Changing Colours of Spring – Ray Colliers Wildlife in the North

stoat in ermineFor the one bird and two animals that have to turn from their winter coat to summer coat at this time of the  year it is now all change.    The smallest of the animals is the stoat with the male about thirteen inches overall and the female  much smaller.   Since last Autumn the stoat has been in its white winter coat, apart from the black tip to the tail.    The coat is called ermine and in the past the white  fur has always been much prized for clothing.    In general it was only used  by  the royalty and  nobility  as it was such a status symbol  The white winter coat can be both an advantage and a disadvantage.  If the snow covers the ground for prolonged periods so  the camouflage allows it  to approach prey such as young rabbits, mice and birds then  it also camouflages the stoat against  would be predators such as birds of prey and foxes.  In contrast if the snow is absent then the white fur is very conspicuous and the  stoat has to seek cover such as under a wood pile, in an old stone wall or any hole in the ground.    It is also more readily seen by its prey.   Its lack of size means that it frequently stands upright, as in the photograph I took in my garden, to get a better view, especially of its prey.   The change from its winter coat to its brown summer coat is not instantaneous and the resulting  pattern of white and  brown fur varies with each individual so no two stoats are the same.

Whilst the stoat can be found at all levels,  even  on the high tops when it is hunting, the mountain hare is different.  They are normally only found between 1,000 to 2,500 feet above sea level.     They moult no less than three times a year, going from brown to grey-brown from early to late summer, brown to white in the autumn to mid-winter and then white to brown again in late winter to early summer.  The rate of moulting depends on altitude and temperature and some hares, particularly  late season young, called leverets,  do not go completely white.   There is an interesting link between mountain hares and the breeding success rate of golden eagles in the north-east of Scotland.   Golden eagles normally lay two eggs and the incubation starts at the first egg.  This means that  one chick is larger, and stronger than the other. If food is short  the older chick will survive and they will often eat their sibling.     In the north-east where there are more mountain hares the breeding success of golden eagles is higher  than elsewhere in Scotland.

The ptarmigan is another mountain  species spending most of its time above  2,000 feet and it has an interesting adaption in  that their  feet are covered with white feathers.  These stop their legs and feet freezing in the extreme temperatures in which they live.  However, the feathered feet and legs also act  as snow shoes and enables the birds get around more efficiently. The adults eat plant shoots, berries, leaves and seeds of various mountain plants  such as heather, bilberry and crowberry and they use their feathered  feet to dig in the snow to find these.  However, the critical food are insects which the chicks need and the number of insects in the early  summer leads to the  success or otherwise of the breeding season. Ptarmigan can still be shot but numbers are more affected by predatory crows and flying into wires from skiing developments.