Nest location, clutch size and nest success in the Scarlet Ibis Eudocimus ruber

Breeding success and nest-site characteristics were studied during the 1996-1997 breeding season in a colony of Scarlet Ibises Eudocimus ruber in south-eastern Brazil to test the hypothesis that nest-site characteristics and clutch size affect nest success. Two nesting pulses produced young, the earlier being more successful. Predation accounted for most failures during the first pulse, wind destruction during the second. A third pulse with few nests produced no young. Adult Ibises abandoned nests when they lost sight of other incubating birds. Logistic regression analysis indicated that nest success during the first pulse was positively related to clutch size, number of nests in the nest tree and in the nearest tree, and negatively to the distance to the nearest neighbour. During the second pulse there were significant negative associations between success, nest height and distance to the fourth nearest nest, and a positive association between success and nest cover. The results agree with the 'selfish herd' hypothesis, indicating that nest aggregation may increase breeding success, but the nest-site characteristics affecting success can differ over the course of one breeding season.

Reproductive data of a threatened bat, Myotis ruber (E. Geoffroy, 1806) (Chiroptera, Vespertilionidae) in a southern Brazilian deciduous seasonal forest

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relative abundance and population biology of the non-indigenous crab Charybdis hellerii (Crustacea: Brachyura: Portunidae) in a southwestern Atlantic estuary-bay complex

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The first zoeal stage of the genus Cronius (Brachyura, Portunidae) from the Brazilian coast, hatched in a laboratory

This study describes the first zoeal stage of Cronius ruber and Cronius tumidulus. The zoeae can be distinguished using the setation of the cephalic appendages and the lateral process on the abdominal somite.

Karyotypic Data on 28 Species of Scinax (Amphibia: Anura: Hylidae): Diversity and Informative Variation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The diet of bats from Southeastern Brazil: the relation to echolocation and foraging behaviour

In this study the incidence of moths and beetles was examined from feces samples of bats that use different foraging behaviors. Twenty sites around the Fazenda Intervales, a Field Research Station located in São Paulo State, in southeastern Brazil were sampled. Feces were collected from bats caught in mist nets, Turtle Traps or hand nets and, in one case, from beneath a roost. Feces samples were taken from six species of bats: Micronycteris megalotis (Gray, 1842), Mimon bennettii (Gray, 1838), Furipterus horrens (F. Cuvier, 1828), Myotis riparius Handley, 1960, Myotis ruber (E. Geoffroy, 1806) and Histiotus velalus (I. Geoffroy, 1824). To record and describe the frequencies dominating bat echolocation calls, an Anabat II bat detector coupled with an Anabat ZCA interfaces and DOS laptop computers were used. The data show that Furipterus horrens feeds extensively on moths, as predicted from the features of its echolocation calls. Gleaning bats, whose echolocation calls are much less conspicuous to moths take a wide range of insect (and other) prey.

Riqueza de espécies de morcegos (Mammalia, Chiroptera) em dois diferentes habitats, na região centro-sul do Paraná, sul do Brasil

Estudo preliminar sobre a riqueza de espécies e a freqüência de capturas de morcegos em dois habitats, mata primária e reflorestamento de Araucária, na Região Centro Leste do Paraná. Foi empregado o mesmo esforço para as duas áreas, resultando na captura de 11 espécies na área de mata primária, contra oito no reflorestamento de Araucária. A uniformidade na distribuição da abundância -equitabilidade - foi maior na mata primária. No reflorestamento de Araucária, noventa por cento dos indivíduos coletados pertenciam somente a duas espécies. Pelos resultados, conclui-se que a floresta primária com numerosos nichos, apresenta uma riqueza de espécies elevada, mas a ação do homem reduz a riqueza de espécies geral, o que se reflete principalmente na dominância de poucas espécies. Destaca-se aqui, nos dois tipos de ambientes, a presença de Myotis ruber, listada como ameaçada de extinção no Brasil.

Breeding biology and nest site characteristics of the scarlet ibis in southeastern Brazil

The breeding biology of the only Scarlet Ibis Eudocimus ruber colony in southeastern Brazil was studied during the 1996-97 breeding season. The ibises began to visit their colony site by mid-September. Nest building and egg laying took place in early November and was synchronous, making the first nesting pulse. Mean clutch size in this pulse was 2.45 eggs/nest, and 0.67 young/nest reached age three weeks, when they were able to walk about the nest tree and environs. Predation was the main cause of nest failures (74% of all losses), followed by nest collapses (19%). A second nesting pulse, also synchronous, started in late December, when the young from the first nests were already able to wander about the colony and make short flights. Mean clutch size of this pulse was 2.05 eggs/nest and productivity was 0.34 young/nest. Nest collapses during storms accounted for 58% of the losses, and predation for a further 27%. A third pulse, with only a few nests, started when the second pulse young were in their third week, but no nest was successful. The incubation time was 21-24 days, and the young were able to fly well when 40 days old, deserting the colony by age 75 days. Nesting early in the breeding season yielded greater success. Nests were built close to each other (a sphere with a 1.8 m radius and centered on an average nest would include the four nearest neighbors) and there was always more than one nest per tree. Most nests were built on the upper third of the nest-tree and had some cover from overhanging branches. There was a trend for the ibises building their nests in even closer proximity during the second pulse, perhaps as a strategy to lessen individual predation risks. Received 30 August 2000, accepted 4 October 2000.

Diversidade e distribuição de siris (Decapoda: Brachyura: Portunidae) e dinâmica populacional de Callinectes ornatus no litoral norte de São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Breeding season diet of Scarlet Ibises and Little Blue Herons in a Brazilian mangrove swamp

We studied the diet composition and overlap of Scarlet Ibises (Eudocimus ruber) and Little Blue Herons (Egretta caerulea in a mangrove swamp in southeast Brazil during the 1996-1997 breeding season, which occurs during the rainiest period. Crabs comprised 95% of all prey taken by the ibises and 80% of the prey of the herons, Nevertheless, diet overlap was small (similar to 30%) due to ibises feeding mostly on Uca spp. and Eurythium limosum crabs, which were taken from their burrows; the herons fed on the arboreal and semi-arboreal Aratus Pisonii and Metasesarma rubripes crabs. Divergent hunting strategies of ibises (tactile foragers) and herons visually-oriented predators) explains the diet segregation when preying on an ecologically diverse crab guild, but it is unclear why herons prey rarely on fiddler crabs. Scarlet Ibises bred successfully while feeding oil estuarine organisms living in low salinities in the mangroves, showing that mangroves may be adequate foraging habitats for chick-rearing ibises during periods of low salinity.

Impacto ecológico, comportamental e fisiológico da bioinvasão sobre populações nativas: o caso do siri invasor Charybdis hellerii

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)