C:\Documents and Settings\SATEL

Сomentários

Transcrição

C:\Documents and Settings\SATEL
Chiroptera Neotropical , 8(1-2), 2002
Brasil (Mammalia, Chiroptera). Rev. Brasil. Zool.
13:61-66.
Terborgh, J. 1986. Keystone plant resources in the
tropical forest. In: Conservation biology: the science
of scarcity and diversity. Soulé, M. E. (ed). Pp. 330344. Sinauer Associates, Inc., Publishers,
Sunderland, Massachusetts.
Vizotto L. D. & Guerra, D. Q. 1981. Ocorrência, no
nordeste Brasileiro, de Chiroderma doriae Thomas,
1891 (Chiroptera-Stenodermatinae). Resumos das
comunicações científicas do VIII Congresso
Brasileiro de Zoologia, Distrito Federal, p. 132-133.
Wendeln, M. C., Runkle, J. R. & Kalko, E. K. V. 2000.
Nutritional values of 14 fig species and bat feeding
preferences in Panama. Biotropica 32: 489-501.
FISH CONSUMPTION BY NOCTILIO
LEPORINUS (LINNAEUS, 1758) IN
GUARATUBA BAY, SOUTHERN BRAZIL
Marcelo Oscar Bordignon1
Adriana de Oliveira França1
1
Departamento de Ciências do Ambiente Universidade Federal de Mato Grosso do Sul. Caixa
Postal 252 , 79304-020 Corumbá, MS, Brasil.
Email: [email protected]
ABSTRACT
Throughout 1999, the fishes consumed by Noctilio
leporinus were documented in a salt-water ecosystem,
by analysing the feces of bats captured in mist nets.
Of the 55 samples analyzed the most frequent fish
species were Atherinella brasiliensis, Mugil curema,
Cetengraulis edentulus, Opisthonema oglinum and
Harengula clupeola. The quantitative result was
similar to that obtained in other studies conducted in
Puerto Rico, but not qualitatively.
Keywords: Noctilionidae, bat diet, piscivorous bats,
mangrove ecossistem
INTRODUCTION
Feces collection of bats which have been captured in
order to study the diet in tropical biomes, are more
common for fruit-eating species (Sipinski & Reis
1995). Therefore, studies involving carnivorous or
piscivorous species are very limited (Nowak 1994).
The recent studies available in the literature about
the diet of N. leporinus use different study methods,
such as stomach content analysis of captured bats
(Cervantes & Solorzano 1991) or collection of fecal
material deposited in their shelters (Hood & Jones
1984, Brooke 1994). In Brazil, the study by Willig
(1985) verified that N. leporinus consumes fish and
insects, but does not specify which one or the frequency
with which these items occur in the diet.
The aim of the present study was to obtain data about
fish consumption by N. leporinus in a salt-water
ecosystem on the southern coast of Brazil by collecting
and analyzing feces obtained from bats captured
during their foraging activities. The study was carried
out in Guaratuba Bay (Chaves et al. 1998) from
January to December 1999. Four nights of capture
were carried out every month, between 18.00 and
06.00 o’clock, using three mist nets of 2.6x9 m in
size, with a black mesh and 38mm in length (CH9
Avinet, Inc. USA model), located perpendicularly to
the bank and above the water surface. Each captured
bat was placed in a black cotton bag, remaining there
until 12.00 o’clock the following day, in order to obtain
the feces. These samples were preserved in 10% formol
and later analyzed in the laboratory. Each captured
bat was released the night after it was captured, at
dusk.
The fish scales found in the bat’s scats were compared
with those from the collection of the Departamento
de Zoologia at the Universidade Federal do Paraná. It
was not possible to identified the invertebrates found
in the scats, because the material was very fragmented.
Fecal samples from 55 individuals of N. leporinus were
obtained, containing six fish families distributed in
eight species. The Atherinopsidae family was the most
frequent in the scats, followed by the Mugilidae,
Clupeidae (sardines) and Engraulidae (anchovies)
families. The Centropomidae and Carangidae were
the least frequent in the N. leporinus diet (Table 1).
Most of the samples collected (68.75%) only had one
species of fish, while 14 samples (29.16%) contained
two species and one sample (2.08%) contained three
different fish species.
The data obtained in this study show that the
ichthyofauna present in the N. leporinus diet is varied.
Quantitatively, this result was similar to that obtained
by Brooke (1994), who recorded eight fish species from
eight different families in Puerto Rico. However,
qualitatively, the fish species present in the diets were
different, even though both studies presented
Atherinopsidae and Clupeidae families in the N.
leporinus diet. This must be due to the particularities
of the ichthyofauna in each study location.
The Mugilidae, Centropomidae and Carangidae
families identified in the bats of Guaratuba were not
cited by Brooke (1994). But Cichlidae (Oreochromis
Page 148
CN8-1-2.pmd
148
15/1/2003, 16:50
Chiroptera Neotropical , 8(1-2), 2002
Table 1. Fishes encountered in 55 individual
scats of N. leporinus.
Species
Frequency
Atherinopsidae
Atherinella brasiliensis
38.18
Mugilidae
Mugil curema
31.00
Engraulidae
Cetengraulis edentulus
18.18
Clupeidae
Opisthonema oglinum
Harengula clupeola
Pellona harroweri
16.36
11.00
3.63
Centropomidae
Centropomus parallelus
5.45
Carangidae
Chloroscombrus chrysurus
1.81
mossambicus), Helotridae (Helotris), Holocentridae
(Holocentrus vexillarius), Gerreidae (Gerres
cinereus), Sphyraenidae (Sphyraera barracuda), and
Exocetidae (Hemiramphus brasiliensis) families
encountered by Brook (1994) were not present in this
study, despite the fact that Gerreidae and Exocetidae
families are also being present in Guaratuba Bay.
The most frequent fish encoutered in the N. leporinus
diet from Guaratuba was Atherinella brasiliensis
(Atherinopsidae), while Brooke (1994) obtained
52.0% for another species (Atherinomorus stipes) in
Puerto Rico. After Atherinopsidae, the most frequent
family in Brooke (1994) was Cichlidae (42.0%),
represented by Oreochromis mossambicus, but in
Guaratuba Bay were Mugilidae and Clupeidae.
Both in Guaratuba and Puerto Rico, N. leporinus has
a large variety of fish. Therefore, the variety and
availability of shoals of these fishes, which are usually
formed of juveniles, will determine whether N.
leporinus captures more or less of them. This
conclusion is based on the fact that the fishing
behavior of this bat depends on the presence and
density of its prey in foraging areas (Romero 1985).
Figure 1. Location of Guaratuba bay in Brazil.
Page 149
CN8-1-2.pmd
149
15/1/2003, 16:50
Chiroptera Neotropical , 8(1-2), 2002
Atherinidae, Mugilidae, Engraulidae and Clupeidae
species are fish which group together in shoals,
moving close to the surface. The typical behavior of
these species therefore makes them vulnerable prey
for the strategy used by N. leporinus when capturing
fish, since it uses an acute method of echolocation to
detect shoals of fish which move close to the surface
(Altenbach 1989, Brooke 1994).
ACKNOWLEDGMENTS
We are grateful to the Iate Clube de Caiobá board of
directors, Fundação “O Boticário de Proteção à
Natureza” and CAPES/CNPq for the logistical and
financial support during the study. To Kesa Lehti and
Fernando C.W. Rosas for their suggestions and
revision of the manuscript.
REFERENCES
Altenbach, J. S. 1989. Prey capture by the fishing bats
Noctilio leporinus and Myotis vivesi. J Mamm 70:
421-424.
Brooke, A. P. 1994. Diet of the fishing bat, Noctilio
leporinus (Chiroptera: Noctilionidae). J Mammal
75: 212-218.
Chaves, P. T. C., Rickli, A. & Bouchereau, J. L. 1998.
Stratégie d’occupation de la mangrove de la baie de
Guaratuba (Brésil) par le Sciaenidae prédateur
Isopisthus parvipinnis (Teleostei, Pisces). Cah Biol
Mar 39: 63 - 71.
Cervantes. M. A. & Solorzano, T. A. 1991. Notas sobre
la dieta alimenticia del murcielago pescador Noctilio
leporinus (Mammalia: Chiroptera). An Esc Nac
Cienc Biol Méx 35: 123-127.
Hood, C. S., Jones Jr., J. K. 1984. Noctilio leporinus.
Mamm Spe 216: 1-7.
Nowak, R. M. 1994. Walker’s Bats of the World.
London, The Johns Hopkins University Press, pp.
123-125.
Romero, A. 1985. Cave colonization by fish: role of
bat predation. The Amer Midl Natur 113: 7-12.
Sipinski, E. A. B. & Reis, N. R. 1995. Dados
ecológicos dos quirópteros da Reserva de Volta
Velha, Itapoá, Santa Catarina, Brasil. Revta Bras
Zool 12: 519-528.
Willig. M. R. 1985. Reproductive patterns of bats from
caatingas and cerrado biomes in northeast Brazil.
J Mammal 66: 668-681.
SOBRE A GRANDEZA E A UNIDADE UTILIZADA
PARA ESTIMAR ESFORÇO DE CAPTURA COM
UTILIZAÇÃO DE REDES-DE-NEBLINA.
Fernando Costa Straube1
Gledson Vigiano Bianconi1,2
1
Mülleriana: Sociedade Fritz Müller de Ciências
Naturais. Caixa Postal 1644. Curitiba, PR. 80011970 ([email protected])
2
Programa de Pós-graduação em Biologia Animal,
UNESP, São José do Rio Preto e Laboratório de
Chiroptera, UNESP, Caixa Postal 341, Araçatuba,
SP. 16050-680 ([email protected]).
Redes-de-neblina são instrumentos utilizados há
poucas décadas, principalmente em pesquisas
envolvendo aves e morcegos. Seu surgimento e
disponibilidade no mercado pode ser considerado uma
verdadeira revolução metodológica, pois favoreceu um
aumento impressionante na possibilidade de obtenção
de informações antes praticamente inacessíveis.
Novas linhas de pesquisa passaram a ser abordadas
com sucesso, uma vez que o número de indivíduos
amostrados é muito superior do que o permitido pelos
métodos anteriores (IBAMA 1994), aumentando o
potencial de análises em ecologia numérica e mesmo
a ampliação de acervos de museu. Particularmente no
caso dos quirópteros, as redes mostram-se
fundamentais em inventários, permitindo uma
amostragem abundante, ainda que seletiva,
considerando-se que os filostomídeos são mais
facilmente capturados (Pedro & Taddei 1997).
Apesar desse notável avanço metodológico, as
informações tornadas disponíveis como consequência
dos inúmeros trabalhos de campo envolvendo captura
de morcegos e aves não têm permitido comparações,
uma vez que não há qualquer tipo de padronização da
unidade de esforço amostral.
É certo que uma série de particularidades dificultam
tais comparações, tais como a seletividade de acordo
com o comportamento do animal, as dimensões da
malha da rede, o horário de exposição, a
representatividade das capturas em relação à área total
e várias outras. Entretanto, essas variáveis não
descartam a necessidade de uma normatização para o
“esforço de captura” nos casos em que se utilizam
redes-de-neblina.
Quando o enfoque na utilização de redes-de-neblina
recai sobre o esforço de captura, este pode ser
decomposto em apenas duas variáveis: área e tempo
de exposição. A primeira grandeza engloba duas
outras: a altura da rede e seu comprimento, ambas
Page 150
CN8-1-2.pmd
150
15/1/2003, 16:50

Documentos relacionados

Descolorao do plo como mtodo de marcar morcegos para

Descolorao do plo como mtodo de marcar morcegos para resulting in pale skin, white fur, and red eyes (Buchanan 1985). Albinism is a rare phenomenon in bats (Barquez et al. 2003). In a recent review, Uieda (2000) reported records of complete albinism ...

Leia mais