Description
Adults 60-80 mm. Tibiotarsal articulation reaches at most the nostril. Hand without webbing, foot completely webbed. Terminal discs of fingers and toes strongly enlarged. Tympanum rather indistinct and small (1/4 of eye diameter). Dorsal skin smooth. Colour olive greenish, especially in subadults, to brown, with lighter or darker indistinct markings. Ventrally white, often with dark spots or marblings on throat and chest. Males without femoral glands.

Similar species: This large species can easily be mistaken with Mantidactylus grandidieri and M. guttulatus which, however, have less expanded discs on fingers and toes. Smaller specimens can also be mistaken with Spinomantis microtis which occurs in south-eastern Madagascar as well but appears to be confined to higher elevations. Juveniles may also be confused with Mantidactylus lugubris and related species which can occur syntopically.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Madagascar

View distribution map using BerkeleyMapper.

Ambana, Andohahela, Bekazaha, Chaines Anosyennes, Isaka-Ivondro, Manantantely, Nahampoana, Soavala. It occurs between 50-1,000m asl in degraded and pristine forest and open area next to relict forest (Nussbaum et al. 2008).

Life History, Abundance, Activity, and Special Behaviors
Habits: Often found on large stones in torrents. Mainly active at night, but sometimes found jumping on the stones in the afternoon, together with M. lugubris. Call: Unknown. The frogs live in very noisy torrents, and considering the reduced tympanum, M. microtympanum may be a non-calling species.
Eggs and tadpoles: Unknown. Juveniles, already with a visible, very small tympanum, and a SVL of 16 mm, were found in January at Nahampoana.

Breeding takes place in fast-flowing, rocky streams (Nussbaum et al. 2008).

Trends and Threats
Endangered because its area of occupancy is less than 500km², all individuals are in fewer than five locations, and there is likely to be continuing decline in the extent and quality of its forest habitat in southeastern Madagascar. It occurs in the Andohahela and Midongy-du-Sud National Parks (Nussbaum et al. 2008).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Urbanization
Habitat fragmentation
Intentional mortality (over-harvesting, pet trade or collecting)

Comments
Taken with permission from Glaw and Vences (2007).

References

Glaw, F., and Vences, M. (2007). Field Guide to the Amphibians and Reptiles of Madagascar. Third Edition. Vences and Glaw Verlag, Köln.

Nussbaum, R., Raxworthy, C., and Andreone, F. (2008). Boehmantis microtympanum. In: IUCN 2008. 2008 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 22 April 2009.

Species Account Citation: AmphibiaWeb 2010 Boehmantis microtympanum <http://amphibiaweb.org/species/4615> University of California, Berkeley, CA, USA. Accessed Jan 23, 2020.

Citation: AmphibiaWeb. 2020. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 23 Jan 2020.

AmphibiaWeb's policy on data use.