Our Island Birds
By Bella Brown
Lesser Antillean Bullfinches are seed-eating members of the Tanager family (Thraupidae) and closely related to the Galapagos Finches, best known for their role
in inspiring Darwin’s theory of natural selection. Like their famous cousins, Lesser Antillean Bullfinches comprise a group of four remarkably similar looking species that show slight variations in bill size: the Lesser Antillean Bullfinch (Loxigilla noctis), the Barbados Bullfinch (Loxigilla barbadensis), the Greater Antillean Bullfinch (Melopyrrha violacea) and the Puerto Rico Bullfinch (Melopyrrha portoricensis) have independently evolved beaks of the same shape, but of slightly different sizes, in order to exploit different types of seeds.
Although Lesser Antillean Bullfinches have plierlike beaks, designed to crush the hardest seeds, they are foraging generalists, feeding on a wide variety of foods including ripe fruit, nectar and insects. They are known to steal the nectar of flowers by biting a small hole at the base of the calyx — by stealing I mean that they avoid the
“flower membership fee” of distributing the pollen. Where necessary, Lesser Antillean Bullfinches use a foot to secure fruit while feeding from it, or to hold flimsy grass stems at ground level to feast on the seeds. Occasionally they eat insects, crushing them with powerful mandibles.
Lesser Antillean Bullfinches are endemic to the Lesser Antilles, occurring throughout the islands, except in the Grenadines. The species also colonized St. John and St. Croix in the US Virgin Islands during the 1960s and is expected to continue expanding its range to nearby islands.
Lesser Antillean Bullfinches are sexually dimorphic, meaning that males and females look different from one other, as opposed to the recently diverged Barbados Bullfinch, whose males resemble the females. The Lesser Antillean adult males have glossy black or charcoal grey plumage, accented by red lores and throat. The undertail coverts (small feathers behind the bird’s legs and under the tail) can vary between all red and all black. Depending on the light, the red markings may appear orange, red or chestnut brown. On the other hand, females have warm gray undersides and rusty-brown mantle, wings and tail, with rusty orange highlights. Immature birds resemble the females at first, but experience a groovy calico phase as they transition into adulthood. Because of their plumage differences, males and females have been given separate names on some islands — for example, in Dominica the male is called “Pere Noir,” while the female is “Moison.” In St. Lucia, the Lesser Antillean Bullfinch may be confused with the St. Lucia Black Finch, however, the latter has pink legs and a heavier beak, and lacks the Bullfinch’s red throat and vent. It also has a habit of bobbing its tail up and down
There are eight recognized subspecies of Lesser Antillean Bullfinches inhabiting a wide range of habitats across all elevations, from sea level to mountaintop, from
shrubbery, gardens and dry scrub to mangroves and rainforest. The subspecies are geographically separated and distinguishable by slight differences in size and
plumage. Some are more grey than black, some have smaller beaks; some have red undertail coverts while others have black. Although Barbados Bullfinches were considered the only non-sexually dimorphic subspecies, they are now treated as a separate biological species, Loxigilla barbadensis, which is thought to have colonized Barbados from St. Lucia 180,000 to 700,000 years ago, becoming one of the most rapid examples of avian speciation. (Speciation happens when a group within a
species separates from other members of its species and develops its own unique characteristics.
Although Lesser Antillean Bullfinches are aerial creatures that forage mainly in the trees or bushes, individuals are occasionally observed feeding on grass stems at
ground level. They are very vocal and can be easily identified by song, producing a variety of sounds, from short trills to sassy, high-pitched “wheet-wheet-wheets” to a
mellow “tsee” and a sharp “chuk.” Those found in suburban settings are highly tolerant of humans and may be seen perched on saucers and cups at outdoor dining
tables, or at bird feeders. The species is well known for stealing small packets of sugar and nuts from restaurant tables.
Females are generally bolder, more resourceful foragers and more likely to attempt new innovative ways to obtain food than the males, often entering homes and overcoming obstacles to reach their goal. They are rarely seen alone, as the males are almost always nearby, watching and taking advantage of their mates’ bold nature.
Contrary to the more reserved males, whom I only see occasionally, the extroverted females can be seen everywhere in our garden — from the fruit and seed feeders to the ground flowers and highest treetops. They are one of the first birds to respond to pishing and will often come within reach, in a curious and almost playful manner. Pishing is a type of repetitive birdcall composed of high pitched and harsh sounds used to attract small birds. I use psst-psst, pish-pish, chit-chit and kissing noises to attract our local tanagers and finches.
Females are aggressive foragers. Sometimes, particularly during the nesting period, females attempt to protect their cache of seeds with aggressive displays, chasing other birds including other female bullfinches. Although females are aggressive foragers, they do not defend territory; males on the other hand, are passive foragers and will defend territory.
The species is socially monogamous, breeding throughout the year, though peaking from February to August. At the onset of the breeding season, males advertise to potential mates by performing displays that highlight their red throat markings. Upon securing a mate, the male becomes very territorial, defending the nest from intruders and remaining close to his mate while she lays and incubates the eggs. Their nests are cleverly built domed structures made with dried grasses and fine twigs, and lined with soft plant matter — dried banana leaves are a huge favourite — with a side entrance. They are placed on a thick shrub, a hedgerow, or a low tree, about two to five metres (six to 16 feet) from the ground.
Wherever possible Lesser Antillean Bullfinches will nest near human habitation as protection against other birds, mongoose and snakes. It is not unusual for them to build and abandon several nests before finally settling on one. I recently discovered a handsome couple building a nest on the guava tree at the bottom of our garden. Curious to find out more about their breeding habits, I placed a wildlife camera a few feet from the nest. When I returned a week later, I realized that they had abandoned the nest, but not before the female probed the camera lens with a good pecking, returning several times to repeat the prank — her strong, pounding beak and dark, liquid eyes relentlessly driven by deeply felt curiosity.
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