data showed no tendency of side dominance at specific levei a1though it may ... For B . constrictor 47.0 % of 119 constrictions observed were to the right, and the ...
CONSTRICfION
HELENA
BEBA VIOR IN SNAKES: A smE DOMINANCE?
R. LOPES*,
CARLOS
FREOERICO
T~ THERE
O. ROCHA
**
and AUGUSTO S. ABE*** .**Setor de Ecologia, Instituto de Biologia, Universidadedo Estadodo Rio de Janeiro, RuaSão FranciscoXavier, 524, Maracanã,20550, Rio deJaneiro,RJ., Brazil ***Departamento de Zoologia, Instituto de Biociências,UniversidadeEstadualPaulista, Campusde Rio Claro, 13500,Rio Claro, SP, Brazil
RESUMO O Comportamento de Constrição em Boideos: Há uma Dominância de Lado? O comportamento de constrição enfocando a dominância de lado foi estudada nos boídeos neotropicais Boa constrictor e Epicrates cenchria em experimentos de predação sobre ratos. Os dados sugeriram que não há uma tendência à dominância de lado de constricção ao nível específico, embora esta tendência possa ocorrer ao nível individual para as duas espécies. Palavras-chave: Serpentes, comportamento de constrição, comportamento variável, Boidae, Boa constrictor, Epicrates cenchria. ABSTRACT Constriction behavior focusing on side dominance was studied iIl the neotropica1 boids Boa constrictor and Epicrates cenchria preying on rats. The data showed no tendency of side dominance at specific levei a1though it may occur at individuallevel for both species. Key words: Serpentes, Subjugation of prey, variable behavior, Boa constrictor, Epicrates cenchria, Boidae. distributed only in Boidae, and Colubridae (Greene and Burghardt, 1978). Although general informations were reported for constriction in snakes (e.g. Ditmars, 1912; Klaubcr, 1956; Pope, 1961) there are few infonnations on behavioral mechanisms by which these snakes kill the prey (Frazzetta, 1966). Constriction behavior in snakes was recently studied and a ventral and dorsal pattem of constricting coi1ing around the prey were recognized (Wi11ard, 1977; Greene and
INTRODUcrION Constriction is a behavior by which some snakes immobilizes their preys throughout pressure made by two or more parts of the body (Greene and Burghardt, 1978). This way of subduing prey is known in some species of the families Acrochordidae, Aniliidae, Xenopeltidae, but is widely *Deceased ReceivedJanuary 11, 1990 Accepted June 7, 1991 Distributed November 30, 1991
851
Rev.
Brasil.
Biol..
51(4):853-856
LOPES, ROCHA and AlIE
Burgardt, 1978; Heinrich and Klaassen, 1985). In addition, the right or left side of the body can be used when the snake constrict the prey. The side dominance in constricting coiling has been a controversia1 subject. Willard (1977) studying constriction in 95 species of snakes belonging to the families Colubridae and Boidae did not find a side dominance either at specific or indivtdua1 leveI, but the data are based on few replicate feedings of any one individua1. On the other hand, Heinrich and Klaassen (1985) observed constriction behavior in ten species of snakes (Colubridae and Boidae), and concluded that there is a definite preference for a particular side by some of the snakes studied (Boa constrictor,. Lampropeltis getulus; Elaphe gutata,. E. obsóleta). According to Heinrich and Kaassen (1985), Boa constrictor is a typica11y ..right sided" species, a1though the conclusion was based in only one specimen. Constriction behavior was observed in the boids Boa constrictor and Epicrates cenchria addressing two questions: i) is there a ventra1 or dorsa1 pattem of constriction for these two species? ii) is there any side dorninance during constriction at specific or individua11evel? MA TERIAL AND METHODS Prey constriction observations were runned with adult and sub-adult subjects being twenty eight Boa constrictor (SVL 70-210 cm), nine of which from the same clutch, and seventeen Epicrates cenchria (SVL 53-106 cm). For each observation the snake was individually housed in a polietilen box (75 x 50 x 45) and laboratory rat (Rattus norvegicus) weighing 60-120 9 offered as a prey. Observations were conducted at room temperature ranging from 25 to 27°C. For every attack it was recorded: ventra1 or dorsa1 coiling pattem {Willard, 1977) and side towards which constriction coils were directed (Heinrich and Kaassen, 1985). A coil was considered complete whenever the snake's body tumed completely around the prey. For each observation a picture or sketch was taken to posteriorly confIrm the constricting pattem.
constriction coils was recorde
