope jaunts done out of necessity. To put it plainly, the arboreal larders of the highlands are empty so they need to find food elsewhere and fast or they starve. Since December, something strange has been going on in the mountain forests of Costa Rica. Although from a distance, the hills look fine and inviting as ever with their jade green, forested texture, all is not well upslope. The local birding community suspects that things aren’t peachy in the cloud forest because there have been an unprecedented number of highland species that have shown up at lowland sites.
Black-faced Solitaries do appear once in a while in the foothills and even at La Selva but never in the numbers that we have experienced as of late. They have even reached Tortuguero along with other species more commonly encountered in cloud forest. Even crazier has been the sightings of a quetzal or two in the Caribbean Lowlands! I have seen female quetzals a few times at Quebrada Gonzalez after they breed but to see them at La Selva is pretty much unheard of. The most insane sighting so far, however, is that of Highland Tinamou at Quebrada Gonzalez!
While guiding there on the 2nd, a tinamou suddenly appeared at the entrance of the trail while we were attempting to stay out of the rain and hoping for some sort of bird action. My assumption that it was a Great Tinamou (because that is the expected species at this foothill site) nearly kept me from raising my bins to my eyes but I am sure glad I did because although the glimpse through the vegetation wasn’t ideal, I noticed speckling on the upperparts as opposed to barring, a gray crown, and a tawny throat. I also thought the bird looked pretty rufous below but despite such obvious signs, it still didn’t click that this was a Highland Tinamou until after it had left the trail. I kick myself for that but I was so slow in realizing that the bird in question was a Highland Tinamou because I never, ever would have expected it there.
The Highland Tinamou is a bird of the cloud forest and has been recorded down to 1,200 meters at the very lowest. Quebrada Gonzalez is at an elevation of around 500 meters! In addition, this bird isn’t exactly known for it’s arial prowess. Heck, they barely even use their wings so for this bird to have made the efforts to walk and glide its way downslope, it must have been pretty darn hungry. What is especially alarming is that Highland Tinamous aren’t strict frugivores. They do consume fruit but also eat lots of litter animals which could indicate that small creatures of the understory may not be doing so well either.
So the million dollar question is “What is causing such a dearth of fruit in the mountains”?
The answer is undoubtedly more complex but the general suspicion is that heavier rains than normal occurring when they usually don’t have delayed flowering and fruiting in the mountains (and even in the lowlands in some areas). Birds appear to be suffering from it so hopefully things will get back to normal or you may see some strange birds in the lowlands this year but quieter cloud forests the next.