Monday, 1 February 2016

February 2016 Mammal of the Month - The Wood Mouse

Wood Mouse - photo Becky Thomas

Happy February everyone! Time for our next mammal of the month.

February's should be a bit easier to spot than January's otter. This month it's the wood mouse. This is the mouse you're most likely to see in most parts of Berkshire, including urban areas, and by far the most common species that we find in our live trapping surveys.

Our top facts for the wood mouse are:

1. They can be easily distinguished from field and bank voles by the size of their ears - as you can see from the photo they are rather large. Those of voles are hardly visible in comparison. See here for other species that they could be confused with and how to tell them apart.

2. They are prolific breeders! The usual season is March to October but can be all year round if there is enough food. Females are able to get pregnant again very soon after each litter.

3. They store food in caches in underground burrows

4. They nest together in groups over the winter

5. They are an important source of food for many other species - anything from foxes to owls (and of course pet cats!) will eat them.

Please record any sightings via
our recording page - we really appreciate all of your records and don't forget, it's not just sightings of the mammal of the month that we're after but any sightings or signs of any wild mammal.

Find out more with the Mammal Society's fact sheet for the species.

Tuesday, 5 January 2016

January 2016 Mammal of the Month - The Otter

Otter - photo credit: Becky Thomas
Season's greetings everyone and wishing you all the very best for 2016.

Our first Mammal of the Month for the new year is.... the otter.

Our top five facts for this often secretive species are:

* They can live up to 10 years in the wild.

* Young are born in dens called holts and the mother looks after the cubs alone.

* They can have very large territories - up to 20 km of river!

* Their poo is called spraint - it smells sweet and musky and is often the only way you know that an otter is in the area.

* After almost disappearing from much of Britain in the last century they are now making an impressive come-back - BMG even has a record from very close to the Oracle Shopping Centre in the centre of Reading.

Find out more about the species on the Mammal Society's fact sheet at:

Otter fact sheet

and please record any sightings (of them or their signs) at:

BMG recording

Thursday, 3 December 2015

December 2015 Mammal of the Month - The Harvest Mouse

Photo Credit: Reg Mckenna via Wikicommons
We're pleased to announce that our Mammal of the Month for December is the harvest mouse!

Our top five harvest mouse facts are:

  * They have 2-3 litters a year

  * They weigh just 4-6 g on average

  * Spotting a nest is the easiest way to detect their presence. These are built at least 30 cm above ground in  grasses or reeds and can be up to 10 cm in diameter for a breeding nest

  * They have prehensile tails - useful for climbing!

  * They live 18 months on average.

Find out more about the species with the Mammal Society's fact sheet at:

Harvest Mouse Factsheet

and don't forget to record any sightings or signs of these or any other mammals for us at:

Mammal Records

Check out the great photos of the harvest mouse nests found on the recent training day - posted a few weeks ago on the BMG Facebook page.

Monday, 30 November 2015

Berkshire Mammal Group Talk - Riversearch

Jim Jones, Surrey Wildlife Trust. 5th November 2015


Speaking to the Berkshire Mammal Group at its new venue in Park Church, Reading, Jim introduced himself as a former dispatch rider and care worker, before he read for a BSc at Plymouth and an MSc at UEA. His first post was with the People’s Trust for Endangered Species and he now works for Surrey Wildlife Trust as Wetland Landscapes Officer. He is also Vice Chairman of Surrey Mammal Group and a trainer for the Mammal Society.

Outline of the talk

Helping riparian mammals recover, especially otters and water voles, and using people in partnership to understand where these animals actually are, is how Jim set out his theme – and to encourage a landscape approach to nature conservation. 

1. Otter and Water Voles

Otters have been in tremendous decline since the 1950s – caused by DDT pesticides and, to a lesser extent, hunting – surviving only in the South West and Wales. Interestingly, a 1905 book on hunting reports an otter hunt in Chiddingfold where Jim now lives. Now, however, the otter is present in every county in England, though still scarce in the South East; the North Downs act as a watershed and otters are few south of them, in Hampshire, Sussex and Kent. 

Water voles
Hedgehogs excepted, the water vole is Britain’s most rapidly declining mammal, a fate propelled by intensive agriculture (ploughing up to the bank, for instance), development of the flood plains, even a lack of management that allows the growth of scrub and trees to prevent the lush vegetations that voles need. On top of this, the American mink is a modern menace. Smaller in size than the otter, the mink has a white chinstrap rather than bib, and creates a bow wave when swimming. Interestingly, when their territories overlap with those of polecats, the sex bias of the latter is affected, with a diminishing number of females.

Jim Jones

The status of river mammals in Surrey
The current distribution map includes records dating back 15 years and so must be regarded as an unreliable reflection of population. Otters are recorded on the Mole and Eden to the east of the county, with more coming into the catchment of the River Wey from Hampshire. The pattern is more marked in the case of voles; ten years ago they were on the Mole, but now are just on the Wey, while mink are found throughout the county, even the central Surrey Hills.

Record keeping
Local records are sent to the National Water Vole Database & Mapping Project, 2009-14, from which ‘alert maps’ are produced and both local and regional key areas proposed for conservation.

2. Water vole recovery plan

A six-point plan to reverse the trend was introduced when Jim became Wetlands Officer:
  1. Going back to the existing sites for a status update
  2. Reintroduction of animals if needed
  3. Inform local authority planning departments
  4. Habitat management where existing sites are suitable
  5. Creation of new habitats in key areas if needed
  6. Mink control – a collective action with landowners, at catchment level.

3. RiverSearch

Building on previous attempts at surveying ‘wet’ mammals, and the work of river wardens, RiverSearch was launched in 2012. Taking its inspiration from the work of Darren Tansley of the Essex Wildlife Trust from 2007, it collects data on the otter, water vole, water shrew and harvest mouse. Starting from scratch, Surrey’s new volunteers are trained at Darren’s house. Volunteers are asked to adopt a one km stretch of river and monitor it at least once a season. The resulting data are captured by a river co-ordinator for prioritisation and planning.

117 volunteers recruited
82 volunteers trained
71 stretches of the Wey and Mole covered
23 mammal surveyors trained

Vole Patrol 2015 is a 60-site survey on the Wey, Mole and Blackwater. There was also a vole-raft project conducted by Nick Mason of Nottingham Trent University, designed to indicate the presence of voles by the traces of excrement left behind. Negative results were obtained at 20 to 30 sites, before Nick moved on and found success in Hampshire.

Vole Reintroduction
Several suitable sites have been identified, including Stoke Meadows, next to the A3 at Guildford, and Nutfield Marshes at Redhill. If no voles are located, then reintroduction on these sites will be attempted. However, £150,000 would be needed to prepare the sites. 
Otter surveys
The 5th Otter Survey of the UK identified two positive sites were in Surrey, and Jim’s Otter Bridge Blitz of 2014 found spraint under selected bridges around Guildford. 
Photography project
A University of Surrey / SWT project was established in 2013 to monitor the riverbanks with cameras. Aaron, a student at the university, installed live-action camera traps and succeeded in obtaining lots of otter pictures that year, supplemented by images from John Hawkins Wildlife Photography. Analysis of the frequency of visits to the traps indicated a pattern a couple of days’ activity followed by absences of either one or two weeks before returning. This was in July and August when such a level of activity is atypical of otters. Eventually one animal was found, injured or unwell, and while at the sanctuary, it was discovered to have been ‘chip-and-pinned’ by a Somerset Hospital that had released one originally from Devon and two originally from North Wales. (Out-of-area releases – possibly due to overcrowding – can be problematic and spread diseases such as liver fluke.) However, no sightings of otters have since been reported in Surrey and presumably they have moved on.

4. Landscape

Jim seeks bigger, joined-up landscapes and asks how mammal projects can indicate or even initiate progress toward this aim. He points to ‘catchment partnerships’ and notes that RiverSearch also monitors pollution, barriers and the presents of non-natives, besides helping in practical work of enhancing channels and maintaining the banks. He gave examples of multiple-benefit projects: Wey Meadows and Wet Heath & Mire Project (Devil’s Punchbowl)

5. Surrey Harvest Mouse
Increasingly found in wetlands, harvest mice are a monitor of how joined-up the landscape might be. For the Surrey project the team experimented to establish which traps would be best: Longworth (“best”), plastic (“OK”) and Sherman (“hated”) – at stalk height or on the ground. Apparently the position made little difference, but many more were found in the morning than after midday. 26 mice were found in one field alone.

Second Phase: Genetics
Genetic testing, by fur plucking, is seeking to establish connectivity or insularity of population. Testing is conducted by the university at Brighton. For success 15-20 animals are required per site, and so volunteers are being trained to search for nests. The first four yielded nothing, but the fifth site, 18; the last, 32; the current, 10 and counting. This is exciting stuff – the first project in the UK to look at population genetics; the only other is in Taiwan, with which Jim keeps in correspondence. Harvest mice inhabit the entire Eurasian land mass.

Questions and Discussion

- Will otters benefit if mink numbers are reduced? Probably not, as they co-exist relatively independently.

- How does the European mink interact with voles. Not sure, but less aggressive than its American counterpart.

- If banks need management, then perhaps riparian mammals are being artificially encouraged by conservationists? Why bother? Because the rest of the landscape is also artificial and man has assumed the responsibility of attaining balance.

- Is harvest mouse trapping only conducted in the autumn? This is the peak time in terms of population. 90% die over winter and the population has to recover in the spring.

- Harvest mice are increasingly found in wetland sedges. Perhaps they always were there, if not as noticeably as in arable grasses. They have declined in fields, but still continue especially around the edges and near the hedgerows.

- RiverSearch is sponsored by the brewer, SAB Miller.

- No sign of otters in 2014 after losing sight of the 2013 family. They travel throughout a 40-50km range, at very low density. There are only ten along the River Itchen in Hampshire!

Edwin A.R. Trout,
Berkshire Mammal Group

Tuesday, 3 November 2015

November 2015 Mammal of the Month - The Fallow Deer

It's November already! Time to say goodbye to the hedgehog and welcome the fallow deer as our November Mammal of the Month.

Our top five facts for this species are:

• They were introduced to the UK by the Normans - they originally come from south-west Asia - and are now the most common deer in the UK.

• They are in between roe deer and red deer in size and have spotty coats and a white bottom edged with black stripes.

• The rutting season is October and November so keep an ear out if you're out and about in the woods this month.

• Females can live up to 16 years in the wild.

• Nearly 2/3 of their diet is grass but they will also browse young trees and eat acorns, beech mast and chestnuts in the autumn.

Please record your sightings at BMG Recording

If you'd like to find out more about this species check out the Mammal Society's fact sheet at: Fallow Deer

Thursday, 1 October 2015

October 2015 Mammal of the Month - The Hedgehog


Photo credit: Becky Thomas

It's getting into hibernation time now so our October Mammal of the Month is our prickly friend, the hedgehog.

Our top 5 facts for the hedgehog are:
1. They live for up to 10 years, though most live only 2-3 years 
2. They breed between April and September, with litter sizes of 4-5 
3. They travel up to 2 km every night hunting for food and in built-up areas have been shown to use up to 10 gardens each.

4. When hibernating they may awaken several times to build a new nest 
5. They are good swimmers (but often get stuck in modern smooth-sided ponds so please consider a ramp using a plank of wood if you have one)

If you see any hedgehogs, or any other mammals this month, please record it for us here

Of course we hope that all of your sightings will be of live hedgehogs but sightings of dead ones are useful records too so please enter these as well.

Check out the Mammal Society's fact sheet here to learn more.

Tuesday, 1 September 2015

September 2015 Mammal of the Month - The Muntjac Deer

Photo Credit: Mel Orros

Our September mammal of the month is the muntjac deer. Here are our top five muntjac facts:

1. They are native to China but were deliberately introduced into the wild in England in 1901 close to Woburn Abbey

2. They breed all year round

3. They don't form herds - if you see a group together it is likely to be a mother and her kid

4. They are only little! In size they are just a little larger than a fox and weigh under 20 kg.

5. Males have long, protruding canines - you should be able to spot these in a photo or if you spot one in the wild, even at a distance.

Check out the Mammal Society’s fact sheet for the species to learn more.

Please record any sightings of muntjac or any other mammals for us here. Every record counts!