Departamento de Ecologia

Litter production in a fragmented Atlantic forest landscape (Ibiúna, SP): the importance of the edge and fragment size). Litter is an important compartment in tropical forests, responsible for most of nutrient cycling. Several environmental factors may affect litter production, and the ones mostly investigated are climate and vegetation structure. The influence of landscape structure on patterns of litter production is poorly studied. This study investigated edge and size effects on patterns of litter production in three Atlantic forest fragments (Ibiúna, SP: 23°35' S -23°50' S; 46°45' W -47°15' W), one large (ca. 175 ha) and two small (ca. 5 ha) with different degrees of isolation. The litter collected was fractioned following the predominant plant material, and grouped into two periods, of high and low production. We used analysis of variance and a posteriori tests to detect differences in litter production between edge and center of each fragment, and among the centers of the three fragments. Most biomass consisted of "leaves+flowers", followed by "twigs £ 0.5 cm" (62.9% and 24.7% of the total), a common pattern in tropical forests. It was possible to perceive an edge effect related to litter production in the three fragments, especially in the large one, and higher litter production in their centers. The observed patterns showed to be strongly related to the vegetation structure, as the size of trees and canopy density. A higher production of "fruits+seeds" in the large fragment or in the small and connected one indicate a relationship between forest connectivity and the activity of disperser animals.

Diet of the American Kestrel, Falco sparverius (Aves: Falconiformes), in the Ecological Station of Itirapina, São Paulo State, Brazil. The American Kestrel is one of the smallest raptors of the world and occurs all over the Western Hemisphere in a great variety of habitat types.

We present natural history information on 66 species of snakes found in the forests of the Mana us region, Central Amazonia, Brazil. For each species, we provide information on size, color pattern, habitat and microhabitat, feeding habits, reproduction, and defense. We also include a partial summary of the information available in the literature for Amazonian localities. Our results are based on nearly 800 captures or sightings of snakes made from 1990-95 at localities around Manaus, mostly at a primary forest reserve 25 km north of Manaus. Field data at this reserve were obtained during over 2600 person-h of visually searching for snakes, ca. 1600 of which occurred during time-constrained search. Temperature and relative humidity in Manaus are high and the amount of annual rainfall (2075 mm/yr) is relatively small, with a long dry season (4-7 mo). Of the 65 species for which information is available, 28 (42%) are primarily terrestrial, 20 (30%) fossorial and/or cryptozoic, 13 (20%) arboreal, and four (6%) aquatic, although many species use more than one microhabitat when active. Nearly all inactive snakes were found on vegetation. In relation to time of activity, 26 (41 %) of the 62 species for which information is available seem to be strictly diurnal, 13 (21%) strictly nocturnal, and 23 (38%) both diurnal and nocturnal. The five prey types most commonly consumed by snakes in the Manaus region are vertebrates: lizards (consumed by 58% of the species), frogs (39%), mammals (23%), birds (18%), and snakes (16%). A cluster analysis combining data on microhabitat usc, die! activity, and diet resulted in several groups of species with similar habits. All these "guilds" included closely related species, as well as distantly related ones that converge in habits. These combined results indicate that in addition to current ecological factors (e.g., predation pressure, differential prey availability in different microhabitats), historical factors (phylogeny and biogeography) may have played an important role in determining the current natural history patterns of this snake assemblage. A high diversity *This study is dedicated to O.R. Cunha and F.P. Nascimento (both now retired from Museu Goeldi, Belem) for their unparalleled contributions to the knowledge of Brazilian Amazonian snakes, including natural history, and the immense collection of snakes at the MPEG, an invaluable source of natural history information for years to come. of defensive tactics was found in this assemblage, and phylogeny may be a strong determinant factor for the occurrence of defensive tactics in each species. Contradicting generalizations on the timing and length of reproductive season in Amazonian snakes, juvenile recruitment seems to occur mainly during the rainy season in most species from the Manaus region, although some species seem to breed throughout the year. This may be a consequence of the prolonged dry season that occurs in the region, during which time some resources occur in limited supplies.

We present natural history information on 66 species of snakes found in the forests of the Mana us region, Central Amazonia, Brazil. For each species, we provide information on size, color pattern, habitat and microhabitat, feeding habits, reproduction, and defense. We also include a partial summary of the information available in the literature for Amazonian localities. Our results are based on nearly 800 captures or sightings of snakes made from 1990-95 at localities around Manaus, mostly at a primary forest reserve 25 km north of Manaus. Field data at this reserve were obtained during over 2600 person-h of visually searching for snakes, ca. 1600 of which occurred during time-constrained search. Temperature and relative humidity in Manaus are high and the amount of annual rainfall (2075 mm/yr) is relatively small, with a long dry season (4-7 mo). Of the 65 species for which information is available, 28 (42%) are primarily terrestrial, 20 (30%) fossorial and/or cryptozoic, 13 (20%) arboreal, and four (6%) aquatic, although many species use more than one microhabitat when active. Nearly all inactive snakes were found on vegetation. In relation to time of activity, 26 (41 %) of the 62 species for which information is available seem to be strictly diurnal, 13 (21%) strictly nocturnal, and 23 (38%) both diurnal and nocturnal. The five prey types most commonly consumed by snakes in the Manaus region are vertebrates: lizards (consumed by 58% of the species), frogs (39%), mammals (23%), birds (18%), and snakes (16%). A cluster analysis combining data on microhabitat usc, die! activity, and diet resulted in several groups of species with similar habits. All these "guilds" included closely related species, as well as distantly related ones that converge in habits. These combined results indicate that in addition to current ecological factors (e.g., predation pressure, differential prey availability in different microhabitats), historical factors (phylogeny and biogeography) may have played an important role in determining the current natural history patterns of this snake assemblage. A high diversity *This study is dedicated to O.R. Cunha and F.P. Nascimento (both now retired from Museu Goeldi, Belem) for their unparalleled contributions to the knowledge of Brazilian Amazonian snakes, including natural history, and the immense collection of snakes at the MPEG, an invaluable source of natural history information for years to come. of defensive tactics was found in this assemblage, and phylogeny may be a strong determinant factor for the occurrence of defensive tactics in each species. Contradicting generalizations on the timing and length of reproductive season in Amazonian snakes, juvenile recruitment seems to occur mainly during the rainy season in most species from the Manaus region, although some species seem to breed throughout the year. This may be a consequence of the prolonged dry season that occurs in the region, during which time some resources occur in limited supplies.

Activity and habitat use in Bothrops atrox are described from central Amazonia using three methods: time constrained search (TCS, in swamp forest in a stream valley and terra firme forest on a plateau), occasional sightings (OS; both in primary forest), and snakes brought to a hospital (IMTM). Results for OS and IMTM indicate that B. atrox is significantly less active during the dry season. The monthly number of snakes found with OS and brought to the IMTM were both correlated with rainfall and relative humidity, but not with temperature. Monthly number of individuals found with TCS did not differ from expectation and was correlated with rainfall but not with humidity or temperature. Encounter rate at night was much higher than by day. Most snakes found at night were hunting in a coiled posture, whereas most snakes found by day were moving. Juveniles were found more frequently on vegetation than adults. The higher incidence of snakebites by B. atrox in summer in the Manaus region may reflect this increase in activity. Unimodal seasonal activity and primarily nocturnal habits are widespread in Bothrops. Ontogenetic shift in microhabitat use is also common in semiarboreal lanceheads and may be related to food availability and perhaps a higher predation pressure at the ground level.

The Cerrado encompasses ca. 2 million km2 in Brazil. Most Cerrado areas have been greatly disturbed in the past decades. Only 20% of this biome remain undisturbed, and only 1.2% is protected. Knowledge on the biology and diversity of Cerrado amphibian assemblages is still incipient. Here we present natural history information (habitat use and reproductive activity) of 28 species of frogs from the Estação Ecológica de Itirapina (EEI), and compare the composition of this assemblage with those of other Cerrado areas, other open areas, and a few forest areas throughout Brazil. We demonstrate that the Itirapina assemblage is more similar to those of other open areas than to those of forests, even when the latter are geographically closer. Six species occurred in the gallery forest at varying levels of dependence (three independent, two semi-dependent, and one totally dependent) while all other species occurred exclusively in open areas. For most species at EEI, reproduction was strongly synchronized with the onset of the rainy season, with the exception of Hypsiboas lundii, which called throughout the year, and Proceratophrys sp. which started calling prior to the beginning of the rainy season. The spatial and temporal patterns observed in this assemblage seem to reflect both ecological (e. g. hydroperiod of water bodies) and historical factors (e. g. early breeding in leptodactylids, late breeding in hylids, both phylogenetically constrained).

The Neotropical pitviper genus Bothrops comprises about 40 species, which occur in all main ecosystems of cis-Andean South America. We explored the relationships of body size and form (tail length and stoutness) with macrohabitat use in 20 forms of Bothrops. Semi-arboreal habits appeared only in forest forms. Semiarboreals are signi®cantly more slender and have longer tails than terrestrials; body size is not signi®cantly different between terrestrials and semi-arboreals. Within Bothrops, independent contrasts for macrohabitat use were signi®cantly correlated with contrasts of tail size (positively) and stoutness (negatively); thus, the more arboreal the species, the longer its tail and the more slender its body. Contrasts of adult body size seems to remain constant over the lower range of macrohabitat use, but to decrease in species of Bothrops which are more arboreal. Reconstructions of character states indicate that: (1) the ancestor of Bothrops was a small, stout, terrestrial species; (2) semi-arboreal habits appeared one to three times in the genus; (3) a decrease in stoutness and an increase in tail length occurred along with an increase in arboreality in some clades. Although macrohabitat use seems to be important in determining body form in Bothrops, our results also indicate that tail size, stoutness and body size may also be affected by selective agents other than macrohabitat use. The selective agents responsible for the shifts in macrohabitat use in Bothrops are still uncertain, although they may have included prey availability and/or predation pressure. The plasticity of macrohabitat use, morphology and body size described in this study may have been key features that facilitated the highly successful ecological diversi®cation of Bothrops in South America.

We describe a new species of Bothrops from Vitória Island, off the coast of São Paulo, southeastern Brazil. The new species differs from the mainland coastal populations of B. jararaca mostly in its smaller and stouter body, number and form of scales, and hemipenial morphology. From B. insularis and B. alcatraz, both related species endemic to islands in southeastern Brazil, B. otavioi sp. nov. differs mainly in its body form and number of scales. The new species has the most common mitochondrial haplotype for mainland populations of B. jararaca, which is also found in B. alcatraz. A mitochondrial genealogy (gene tree) shows the new species nested within the northern clade of B. jararaca. This genealogical pattern can be explained by a recent speciation event for B. otavioi sp. nov. The isolation of insular species of Bothrops from continental ancestor populations are probably related to the same vicariant process, the oscillations of sea level during the Pleistocene. The new species feeds on small hylid frogs, and attains sexual maturity at 388 mm snout-vent length (SVL; males) and 692 mm SVL (females). Bothrops otavioi sp. nov. is endemic to Vitória Island, and should be listed as critically endangered because it is known from only a single area (an island), its geographic range covers less than 100 km 2 , and there is a projected continuing decline in the quality of its habitat because of increasing human settlement.

Bothrops moojeni is a member of the atrox group that occurs in central and southeastern Brazil and adjacent Paraguay and Argentina. We describe habitat use, diel and seasonal activity, biometry, feeding habits, and reproduction of B. moojeni, based on field studies and analysis of 207 preserved specimens. Bothrops moojeni predominantly uses riparian vegetation in the Cerrado (central Brazilian savannas), such as gallery forests and adjacent wet grasslands, although they occasionally use drier interfluvial areas. Sexes are dimorphic in snout-vent length, relative tail length, relative mass, and relative head length. Main prey types were mammals, frogs, and lizards. There is an ontogenetic dietary shift from ectotherms to endotherms. Preypredator mass ratio ranged from 0.008-1.079, and prey mass was positively correlated with predator mass. Although prey absolute mass was positively correlated with snake mass, large snakes did not eliminate small prey from their diets. There was an ontogenetic decrease in prey relative mass. Females consumed more endothermic prey than males, and this difference probably reflects size differences. The reproductive cycle is lengthy and seasonal, with recruitment restricted to the rainy season. Fecundity is positively correlated with female body size. Life-history characters of B. moojeni are similar to those of other members of the atrox group, even though B. moojeni occurs in the Cerrado, a drier and more seasonal biome. 4 Corresponding Author.

We measured the distance between fang tip punctures in defensive bites by western diamondback rattlesnakes (Crotalus atrox) and the distance between their retracted fangs. Because the fang tips at penetration average 112% further apart than their bases at rest, The Extractor®, a device widely marketed in the United States for snake bite first aid, will not simultaneously cover both punctures of most adult New World pitvipers.

Nests and larval development of the nest building gladiator frog, Hyla faber were studied in southeastern Brazil, during the rainy season of 1988-1989. Nests were built at the pond margins, exclusively by males, and varied in shape, size, and composition in relation to the substrate. Nests were used by 1-4 individual males and housed larvae for a mean of 26 days; 0-6 egg clutches were deposited in a nest. Larvae from individual clutches stayed inside the nests for 8-38 days. Embryonic development occurred within the first 210 h after fertilization and larval development, inside an enclosure installed in a pond, lasted over 8 months. Mortality inside the nests was due to nest water evaporation and/or drainage, to eggs sinking in the first hours after fertilization, or to predation by aquatic insects. Slow larval development in Hyla faber seems to be related to breeding in permanent ponds. Nest building in Hyla faber and related species may have evolved from the habit of using natural depressions for egg laying observed in other morphologically similar species.

: The Lizards of Balbina, Central Amazonia, Brazil: A qualitative Analysis of Resource Utilization. Studies on Neotropical Fauna and Environment 26, Twenty one species of lizards (four families) were found in the region of Balbina Hydroelectric Station, Uatumã river, 60 km east of Presidente Figueiredo, Amazonas State, Brazil. Most lizards are exclusive forest dwellers exploring horizontal, vertical, or both spaces. Twenty species are diurnal and one is nocturnal; no marked seasonal difference in activity was observed. Except for the known food specialists Iguana iguana (leaves) and Plica umbra (ants), and the omnivorous Tupinambis nigropunctatus, all other species seem to be arthropod generalists. Three guilds with widely overlapping resource utilization are evident. These patterns are very similar to those found in other localities in the Amazon Basin, probably because of the similarity among their herpetofaunas and structural habitats. A brief review of the hypothesis that tries to explain how the members of these complex assemblages coexist shows that, although some authors suggest that competition is weak or inexists in these assemblages, there is no published study demonstrating the role of competition and/or predation in an Amazonian lizard community.

Rev. Bras il. Biol., 48(4):969-977 ovembr o, . 1.988-Ri o de Jnnciro, RJ Cai.u Postal 478, 6 9083 Manaus, AM *"' (Com 4 figu.ras) RESUMO S ão apresentadas informações sobre a biologia reprodutiva de LeptodactyliJs fuscus em uma lagoa semipermanente em região de cerrado, a 10 km de B oa Vista, Roraima. Durante os meses de março a juribo de 1986, foram realizadas observações e coletas e m 34 noites na lagoa estudada. Machos de L. fuscus cons truiaro tocas subterrâneas nas margens da lagoa c vocalizavam pr6x.imos às suas e ntradas. Ao aproximar-se uma fêmea, o macho a guiava para a toca o nde eram depositados os ovos em ninho de espuma. Ap6s a eclosão, os girinos permaneciam no ninho de espuma até que a toca fosse inundada pela água da Lagoa ou por enxurradas em dias de chuvas fortes. Na lagoa , os girinos tinham atividade diurna e não apresentavam comportamento gregário. Não foi observada marc ante diferença entre a reprodução de L. juscus observada em .Boa V is ta e a conhecida para o ulras regiões, fato que, associado aos dados morfológicos apresentados por outros autores, confirma a existência de pouca variabilidade entre as diferentes populações desta espécie, ao l ongo de sua ampla distribuição.