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) mating systemmating typeOSR polygynyFemale defenceUnpredictable Resource defence ♂ biased Lek ？ Scramble CompetitionUnity polyandryMale defence ♀ biased Resource defence ♀ biased monogamyMate-guarding/assistanceUnity polygamyResource useUnity (modified from Sullivan et al 1995)

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 Shoulder gland ♂♀ (Duellman and Trueb 1986) (Thomas et al 1993)

*** The species- sexual dimorphism t=6.1 df=133 p<0.0001t=5.61 df=133 p< ♀>♂♀>♂

Study site

Field procedure 27 nights (12 Aug – 7 Sep) Censuses during whole night Body size measurement (SVL & weight) Individual mark ( waist bands, tags, toe clipping ) Numbered waist band tag

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 males

Behavior of males-Playback experiment

Behavior of males

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 ♀ ♀ ♀ ♂

24% (9/38) marled males mated at least once 1.37 ± 4.69 for all males 5.78 ± 8.56 for mated males 52 egg mass in 27 nights

Male mating success R=0.63 P=0.067 Dependent variable Independent variable rP Male mating success SVL Body mass Shoulder gland No. nights present ﹢ ﹢ p<0.1

Mating system 1. Prolonged breeder lasting at least 6 month Sex ratio (adult females/adult males) Overall – 2.82 (107/38) Highly biased toward females !! (Wells 1977a) (Chuang 2006)

Males and females qualified to mate Mating system Males competition results in a female-biased operational sex ratio (Ahnesjo et al 2001 ) Adult sex ratio

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 ） SpeciesFemales favorsource R. catesbeianawarmer water Howard 1978 R. clamitansdense vegetation Wells 1977b R. kuhliiweak current creek Tsuji 1998

Mating system 3. Polygamy Frequent oviposition by females in a breeding season (Sullivan et al 1995, Tsuji 2004 ） Female No.Oviposition dateclutch size 158/ / / /2238

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