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.
The White Ibis is, well… entirely white in plumage. When spotted from a distance it can resemble a Great Egret, Cattle Egret or Snowy Egret, however the pink legs and face, along with the long, skinny downcurved bill is diagnostic. The tips of the wings are black, although that is only visible during flight. The juvenile has brown upperparts, and the neck is striped in brown and white, with gray legs and a darker bill. It is found in ponds and marshes in Guanacaste and the northern area of the country; also along the pacific coast of Costa Rica. Given its habitat, they usually wade in the shallow waters and mudflats, where pick small crustaceans and fish, just like Egrets do.
The Smooth-skinned Toad (or Leaf-Litter Toad as it is called sometimes) is a species of true toad that bears a dead-leaf pattern on its skin, concealing it from most predators when they lie motionless in tree bark or the ground. Furthermore, their lifestyle is nocturnal, so during the day they don’t move much, unless spooked. They rely on that camouflage to be safe, even around streams, where their dull colors can match the colors of some rocks. They are small, around the size of a female Green and Black Poison Dart Frog, but their overall coloration is a dull brown with orange and dark blue patches, making them incospicuous against the brown layer of leaf litter.
The Strawberry Poison Dart Frog, along the Green and Black Poison Dart Frog, are one of the common diurnal species that can be found in tropical rain forests in Costa Rica, particularly at the Caribbean side. It is common to go hiking and see these bright red and blue frogs suddenly jump from the trail. Due to the color of their legs, they are also called the “Blue Jeans”, although in Costa Rica some individuals are found that have red legs and arms, and in other countries like Panama there are many more morphs with entirely different color patterns. Regardless of the specific colors, they are very conspicuous and do not camouflage well on the leaf litter that tends to be brown to black. They are tiny when compared with many Tree Frogs.
As with the Green and Black Poison Dart Frog, caution must be taken not to touch these frogs when photographing them with macro lenses, as their skin is poisonous and any contact of their secretions with our eyes, nose or mouth can cause much discomfort. While handling them does not produce any symptons, if one is careless, then it is possible to touch one´s sensible organs with the hands and experience significant effects, up to partial blindness.
The Red-eyed Tree Frog is easily one of the best recognized frogs in Costa Rica. It is featured in most ads promoting eco-tourism activities to both nationals and foreigners. Its colors are very bright and varied, ranging from the white belly and throat, green dorsum and sides of the arms and legs, blue on the inside part of the arms and legs, orange hands and feet, and the reddish eyes with conspicuously vertical black pupils; such a cocktail of colors is sure to attract predators.
With so much separation between both eyes, these frogs can almost look in two opposite directions at the same time, an incredible adaptation that enables them to spot potential predators and prey. They also have what’s called a nictitating membrane, which is transparent skin below the lid that helps protect the eye and keep moisture when the eye lid is open. The iris is all covered in veins and the eye is large in comparison with the body, helping this species see very well in the dark forest
Rain can be easily simulated during a night photoshoot using a spray bottle, as the flash will illuminate the drops as they fall and freeze the action. If one would want longer looking drops, then the use of a continuous source of light can help. This makes for more natural looking images, as most tree frogs are nocturnal in nature and become more active during or after rainy evenings. It is common to hear them calling from ponds and branches, most normally males trying to attract females to mate.