Marco Antônio Manhães

Dieta de Traupíneos (Passeriformes, Emberizidae) no Parque Estadual do Ibitipoca, Minas Gerais, Brasil

ABSTRACT DIET OF TANAGERS (PASSERIFORMES, EMBERIZIDAE) IN IBITIPOCA STATE PARK,MINAS GERAIS, BRAZIL. Eleven species of tanagers in Ibitipoca State Park, Minas Gerais,southeastern Brazil, were studied for 12 months and the birds diet was described. Fruits of 52 plantspecies were the main item consumed for all tanagers, representing 59.70% of all items in 1330events, although different proportions in the use of this resource have been found among the birdspecies. The main plant families found were Myrtaceae with eight species accounting for 22.29%(n=177), and Melastomataceae with seven species accounting for 22.29% (n=177) of fruit intake.The most frequent plant species in the diet was Cecropia glaziovi Snethl. (Cecropiaceae), whichmade up 17.76% (n=141) of fruit intake of all species of tanagers. Arthropod consumption camesecond with 22.63% (n=301), but flowers, leaves, nectar, food remains left by tourists and galls werealso represented. Several environmental features influenced diet composition. An Asteraceae,

Feeding resource partitioning between two understorey insectivorous birds in a fragment of Neotropical cloud forest.

The food habits and niche overlap based on diet composition and prey size of two species of understorey insectivorous birds were investigated in an area of montane rain forest in the state of Minas Gerais, southeastern Brazil. A total of 43 birds were captured: 33 individuals of Conopophaga lineata (Conopophagidae) with 13 recaptures, and 10 individuals of Myiothlypis leucoblephara (Parulidae) with 12 recaptures, from which were obtained respectively 33 and 10 fecal samples. Fragments of 16 groups of arthropods, plus insect eggs, were identified in these samples. Conopophaga lineata predominantly consumed Formicidae (32%) and Isoptera (23.6%). However, the index of alimentary importance (AI) of Isoptera (3.53) was lower than other groups such as Formicidae (AI = 61.88), Coleoptera (AI = 16.17), insect larvae (AI = 6.95) and Araneae (AI = 6.6). Myiothlypis leucoblephara predominantly consumed Formicidae (28.2%) and Coleoptera (24.4%), although Coleoptera and Hymenoptera non-Formicidae had the highest values of AI (38.71 and 22.98 respectively). Differences in the proportions of the types of arthropods consumed by birds were not enough to reveal their separation into feeding niches (overlap = 0.618, p observed ≤ expected = 0.934), whereas differences in the use of resources was mainly due to the size of the prey (p<0.001), where C lineata, the species with the highest body mass (p<0.001) consumed larger prey. It is plausible that prey size is an axis of niche dimension that allows the coexistence of these species.

Hábitos alimentares de Basileuterus culicivorus (Aves: Parulidae) em uma área de Mata Atlântica secundária, sudeste do Brasil

The feeding behavior of the Stripe-crowned Warbler, an understorey foliage-gleaning insectivore, was studied based on fecal and foliage arthropod samples collected in an area of secondary Atlantic Forest in southeastern Brazil. In 32 fecal samples, 220 arthropod feeding items were identified. The most represented groups in the diet were Coleoptera, Araneae, insect larvae and Hymenoptera non-Formicidae, which accounted for almost 80% of the ingested items. Araneae and Coleoptera were also the most abundant taxa found on the foliage. The bird showed preference for prey of a certain type (Hymenoptera Formicidae, Hymenoptera non-Formicidae and insect larvae) and above a particular size (over 4 mm in length), which were the most consumed food items among those found in the environment. The consumption of larger prey items seems to be a way in which the species optimizes its energy intake.