Scaled Antpitta Grallaria guatimalensis

  • Order: Passeriformes
  • Family: Grallariidae
  • Polytypic: 9 subspecies
  • Authors: Harold F. Greeney, A. Rivera-Ortíz, Claudia I. Rodríguez-Flores, Carlos A. Soberanes-González, and Marîa del Coro Arizmendi
Sections

Breeding

Nests.Not surprisingly, due to its extensive range, there are more published reports of nests for Scaled Antpitta than for any other species of Grallaria antpitta (Greeney et al. 2008). Nests are bulky, deep, open cups composed externally of a variety of materials, predominantly dead plant materials such as sticks, leaves, and grasses. Some nests, however, are reported to include moss, especially in particularly humid habitats. The inner egg cups are sparsely lined with thin, flexible materials such as pine needles, rootlets, and fungal rhizomorphs. Nests are placed in relatively well-supported locations such as tree stumps, fallen logs, and large forking or overlapping branches, at heights ranging from 0.5-1.5 m (mean ca. 1 m; Greeney et al. 2008). The above generalizations on nest construction and location are taken from the following references: Edwards and Lea 1955, Miller 1963, Rowley 1966, 1984, del Toro 1971, Dobbs et al. 2001, 2003, ffrench 1973.

Eggs.Descriptions of the eggs of Scaled Antpitta are all remarkably consistent and it appears that this species lays unmarked, sky-blue to blue-green eggs throughout its range (Edwards and Lea 1955, Rowley 1966, 1984, del Toro 1971, Dobbs et al. 2001, 2003). Greeney et al. (2008) summarize information on eggs for Scaled Antpitta: clutch size is apparently two eggs, throughout the species’ range, with an interval of ca. 48 h between eggs; eggs hatch after 19 days and are laid in the late afternoon; the percent of diurnal incubation ranges from 87-96% across the incubation period; and eggs loose around 0.85% of their mass/day during the course of development. Egg measurements published in the literature are as follows: 35 x 26 mm, Edwards and Lea 1955; 33.1 x 26.0 mm (11.2 g), 31.6 x 25.9 mm (10.9 g), Rowley 1966; 30.7 x 25.3 mm, 29.8 x 25.5 mm, Rowley 1984; 29.84 x 24.15 mm (9.2 g), 29.05 x 24.05 (8.9 g), Dobbs et al. 2001; 30.11 x 23.63 (9.0 g), 29.13 x 23.65 mm (8.6 g), Dobbs et al. 2003.

Nestling. Scaled Antpittas are born with dark pink or black skin and long, wispy tufts of dark gray or black down on the head, back, and wings (Miller 1963, Dobbs et al. 2001, 2003). Like other species of antpittas (Greeney et al. 2008), the young have bright orange rictal flanges, and striking crimson-orange mouth linings (Dobbs et al. 2001, 2003). Scaled Antpitta nestlings take 17-19 days to leave the nest and, while young, are brooded roughly 80% of daylight hours and fed at a rate of 0.5-1.3 times per nestling per hour (Dobbs et al. 2001, 2003).

Recommended Citation

Greeney, H. F., A. Rivera-Ortíz, C. I. Rodríguez-Flores, C. A. Soberanes-González, and M. d. C. Arizmendi (2013). Scaled Antpitta (Grallaria guatimalensis), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.scaant1.01