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system will reveal not only the causes of malformations, but also
how these malformations affect these frogs if they are to survive to
reproductive age (Fig. 8, 9, 10).
Over the past ten months we have begun noticing greater
incidence of fly attacks on the foam nests of P. cruciger. So far,
we have observed nearly 15 foam nests of these frogs, of which
five were infected with fly larvae. These larvae often destroy entire
nests or sometimes tadpole survival is dramatically reduced.
There seems to be a correlation with the advent of rain and
fly infections; we continue in gathering more data to test this
Fig. 11. Pseudophilautus femoralis is one of a very few species that lay direct
developing eggs on leaves. Photo: Madhava Meegaskumbura.
the conservation effort, by understanding the critical conditions
needed for their breeding and factors needed for survival of
various life history stages.
Function of foam nest material
We are studying how foam-nesting material may facilitate the
survival of eggs and early stage tadpoles within the foamy mass
in both Polypedates and Taruga. We are now beginning to test
chemical composition and protein structure of the material that
the foam nests are made with. We are finding that the blue color
observed in P. cruciger nests is due to Cu 2+ ions. We are also
testing the anti-fungal and anti-bacterial nature of the foam nest
material.
Fig. 8. (top left) A severely malformed P. cruciger tadpole swimming upside down,
Fig. 9. (top right) Malformed froglet of P. cruciger ready to metamorphose. Photo:
Madhava Meegaskumbura. Fig. 10. (bottom) A. Deformed urostyle region of a
double stained froglet and B. the normal condition. Photo: Gayan Bowatte.
hypothesis statistically. Surprisingly, we are not noticing fly larvae
attacks in nearly 15 Taruga eques nests that we observed; however
we are not sure if this is due to the absence of the fly species under
issue in T. eques habitat or if these nests are tolerant of these fly
attacks.
Amphibian microhabitat monitoring
Shrub frogs are restricted largely to the rain-forested
southwestern ‘wet-zone’ region of the island, where annual
precipitation usually exceeds 2000 mm (only a single species is
restricted to the dry zone). Many of these frogs are specialized in
habitat use (Meegaskumbura and Manamedra-Arachchi 2005;
Meegaskumbura, PhD thesis work). Of the 43 extant species, it
is of concern that as many as 15 are known only from a single
site each, and 11 from only two—usually nearby—sites each
(Manamendra-Arachchi and Pethiyagoda 2005; Meegaskumbura
and Manamendra-Arachchi 2005). Since 1815, about 95% of Sri
Lanka’s rainforests have been lost to coffee, cinchona and tea
plantations (Meyer 1998), supporting the idea that extinctions are
mainly caused by habitat loss.
We also continue to swab the amphibians to determine the
presence of the dreaded Chytrid fungus, which if spread in Sri
Lanka could potentially cause havoc as
has been observed in many regions of
the world. Studies done on Sri Lankan
frogs so far indicate that the fungus
is probably present in Sri Lankan
frog populations, mandating urgent
continuation of monitoring activities.
Amphibian breeding observations
We are now observing the breeding
patterns of various frog species (Fig. 11).
We are concentrating on the endemic
forms in the wild, and later when we get
government permission, we are hoping
to also do captive breeding trials, not
for reintroduction, but to fine tune
28 | FrogLog Vol. 98 | September 2011
Fig. 12. Measuring microhabitat parameters in the field. Photo:
Madhava Meegaskumbura.
We also suspect that recent climatic changes may also have served
to stress the shrub-frog populations. Bahir et al. (2005) show for
several highland species, that breeding
only occurs during periods of sustained
rainfall that is reflected by continuously
high relative humidity (80-100 %).
While historical relative-humidity
data are lacking for Sri Lanka, trends
calculated by Schaefer (1998) show that
at Nuwara Eliya (1,800 m elevation)
in central mountains, average annual
temperature had increased by 1.3° C
and average annual precipitation had
decreased by ~20 % in the period 1869-
1995; similar desiccation and warming
trends were noted also in other parts of
the country.