Life history of an African caecilian: Boulengerula taitanus Loveridge 1935 (Amphibia Gymnophiona Caeciilidae)

Abstract

The life histories of amphibians are considered to be well recorded and
are frequently regarded as the model complex life history for vertebrates. However,
only the most basic information exists for caecilians. Boulengerula taitanus
Loveridge 1935 is a direct developing terrestrial caecilian commonly found in
agricultural settings of the Taita Hills, Kenya. During 12 monthly visits we collected
239 caecilians by digging into soil. Caecilians were captured on every visit,
although increased searching time and low capture numbers coincided when
soils were dry. The condition index (ML–3) defines three ontogenetic stages, for
which growth can be approximately followed over the sampling period through
frequency histograms. Juveniles (< 140 mm) appear to become subadults
(< 240 mm) around a year after hatching, while subadults mature into adults
(> 240 mm) after a further year. Adult males are significantly longer than females.
Mating occurs in the soil prior to egg laying at the beginning of the short rains.
Females construct a chamber before laying eggs (x¯ = 5), and are found attending
eggs during incubation and after hatching. Juveniles make up the smallest proportion
of the population (maximum 24% in April and May). Information produced
during this study is used to develop a tentative life-table for this species.
KEY WORDS: Afrocaecilia taitana, Boulengerula taitanus, caecilians, East Africa,
Eastern Arc Mountains, ecology, life-table, parental care.