The Tennessee Warbler is a difficult bird to identify, given how many warblers have a yellowish plumage. The best tell-tale sign is the dark stripe through the eye and the bright supraciliary. A little more difficult to see is the white feathers on the underside of the tail. Unexpectedly, it arrived to the fruit feeder at my home in San Bernardino. At first I thought it was a female Red-legged Honeycreeper, because in lowlight the warbler looks greenish, but its behavior is different, and it would never vocalize, while the honeycreepers vocalize rather frequently, specially when having quarrels over pecking order.
Photographing the Sunbittern has been one of my goals ever since I started birding. This is a majestic bird, with a intriguing pattern on the wings which it flashes when flying from one rock to another. I have seen it plenty of times already, particularly in a small rocky stream 2 kms from home in San Bernardino, where it forages. Other times I have only seen the footprints on a rock, where presumably an individual stood just a few minutes before I arrived. It is very wary of people, flying away to keep at a distance when spotting them or hearing noise.
The Slaty Spinetail is a commonly heard bird near abandoned lots, where grass and bushes had time to grow. They are more difficult to spot than to hear, in part because they choose to stay low inside the vegetation. The adults are dark gray overall, with orange-brown wing feathers and a head cap of the same color. Their tail is relatively long when compared with other birds that share their habitat, and as the name implies, looks rather untidy, like an old broom that has been used to its life span. The juvenile has similar colors with less saturation and lacks the defined head cap.
The Olive-throated Parakeet is a resident species of the northern and Caribbean regions of Costa Rica. Like most other parrot species in Costa Rica, its plumage is green overall, with blue flight feathers that are barely noticeable when the wings are folded. The upper side of the tail feathers look brownish, and the throat has a somewhat dark olive color as the name suggests. A member of the Aratinga family, it only shares its habitat with Crimson-fronted Parakeet, which is larger and has conspicuous red patches on the should section of the wings, visible both in flight and with folded wings. They are usually seen in groups, cracking fruits with their beaks, producing a characteristic sound.
The Stripe-headed Sparrow is a small bird resident of the northwestern region of the country, but also found in the western portion of the Central Valley. They have a gray to white belly, with orangish to brown feathers on the back and wings. As the name suggests, the head pattern consists of a series of stripes, with a white throat, followed by a broad black stripe covering the black eyes, then one white stripe and another black stripe, each narrower than the previous one. The look is finished with a central white stripe. They are most likely found foraging in groups of at least three around an area. They perch at a lower level in many places, including fences, but also get down to the ground sometimes.
The Rufous-naped Wren is a commonly seen bird close to people’s homes at urban towns in the Central Valley, in Costa Rica; the House Wren is smaller and more common in the countryside, and the Rufous-naped is more colorful, with its black and white pattern on the back and the whitish underside. Compared to that, the House Wren is featureless. Rufous-naped Wrens are very noisy, usually found in pairs or small groups that climb to roofs. I have seen them build their nests under the roof or even in metal doors.
The Buff-rumped Warbler is a small, loud bird of the Caribbean and Pacific lowlands, usually found in close proximity to water streams and rivers, much like the Torrent Tyrannulet does in higher elevations. The places it inhabits are dark, hence it is difficult to see; look for two essential clues: 1) An accelerating high pitched song that seems to come from a water source and 2) a small white patch that swings from one side to the other close to the ground, which is caused by the bird’s habit to swing its tail in such a fashion. It can also be spotted as it flies away rapidly when people approach them.
The Grayish Saltator belongs to the same family as the Black-headed Saltator, which at my parent’s home in Río Frío is much more common. As it name implies, its upperparts are gray, but the underparts are brownish, particularly close to the vent. The throat has a central white stripe, bordered by two black strips. It also shows a white supercilliary which ends right after the eye. The beak is strong as other Saltators. They sometimes come to fruit feeders, but are more wary that most other birds.
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.
The Western Wood-Pewee is part of the Contopus family, a very difficult family to identify to species level in the field. It is very similar to the Tropical Pewee and the Eastern Wood-Pewee. The best field mark is the bill, were only the base of the lower mandible is orange. This species, unlike the Tropical Pewee, is a passage migrant and will only stay in the country from mid-August to November, and from mid-March to May. In similar fashion to the Eastern Wood-Pewee (and further differentiating from the Tropical), this bird will return to the same perch after a sally, so observing the behavior can help with identification.