Species of the month: April
Species: Common
Frog
April is the time of year to look out for frog
spawn and tadpoles. The common frog is the most familiar of
Kent’s amphibians and is distributed throughout the county.
During the winter frogs hibernate at the
bottom of ponds; these are often different from the breeding ponds,
which they may travel some distance to find in the spring.
Frogs can gather in large numbers to lay eggs, which are protected
by big clumps of floating protective jelly called frog spawn.
Each female frog can produce up to 2,000 eggs,
but only a small number will become frogs, instead, much of the
spawn is food for a range of animals, including ducks, fish and
newts.
Snails are a favourite food of frogs, but they
will also eat a range of invertebrates such as beetles and
worms.
By April, fully developed frog spawn can be
seen, dotted with the black embryos that quickly grow into
tadpoles.
The life cycle of frogs is fascinating to
watch. Over just a few weeks, the tadpoles go from being
black dots with a tail and gills, to tiny frogs, complete in every
detail.
The common frog is not the only frog species
in Kent, in 1935 the marsh frog, its louder and greener continental
counterpart, was introduced to Walland Marsh (near
Dungeness). The marsh frog is now common at various coastal
locations, but its effect on native wildlife is unknown. This
species makes a loud cackling noise, but the common frog is fairly
quiet, making some croaking calls when gathering in numbers.
How you can help
With a decline in countryside ponds, our
garden ponds are becoming an increasingly vital habitat for frogs.
Creating one is a great way of helping nature. Ideally it is
best to dig a pond in the winter, ready for frogs and other
wildlife in the following spring. The larger the pond the
better, but for frogs a minimum depth of 60 cm and sloping sides
for entry and exit, are essential. Further information on
pond construction is available from the
Kent Biodiversity Partnership (PDF, 408KB).
What else to look out for in April
This is the month when swallows appear on our
shores, after a winter in Africa. With iridescent blue
plumage, they swoop low of fields and water, feeding on insects.
These birds remain faithful to old nest sites and will return to
the same nest, often on a ledge in a barn, each spring. The
closely related house martin builds a nest under the eaves of
houses and sand martin nest in holes excavated in riverside banks
and quarries.