Kaloula pulchra Gray, 1831

Species Introduction

The banded bullfrog (Kaloula pulchra Gray, 1831) is a medium-sized frog with a stocky, triangular body and a short snout.

Adult Size

Males reach a snout–vent length (SVL) of 5.4 to 7.0 cm (2.1 to 2.8 in), while females are slightly larger, with an SVL ranging from 5.7 to 7.5 cm (2.2 to 3.0 in). Apart from this small size difference, sexual dimorphism is very limited in this species. Adult banded bullfrogs have a body weight between 80 and 120 g (2.8–4.2 oz).

Adult Coloration

Their back is dark brown with stripes that range in color from copper-brown to salmon pink, and their abdomen is cream-colored.

Tadpole Size

Newly hatched tadpoles are around 0.5 cm (0.20 in) long, and reach an SVL of about 1.1 cm (0.43 in) when they complete metamorphosis.

Tadpole Morphology

Tadpoles have an oval brown or black body with a pale belly, a round snout, and a moderately long, tapered tail marked with yellow speckles that has tall fins. Their relatively small eyes are positioned on the side of the head, with black or dark gray irises and a golden ring around the pupil, and tadpoles of this species do not have a tail filament.

Metamorphosis Process

During metamorphosis, the eyes increase in size and begin to bulge, and the tadpoles develop slender limbs and digits with rounded tips. Metamorphosis begins when tadpoles are two weeks old.

Native Range

This species is native to Southeast Asia. Its natural range extends from northeastern India and Nepal, through southern India and Sri Lanka, to southern China (especially Hainan) and Myanmar, and south to the islands of maritime Southeast Asia.

Distribution Comparison

Its wider distribution compared to the closely related species Kaloula assamensis has been linked to its burrowing ability.

Habitat Characteristics

Banded bullfrogs are found at elevations between sea level and 750 m (2,460 ft) above sea level, and can live in both urban and rural areas, as well as in forest habitats.

Breeding Trigger

Breeding is triggered by heavy monsoon rains, after which the frogs move from underground to rain pools or ponds to breed.

Activity Pattern

They are most often seen on wetter nights. While they are not reproductively active during dry periods, their gonads remain ripe so they can mate soon after rainfall arrives.

Male Calling Period (India)

In India, male frogs begin calling after the monsoon season starts in April or May.

Call Parameters (India)

Recorded calls from India have 28–56 pulses per second and a frequency range of 50–1760 Hz.

Call Parameters (Thailand)

In Thailand, calls have a dominant frequency of 250 Hz (with a call duration of 560–600 ms) and 18–21 pulses per call.

Locomotion Adaptation

The body shape of the banded bullfrog is adapted for walking and burrowing, rather than jumping.

Burrowing Function

It can survive dry conditions by burying itself in the ground and waiting for rain, and burrowing also helps it avoid predators.

Burrowing Behavior

When burrowing, it digs downward hindlimb first, then uses its forelimbs to push itself several inches under the soil, where it stays for the entire dry season.

Daily Activity

Banded bullfrogs hide under leaf litter during daylight hours, and feed in the evening.

Foraging Behavior

They have been found in trees, and have been observed hunting termites there.