Vanderlaine Amaral Menezes

The terrestrial reptile fauna of the Abrolhos Archipelago: species list and ecological aspects

We have studied the terrestrial reptile fauna of the Abrolhos Archipelago (a group of five islands located ca. 70 km off the southern coast of the State of Bahia, Brazil) and analyze here some of its ecological aspects such as diet, thermal ecology, activity, and some reproductive parameters. Three lizards comprise the archipelagos terrestrial reptile fauna: Tropidurus torquatus (Tropiduridae), Mabuya agilis (Scincidae), and Hemidactylus mabouia (Gekkonidae). The first two are diurnal and the latter is crepuscular/nocturnal (initiating activity at ca. 17:30). The activity period of T. torquatus extended from 5:30 to 18:30 h. Mean field body temperatures of active T. torquatus, M. agilis, and H. mabouia were, respectively, 34.0 +/- 3.7 degrees C (range 23.8-38.0 degrees C; N = 75), 34.5 +/- 2.2 degrees C (range 30.8-37.0 degrees C; N = 6), and 26.3 +/- 1.1 degrees C (range 24.8-28.0 degrees C; N = 8). The predominant prey items in the diet of T. torquatus were ants, coleopterans, and hemipterans. In the diet of M. agilis, coleopterans were the most frequent prey items. For H. mabouia, the most important dietary items were orthopterans. Clutch size of T. torquatus averaged 4.1 +/- 1.1 (range 2-6; N = 15) and was significantly related to female size (R2 = 0.618; p = 0.001; N = 15). Clutch size for H. mabouia was fixed (two) and mean litter size of the viviparous M. agilis was 3.3 +/- 0.6 (range 3-4; N = 3). Tropidurus torquatus and H. mabouia deposit their eggs under rocks in the study area, with the former burying them but not the latter; in both species, more than one female often oviposit under the same rock.

Helminths infecting the parthenogenetic whiptail lizard Cnemidophorus nativo in a restinga habitat of Bahia State, Brazil.

A sample of 101 specimens of the unisexual whiptail lizard Cnemidophorus nativo (Squamata; Teiidae) from a coastal site in Bahia State, Brazil were examined for the presence of endoparasites. Of these, 35 (34.7%) harboured helminths. Six helminth species were recovered from C. nativo, including five nematodes (Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia, Skrjabinelazia intermedia and Parapharyngodon sp., and one cestode (Oochoristica ameivae), all representing new host records. Most lizards were infected by a single species of helminth and none by more than three. Infection rates were neither significantly influenced by host body size nor by environmental factors. The results are compared with data from studies on other whiptail species in both South and North America.

Reproductive Ecology of the Parthenogenetic Whiptail Lizard Cnemidophorus nativo in a Brazilian Restinga Habitat

Abstract We studied the reproductive cycle of the teiid lizard, Cnemidophorus nativo, at the restinga of Guaratiba, in Prado municipality, Bahia State, northeastern Brazil. The population was all female. For each female, we recorded total number of follicles, number of vitellogenic follicles in each ovary, size and color of the largest follicle, presence and size of corpora lutea, and number and size of oviductal eggs. The smallest reproductive female measured 48.8 mm (SVL). Clutch size varied from one to four eggs (mean = 2.2 ± 1.0; N = 37) and was significantly affected by female size (F1,35 = 8.437; R2 = 0.194; P = 0.006). Fifty percent or more of sexually mature females were reproductive each month, containing either oviductal eggs or vitellogenic ovarian follicles and juveniles (30–48.3 mm SVL) occurred in nearly all months studied, indicating an extended period of reproduction by the species. The number of reproductive females was not significantly related to monthly rainfall or to temperature in the area. We conclude that the population of C. nativo at Guaratiba is unisexual, oviparous and that reproduction occurs throughout the year, independent of habitat seasonality.

A method for testing the host specificity of ectoparasites: give them the opportunity to choose

Host-choice experiments were carried out with rodent and bat ectoparasites on Ilha Grande, state of Rio de Janeiro, Brazil. We constructed experimental chambers that enclosed three different rodent or bat host species, and then introduced a selected set of ectoparasitic arthropods. When given the opportunity to choose among host species, the ectoparasites showed a strong tendency to select their primary hosts, and reject novel host species. These kinds of simple experiments can be valuable tools for assessing the ability of ectoparasites to locate and discern differences between host species, and make choices about which hosts to infest, and which hosts to avoid.

Ecology of Ischnocnema parva (Anura: Brachycephalidae) at the Atlantic Rainforest of Serra da Concórdia, state of Rio de Janeiro, Brazil

Ischnocnema (Brachycephalidae) includes many species that are important members of the leaf litter frog communities in the Atlantic Rainforest of Brazil. Ischnocnema parva (Girard, 1853) is endemic to the Atlantic Rainforest biome and is restricted to the forests of southeastern Brazil. Currently, the available information about the ecology of I. parva is scarce. We studied the diet, the habitat use, reproduction and density of I. parva in an area of Atlantic Rainforest at the Concordia mountain range, Rio de Janeiro. Individuals of I. parva were captured in April 2005 using different sampling methods: time constrained search (transects), plots of 5 x 5 m (25 m2) on the litter, and pitfall traps with drift fences. We found 240 frogs; 35 females and 205 males. Females (mean SVL = 19.1 mm) were significantly larger (F1,238 = 143.016, R2 = 0.375, p < 0.001) than males (13.2 mm). The species preyed mainly on arthropods, with ants and isopods being the most important items, both showing high values of importance index (Ix = 50.0 and 26.7, respectively). Ischnocnema parva is a terrestrial species whose preferential microhabitat at the Serra da Concordia was the litter of the forest floor (78.7%). The activity was predominantly crepuscular-nocturnal and the estimated density of I. parva was 24.9 ind/100 m2. For the eight ovigerous females captured, the mean number of mature oocytes per female was 25 (range: 22-30) and the oocyte mean diameter was 1.11 mm (N = 40 oocytes). Oocyte number increased with female body size (R2 = 0.504, F1,6 = 6.107, p < 0.05, N = 8), indicating that as females increase in size they produce larger clutches. Some ecological aspects such as diet and microhabitat use were similar to that observed for an insular population of I. parva, whereas reproductive traits differed. Thus, long term studies are necessary to understand the extent to which these differences are explained by environmental factors.

Ecology and Natural History of the Easternmost Native Lizard Species in South America, Trachylepis atlantica (Scincidae), from the Fernando de Noronha Archipelago, Brazil

Abstract We studied the ecology of Trachylepis atlantica, the easternmost native lizard species in South America, endemic to the Fernando de Noronha archipelago, approximately 350 km off the northeastern coast of Brazil. Activity of this species extended from dawn to dusk, with a peak from 1200–1400 h. Mean body temperature of active T. atlantica was 32.2 ± 2.9°C and was significantly related to both air and substrate temperatures. Trachylepis atlantica used most types of available substrates in the area but was found most frequently (72.5% of observations) on rocks and normally used perches up to 80 cm high. There was sexual dimorphism in body size, with males larger than females. Trachylepis atlantica had an omnivorous diet, with plant material comprising 77% of the volume ingested and being present in 67% of stomachs with food. Formicidae and insect larvae were the main animal items in the diet. Mean prey volume (6.9 ± 5.3 mm3) was small compared to other related species. This, coupled with the high plant consumption, suggests that local availability of suitable prey may be limited, as expected for small islands in general.

Feeding habits of the endemic tropical parthenogenetic lizard Cnemidophorus nativo (Teiidae) in a restinga area of northeastern Brazil

The population of Cnemidophorus nativo in the restinga of Guaratiba, Bahia State, Brazil, is carnivorous with a diet consisting predominantly of insect larvae and termites, which is similar to that of other cnemidophorines. The absence of seasonal variation in diet may be a consequence of the availability of termites throughout the year. The small size of the termites and the ease with which both juveniles and adults eat larvae independent of their length were probably the cause of the poor relationship between lizard body measurements and mean number and volume of prey consumed.

An unusual ecology among whiptails: the case of Cnemidophorus lacertoides from a restinga habitat in southern Brazil

We studied the ecology of Cnemidophorus lacertoides at a restinga habitat in southern Brazil. Peak activity occurred between 12.00 and 15.00. The mean body temperature of active lizards (35.0 ± 2.9°C) was relatively low compared with other whiptails and was significantly influenced by environmental temperatures. Mean snout–vent length and mean body mass of individuals were 56.5 mm and 4.4 g, respectively. Male and female C. lacertoides were not significantly different in body size. Cnemidophorus lacertoides consumed 12 types of prey, with ants and spiders being the most important items. Unexpectedly, lizards did not consume termites, which tend to be very important items in the diets of most whiptails. We conclude that the population of Cnemidophorus lacertoides we studied deviates from the typical whiptail ecology because many of its ecological features differ from those of most other cnemidophorines of similar size.

Effects of a fire on a population of treefrogs (Scinax cf. alter, Lutz) in a restinga habitat in southern Brazil

The area of the Dunas da Joaquina, in Santa Catarina island, contains one of the most important remnants of restinga habitat in Santa Catarina State, southern Brazil. In December 2003, a fire occurred in a portion of this area, affecting most of the vegetation, including the bromeliad community. In this study, the density of individuals and the diet composition of the bromelicolous treefrog Scinax cf. alter were compared between the area affected by the fire and an adjacent unburned area. One-hundred-and-fifty-eight ground bromeliads (Vriesea friburguensis) were dissected and searched for the presence of treefrogs among their leaves. We found 30 frogs in 29.5% (23/78) of the bromeliads from the unburned site, with a mean of 1.3 frogs per rosette, and 15 frogs in 12.5% (10/80) of the bromeliads from the burned site, with a mean of 1.6 frogs per rosette. Eight (27%) of the frogs from the unburned site and eleven (73%) of those from the burned site had empty stomachs. Frogs from the burned site also contained less prey per stomach than those from the unburned site. The data suggest that the fire has negatively affected the local population of Scinax cf. alter, though it is possible that the population can recover.

Anurans from the “Restinga” of Parque Natural Municipal de Grumari, state of Rio de Janeiro, southeastern Brazil

We present a list of the anuran amphibians from “restinga” of Grumari, part of the Parque Natural Municipal de Grumari (PNMG), Rio de Janeiro municipality, state of Rio de Janeiro, southeastern Brazil. This study was carried out from May 2009 to December 2010 using two active sampling methods: quadrant plots and acoustic/visual transects. We recorded 22 anuran species distributed in six families: Bufonidae (1 species), Craugastoridae (1), Hylidae (14), Leptodactylidae (3), Microhylidae (2) and Strabomantidae (1). The presence of endangered and endemic species evidence Grumari’s importance as an area for conservation of the “restinga” habitat remnants in Rio de Janeiro. Grumari is also one of the richest known areas in terms of amphibian species among the “restinga” areas studied to date in Brazil, second only to Mata de Sao Joao, Bahia.