We found the White-lipped Rain Frog as we hiked during the night in search of the Annulated Tree Boa at Yatama Ecolodge. It has a brownish coloration, which would help it camouflage really well against the ground and the leaf litter. Both front and back legs are lightly striped, just barely noticeable when looking from very close. It actually was a pretty common sight in the area, although most frequently heard than seen.
This little pretty bird is sought after by many birders in Costa Rica, myself included. Like the White-collared Manakin, it is found in the Caribbean lowlands and foothills, but given that its preferred habitat is dense rain forest undergrowth, it is difficult to find and even more difficult to photograph. But then one can be lucky, and for me that means finding one male whose home habitat was very close to a fruiting tree, located right by the window of my room at Yatama Ecolodge; it actually came every single day to feed on the little purple fruits, sometimes having fights with a female Violet-headed Hummingbird which came to drink nectar from the tree’s white flowers. What’s even better, a female also visited a few times. We also heard other individuals as we hiked through the trails, although spotting them there is a lot more work.
The Russet-naped Wood-Rail was recently split from the Gray-cowled, with which it obviously has a lot of similarities. As its name indicates, the differentiating feature versus the Gray-cowled is the brownish patch on the back of the neck. The rest of the body is essentially the same, starting with the yellow bill, gray neck, rufous chest and back, deep red eyes and pink legs. These are noisy birds that are usually found in pairs, presumably male and female. A pair of these birds frequently arrived to forage close to our room at Yatama Ecolodge; most of the time they would make a weird low frequency sound, similar to the noise your throat makes when drinking water very fast.
We found this frog during a night time hike in search of the Ghost Glass Frog at Yatama Ecolodge. It acted very docile, barely moving its head down from its upward position. The easiest way to recognize it among the Glass Frog family is by the dark spots on an otherwise uniform green skin. Males feature a blue-green hook, seemingly at the shoulder joint as in the left-hand side picture below; one can only ask what purpose this structure it might serve. The eyes are relatively forward facing, like in most other species in the family.
The Mexican Tree Frog is among Costa Rica’s biggest frogs. It is somewhat similar in appearance to the Masked Tree Frog, however the Mexican is bigger; its overall color is brown instead of green, and does not show such a definite dark brown patch behind the eye. The eyes are very similar between both species. It does occur in the Guanacaste province, from which the Masked is absent, however it is not found on the Pacific south from the Tarcoles river. They are nocturnal and arboreal like most tree frogs.
Glass Frogs are fascinating, given their transparent ventral skin, which lets us peak into the internal structure of a frog. The organs that are visible varies according to the species, with some species showing the intestines and lower organs, while others show the heart and upper structure. In some of them, the bones are also visible inside the legs. Most of these frogs are overall green in coloration, which provides camouflage in the forest environment they live in.
This species is called Dusty given how the dorsal skin is covered in very small white spots. They are intermediate between the sizes of Strawberry and Green and Black Poison Dart Frogs, and definitely bigger than the Dwarf Glass Frog, which belongs to the same family of frogs. Their skin is mostly green, with yellowish tints in the ventral surfaces of the limbs and in the tips of fingers and toes. Given these colors, it is not surprising that one could be staring directly into one of these on a leaf and still not find it. The eyes are very large, located at each side of the head, enabling the frog to spot predators from both sides; the pupil is horizontally eliptical, while the iris is covered with an intricate pattern of blue and gray.
There are three Long-snouted Tree Frog species in Costa Rica, with the Boulenger’s and Olive being both widespread and common accross wet lowlands in the country, and the Dry Forest species being common in the northwestern region (Guanacaste). The Boulenger’s is mostly light brown, including the iris, with small patches of green and darker brown that provides better camouflage. It is colloquially known as “Rana Lagarto” (crocodile frog) in Costa Rica due to its unusually long snout.
It is arboreal and nocturnal, and males frequently call with their body upside-down during the wet season. To help hold this position, the innermost finger can be rotated up to 90 degrees, essentially pointing upwards, which provides a better grip on smooth surfaces like tree branches and trunks. The skin is granular, which might put off some people that feel that its appearance is gross. Yet amphibians have a very important role in wet ecosystems, as some of the insect prey they consume might develop into plagues if unchecked. Most amphibian species have been battling with declining populations, and protecting them from extinction is one of our biggest challenges.
The Common Ground-Dove is very similar to related species Ruddy and Plain-breasted Ground-Doves, however the Common is lighter in coloration, with a pink bill that is diagnostic; it also shows a scaled pattern in the throat and neck, which is missing from the other ground doves. Also similar to these species is the Inca Dove, which even behaves similarly as it forages most of the time on the ground, however the scaled appearance in the whole body should preclude any confusion. The male is ligher than the female, which looks grayish. All ground doves feature dark spots in the tips of primaries and secondaries, which look like a curved line when the wings are closed, although the Common’s should area spots are more numerous and do not form a line.
Purple Gallinules are some of the most brightly colored birds that you can see walking in Costa Rica. Indeed while they can also fly, they more commonly wade in shallow waters and in dense grass plains, looking for prey. I have seen them in Palo Verde in big numbers, and spotted individuals in Rio Frio, where they join chickens and forage in the backyards of houses; indeed I was able to see two adults rearing four young hatchlings, which were still covered in black fluffy hairs, getting along with the chickens just fine. The underside and head is entirely purple with a metallic look, showing a small light blue patch on the forehead. The beak is mostly bright red, with a yellow tip. The upperparts show blue to olive green hues, particularly on the wings. The yellow legs are long, letting them to wade in shallow edges of lagoons without having to swim.
The Black-and-yellow Silky-flycatcher is one of the four species in a unique family around the world, with the Long-tailed Silky-flycatcher being the only other species to be seen in Costa Rica. The male shows a combination of yellow rump, chest and undersides, with gray belly and vent; its throat and head it black, as well as it tail and wings. The Female has a gray throat with a black cap, olive chest, wings and tail. Their shape is similar to other Costa Rica thrushes, as they look rather plump when compared with the Long-tailed. Although Flycatchers by name, they prefer to eat fruits, specializing in berries that are abundant in the highlands; indeed their range is restricted to Guanacaste, Tilaran, Central and Talamanca Cordilleras. They are endemic to Costa Rica and western Panama, thanks to the fact that the Talamanca Cordillera stretches out into Panama.