The genus Myrsidea Waterston (Phthiraptera: Menoponidae) from tyrant-flycatchers (Passeriformes: Tyrannidae), with descriptions of 13 new species

The two species of previously named Myrsidea from tyrant-flycatchers are redescribed. Thirteen new species are described and illustrated. The new species and their type hosts are: Myrsidea pitangi ex Pitangus sulphuratus (L.), Myrsidea seversoni ex Tyrannus verticalis Say, Myrsidea melancholici ex Tyrannus melancholicus Vieillot, Myrsidea barbati ex Myiobius barbatus (J. F. Gmelin), Myrsidea flaviventris ex Tolmomyias flaviventris (Wied), Myrsidea similis ex Myiozetetes similis (Spix), Myrsidea elaeniae ex Elaenia flavogaster (Thunberg), Myrsidea contopi ex Contopus cinereus (Spix), Myrsidea oleaginei ex Mionectes oleagineus (M. H. K. Lichtenstein), Myrsidea neocinereae ex Serpophaga cinerea (Tschudi), Myrsidea cayanensis ex Myiozetetes cayanensis (L.), Myrsidea olivacei ex Mionectes olivaceus Lawrence, and Myrsidea spadicei ex Attila spadiceus (J. F. Gmelin). Keys are provided for the identification of females and males of the 15 Myrsidea species known from the Tyrannidae.

Quantifying Differential Responses to Fruit Abundance by Two Rainforest Birds Using Long-Term Isotopic Monitoring

Most tropical passerines feed on insects, fruit, or a combination of the two. The sugary pulps of fruit have lower amounts of protein than insects. We used stable-nitrogen isotope analysis (δ15N) of blood from two tropical rainforest birds that regularly feed on fruit—Red-throated Ant-Tanager (Habia fuscicauda) and Ochre-bellied Flycatcher (Mionectes oleagineus)—to quantify the relative amounts of assimilated protein from animal and plant sources. Because fruit and insect abundances vary seasonally in the tropics, the study was conducted during one year in Los Tuxtlas, Mexico. The study site has one major fruiting peak between April and July and a secondary peak between September and October. Some insects are more abundant from May to August. Red-throated Ant-Tanagers and Ochre-bellied Flycatchers rely heavily on insect protein when fruit is scarce, and then steadily increase their input of fruit protein as fruit abundance increases. Red-throated Ant-Tanagers rely almost entirely on fruit protein during the major fruiting peak, whereas Ochre-bellied Flycatchers have the largest input of fruit protein during the secondary fruit peak. Incubation in both species occurs from June to August, and most incubating individuals rely on a mixture of insects and fruit. In both species, examination of fecal contents showed the ingestion of the largest number of fruit species during the major fruiting peak. Cuantificación de la Respuesta Diferencial a la Abundancia de Frutos por Dos Especies de Aves Selváticas Mediante el Monitoreo Isotópico a Largo Plazo