Costa Rica mammals

During our birding trip to Costa Rica in Dec 2007, we were very interested in locating and photographing mammals, at least diurnal ones. The absolutely fabulous new field guide (Wainwright 2007) added to our interest. We managed to find a nice selection of more common species, but did not have the luck to encounter cats, anteaters, or tapirs. Those will have to await other trips.

We very much wanted to find a sloth during the trip, and these desires were fulfilled. We saw three different Hoffman's Two-toed Sloth, including this mother (above) and baby (right). Alex Martinez, the owner of Posada Andrea Christina in Puerto Viejo de Sarapiqui, told us that she lived on the grounds of this bed & breakfast. We kept checking every day until this one day Rita spotted her. We got these photos then, but by the next day she must have changed trees and we never found her again. The baby clings to its mother for 5 months, and may stay near for up to 2 years. This species is mostly nocturnal, but does visit different trees to acquire a variety of leaves for its diet. This is a species that ranges from Honduras to Bolivia. I had seen it once before in Ecuador.

There are 109 species of bats in Costa Rica — really an amazing number for such a small country — and we managed to identify 3 species that were at day roosts (two species photo'd). Some of these same species were seen at dusk at La Selva or Rio Tigre, but other dusk-flying bats got away unidentified. The photo below shows four Greater White-lined Bats at a day roost in a hollow of a giant forest tree at La Selva. Note that two of them are banded from an on-going research project. These are in the sac-winged bat family, Emballonuridae; elsewhere in the reserve we saw a roost of Lesser White-lined Bats. You can see the zigzag white lines down their backs.

A more amazing day roost was at Bosque del Rio Tigre on the Osa Peninsula. Abram had located the day roost of four Long-nosed Bats high in the canopy, on the underside of a branch (right), but this roost could be scoped from the lodge's portico. These four bats were there daily, and probably were the same ones seen flying around the clearing each dusk. Some entered the open-sided lodge and perched briefly on the ceiling, giving us a great look at this small bat (below).

There are fewer than 50 species of rodent in Costa Rica, and we did not see any of the small, nocturnal ones. We just did not get out at night on this trip. The selection of diurnal rodents was nice, though: an agouti (above) and three species of squirrel (below). The Central American Agouti (above) was photographed inside the forest at La Selva as it sat up and feasted on a nut of some type. A flash shot was necessary in the dark undergrowth, and the flash creates the orange-eyed effect.

I was very pleased to locate and photograph 3 of the 5 squirrels that occur in Costa Rica. The widespread lowland species is Variegated Squirrel (above). Body pelage varies widely throughout the county, from red to black to white, but the tail is always gray. This one lived in the trees in the courtyard of Posada Andrea Christina, Puerto Viejo de Sarapiqui. Another subspecies was seen at Rio Tigre.

The common montane species is Red-tailed Squirrel (right). It is not restricted to high elevations but we saw it only there at Savegre.

Most unexpected was Poas Squirrel (below), a species known only from three volcanic mountaintops in the world, one in Panama and two in Costa Rica: Tapanti NP and Poas Volcano. Our squirrel was visiting the feeder at Mirador Cinchona, which is at ~1200m (4000') on the slopes of Poas Volcano, and at the lowest known distributional limit for the species. It looks a lot like Red-tailed Squirrel but is placed in a different genus (Syntheosciurus) on skeletal characters. It can be identified in the field by its decidedly small, short ears compared to Red-tailed Squirrel.

We saw 3 of the 4 species of monkey found in Costa Rica, and I managed marginal shots of all. All were in the forest, were quite shy and/or upset with us as human observers, and thus presented a significant photographic challenge. During my first encounter with White-faced Capuchin (right & below) in the forest at Rio Tigre, and shooting dozens of photos, I was happy only with this one shot of a monkey in mid-leap (below). On our final morning there, a troop of capuchins passed through the canopy right over our hut. They seemed annoyed to find us there, and one even threw branches (!) in our direction. Might have been this one (right).

Our other two primates were in the forest at La Selva, and troops of both stayed well up in the canopy. Of course we heard Mantled Howler (below left) daily in the lowlands, but seeing them can be difficult. A few quickly disappearing shapes was the usual fare. The Central American Spider Monkey (below right) is very arboreal, and moves rapidly with swings of their long arms, helped by the prehensile tail.

Encounters with Collared Peccary were limited to La Selva, but there they have become quite accustomed to visitors. One often could smell their pungent odor before seeing them in the forest, or crossing the trail, but they seemed entirely unconcerned with us. This one (right) have found something to eat right within the main compound, just over the bridge from the entrance headquarters, and permitted long observation and video.

We had but one encounter with White-nosed Coati (left) but it was memorable. A band of about 30 suddenly appeared at roadside during our drive with Alex Martinez to the hummingbird feeders at Mirador Cinchona, and they caused an animal 'traffic jam' recalling the old days at Yellowstone National Park when I was a kid. Cars were suddenly parked every which way along the narrow winding road, with folks pouring out with cameras or food. We stayed in the car; this shot was from the window.

Literature cited:

Wainwright, M. 2007. The Mammals of Costa Rica: a Natural History and Field Guide. Cornell Univ. Press, Ithaca, NY.