| determinants of partial bird migration in the amazon basin. | 1. little is known about mechanisms that drive migration of birds at tropical latitudes. because most migratory bird species in south america have populations that are present year-round, partial migration (in which only some individuals of a given population migrate at the end of the breeding season) is likely to be common, providing an opportunity to assess proximate mechanisms of migration. 2. two non-mutually exclusive hypotheses explaining intraspecific variation in migratory behaviour were ... | 2010 | 20546065 |
| a comparative study of the forebrain of 4 species of south american birds. | the brains of the swift streptoprocne zonaris, the flycatcher tyrannus melancholicus, the tanager ramphocelus dimidiatus and the finch oryzoborus angolensis were compared with respect to the hyperstriatum accessorium, hyperstriatum dorsale, hyperstriatum ventrale, neostriatum, ectostriatum, paleostriatum augmentatum and paleostriatum primitivum. in each of these brain parts the average number of cells and the average cell size were calculated, and the species were compared with respect to the sa ... | 1978 | 742725 |
| the effect of mangrove restoration on avian assemblages of a coastal lagoon in southern mexico. | mangrove forests provide many ecosystem services, including the provision of habitat that supports avian biodiversity. however, hurricanes can knock down trees, alter hydrologic connectivity, and affect avian habitat. in 1995, hurricanes opal and roxanne destroyed approximately 1,700 ha of mangrove forest in laguna de términos, mexico. since then, hydrological restoration has been implemented to protect the mangrove forest and its biodiversity. | 2019 | 31423362 |
| plasma cholinesterase activity in wild birds from undisturbed woodlands in the central monte desert. | plasma cholinesterase activity is a biomarker sensitive to the effect of organophosphate and carbamate pesticides, and its enzymatic levels have been previously unknown for most of the wild birds analyzed in the present study. our objectives were to establish plasma acetylcholinesterase levels in songbirds of 2 undisturbed sites in the central monte desert (argentina). we also examined the influence on cholinesterase activity of age, sex, body condition, feeding and migratory habits, and species ... | 2019 | 31063226 |
| two new and two redescribed species of anonchotaenia (cestoda: paruterinidae) from south american birds. | morphological examination of novel specimens of paruterinid cestodes from passerine birds from brazil and chile and of museum specimens from paraguay revealed two new species: anonchotaenia prolixa sp. n. from elaenia albiceps chilensis hellmayr from chile, and anonchotaenia vaslata sp. n. from tyrannus melancholicus (vieillot) (type host) and myiodynastes maculatus (statius muller) from paraguay. the generic diagnosis of anonchotaenia conn, 1900 is amended, prompted by the presence of the armed ... | 2014 | 25549500 |
| two new species of trouessartia canestrini, 1899 (astigmata: trouessartiidae) from passeriform birds in brazil. | two new feather mite species of the genus trouessartia canestrini, 1899 (analgoidea: trouessartiidae) are described from passerines (aves: passeriformes) in brazil: t. calcealgiana n. sp. from philydor atricapillus (wied) (furnariidae), and t. gigaphallus n. sp. from tyrannus melancholicus vieillot (tyrannidae). both species have unique features, such as the large hook-like seta sr on trochanters iii in t. calcealgiana, and the large male genitalia in t. gigaphallus, which are at least twice as ... | 2017 | 29022214 |