Reproductive biology

Some, perhaps all, tapaculos might form permanent pair bonds. Most small birds quickly replace a lost mate, and tapaculos are no exception. In Scytalopus tapaculos, a new male appears almost immediately after the old one has been removed.

Al though nests of 18 of the 54 species of tapaculos are known, details of nesting have been studied in only a single species, Rhinocrypta lanceolata.

A few build cup nests, but most construct closed nests with a side entrance or place their nest in a tunnel. The nest is fairly soft, made of root fibers, grass, moss, and a few small twigs. Nests of Eugralla and Rhinocrypta are bulky. Rhinocrypta, Eugralla, and sometimes Melanopareia place their nest above ground, but most tapaculos nest at the end of a tunnel or hollow trunk. Tunnels may be dug by the bird or an abandoned rodent burrow may be used.

Most tapaculos lay two to three eggs that are white, large for the size of the bird, rounded and lacking in sheen. Melanopareia is an exception, as it lays ovoid and spotted eggs.

The incubation period is 15-17 days and the gestation period is 14-15 days for Rhinocrypta. Males take part in the incubation in some species, but apparently not in Scytalopus, where brood patches have been found only in females.

The young hatch naked. Both parents care for nestlings, but apparently fledglings are sometimes fed by the female alone.

The oscellated tapaculo (Acropternis orthonyx) spends much of its time in the forest undergrowth. (Photo by Doug Wechsler/VIREO. Reproduced by permission.)

are Merulaxis stresemanni and Scytalopus psychopompus, both restricted to small areas in coastal Bahía in eastern Brazil, where deforestation continues at an alarming rate. The former has not been seen since 1995 and the latter not since the 1980s. Hope for their survival is slight.

The recently discovered Scytalopus iraiensis inhabits the few remaining rushy marshes in eastern Paraná in southern Brazil, a habitat under constant pressure from human development. It is considered Endangered and needs human support to insure its survival.

Scytalopus panamensis is confined to the Tacarcuna Massif in the Darién gap on the border of Panama and Colombia. Owing to forest clearance within its very restricted range, the species is considered Vulnerable. It is still common, but if the Panamerican Highway is completed as planned, the pressure on its habitat will accelerate drastically.

Five species are considered Near Threatened owing to small ranges and continuing loss of habitat. These are Scytalopus novacapitalis of swamp gallery forest in a small area in central Brazil; Scytalopus indigoticus, Merulaxis ater, and Psilorhamphus guttatus, all confined to the rapidly dwindling Atlantic forests of east and southeast Brazil; and Melanopareia maranonica of dense arid scrub in a small area in the Río Marañón drainage in northern Peru, a habitat increasingly disturbed and giving way to agriculture.

Additionally, Scytalopus robbinsi, which is confined to an area in southern Ecuador that will be nearly completely deforested over the next few decades unless protective measures are taken, should be added to the species of concern. Several other species of Scytalopus have very small ranges and are therefore vulnerable but not presently considered to be at risk.

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