Wednesday, 8 April 2020

M is for Mammals

Please remember! We ask that people do not visit the Reserve particularly if you have to travel. All car parks on Holy Island are closed to visitors until government restrictions are lifted. Many residents on Holy island fall into the vulnerable category. Please adhere to these guidelines for the health and safety of yourself and others during this time.

Lindisfarne National Nature Reserve is famed for the avian visitors that spend time here. Whether that be Terns migrating from the tropical climes to breed in the summer or Geese and waders retreating south for winter from the cold harsh arctic tundra.

However, there is an abundance of mammals - not just the humans that call Lindisfarne National Nature Reserve home. There are species that are regularly visible on an afternoon stroll. Seals can be seen and heard hauled out on the sand bars with in the vast intertidal areas and can number well into their thousands. In the dunes Rabbits and stoats can often be seen darting left and right into the undergrowth to avoid human detection. Rabbits can perform the vital task of grazing the dunes although outbreaks of myxomatosis have left numbers relatively low.

During the autumn and winter a small number cattle and sheep are bought onto the Reserve to undertake conservation grazing. The purpose of this is to allow the livestock to remove the rank vegetation to allow the floristically diverse dune system to flourish come spring. The cattle can move freely over 100 hectares of the links area of Holy Island but the sheep can be deployed in a more targeted way. They are routinely moved in 1 hectare blocks, focusing on some of the most botanically rich dune slacks removing the unwanted vegetation. If visiting at this time of year be aware of the grazing signs. The cattle are chosen for their docile nature but they should still be given space and not be approached, particularly if you have a dog.
Cows grazing in the links on Lindisfarne NNR
Hiding deep in the undergrowth are an array of small mammals. The long marram grass and upper salt marsh vegetation provide an ideal place for shrews, voles, mice to inhabit. Mice and Voles are species of rodents a name that originates from the latin 'Rodere' meaning to gnaw due to their constantly growing incisors. However, shrews are not rodents despite looking very much like a mouse with a long nose. In fact Shrews are insectivores and more closely related to Hedeghogs than Mice!
Every spring Veronica Carnell from the Northumbria Mammal Group carries out small mammal surveys in the dunes to ascertain species and abundance. The survey involves live trapping mammals in Longworth traps and is conducted under a licence obtained from Natural England. The bait used such as sunflower seeds are kibbled to ensure that they are not viable which is vital on the Reserve as we don't want to spread any invasive species. For the insectivore Shrews, blowfly casters are used. Bedding is stuffed into the trap along with the bait to make it a cosy enticing place to hide in and then concealed in the undergrowth. After a few hours the traps are checked and any small mammals are recorded and weighed and released. Then the traps are reset and the process repeated. Survey results have shown populations of Wood mice, Common and Water Shrews inhabit the Reserve. Voles are also resident but are very trap shy so are often not caught.

Truck loaded with Longworth traps, bait and bedding

Shrew being weighed in a bag

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