Notes on Siptornis striaticollis (Furnariidae) in Peru

Abstract

The Spectacled Prickletail (Siptornis striaticollis) is a monotypic furnariid previously recorded only from the subtropical zone of the middle and upper Magdalena Valley in Colombia and the east slope of the Ecuadorian Andes (Mapoto) (Chapman, Bull. Am. Mus. Nat. Hist. 36, 1917; Chapman, Bull. Am. Mus. Nat. Hist. 55, 1926). In view of the paucity of information on Siptornis, we offer the following observations and report the first occurrence of the species in Peru. In 1978, during ornithological investigations in the Department of Cajamarca in northern Peru, we found Siptornis striaticollis northeast of Huancabamba, ca. 2 km south of Carmen, on the Sapalache-Namballe mule trail (OSOS’ S, 7922’ W). We saw these birds daily from 2 to 17 July foraging with large mixed-species flocks in patches of cloud forest between 1,660 m and 1,880 m elevation. Occasionally when a mixed-species flock assembled in an isolated cluster of trees, we made exact counts of arriving and departing individuals. Siptornis was a regular, low-density participant, with a maximum of three to four individuals per flock. Common flock members included the furnariids Crunioleuco curtata, Anabacerthia striaticollis, and Xenops rutilans, and the antwren Terenuru callinota. The prickletails foraged by creeping along branches, and probing moss clumps, clusters of dead leaves, fruticose lichens, and bark crevices at the level of the forest subcanopy and edge 5-15 m above ground. Several times individuals were seen hanging “paridlike” from petioles of Cecropia leaves, picking unidentified food items from undersides of leaflets. Among species that occur in the same area, Siptornis most closely resembles Xenops rutilans in behavior, size, coloration, and plumage pattern. Both Siptornis and Xenops tapped sporadically on limbs, often bracing the tail against the bark when probing deep crevices. During light rain or dense fog we often located these birds by their faint tapping sounds. On 9 July, after watching a large mixed-species flock pass over the trail, Eley heard a peculiar high-pitched trill coming from the top of a nearby bush. Immediately afterward, a Siptornis hopped into view and perched upright in the bush about 2 m above the trail. Another motionless individual about0.5 m from the first bird and in the interior of the bush answered the trill with a similar call. We heard no other vocalizations of this species. Siptornis striaticollis appeared most closely to fill the ecological niche of piculets of the genus Picumnus. In most subtropical cloud forest throughout eastern Peru and Bolivia at least one species of piculet occurs (Meyer de Schauensee, A guide to the birds of South America, Livingston Publ. Co., Wynnewood, Penn., 1970, and pers. observ.), but piculets are unknown in subtropical forest in the eastern Andes north of the Mararion River, where Siptornis occurs. Perhaps Siptornis and Picumnus are ecologically incompatible. Our three specimens, all males, are deposited at the Louisiana State University Museum of Zoology (LSUMZ). Data from these specimens are listed in Table 1. We thank Richard D. Semba and Manuel Sanchez S. for field assistance. J. Van Remsen, H. Douglas Pratt, John P. O’ Neill, and John Weske read the manuscript. We are most grateful to John S. McIlhenny and Babette M. Odom for their generous support of the field work of the LSUMZ.