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Mammal Report for 2010

by Gordon Woodroffe

The highlight of 2010 International Year of Biodiversity was the addition of a new bat species to Britain’s native mammals. Professor John Altringham (University of Leeds) and his research team discovered the Alcathoe bat Myotis alcathoe in the Rievaulx area and at other swarming sites in southern England. M. alcathoe was first described in 2001 from bats caught in Greece although the species’ known range has steadily expanded across much of Europe. While the Alcathoe bats discovered in Sussex may possibly be recent colonists, perhaps moving in response to climate change, the researchers consider this to be unlikely because of finding its presence 350 km to the north in Ryedale. However the simplest explanation is that M. alcathoe is a resident UK species that has gone undetected due to its similarity to other small Myotis species such as Whiskered M. mystacinus, and Brandt’s M. brandtii which have both been recorded at Rievaulx. Whiskered bats have also been recorded in Sinnington. Pipistrelle bats Pipistrellus pipistrellus, unsurprisingly, have been the most recorded species with reports from Gilling, Sinnington and at Sykes House but this species will have a much wider distribution throughout Ryedale. A colony of Daubenton’s bats Myotis daubentonii is also being monitored at Kirby Mills, Kirkbymoorside and there are two records of Grey long-eared bats Plecotus auritus from Sykes House and Rievaulx but again the distribution of both these species in the area will be much wider.

Rabbit Oryctolagus cuniculus records have been confined to Sykes House, Sinnington and Whitwell but this is a mere snapshot of their overall distribution in Ryedale. It is interesting that there have been far more reports of Brown Hares Lepus europaeus although this does not mean that the hare population is greater than the rabbit; it merely reflects that as hares are less easily seen they merit recording rather than the more common rabbit. However, it is important that common species are recorded at every opportunity because it is only when we have accurate records over a long period that it is possible to ascertain how a species is faring. Gilling, Nunnington and Sinnington are all residential areas for Brown Hares; dead hares have also been seen on the A170 by Dawson Wood and on Blakey Ridge. However, the main hare strongholds are on the Castle Howard and Wykeham shooting estates.

As Tom and Janet Denney pointed out in their records, Mole Talpa europaeus activity in the shape of molehills can be seen almost everywhere especially during the winter months. These are particularly noticeable along river banks and grass verges. The fact that during 2010, 40 moles were trapped in 16 acres of grassland on Rudland gives some idea of how robust mole populations can be.

There is some concern nationally that Hedgehog Erinaceus europaeus populations may be on the decline. While there are insufficient long term records to comment on the hedgehog’s plight in Ryedale I seem to have seen far fewer road casualties during 2010. This may be because hedgehog are using garden refuges more. Families have been recorded at Sykes and Sinnington. One possible reason for this maybe due to increased predation by badgers although this is pure speculation.

Carnivores are well represented in Ryedale. It is not that unusual to find Badgers Meles meles killed on our roads, especially on the A170 (19.06.10 and 24.06.10) and A64 where there is badger hotspot near Malton. There are well established badger setts in Sinnington, Cropton, Dalby, Gilling and Castle Howard while many more will be known to the Ryedale Badger Group. Stoats Mustela erminea and weasels Mustela nivalis also have a good distribution in spite of having to run the gauntlet imposed in the interests of game preservation. Stoats have been seen in Gilling, Brandrith, Rosedale, Coulton and Tranmire and one in ermine at Five Ways, Sinnington. Weasels being much smaller are less likely to be seen although there was a good sighting of one with a leveret in Sinnington. Otters Lutra lutra are doing well and signs can be found along most of the rivers in the Rye catchment. Several sightings have been reported on the River Seven in the centre of Sinnington as well as further downstream and there are usually plenty of otter tracks under the A170. Furthermore a bitch and youngsters were seen earlier in the year. A female with three young were also seen on the River Dove at Kirby Mills by Lesley Helliwell as she was carrying out a Daubenton bat survey when all four animals swam past her. Otters have been recorded on the River Rye at Nunnington and upstream at Hawnby; in fact, otter signs can be found along the whole river. However, it has to be remembered that otters have very large home ranges and will cross between rivers. Until we know how otters space themselves on our watercourses it is impossible to put a meaningful number on the size of the otter population.

There have been two records of Foxes Vulpes vulpes: in the woods at Gilling and walking across a field behind the houses in Croft Green, Sinnington. I hardly think that this is indicative of a decline in fox numbers. It is well known that foxes are not tolerated on many of the shooting estates but a better idea of the fox population might be obtained from the master of foxhounds.

Meanwhile the search for the Pine Marten Martes martes continued in 2010. The Vincent Wildlife Trust with many volunteers mounted another survey throughout the forests of Ryedale. No pine marten scats were identified. Although the occasional animal has been seen in other local areas I am of the opinion that such sightings may be the result of covert releases. Nonetheless, a pine marten was thought to have been seen around Ampleforth but this has not been confirmed by any field signs. The debate continues.

Ryedale has healthy deer populations. Roe deer Capreolus capreolus are flourishing and scattered everywhere from Helmsley, Sproxton, Kilburn to Rievaulx and Hawnby. Fallow deer Dama dama originate from the animals originally kept in the deer park at Duncombe. They are now found around the Sutton Bank area, Rievaulx and Hawnby. Red deer Cervus elaphus, on the other hand, are hanging on in Cropton Forest and are escapees from now redundant deer farms. These deer do stray into farmland where they are often shot for venison. But there has recently been a disturbing event at a farm in Great Barugh where two dead deer were found lying in one of the fields together with a dead fox. It seems that these were victims of lamping whereby just about everything that moves gets shot in the headlights of a 4×4 vehicle: an activity that is pretty rife in Ryedale. In other words, killing for the sake of killing! It can have a disastrous effect on wildlife populations. A classic example of this activity was responsible for the near extinction of the Arabian Oryx which was shot from vehicles using automatic weapons.

Bank Vole Myodes glareolus Grey squirrels Sciurus carolinensis have been recorded in Sinnington and Gilling but their distribution is much larger and they are found in most of the woods. Last but not least, small mammals such as Bank Voles Myodes glareolus (left), Field Voles Microtus agrestis, Common Shrews Sorex araneus, Pigmy Shrews Sorex minutus and Woodmice Apodemus sylvaticus are found throughout Ryedale but will tend to be under-recorded because they are usually nocturnal and very difficult to find. They can best be found by carrying out live trapping programmes as carried out by the Yorkshire Mammal Group. To end on a positive note, a colony of Water voles Arvicola amphibus has been identified on Fylingdales Moor.

© Gordon L. Woodroffe & Ryedale Natural History Society 2010; photo © Adrian Smith 2011 Back to the Annual Report Contents and Home page