Gray-crowned Yellowthroat (Geothlypis poliocephala)

The Gray-crowned Yellowthroat is a member of the Warbler family. Its body is generally yellow, with a small black mask and gray crown in the male, features which are much smaller in the female. They have a longer tail and thicker bill than the other Yellowthroat species that occur in the country. The Gray-crowned Yellowthroat is resident and occurs throughout most of the country, while the Masked Yellowthroat is confined to a very small territory in San Vito, and the Olive-crowned Yellowthroat is only found on the caribbean lowlands and mid elevations. The Common Yellowthroat, on the other hand, is a passage migrant, seen from mid October to early April, with some individuals spending the whole winter in the country.

Black-and-yellow Silky-flycatcher (Phainoptila melanoxantha)

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.

Eyelash Palm-Pitviper (Bothriechis schlegelii)

The Eyelash Palm-Pitviper is an arboreal venomous snake, found in Central and South America, with a diverse array of skin colors, the yellow color potentially being the most impressive and rendering them unmistakable, which gives them one of its most recognizable nicknames: “Oropel”, whose root is “oro” that means gold. It shares its genus with the Side-striped Palm-Pitviper.

It is called Eyelash due to the scales right on top of the eyes. They grow up to 82 centimeters in length, which is not very long between viper species. Its head is triangular in shape and its tail is prehensile, helping it grab branches to maintain its balance. They hunt by ambush, waiting in a spot for prey, particularly birds during the annual migration.

Brown-crested Flycatcher (Myiarchus tyrannulus)

The Brown-crested Flycatcher is a resident species, member of the Myiarchus family, which is notably difficult to identify at a species level. The Brown-crested is found only in the northern Pacific area, up to about the Tarcoles river. It shares distribution with the Nutting’s Flycatcher, and are difficult to differentiate given its essentially equal coloration except for the rump; their song is an important trait to identify them. The Brown-crested is found in mangrove forest edge, whereas the Nutting’s is not. It was interesting to see this individual raising its crest, most probably a display to let us know we were in his/her territory.

Red-webbed Tree Frog (Hypsiboas rufitelus)

This species has a mostly green body, with light blue patches in some dorsal parts. The eye is yellow with an horizontal black pupil. The disks at the end of the fingers are expanded, featuring a yellowish coloration. The best field mark for identification is the red webbing between its fingers, just like its name suggests. It is mainly nocturnal, hence not commonly seen during the day. It is curious how the skin color of this frog species changes from day to night time. During the day, the color is similar to a turquoise, while in the night the skin turns yellowish.

A friend of mine found an individual on the edge of the trail that leads to the Agami colony at Pacuare Reserve. It was late in the day, so it was still sleeping and let me have a half-hour photoshoot session with it without a single sign of being disturbed. One of the shots was taken only using natural light during a fairly strong wind that constantly moved the leaf up and down. I thought of artificially creating the night, although the frog was still sleeping. To create the black background on the second picture, I lighted the frog from very close using a bike lantern. The light did not need to be very powerful, since at macro distances the difference between the light intensity at the subject and the background can be exaggerated.

Velvet-fronted Euphonia (Euphonia concinna)

Euphonias are among the most difficult species to identify, particularly the females since most of them are equally alike with olive coloration and not a single field mark. When they travel in pairs it is easier, since once the male is identified, one can assume the species of the female relatively safely. In this species, the male is identified by having a yellow forehead that extends back to the nape, and showing a blue/black mask and throat. The upperparts are also blue-black depending on the light, while the chest and belly are bright yellow.

Slate-throated Whitestart (Myioborus miniatus)

The Slate-throated Whitestart is part of the Myioborus genus that includes also the Golden-fronted and Collared Whitestart or Redstart, as are called sometimes. It is a varied genus of warblers that are present in all of the American continent, in different species. In Costa Rica, the Slate-throated is also found along with the Collared species, although here they are called Redstarts instead. They forage very actively on the ground or low in the bushes, flashing their tail to frighten insects that are then caught in the air. Their upper parts and throat are dark grey, while their underparts are yellow in the south, and red on the northernmost part of their range. It also shows a dark red crown that’s difficult to see unless in good light.

Saffron-crowned Tanager (Tangara xanthocephala)

The Saffron-crowned Tanager is very confusing, since its plumage coloration can change a lot depending on the prevailing light. One thing that not changes and that really identifies this species is the yellow head with black mask. The body is either turquoise with green patches, or light green with turquoise patches. Whichever the color seen, it has a spotted appearance on the back and black wing feathers with turquoise/green linings. The belly and vent are white. In terms of body shape, it is very similar to the Gold Tanager, but with a very different coloration; this made them unmistakable even though they often shared the same feeder at Finca Alejandría.

Saffron Finch (Sicalis flaveola)

The Saffron Finch is pretty conspicuous, since it has a bright yellow coloration and forages on the ground in groups of three or more, making them easy to spot against the green grass. The adult has an orange patch on the front of the head. The juvenile is streaked on the back and wings, and have a lighter yellow coloration on the belly. They are often kept caged by people, and when free they frequent suburban areas and are very tolerant of human presence.