|
The mountain burnet (Zygaena exulans) is closely related to all the other burnet moths, many of which are found only on sunny slopes further south, or on the extreme western fringe of
Scotland on frost-free coasts. In contrast this burnet lives only on the exposed summits of some of the upper Deeside hills, where it has to endure fierce frosts, heavy snowfalls and brief generally cool summers. All
burnet moths are basically black with crimson spots, but the mountain burnet is darker than most, perhaps so that it can absorb the sun's heat more readily. The caterpillar feeds on crowberry, a common heathland plant,
and so its very restricted distribution must surely be connected with climate preference. The adult moth also needs to feed on nectar and its chosen hilltops do seem to be richer in flowers, such as birds foot trefoil,
than other nearby hills where the moths are not found. Because of the very brief growing and feeding season the mountain burnet's caterpillars take more than one year to grow to full size, as do several other upland
moth caterpillars. |
