Nest: described (n = 1) Egg: described (n = 1) Nestling: hatchling described (n = 1), older nestlings not described Nesting behavior: Very poorly known.
Frederickena fulva was originally described as a subspecies of Undulated Antshrike Frederickena unduligera but was recently elevated to species rank, based largely on vocalizations. Thus, in all but the most modern treatments, the taxon treated here was referred to as Undulated Antshrike. Fulvous Antshrike, as currently defined, is monotypic and occurs in the lowlands of westernmost Amazonia from southern Colombia to northern Peru.
Country Keywords: EspecieEcuador
The single described nest was a large, thin-walled cup, and its contents were partially visible from below. It was attached by the rim, via two sparse ‘wings’ extending up on opposite sides to two narrow, parallel, horizontal branches (6 and 8 mm diameter). These attachment points extended c.3 cm above the rim and consisted of no more than 15–20 rootlets each. The nest was fairly uniformly comprised of thin, slightly branched rootlets, criss-crossed and interwoven,with only those circling the slightly thickened rim being coiled. The inner portion had a sparse, poorly defined lining of smooth, un-branched flexible fibres of unknown origin,as well as 4–5 black fungal rhizomorphs. The cup was 10 cm in diameter inside by 7.5cm deep. Externally the nest was 14 cm wide by 9 cm tall. (Greeney et al. 2012).
A single egg, measured just prior to hatching, was 30.5 × 22.8 mm and weighed 7.9 g. The egg was slightly off-white with copious cinnamon and lavender flecks and narrow scrawls,concentrated at the larger end (Greeney et al. 2012).
A recently hatched nestling was completely devoid of natal down and had pinkish-colored skin which was slightly duskier dorsally. The bill was dark orange, yellower near the tip except for the dorsal portion of the mandible, which was dusky and bore a bright white egg tooth. The rictal flanges were bright yellow and the mouth lining was bright yelloworange.The nestling weighed 6.5 g and the right tarsus measured 11 mm (Greeney et al. 2012).