Ray Collier Country Diary- Bats
Bats - 22nd September 2009
There are 16 resident species of bats in Britain although only four of these are found in the Highlands and one of these is very restricted in its distribution. The Natterer’s bat is not found north of a line roughly from Tain to Kyle of Lochalsh. Perhaps the reason for this is that it is a bat that favours a wide range of broadleaved woodland, large gardens and open parkland and there is not much of any of these north of that line. The Daubenton’s bat is found over almost all of the mainland but absent from either the Northern or Western Isles. It feeds low over water of lochs, rivers and burns and forages almost exclusively in the one metre airspace above the water. Insects are taken on the wing by the large feet or tail membrane and quickly transferred to the mouth whilst it continues its flight. The insects are taken both in the air and from the surface of the water and some of these bats have been seen taking as much as 40% of their prey from the water surface. The brown long eared bat with, as the name suggests, large ears, is more widespread in that it also occurs on the Northern Isles as well as the mainland. It prefers open woodland and parkland and is found in urban areas with large gardens and trees. The pipistrelle bat is the most widespread and commonest of the four in the Highlands and it occurs on the mainland and Northern Isles. Recent distribution maps show no records for the Western Isles but there have been a few roosts found in Stornoway although, as yet, none in the Uists Its abundance must be due in part to their adaptability as they feed wherever there are enough plants to support an adequate number of insects. Pipistrelles also come out earlier than the other bats and are often seen flying in the daylight before the light fades.
Just in the same way as bird boxes can help birds so bat boxes can help the four bats found in the Highlands as all of them will frequent such boxes at varying times of the year. Pipistrelles are unusual in that they more frequently use the boxes as mating roosts in the autumn. The boxes are meant to compensate for the lack of suitable holes in old trees, old buildings being renovated and new ones designed so that birds or bats cannot find a niche there. There are many thousands of bat boxes in Britain and one of the very first efforts was a large number of such boxes erected in Ardross Forest by the Forestry Commission. The bat box schemes vary from a few put up by individuals or large schemes involving hundreds of boxes put up by various organisations including bat groups. The success rate varies considerably with some only having 10% occupation and others even 100% although occupied boxes may only be used for a few weeks in the year. Daubenton’s, Natterer’s and brown long-eared bats will use the boxes as nursery roosts. The boxes vary from a simple design with a slit in the bottom and grooves cut to enable the bat to crawl up inside the box to other designs that have been used with success such as one with a variable number of narrow chambers stacked together, each just wide enough for a bat. Bats could well be the most successful mammals ever to have evolved and it is an interesting thought that in Britain one in three of the native land mammals is a bat.
There are 16 resident species of bats in Britain although only four of these are found in the Highlands and one of these is very restricted in its distribution. The Natterer’s bat is not found north of a line roughly from Tain to Kyle of Lochalsh. Perhaps the reason for this is that it is a bat that favours a wide range of broadleaved woodland, large gardens and open parkland and there is not much of any of these north of that line. The Daubenton’s bat is found over almost all of the mainland but absent from either the Northern or Western Isles. It feeds low over water of lochs, rivers and burns and forages almost exclusively in the one metre airspace above the water. Insects are taken on the wing by the large feet or tail membrane and quickly transferred to the mouth whilst it continues its flight. The insects are taken both in the air and from the surface of the water and some of these bats have been seen taking as much as 40% of their prey from the water surface. The brown long eared bat with, as the name suggests, large ears, is more widespread in that it also occurs on the Northern Isles as well as the mainland. It prefers open woodland and parkland and is found in urban areas with large gardens and trees. The pipistrelle bat is the most widespread and commonest of the four in the Highlands and it occurs on the mainland and Northern Isles. Recent distribution maps show no records for the Western Isles but there have been a few roosts found in Stornoway although, as yet, none in the Uists Its abundance must be due in part to their adaptability as they feed wherever there are enough plants to support an adequate number of insects. Pipistrelles also come out earlier than the other bats and are often seen flying in the daylight before the light fades.
Just in the same way as bird boxes can help birds so bat boxes can help the four bats found in the Highlands as all of them will frequent such boxes at varying times of the year. Pipistrelles are unusual in that they more frequently use the boxes as mating roosts in the autumn. The boxes are meant to compensate for the lack of suitable holes in old trees, old buildings being renovated and new ones designed so that birds or bats cannot find a niche there. There are many thousands of bat boxes in Britain and one of the very first efforts was a large number of such boxes erected in Ardross Forest by the Forestry Commission. The bat box schemes vary from a few put up by individuals or large schemes involving hundreds of boxes put up by various organisations including bat groups. The success rate varies considerably with some only having 10% occupation and others even 100% although occupied boxes may only be used for a few weeks in the year. Daubenton’s, Natterer’s and brown long-eared bats will use the boxes as nursery roosts. The boxes vary from a simple design with a slit in the bottom and grooves cut to enable the bat to crawl up inside the box to other designs that have been used with success such as one with a variable number of narrow chambers stacked together, each just wide enough for a bat. Bats could well be the most successful mammals ever to have evolved and it is an interesting thought that in Britain one in three of the native land mammals is a bat.
posted by Corinne @ 6:40 AM
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