Tuesday, 11 September 2012

Toads much in evidence

Even though I have had little time to spend working in the garden this summer, I seem to have seen the resident toads more frequently than in previous years. Last thing at night I have often come across one on the gravel path that snakes its way up the garden. Sometimes one can be seen on the patio, where it attracts the passing interest of the dogs and, occasionally, one appears outside the back door causing my heart to skip a beat as I almost tread on its vulnerable form.

The toads have never bred in the garden, the pond perhaps too small and dominated by other amphibians, whose tadpoles would out-compete those of a toad, but they have been ever-present since we moved in here more than a decade ago. There are larger ponds in nearby gardens and these may be the source of the smaller toads that are seen from time to time in the garden, for it is the larger individuals that are most often encountered. The largest of these may well be females, the bigger of the two sexes. The two sexes are fairly similar in appearance, though the warts are less prominent on the female and the toes of the front legs more delicate. Mature males develop characteristic pads on their inner toes during the breeding season, these being used to grip the female.

Common toads are terrestrial in habits for most of the year and seem well adapted to life on land. The garden almost certainly holds sufficient prey to support several toads and I suspect that our resident population is, judging by the sizes encountered, a mixture of immature and mature individuals – maturity is reached three or more years of age in females and two or more in the males. One particular individual must hide up near the shed, for it is often seen here during early evening. Although the background colour of her skin (I think of this particular toad as a female) changes with the light, from dull olive green to a warmer green-brown, she has a characteristically-shaped black splodge behind her right eye. The most colourful feature is the eye, a black horizontal pupil bordered by a yellow-orange iris, which darkens where it meets the horizontal to create a three-dimensional effect and the illusion that the top part of the iris is jutting out like a baseball cap.

Seen close-up, best accomplished by lying prone on the ground next to the toad, the delicate pattern of the warts can also be seen, as can the paratoid glands, positioned behind the eyes. It is from these that the toad can release its foul-tasting toxin. Little wonder the dogs leave them well alone.

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