Saturday, 2 April 2011

Frogs of Bristol 4: Splendid Leaf Frog

One of the more spectacular frogs we have at Bristol is the Splendid Leaf Frog, Cruziohyla calcarifer. Unfortunately, visitors usually do not get to appreciate their full colour, as like many frogs they are nocturnal and during the day they spend their time fixed to a large leaf, where their camouflage green makes them hard to spot.

In the wild of course it is much harder, as they are a thinly distributed species that spends its entire life in the rainforest canopy. Only when they are active are their bright flank colours visible, and these are usually only seen briefly in daylight, as they act as a warning flash as a disturbed frog leaps to another resting place. At present we only have males on show, but hopefully we will get a few females soon and be able to breed some of these impressive frogs ourselves.

Originating from Costa Rica and Panama, it is a specialist in lowland primary rainforest, avoiding disturbed areas. This is probably a reflection of their breeding behaviour, as they need hollows in fallen trees to breed in. As with most of the phyllomedusine tree frogs, they lay their eggs out of water, above the water-filled depressions in the logs where their tadpoles develop. The tadpoles are probably omnivorous, but are certainly capable of taking some animal protein if it is available.

The pools they develop in are small, so there would usually only be a few successful metamorphs from each site. This is probably one of the reasons it appears scarce – it is adapted to make use of small, widely scattered breeding sites rather than large population concentrations. This may also make it vulnerable to deforestation – in any one area the numbers are probably quite low, so connected areas of forest are needed to sustain a viable population.

As with most tree frogs, the diet is mainly insects of various types in the wild. In captivity they will take crickets and small locusts. These are ‘gut loaded’ – a term for ensuring the insects have fed on a high quality diet before being eaten by the frog. This is very important for all captive animals – wild insects will have fed on a variety of leaves and fruits, which provides essential vitamins and minerals.

The trick of encouraging breeding in many amphibians involves the use of a ‘rain chamber’. This is basically a container with several inches of water in the bottom containing a water pump that circulates water through a spray bar at the top. When the pump is on, a continuous spray of water falls on the inhabitants. This mimics the rainy season, which is when most rainforest frogs in particular will breed.

For a video of a breeding set up for this species, see here:

(image from wikipedia)

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