In search of harvest mice again… and again… and again

For my British Animal Challenge I am trying to see every species of mammal, reptile and amphibian living in the wild. For some that’s been fairly straightforward – a case of going to the right place at the right time. Others have been more elusive. My focus this month has been on two of the trickier subjects: harvest mice and water shrews (more on the latter in my next post).

Harvest mice live up to their scientific name: micromys minutus. They are tiny. As their common name suggests, they like living among crops (grains) or areas of tall, seedbearing grasses. This makes spotting them while out and about unlikely.

Harvest mouse on seedhead

Helping out with some scientific harvest mouse trapping projects was likely to be my best chance to see them. So last autumn I volunteered to help with harvest mouse surveying at Gatwick airport. While it was a fascinating experience, we didn’t find any harvest mice. Undeterred, I volunteered for a session this year at Gatwick (work has been pretty intense lately, so I could only get to one).

Once again I got to drive through 10ft high gates topped with barbed wire, past the intimidating signs saying authorised vehicles only, before leaving the car in the glow of the runway lights, and heading off into the mini wilderness just a few hundred metres from the runway, by the River Mole. I was helping out Gatwick’s resident ecologist, Rachel Bicker (they do a surprising amount of biodiversity work at the airport). Like last year, we didn’t find any harvest mice, although we did have a good crop of voles, shrews and woodmice.

Surrey Mammal Group (working with Surrey Wildlife Trust) have been busy on a new harvest mouse project this autumn. They’re working with geneticists to see if hair samples from harvest mice can tell us about connectivity across the landscape. How related are populations in different sites to each other? Are they isolated by habitat fragmentation, or are they able to disperse and mix? This is important for the resilience of the population. And if harvest mice can move between sites, other animals will be able to as well.

Of course, to test this we first need to get samples from harvest mice. Last year the mammal group did a lot of work surveying various sites for harvest mice, and, while they were at it, tested 3 different trap designs. Based on these findings, they selected the sites with the most harvest mice last year to resurvey this year to get the samples, starting with the most harvest mousey site.

Frustratingly, work commitments meant I couldn’t get along to any of the checks at the first site, and I was ill for the week of the second site. I was restricted to seeing the updates on Facebook. The weeks progressed with plenty of voles and shrews (including my nemesis, the water shrew), but not a single harvest mouse. The dedicated volunteers consoled themselves by collecting mouse, vole and shrew poo for students to analyse for parasites.

I was finally able to help for the last check on the third site. Once again, it was the same story, the harvest mice from last year seemed to have disappeared, leaving only voles, woodmice, shrews. It was an interesting and pleasant way to spend the Friday evening, after a stressful week at work, but did leave me wondering what’s happened to the Surrey harvest mouse population.

The next site I volunteered at was by the River Wey, where I used to walk during my student days. I’d never thought about the wildlife that might live in that meadow, but looking at it now, it seems like ideal habitat for small mammals. The news from Facebook was encouraging – the group had finally caught some harvest mice, and got enough samples to analyse the population at that site, at least. Was it the night I would finally see a harvest mouse in the wild?

Harvest mouse site by the River Wey
Harvest mouse site by the River Wey

There are two moments of suspense in checking the Longworth traps. Firstly looking to see if it’s been triggered, and then, once you’ve opened the trap in a bag, waiting to see what will emerge.

Checking a longworth trap
Checking a longworth trap

We hit gold with the first triggered trap we found that evening: a harvest mouse. They are tiny. And lovely. This particular mouse had already been caught, fur clipped and sampled earlier in the week, so we didn’t need to weigh or take a sample from him again.

A not very good photo of the harvest mouse we found
A not very good photo of the harvest mouse we found

In total we had 10 small mammals in traps that night, but only one harvest mouse. Still, I had finally done it: I had seen one of Britain’s smallest and cutest mammals in the wild for the first time.

The surveys are continuing for another week or two, and hopefully we will get enough samples from other sites to compare. It will be interesting to hear the results from the lab. And hopefully it will help us find out more about habitat connectivity in Surrey. If this approach works it may help other parts of the country monitor their living landscape.

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Scrumping badgers: the proof

Last year my parents moved house, and I was delighted on my first visit to see badgers in garden several times. My suspicion was that they were scrumping the windfall apples. Sadly my camera trap let me down – the infrared light was broken, so I got lots of clips of darkness. Subsequent fleeting visits didn’t result in any badger footage either – maybe I put the camera in the wrong place, or maybe the badgers didn’t come on those nights.

A year later I returned, with a new and better camera trap, which I was able to leave in place for almost two weeks. Would I find definitive proof that the badgers were committing the crime of stealing the apples?

The camera trap triggered well over a hundred times those nights, so it took a while to sift through. There were plenty of clips of the neighbours’ cats out on the prowl, and quite a few of blackbirds.

There was also the footage I’d been hoping for: badgers. I don’t know how many individuals I recorded. There’s only ever one in frame at the same time, but it could be different ones in different clips. They seemed to visit for three nights in a row, and then disappear for a few nights, before showing up now and then.

And yes, I was able to confirm my suspicions: they were eating the windfalls.

My dad is highly indignant that badgers are stealing his apples, but given that he would have just left them on the lawn to rot, or have to move them to mow the lawn, I don’t think he’s got much of a case. If he wanted them himself, all he needs to do is pick them up before nightfall. It’s lovely to finally get pictures of badgers, in the wild, snuffling about.

Sumo dormouse

I was buzzing all weekend thanks to a remarkable dormouse box check on Saturday. Firstly, we found five dormice – as many as we’ve seen in total for the rest of the year. All five looked in good condition. Two were clearly mums whose youngsters had mostly left the nest (although one of the litter of three we saw last month was still living with mum). Two were this year’s young, now at or near a weight that would probably see them through hibernation.

The fifth dormouse was definitely the most remarkable. It was a giant, weighing 34.5g. It looked like it was wearing a dormouse sumo costume. It’s easily the biggest dormouse I have ever seen. I am analysing data from all the Surrey Dormouse Group sites over the last five years at the moment, so was able to see how it compared. It’s the second biggest dormouse recorded: out of more than 2,000 dormice, only one was heavier (at 35g).

Sumo dormouse: 34.5g!
Sumo dormouse: 34.5g!

It’s not surprising that we had such a good month for both numbers and sizes of dormice. October tends to be the peak for numbers, as this year’s young disperse. And dormice have been busy fattening up for winter, gorging on plentiful hazelnuts. Most animals look cutest when they are small. But I think chubby dormice must be the most adorable things ever.

This time next month many of them may already be hibernating. Dormice can gain weight surprisingly quickly. Assuming it’s the same mouse, the mother we found in the same box as last month has increased from 20g to 31.5g – she’s increased her bodyweight by 58% in 28 days. She also seems to have become fiestier, managing to bite both me and one of my volunteers. It’s only the second time I’ve been bitten by a dormouse in 6 years.

The juvenile we found in a nest box by himself had taken advantage of the nest left by the dormouse we found in June. The other post-lactating female hadn’t even bothered to make a proper nest, nestling down in a thin layer of leaves on top of a bed of moss.

Dormouse who hasn't made a proper nest yet
Dormouse who hasn’t made a proper nest yet

Quite a memorable check, all in all.

Seeing Seals

In September I was lucky enough to go snorkelling with seals again, with St Martin’s Dive School on the Isles of Scilly. So often, when you see seals, they’re just a big, clumsy lump on a rock, or a nose and a pair of eyes poking out of the water. Neither of these views really does a seal justice. To get an idea of their grace and beauty you need to see them in their element, below the waves.

Grey seal
Grey seal

A couple of years ago I posted some pictures of snorkelling with seals, taken on a disposable waterproof camera. This time I was able to take my GoPro along, so the pictures are better quality, but sadly the seals weren’t as inquisitive this time, preferring to observe from a distance, rather than play with us. The water was rather murky as well, meaning seals floated slowly by, like pale ghosts, then disappeared into the green gloom. Still, it was a magical experience – it’s a privilege to see seals in their territory, and on their terms.

September Photography Challenge: seascapes

I had no shortage of opportunities to take photos for September’s Photography Challenge, the theme of which was seascapes. The photos below are a mix of ones taken with a proper camera, and ones taken by my phone.

Near Kynance Cove
Near Kynance Cove
Near Kynance Cove
Near Kynance Cove
St Agnes sunset
St Agnes sunset
Bishop Rock lighthouse, west from the Isles of Scilly
Bishop Rock lighthouse, west from the Isles of Scilly
St Agnes, Isles of Scilly
St Agnes, Isles of Scilly
A sailing boat and Cromwell's Castle, Tresco
A sailing boat and Cromwell’s Castle, Tresco
Looking from Byher to Tresco
Looking from Byher to Tresco
Isles of Scilly
Isles of Scilly
Isles of Scilly
Isles of Scilly
St Agnes, Isles of Scilly
St Agnes, Isles of Scilly