Marta Elena Fabian

Dolphin interactions with the mullet artisanal fishing on Southern Brazil: a qualitative and quantitative approach

A detailed analysis of the interactions between Tursiops truncatus (Montagu, 1821) and the artisanal fishing of mullets (Mugil spp.) is presented at two localities in the south of Brazil: Laguna (Santa Catarina) and Inibe/Tramandai (Rio Grande do Sul). Its behavioral strategies and the advantages of their association are re-described and quantified based on the success of the capture and on the selectivity of the prey sizes. The mullets are the main resource involved (92% to 75%) both at numerical level and as biomass. Twenty individuals of Tursiops truncatus participated in the interactions in Laguna and 9 in Imbe/Tramandai. The participation and learning of calves is also reported.

Contribuição ao conhecimento da biologia reprodutiva de Molossus molossus Pallas, 1766) (Chiroptera, Molossidae)

Study of 179 specimens of Molossus molossus in Ceara, Brazil, showed morphological and functional ovarian asymmetry in adult females, with the right side more developed. Blastocyst implantation occurred also in the right uterine horn. Active male testicles were bigger (x = 5,38mm) than inactive ones (x = 3,25mm). Pregnancy with subsequent offspring was found in March-April and November, during the wet season.

Sexual size dimorphism in Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from south Brazil

Among Vespertilionidae species, sexual size dimorphism is very well documented, in which females are larger than males. The differences are mainly in body weight, skull measurements and forearm length. Studies have discussed some hypothesis for this phenomenon. However, very little information is known about sexual size dimorphism in Myotis nigricans (Schinz, 1821) in Brazil. In this sense, the goal of this paper is to present a study of this phenomenon in the species. For this, we present a quantitative analysis of sexual size dimorphism assessed by traditional morphometrics. Ten skull measurements in addition to the forearm length of adult specimens were taken. Results of traditional morphometrics revealed sexual size dimorphism in five skull measurements and in the forearm length. Females were larger than males. These differences can be attributed to natural selection on large female size for increase fecundity. Bat females of the Vespertilionidae family are usually larger than males in order to perform parental care appropriately and to provide a successful reproductive process.

Size and shape variability in the skull of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from two geographic areas in Brazil

We present a quantitative analysis of sexual dimorphism and geographic variation in the skull of Myotis nigricans (Schinz, 1821) assessed by geometric morphometrics. Differences in size and shape of skulls were investigated using 30 landmarks plotted on two-dimensional images of lateral and ventral views. Results of geometric morphometrics revealed sexual dimorphism in the centroid size of the skull in both views. Females were larger than males. Nevertheless, there was no sexual dimorphism in skull shape of M. nigricans. Geographic variation was detected in size and shape of the skull. South Brazilian specimens were significantly larger than Ceará specimens only in the lateral view. Differences in skull shape were statistically significant in both views: specimens from South Brazil were brevirostri and presented a more expanded skull in the posterior region while Ceará specimens were longirostri and do not present any expansion in the brain case. Ecological factors for these phenomena are discussed in the text.

Evidence of vertical migration in the Ipanema bat Pygoderma bilabiatum (Chiroptera: Phyllostomidae: Stenodermatinae)

Migration is defined as a seasonal and cyclic population movement observed in all animal classes and studied mainly in vertebrates. A considerable part of the knowledge on migration comes from birds, for which migration is an important aspect of their biology. In the case of bats, females usually migrate larger distances than males in some species. The present study analyzes the seasonal occurrence of Pygoderma bilabiatum (Wagner, 1843) at different elevations, in order to test for a pattern that evidences migration, using data from the states of Espirito Santo, Minas Gerais, Rio de Janeiro, Sao Paulo, Parana, Santa Catarina, and Rio Grande do Sul, Brazil. A total of 529 specimens of P. bilabiatum were captured. Pygoderma bilabiatum seems to be more frequent at intermediate and high elevations (over 80% of all captures were made above 250 m a.s.l.) and at latitudes above 22°S, where rainfall is high (over 1,500 mm) and temperatures are mild (16-23°C). Sex ratio varied with elevation; it was skewed towards males at lower elevations (N = 9, r2 = 0.60, F = 12.311, p = 0.008, Sex ratio = 0.0004*elevation + 0.976), though females predominated at all altitudinal bands and in all states analyzed.

Mammalia, Chiroptera, Phyllostomidae, Platyrrhinus recifinus (O. Thomas, 1901): first confirmed record in the state of Santa Catarina, southern Brazil

We report the first confirmed record of Platyrrhinus recifinus to Santa Catarina state, south of Brazil. The distribution of this species was expanded approximately 350 km south of its previous known limit.