The Yellow-throated euphonia ranges from southern Mexico to western Panama, through the lowlands of both coasts and into the highlands to an altitude of possibly 4000 feet above sea level. Like other euphonias, it is a restless bird of the treetops. Except when a nest binds, it rarely appears to remain long in one spot. However, wanders widely in search of food through plantations and pastures with scattered trees and doubtless also over the roof of the forest, where it is difficult to see.

The male is a brilliant little bird, black glossed with violet and blue over all the upper plumage except the forehead and forepart of the crown, which bright yellow like the entire underparts are. The black area includes the sides of the head, the wings, and most of the tail, which is marked with white on the outer rectrices.

From the other black and yellow euphonias that inhabit northern Central America, he is readily distinguished by his yellow rather than black throat and by his notably thicker, black bill. The female is olive-green above, with dull yellow under plumage. These euphonias subsist largely on berries of mistletoe, as do other members of the genus.

The Yellow-throated euphonia ranges from southern Mexico to western Panama, through the lowlands of both coasts and into the highlands to an altitude of possibly 4000 feet above sea level.

VOICE

The only song you will hear from this little tanager is a short whistle, usually repeated two or three times in rapid sequence, sometimes clear and bell-like, more rarely with a plaintive intonation, reminding me of the opening notes of the White-throated Sparrow’s song, but fuller in tone. The female’s song, or perhaps it should be considered a call, at its best, resembles that of the male, but more often it is thin and chaffy in quality and again is high-pitched and almost trilled.

NEST BUILDING

Male Yellow-throated euphonia with a dry grass blade in his bill led to building a nest of the species. The nest was situated in a cranny in the top of a rotting fence post five feet high. It was beside a small corral amid extensive pastures with scattered trees. It was so well shielded behind a small aroid that grew should never have discovered it, had the movements of the building birds not betrayed its position to me.

It was a roofed structure with a little round entrance on the outer side. It was composed of fine tendrils and other bits of vegetation, all bound together with cobweb. The outer shell appeared to have been completed, for the birds were lining the interior with small, dry grass blades.

The male and female worked in the closest harmony. Usually, they arrived together, each with a length of the grass blade in its bill. And one would vanish behind the arrow-shaped leaves of the aroid while the mate perched close by, waiting its turn to place the material in the nest. Either male or female might enter first; there was no set order of precedence.

As soon as the second member of the pair had come out of the nest, the two were off like a flash for more material. Sometimes the male would follow his mate back to the nest without bringing anything. Then while she took her grass blades inside, he lingered close beside the fence post, uttering a fine metallic pink that sounded much like the notes of the Cardinal as he goes to roost on a chill wintry evening, but even fainter.

The male and female worked in the closest harmony. Usually, they arrived together, each with a length of the grass blade in its bill.

Although this nest was nearly finished when found, the first egg was not laid. Another was deposited on the following day. When I returned to the nest on April 8, there was a male Boat-tailed Grackle resting atop the post where it was hidden. The nest was in ruins and the eggs had vanished.

Although not an actual witness of the grackle’s predation, the circumstantial evidence against him was very strong, especially when it is remembered that grackles, in general, are notorious nest robbers. This nest had been so well concealed that the grackle must have found it; by seeing one of the pair of euphonias enter.

The female euphonia was perching nearby, calling incessantly with a triple, or sometimes double reedy whistles; but her mate did not appear while I waited. Possibly I should have found additional eggs in this nest if the grackle had not destroyed it. A pair of Bonaparte Euphonias building a nest in the axil of the lowest frond of a young coconut palm, 7% feet above the ground.

Again both sexes were bringing material. This nest was never completed. The Bonaparte Euphonias choose a considerable variety of nest sites. In the central plateau of Costa Rica, they have been found nesting in the banks beside streams and roadways, in holes that they most probably found readymade.

A more fortunate nest was situated in the decayed top of a post only forty inches high, in a fence line between a bushy pasture and light second-growth woodland, on the same plantation where the first was found. This nest measured 2% inches from front to back; the doorway was 1% inches in diameter. It had no concealment beyond that afforded by the sides of the cranny in the top of the post.

THE EGGS

When discovered, the nest on the fence post contained three eggs. The female euphonia flew out and was probably then preparing to lay the fourth egg. On the following morning, the set of five eggs was complete. For a tropical bird, this is an unusually large clutch of eggs, and especially so in the tanager family, in which sets of two eggs are the rule and those of more than three are very rare.

The eggs of the Yellow-throated euphoniare short ovate. They are white, heavily blotched with umber in a crown on the thicker end, with a scattering of spots of the same color over the remaining surface. Some have a brownish wash over the entire blunt end, on which the more solid blotches and speckles are laid. Six eggs measured 16.7 by 13.5, 16.7 by 12.3, 16.7 by 12.7, 15.9 by 12.7, and 15.9 by 12.7 and 15.9 by 12.7 millimeters (average of the six, 16.3 by 12.8 millimeters).

The male is a brilliant little bird, black glossed with violet and blue over all the upper plumage except the forehead and forepart of the crown, which bright yellow like the entire underparts are.

INCUBATION

To learn something about the Euphonia's mode of incubation, the day dawned with a dense mist; there was still insufficient light to distinguish the little tanager in the closed nest. A bird flew out, too rapidly to be recognized with certainty, but beyond any reasonable doubt, it was the female. She heard her mate calling in the distance, answered him while sitting, and then flew out and away to join him. The pair returned together and both flew toward the nest, the female a little ahead, but the male following closely.

Each seemed to be trying to reach the doorway before the other. The female won the race and entered; the male turned just short of the doorway and flew off. There was a light flurry of rain. The male, unseen in the distance, called with clear double whistles; the female answered from the nest with similar whistles, but less clear, then left her eggs.

The pair came back together, and with a loud whirr of tiny wings raced each other to the nest. Again the female won by her own length and entered, while the male veered aside just in time to avoid striking the fence post, then continued to some neighboring bushes, where he repeated his double whistles.

Twice more in the morning, the pair of euphonias engage in this race to reach the nest. Each time the female won by the smallest margin. It seemed that this apparent competition was only a formality. The male had no real desire to get there first and sit on the eggs but merely escorted his mate back to her duty in this dashing fashion.

From the other black and yellow euphonias that inhabit northern Central America.

A similar ceremony may be witnessed at nests of the Yellow-crowned Euphonia, the Tawny-bellied Euphonia, the Turquoise-naped Chlorophonia, the Black-crowned Tody-Flycatcher, and the Slate-headed Tody-Flycatcher. All these tiny birds build closed nests with a round doorway in the side. In all both sexes share the work of construction, but only the female incubates, as in the Bonaparte Euphonia.

The female euphonia, upon winning the formal race with her mate, did not appear to alight in the doorway of the nest and then step inside, but on the contrary, passed through the narrow aperture with no apparent break in her movement. She turned around so rapidly that she hardly seemed to have touched the nest before she was seated on her eggs with her head outward.

She always incubated in this position, looking out. For so diminutive a bird, she sat very patiently. Her sessions on the eggs showed a progressive increase in length in the course of the morning, first 32, then 54, 69, and 83 minutes. Her corresponding recesses were 16, 8, 44, and 40 minutes. Her average session was 59.5 minutes, her average recess 27 minutes; and in six hours of the morning, she kept the eggs covered 68.8 percent of the time.

Although the male euphonia appeared to be very attentive, he was nearly always out of sight and hearing while his mate sat in the nest. Whenever I was obliged to force her to leave the eggs so that I might see whether they had hatched, she would perch close by and call incessantly until I departed. While I measured the eggs, an operation that required about twenty minutes because of the difficulty of removing them through the narrow doorway, she continued her calls of distress without interruption during the whole time.

Yet the male never appeared on these occasions; he seemed to forage at a good distance, only approaching the nest when he escorted his mate on her return from a recess, or in the early morning, to call her out to join him. Later in the morning she ended her sessions spontaneously, called to him from near the nest without receiving a reply, then flew off alone to seek him.

That she was successful in establishing contact with him, despite the distance at which he habitually foraged, was clear from the fact that on the two occasions when she left the nest alone, she later returned in his company. It will be recalled that when the Boat-tailed Grackle destroyed the first nest, the female euphonia likewise called for a long while in its vicinity without succeeding in attracting her mate. The set of five eggs had been completed. All five were pipped and had hatched by the following day, thus having an incubation period of sixteen days.

THE NESTLINGS

The young euphonias developed slowly, however when eight days old their black skin was still nearly naked. Their short, thick bills were black with yellow edges, and, when opened, revealed a bright red interior - an attractive combination of colors. Only three nestlings survived.

Time did not permit a study of parental care; but from the fact that the male helped to build the nest, and in view of subsequent observations on related species, there can be little doubt that he took a large share in feeding the nestlings, as appears to be the invariable custom in the tanager family. At the age of fifteen days, the young birds were well feathered and could fly a little.

One afternoon the adjoining pasture was burnt off, and the smoke enveloping the nest became so dense that removed the nestlings for a while to prevent their suffocation. On May 19 the three young euphonias left the nest, at the age of seventeen days. Possibly their departure had been hastened by their premature experience in the open on the day of the fire, for young Yellow-crowned Euphonias stay in the nest until from 22 to 24 days old.

The young male Bonaparte euphonias do not attain the adult plumage in the first year, but begin to breed in transitional plumage, as do the Yellow-crowned Euphonias;  the same is true of the Thick-billed euphonias.

SUMMARY

Yellow-throated euphonia wanders widely through clearings and plantations with scattered trees, where they feed largely on the berries of mistletoes. In the Motagua Valley of Guatemala, they nested from March until at least the end of May. Nests were found in the decayed tops of fence posts and in the axil of a coconut palm. In other regions, they have been discovered in holes in banks.

The globular nest with a sideward-facing doorway is built by both sexes, either of which may deposit its material first when they come together. One of the nests in Guatemala contained five eggs, and a set of the same size has been reported from Costa Rica. The female alone incubates. In six mornings hour’s one female took sessions averaging 59.5 minutes and recesses averaging 27 minutes; she covered her eggs 69 percent of the time.

He returns to the nest were the occasion of a spectacular ceremony, in which the male seemed to race her to the doorway; but she always arrived first. Her eggs hatched after 16 days of incubation. This brood left when 17 days old, but possibly their departure was hastened by their temporary removal when fire threatened their nest several days earlier. Read More - The white-throated magpie-jay

Yellow-throated euphonia wander widely through clearings and plantations with scattered trees, where they feed largely on the berries of mistletoes.

References – Alexander F Skutch by Life Histories of Central American Birds.

Lesser Striped Swallow (Cecropis abyssinica)

Lesser Striped Swallow (Cecropis abyssinica) is a common species, which is distributed along the coast and adjacent interior of the Eastern Cape Province and Transkei, throughout much of KwaZulu-Natal, the Transvaal woodland areas, and most of Swaziland and Zimbabwe. In Botswana, it occurs in the east and commonly in the Okavango, and in Namibia it is found along the Kunene and Kavango rivers, the Caprivi Strip, and scattered records further south. This is one of the most abundant African swallows. It ranges over the greater part of Africa south of the Sahara, except for the open regions in the south and southwest. It is frequently confused with the similar Greater Striped Swallow “H. cucullate” in southern Africa.

Habitat:

It occurs in a variety of woodland and savanna habitats, but for semi-arid Kalahari savannas. Within these regions, it can also be found in cultivated and sub-urban areas. Also, it is very common in lower-lying than higher-lying areas within its range. It is recognized to nest frequently on riverbanks and trees. The bird flight is normally very strong gliding but can be very fast, like that of a Barn Swallow.

Movements:

This species shows complex patterns of movement in the region. It is largely a summer-breeding migrant in South Africa, but some birds are present throughout the year. Especially in the lower-lying eastern areas along the KwaZulu-Natal coast and in the Lowveld of the Transvaal and Swaziland. A winter exodus is also apparent in Zimbabwe. But the presence of birds in this country during the winter is more frequent than in most of South Africa, and birds from the south may pass through or winter in Zimbabwe.

It has been suggested that the Zimbabwean breeding population leaves that country and is replaced by South African migrants during the winter. Hence, mainly from March to October, but the passage of the southern race unitatis through this area is likely from August to September and March to April.

The models for Zones 5 to 8 suggest reduced overwintering, and later arrival and departure times with increasing latitude for unitatis. The departure of birds from their breeding grounds are spread over several weeks and is probably influenced by the stage of breeding of individuals.

Also, the populations start to weaken as early as February and March in most regions. Some nests in the northern Kruger National Park was occupied throughout the year but different individuals used the nests during the summer and winter months, indicating that ‘residency’ does not necessarily involve the same individuals.

Breeding:

A summer-breeding the pattern is shown by the race unitatis in the Eastern Cape Province (Zone 8), KwaZulu-Natal (Zone 7), and Transvaal (Zone 6), with the most breeding recorded August-May and peaking November–December. Breeding starts earlier in the Transvaal than in the Eastern Cape Province. In Zimbabwe breeding occurs throughout the year, but this contains records of unitatis on the plateau and ampliformis in the west, and most records refer to unitatis whose breeding peaks August–December. In Namibia and north-ern Botswana (Zone 1), breeding was recorded March–October for ampliformis indicated peak egg-laying for this race in May.

Interspecific relationships:

This little bird often occurs alongside the Greater Striped Swallow but typically one species tends to be much more common than the other in areas of overlap. Because both species use man-made structures for breeding, they may compete for nest sites and the smaller Lesser Striped Swallow may be at a disadvantage in such situations.

There could also be competing with the much larger Red-breasted Swallow H. semirufa for nest sites, but that species usually nests in more constricted sites than the two striped swallows. Lesser Striped Swallow nests are regularly usurped by White-rumped Swifts Apuscaffer.

Historical distribution and conservation:

Like many Hirundinidae, this species has benefited from nesting in manmade structures and has probably increased, at least in density, in many areas owing to this habit.

Nesting

Lesser Striped Swallow has a soft lining nest, built in a cave or under a rock overhang or a tree branch. However, given the selections, it can opt to make a nest at high places. This little bird willingness to use buildings, bridges, culverts, and similar structures.

Description

Lesser Striped Swallow is 10 to 14cm long, with dark blue upperparts with a vibrant red rump and a rufous-chestnut crown nape and sides of the bird's head. The white and dark streaking showing at underparts white, tawny underwing flight feathers and upper wings are blackish brown. The long beautiful blackish tail normally longer in males than females. However, the young one is a bit browner and dull with less contrast.  

Diet and Foraging

Lesser Striped Swallow diet normally consists of bees, flying ants, beetles, flies, lepidopterans, fruits, and seeds. It feeds alone, or in pairs, also, mixes with other swifts. The bird habitually forages six-meter above ground and 8 to 22 meters over treetops and often over the water. Hence, the birds also hover over vegetation to catch caterpillars and feed around different animals to take insects, perches when eating fruit. Source - CP    

Reference - R.A. Earlé and M. Herremans

The white-throated magpie-jay

 

One of the largest and most conspicuous songbirds in Guanacaste is the White-throated Magpie-Jay (Calocitta formosa). This social and vocal bird is normally seen in family groups of five to ten birds and is quite attractive. The blue body, white breast, exceptionally long blue tail, and tall, forward-curving topknot feathers on its head make it unmistakable. The large Central American species of magpie-jay range in the Pacific-slope thorn forest from Jalisco, Costa Rica, and Mexico to Guanacaste. It is common in thorn forests, deciduous woodland, gallery forest, forest edges, and cultivated areas like coffee plants.

Also, a closely related species, the Black-throated Magpie-Jay, is found in Mexico. The White-throated Magpie-Jay is found in savannas, dry forests, gallery forests, farmsteads, ranches, backyards, and woodlots. Roaming in family groups, these intelligent and omnivorous jays search for small lizards, caterpillars, frogs, beetles, grasshoppers, katydids, and cockroaches. Other foods include fruits, corn, eggs, and nestlings of other birds, fruits, grains, seeds, the young of other birds, and the nectar of balsa (Ochroma) flowers. At La Ensenada Lodge, they boldly enter the open-air restaurant to pick up fallen food scraps. The nesting season occurs from February through July.

While incubating, the female is visited by several family members and the male, who all take turns feeding her. The young are fed by the parents and by the young from previous broods. This magpie is omnivorous, consuming an extensive range of animal and plant matter. The juvenile birds take several years to acquire the full range of foraging skills of their parents. White-throated Magpie-Jay does not take on any migratory movements, though males disperse away from their natal territories a few years after fledging, and it is not considered threatened by human activities.

The White-throated Magpie-Jay can be found in Guanacaste's NPS-Guanacaste, Palo Verde, Santa Rosa, and Las Baulas-and in the Lomas Barbuda! BR. It can also be seen at Sugar Beach, Tamarindo, Hacienda Solimar, La Ensenada Lodge, Playa Dofia Ana, La Pacifica, east to Hotel Borinquen Mountain Resort, and southeast to Tarcol Lodge at the mouth of the Rio Tarcoles. The white-throated magpie is a very noisy, gregarious bird, mostly likes to travel with flocks, mobbing its observers. Source CP

Facts:

Calocitta Formosa

Costa Rican names: Urraca copetona; urraca; piapia azul.

Status: Permanent resident.

length: 18 to 22 inches. (43 to 56cm)

Weight: 7.2 ounces (205 to 210 grams).

Range: Central Mexico to Costa Rica.

Elevational range: Sea level to 4,000 feet

 

The Cloud Cisticola or tink-tink cisticola

 

The Cloud Cisticola or tink-tink cisticola is near-endemic to southern Africa and occurs in South Africa, Angola, Mozambique, Lesotho, and sparsely in Swaziland. However, a widely separated relict population occurs in Zambia and southern Zaire. It occurs in the western and southern Cape Province and from 22°E through the Eastern Cape Province and Transkei (where it is sparse), to the Free State, Transvaal, Lesotho lowlands, and inland KwaZulu-Natal.

Cloud Cisticola is most abundant in the southern Transvaal and the southern and eastern Free State. There is a remarkable cut-off west of25° E. It is included in southeastern Botswana in its range, but it was not recorded there during the atlas period, nor does there seem to be any other confirmed record from that country. Easily confused with four other small grass cisticola species, it is identified mainly on the basis of its call, except for the isolated nominate race in the Western Cape Province, which can be identified by its ventral streaking.

This race is sometimes considered to be a separate species. The atlas records primarily reflect the summer distribution and the map is probably fairly accurate, although some misidentifications are inevitable in this group.

Habitat:

It occurs in short grasslands with relatively low basal cover, mainly in the grassland biome and in the Grassy Karoo; it is absent above 2000 m. It requires open grassland and does not tolerate invasion by scrub and trees. In the Western Cape Province it has colonized and breeds in fields of winter cereal crops. It was reported from estuarine marshland near Port Elizabeth. It is common in Themeda triandra grassland on the Highveld where it over-laps mainly with Ayres’ Cisticola C. ayresii.

Movements:

There is strong seasonality in reporting rates with a drop in winter when the species behaves unobtrusively and is difficult to identify without the help of diagnostic calls and displays. Records from the Western Cape Province show no seasonality, presumably because this population can be identified year-round on plumage. Droughts, overgrazing, and burning affect its habitat and must prompt local movements. There is apparently no record of regular seasonal movements in the literature.

Breeding:

Atlas records confirm that breeding occurs earlier (July–December) in the nominate race in the Western Cape Province than elsewhere, where egg-laying spans late spring and summer (September–March)

Inter specific relationships:

It is most closely related to Ayres’ and Pale crowned C. brunnescens Cisticolas. It overlaps extensively with all four similar small cisticolas. It is a host of the brood-parasitic Cuckoo Finch Anomalospiza imberbis.

Historical distribution and conservation:

It has almost disappeared from the Cape Flats where it was displaced by alien vegetation and development for agriculture and housing. It is suggested that it is more widely distributed in KwaZulu-Natal than recorded in this atlas, but there was some confusion between this species and Ayres’ Cisticola in Cyrus & Robson. It expanded its Transvaal range westwards during the years of good rain in the 1970s.The Cloud Cisticola is not threatened. The ability of the western race to adapt to agriculture means that it was not displaced on a large scale by the loss of indigenous fynbos. Source - CP