Herpetology Notes, volume 7: 787-789 (2014) (published online on 21 December 2014)

Defensive Behaviour of (Blyth, 1856) (Anura: ) from Peninsular Malaysia

Shahriza Shahrudin

Microhyla berdmorei is a microhylid that can be this behaviour, a frog remains motionless even when recognized by having a head about as long as broad, touched (Toledo et al., 2010). Previously, this type snout obtusely pointed, rounded in profile, tympanum of defensive behaviour has not been reported in M. visible but not visible through skin, broad webbing berdmorei. Thus, herein we report the death feigning reaching disks of all toes, skin smooth or with very and crouching down behaviours of this species as a way small scattered tubercles on back and yellowish belly. to avoid from predator. Total length for adult males and females may reach up On 16 March 2014, between 2000-2100 hours, seven to 25 and 45 mm (Berry, 1975). This species is widely adult males of M. berdmorei (Fig.1) were collected distributed ranging from Southern Yunnan Province, from Sedim Receational Forest, Kedah (5025’N, Northeast India, Eastern Bangladesh, through 100046’E; < 200 m asl). All specimens that were Myanmar, Thailand, Laos, Cambodia and Vietnam, detected were actively calling under dead leaves at south to Peninsular Malaysia, Sumatra and parts of the edge of a river. The specimens were brought to the but is absent in Singapore (IUCN, 2013). laboratory and measurements on snout-vent length, In Peninsular Malaysia this frog can be found on the head width and weight were taken using digital calliper forest floor of primary forest and along logging tracks and electronic balance. When handled and approached in disturbed areas (Berry, 1975). Several forested areas during photographic season, three individuals showed such as Pulau Langkawi Kedah, Janda Baik Pahang, several defensive behaviours such as death feigning, Gombak Forest Selangor, Gunong Benom Pahang motionlessness, stiff-legs and crouching down. The (Berry, 1975) and Peta Endau-Rompin (Shahriza et al., other four individuals did not showed any defensive 2012) are known localities for this species. sign. are exposed to a wide variety of predators. To avoid predation, anuran developed various defensive behaviours such as death feigning, stiff-legs, contracting, mouth-gaping and body-raising (Duellman and Trueb, 1986; Toledo et al., 2011). Totally 30 categories of defensive behaviours have been documented in anurans and the most commonly defensive behaviour was fleeing, followed by remaining motionless (Toledo et al., 2011). Death feigning or thanatosis is mostly displayed by non-toxic species and while displaying

School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang Malaysia Figure 1. An adult male of M. berdmorei from Sungai Sedim, E-mail: [email protected] Kedah. 788 Shahriza Shahrudin

Figure 2. Death feigning behaviour of M. berdmorei. Figure 3. Stiff-legged behaviour of M. berdmorei.

In the first case (individual 1), we transferred the frog stretched out its legs. It remained in this stretching from the aquarium to a substrate (dead leaves) for a legs position for about two minutes (Fig. 3). The frog photo shoot season. Suddenly, the frog turned its belly showed this kind of behaviour after we approached it for up, inflated the body and exposed its yellowish belly. about three to four minutes. Later the frog turned back Both of his front limbs are upward and rear limbs close to normal position and took approximately one to two to the body. The frog stayed in this motionless position minutes before it leaped away. This type of behaviour for about 2-3 minutes, with both of its eyes opened (Fig. might not be a real antipredator behaviour but instead 2). Afterward it slowly turned back to normal position, a sign of exhaustion. The SVL, HW and W were 30.4 leaped away and went hiding under dead leaves. The mm, 9.54 mm and 6 g respectively. snout-vent length (SVL), head width (HW) and weight In the third case (individual 3), the specimen was (W) were 34.2 mm, 10.8 mm and 7 g respectively. trying to escape by hiding beneath the dead leaves. We In the second case (individual 2), the specimen was slowly removed the leaves that covered the frog to take leaping away in order to escape. We captured the frog a photo shoot. Surprisingly the frog did not leap, but again using bare hand and put it on dead leaves to stayed motionless in a crouching down position. The take photos. Suddenly the frog flattened its body and chin, belly and limbs of the frog were flattened and touched the substrates. The frog tucked its limbs and head tightly onto its body causing the body to become crouching. The snout of the frog was facing down but the eyes were still opened (Fig. 4). After 1.5 minutes, the frog suddenly turned its body back to normal position and leaped away. The SVL, HW and W were 30.64 mm, 9.6 mm and 6 g respectively.

From this observation, it showed that a single species of frog may demonstrate a variety of defensive behaviours in order to protect themselves from a potential predator. Subsequently, all the specimens (14USM-SS-MB01, 02, 03, 04, 05, 06, 07) were euthanized, tagged, fixed with 10% formalin, stored in 70% ethanol and being deposited at School of Pharmacy, Universiti Sains Malaysia (USM) for references. Figure 4. Crouching down behaviour of M. berdmorei. Defensive Behaviour of Microhyla berdmorei from Peninsular Malaysia 789

Acknowledgements. We wish to express our heartfelt gratitude to Universiti Sains Malaysia, Penang for the facilities and amenities provided. This manuscript was greatly improved by constructive comments from Gernot Vogel as a pre-reviewer. This research project was funded by Universiti Sains Malaysia, Short Term Grant (304/PFARMASI/6312127).

References

Berry, P.Y. (1975): The Amphibians Fauna of Peninsular Malaysia. Tropical Press, Kuala Lumpur. Duellman, W.E., Trueb, L. (1986): Biology of Amphibians. McGraw-Hill Book Company. New York. IUCN (2013): IUCN Red List of Threatened Species. Version 2013.2. www.iucnredlist.org. Downloaded on 21 Mac 2014. Shahriza, S., Ibrahim, J., Shahrul Anuar, M.S., Abdul Muin, M.A. (2012): Herpetofauna of Peta Area of Endau-Rompin National Park, Johor, Malaysia. Pertanika Journal of Tropical Agricultural Science. 35(3): 553-562. Toledo, L.F., Sazima, I., Haddad, C.F.B. (2010):Is it all Death Feigning? Case in Anurans. Journal of Natural History. 44: 31- 32. Toledo, L.F., Sazima, I., Haddad, C.F.B. (2011): Behavioural Defences of Anurans: An Overview. Ethology Ecology & Evolution. 23(1): 1-25.

Accepted by Miguel Vences