Rain-soaked badger (Image: dwright / NHMP Warwickshire) |
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In painfully British style, our last newsletter - in April - began with some grumbling about the weather. The sodden badger, above, is a testament to the kind of climate we were experiencing. Sadly, it's far from obvious that the weather has since improved. Nonetheless, summer is here and, for many of us, that means a break from work and/or a change of scene. For that reason (specifically, in fact, because there's a suitcase upstairs waiting to be filled), this newsletter will be a relatively short one. There's still room, however, for an update from the front lines of searching for one of Britain's most recent invasives; our regular spotters league, celebrating the achievements of our top spotters over recent times; and a selection of fantastic, recently favourited images. Interested? Then read on ... |
| Searching for shrews: an update |
Many of you will be aware of the new threat to our native biodiversity that has arisen in the form of the Greater White-toothed Shrew. This has been the focus of a Mammal Society initiative: Searching for Shrews. There is uncertainty regarding how long the shrews have been in mainland Britain, and how widespread they have become. Owl pellet analysis indicates a particular concentration in the North East of England - see map below. One of the newest members of the MammalWeb team - Charlotte Sharpe, currently based at Durham University - is currently conducting a local trial of approaches to monitoring small mammals with camera traps. She has sent us the update below. |
Presence of Greater White-Toothed Shrews in Tyne & Wear and County Durham, based on owl pellet analyses by Ian Bond and Terry Coult (unpublished data). Map provided by Vivien Kent. |
Together with my supervisors, Professors Russ Hill and Phil Stephens, we have constructed 24 structures to house camera traps optimised to detect small mammals. Conventional camera traps typically fail to capture high resolution pictures of small mammals due to the animals' body size and fast speed of movement, meaning that monitoring efforts have previously depended on intensive live-trapping efforts that involve substantial time commitments by researchers. By attaching a close-focus lens and reducing the camera’s field of view within a small wooden box, our modified traps permitted observations of several species during a pilot study at the Durham Botanic Gardens, including the wood mouse (Apodemus sylvaticus), the bank vole (Clethrionomys glareolus) and the pygmy shrew (Sorex minutus). Typically, the cameras picture only one animal at a time, but we also captured an interaction between the wood mouse and the bank vole – caption suggestions are welcome! |
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Our camera trapping structures (top) are based on the 'Littlewood box' design ofNick Littlewood, and often yield high quality images of small mammals, such as this intriguing interaction between a bank vole and a wood mouse. (Image: cs0911) |
As well as examining the effect of different bait treatments on the detection probability of different species, my fieldwork aims to assess the presence of a newly invasive species in the UK, the greater white-toothed shrew (GWTS) (Crocidura russula). Concern is mounting, owing to this species’ recent invasion of Ireland where it has displaced Ireland’s only native shrew species, the pygmy shrew (Sorex minutus). Initially observed in Sunderland, skeletal remains from owl pellets suggest there are established populations in the wider area, as shown on the map above. This data has informed our site selection, and we are now deploying the cameras in and around Sunderland as part of a collaborative effort to understand the threat faced by native small mammals in the presence of a formidable new competitor. So far, we have yet to find unequivocal evidence of GWTS, although we have been finding reasonable numbers of pygmy shrews - and even a water shrew (Neomys fodiens)! If you feel confident enough to help, we'd appreciate assistance with working through the footage we are obtaining in this project. You can help out as a Spotter, here. |
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Shrews captured in this project include the pygmy shrew (top) and the water shrew (bottom). (Images: cs0911) |
| MammalWeb Activity, April to June |
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Several things are worth noting about this. First, the sheer number of image sequences classified is staggering! The number of sequences classified in this 3-month period is very nearly 6 times as many as were classified in the whole of 2023! We're enormously grateful for the scale of effort that has gone into this, which makes our job - of ascertaining what is shown in each sequence of images - so much easier. Second, the number of image sequences uploaded is also huge. We have had some emails from Trappers concerned about how long it's taking to process images before they're available to view. Unfortunately, this is simply a result of the huge amount of processing the system's doing, at present. Thanks to everyone for their patience whilst we work through the (ongoing) backlog. Third, it's also worth pointing out that almost 1,700 people contributed to image classifications during this period. Thank you to each and every one of you - and kudos to those named above, who managed to come out on top! |
| What images are people liking? |
They do say that 'a picture is worth a thousand words'. Well, with time to put words on paper at a premium, this month, we've decided to let some pictures do the talking.
With all the image sequences that have been processed over recent months, a huge number have received a 'thumbs up' from one or more contributors. Sadly, time doesn't permit us to go through all of those. An ambition is to have a gallery of 'liked' images that viewers can up- or down-rate to curate a set of particularly popular images. However, as those of you who occasionally write with suggestions for the site will know, our list of ambitions is long, whereas the resources available for site improvements are decidedly finite! For now, we have contented ourselves with a look at a few sequences that have received multiple likes. Here, in turn, and in no particular order, are a few of those. They are - by chance - all from the National Hedgehog Monitoring Programme, which you can help out with by classifying images here. |
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The initial ambition was to limit this to a round(?) half-dozen but the available selection was just too glorious (and, if we're honest, we only checked a score, or so). From the top: anyone who has tried to photograph the glory of a goldfinch will recognise that this camera trap has achieved what most enthusiastic wildlife photographers fail to do (Image: TCV Scotland / NHMP Clackmannanshire); as pernicious as they are, as an invasive species, we enjoyed this touching muntjac-moment amidst the bluebells (Image: shannonwatts / NHMP Warwickshire); the next three are all from the same site - a testament to the wonders of a well-placed camera trap - catching an elusive jay, a young male roe deer and a handsome red fox (Images: AbbyLWhitmore / NHMP Cornwall); a timorous brown hare (Image: Animex International / NHMP Hampshire & Isle of Wight); sparring roe deer bucks (Image: jsnellgrove / NHMP Dorset); the uphill struggle of the imperilled hedgehog (Image: TCV Scotland / NHMP Clackmannanshire); a great spotted woodpecker, coming in to land (Image: AbbyLWhitmore / NHMP Cornwall); and, to finish, two more images of invasives: a browsing muntjac and a pair of grey squirrels doing battle (Images: shannonwatts / NHMP Warwickshire). |
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