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The mating system of Rana adenopleura. 2007/12/4. Introduction Methods Animal model and study site Field procedure Preliminary result Behaviour Male mating success Mating system. Introduction Methods Animal model and study site Field procedure Preliminary result Behaviour
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The mating system of Rana adenopleura 2007/12/4
Introduction Methods Animal model and study site Field procedure Preliminary result Behaviour Male mating success Mating system
Introduction Methods Animal model and study site Field procedure Preliminary result Behaviour Male mating success Mating system
Mating systems are according to polygamy level (Emlen and Oring 1977; Wells 1977a; Davies 1991)
Life histories and biological factors that influence mating system Parental care Breeding period Inter sex and intra sex selection Operational sex ratio Timing of reproduction Territorial behavior was well known in the taxa of fishes, reptiles, avian, and mammals
However, Resource defense polygyny has been reported rarely in anuran The details of breeding biology are not known for most anuran species, especially in tropical regions (Sullivan et al 1995) (Tsuji 2004)
Purpose 1) Identify territoriality of R. adenopleura males 2) The temporal and spatial pattern of males 3) Identify the factors of male mating success 4) Confirm the mating system of R. adenopleura
Experiment 1 The mating system of Rana adenopleura Introduction Methods Animal model and study site Field procedure Preliminary result Behaviour Male mating success Mating system
The species Oliver frog (Rana adenopleura) Family Ranidae, genus Rana) (Chuang 2006)
The species- sexual dimorphism Vocal sac (Duellman and Trueb 1986) ♂ ♀ Shoulder gland (Thomas et al 1993)
The species- sexual dimorphism ♀>♂ *** *** t=6.1 df=133 p<0.0001 t=5.61 df=133 p<0.0001
Field procedure 27 nights (12 Aug – 7 Sep) Censuses during whole night Body size measurement (SVL & weight) Individual mark (waist bands , tags, toe clipping) tag Numbered waist band
Experiment 1 The mating system of Rana adenopleura Introduction Methods Animal model and study site Field procedure Preliminary result Behaviour Male mating success Mating system
Behavior of males Males defended their territory by vocalization and aggressive behavior Most territories were near shore
Behavior of females Females adopt a low posture to close calling males Females approach males very slowly and easily disturbed
Oviposition behavior Female spontaneously back her body under male’s Males do not clasp female until physical contact After laid eggs, males restart calling immediately
How to establish a calling site Males without territory often adopt trial and error fight
♀ ♂ ♀ ♀ Male mating success
Male mating success 52 egg mass in 27 nights 24% (9/38) marled males mated at least once 1.37 ± 4.69 for all males 5.78 ± 8.56 for mated males
Male mating success R=0.63 P=0.067
Mating system 1. Prolonged breeder lasting at least 6 month Sex ratio (adult females/adult males) Overall – 2.82 (107/38) (Chuang 2006) Highly biased toward females !! (Wells 1977a)
Mating system Males and females qualified to mate Adult sex ratio Males competition results in a female-biased operational sex ratio (Ahnesjo et al 2001 )
Mating system 2. Resource-defense polygyny Males defend territories include oviposition sites Males may be able to predict suitable oviposition sites (Emlen and Oring 1977, Sullivan et al 1995)
Mating system 3. Polygamy Frequent oviposition by females in a breeding season (Sullivan et al 1995, Tsuji 2004)
Conclusion Male R. adenopleura have strong aggressive territoriality, they defense a territory for calling, mating, and oviposition The territorial males tend to maintain a site for a long time The male body size and present days were not correlated to mating success Mating system prolonged breeder, resource-defense polygyny, polygamy