Fragmentation and hedges

I saw this interesting article on the BBC website a couple of days ago. It’s about a study in Thailand that found that small mammals become extinct from an area of forest within 5 years, when the area was less than 10 hectares (25 acres), and separated from other areas of suitable habitat. Even in bigger fragments of up to 56 hectares, small mammals were still extinct within 25 years. Large and medium mammals also died out in these areas. The areas in question in Thailand really were unconnected pockets of forest, surrounded by water from the creation of a reservoir. But it’s also a timely reminder for other settings.

Habitat loss and fragmentation has been blamed for the decline of species such as the hedgehog and dormouse in the UK. It’s obvious how the loss of habitat could damage a population, but why does a species become extinct if it has an area of habitat to live in, but that is small and separated from other suitable areas?

Habitat fragmentation is bad news for mammals. Lack of genetic diversity and opportunities for repopulation from other areas make populations vulnerable to disease, predation and competition from other species.

A major factor in the fragmentation of woodland habitats in the UK has been not just the destruction of woods for building or farming, but also the disappearance of proper hedges. In the post-war drive to increase agricultural production many hundreds of miles of hedges were pulled up to allow for bigger fields with less bulky boundaries. This was a tragedy for many wildlife species, who use hedges as safe highways between areas of suitable habitat. Hedges are used by hedgehogs (as the name suggests), dormice, otters, bank voles and many other species. The loss of hedges for these animals was like one day waking up and finding there’s no longer a road from your house to the shops or your work.

Where I grew up, in south Devon, seems so far to have escaped from the worst of the uprooting of hedges. Perhaps that’s partly why Devon has been a stronghold for otters and dormice, even when the former were completely wiped out of most of the rest of the country. I love the patchwork of small fields and species-rich hedgerows you get in the South Hams.

It’s not enough to protect small pockets of land for our wildlife. Small populations in small, isolated areas are just not sustainable. We need to be thinking at a landscape level – how can we join up areas for our wildlife. This will involve replanting hedges, building wildlife bridges over roads, protecting some areas from development, making sure river banks can be climbed by aquatic mammals and making sure there are gaps in our fences that hedgehogs can get through. It was also involve rethinking how we manage other areas of land. The Wildlife Trusts’ Living Landscapes programme is trying to address this at a national level.

As one of the co-authors of the study in Thailand said, “The bottom line is that we must conserve large, intact habitats for nature. That is the only way we can ensure biodiversity will survive.”

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Bird nerd part one: a confession

I have a confession to make. I am the garden bird equivalent of a trainspotter. For the last three years I have not only been watching birds in my garden, but recording details of the numbers of individuals of each species I see.

Each day that I work from home I keep an eye (and ear) out for birds in the garden, and record the maximum number of individuals seen at the same time from each species. Over the last 3 years I have clocked up 153 days worth of observations, and lots of completed forms.

Bird observation forms
Some of the completed forms…

While I appreciate that this makes me seem slightly obsessive and sad, it also means I have lots of lovely data to play with. This allows me to monitor trends over time, and see how changes in the garden, weather and seasons affect my feathered visitors.

This behaviour came as a surprise to me. I’ve always considered myself more of a mammal person than a bird fan. I saw birds as nice, but a bit dull (unless they were spectacular kingfishers or powerful birds of prey).

Then we moved house and got a garden. I don’t know when I changed my mind, but soon after moving we installed the bird feeding station, and waited for our first feathered visitors. And waited. And waited.

We had to wait almost a month before we saw the first bird in our garden. Our first visitors were a pair of collared doves. Then more and more types of birds started visiting. Something clicked, and I realised that the garden birds were wild creatures I could watch from the comfort of my own home. And they had their own characteristics. And I could watch real life mini dramas being played out in front of me.

I’m still not sure where the urge to obsessively keep records comes from. I think it must be from working with statisticians for too long. And the transformation is not complete – real twitchers wouldn’t consider me as one of their own. I don’t travel the country in the hope of seeing a rare small brown bird. I’d still choose a glimpse of otter or badger over the rarest of feathered migrants any day.

But I do enjoy watching the birds in the garden. Observing a species we’ve never seen in the garden before makes my day.

Having got that confession out of the way, I’ll try and share some of my observations with you in future posts…

Snorkelling with seals

This summer we were lucky enough to go back to my favourite place on earth – the Isles of Scilly. They’re stunningly beautiful, and I had a wonderful time sailing about the channel between the islands. But the highlight of the trip was easily snorkelling with seals (thanks to St Martin’s Dive School for taking us out!).

This was the third time that Dr C and I have snorkelled with seals, and each time we’ve been very lucky, as they’ve been in a playful mood. The first time we did it we both swallowed quite a lot of seawater when a big bull seal swam straight up to us, kissed Dr C on the mask, and gave me a hug with his flippers. Since then we’ve been a bit more prepared (and less scared), but snorkelling with them does give you a different perspective from just watching them from a boat or land. They seem to enjoy sneaking up on snorkelers, and I have been made to jump more than once by a seal nudging me when I didn’t know it was there.

From a boat or dry land, you don’t really get a sense of their size. When you’re in the water with them they seem huge. An adult bull grey seal can weigh up to 250kg, and be up to 2.5m long. When they’re hauled up on rocks or beaches they are pretty ungainly, but see them in the water and even the biggest bull is graceful, agile and pretty speedy. Some of them seemed to enjoy showing off by corkscrewing around in the water, hanging upside down or doing headstands, before zooming off when they got bored.

Our encounters with the seals have been on their terms. They’re in their element, graceful and fast, while we are clumsy and slow in our wetsuits. I’m sure, if they wanted to, they could do a lot of damage, as they are fearsome predators, but luckily they’ve been content with nibbling my fins or gloves.

I’ve done a fair amount of wildlife watching in my time, from garden birds in Surrey to elephants in Africa. But snorkelling with seals is a very different experience. While usually, when watching wildlife, it’s very much you watching them (and trying to keep out of sight, sound and smell), snorkelling with seals is definitely a two-way experience. They seem as curious about us as we are about them. It’s an amazing feeling of connection: a wild animal taking time to investigate and play with me, for no other reason than curiosity.

Seal
Seal
Seal
Seal
Jellyfish
Jellyfish
Seal
Seal
Inquisitive seal
Inquisitive seal
Two seals
Two seals
Seal
Seal

Profile: dormice (the cutest creatures in existence?)

Torpid dormouse
Torpid dormouse

Hazel dormouse, muscardinus avellenarius

I thought I would start a series of species profiles with the hazel dormouse, as over the last few years I’ve spent quite a bit of time monitoring them, and they are just about the cutest creatures in existence. (If you’re not sure you agree with that, watch this and then tell me what is cuter).

Hazel dormice are small, nocturnal mammals that spend most of their lives up trees, so few people get to see them in the wild. They have quite a varied diet, depending on what’s available at the time, including small insects, pollen, fruit, and nuts. They get the first part of their name from their fondness for hazel nuts. They live in woodlands, and prefer woods with a wide range of trees and a good understory, so food is available for them all the period they are active. Hedges are also important for them, both as a source of food and as a corridor between woodlands.

Dormice seem to enjoy proving dormouse experts wrong, so are sometimes found in unlikely places, including conifer plantations and small strips of wood between the carriageways of the A30.

Hazel dormice are the only dormouse species that is native to the UK, although there are a few rogue glis glis (edible dormice) (a much bigger, more troublesome type) in a small part of the country. (By the way, edible dormice really need to work on their branding – having ‘edible’ as part of your name has got to be bad news… how about adding an ‘in’ to the start of ‘edible’?)

While the dormouse’s range used to cover much of the UK, it is now largely confined to the south of England, with a few small pockets further north. This is thought to be largely due to habitat loss and fragmentation. Because of this, they are protected by legislation that means that you must not catch or disturb dormice without a licence. Any developments that threaten areas where dormice live must put in place mitigation measures to compensate for the damage caused.

Unlike other types of mice, they are not prolific breeders. Mature females will usually have 1 litter of around 4 young per year. Survival of these young depends on enough food being available for them to fatten up before hibernating.

Dormice are not the most active creatures. They spend about 6 months of every year hibernating. Even when they’re not hibernating they go into a state of torpor (very deep sleep) when it is a bit chilly (like the snoring chap in the video).

The People’s Trust for Endangered Species coordinates the National Dormouse Monitoring Programme, which keeps track of how the dormouse population is doing.

If you would like to learn more about these adorable creatures, I can recommend the following:

  • Dormice by Pat Morris: an accessible book focusing on Hazel dormice and edible dormice in Britain.
  • The Hazel Dormouse by Rimvydas Juškaitis & Sven Büchner: a scientific monograph summarising what is known from studies of the hazel dormouse in Europe.

If you would like to help dormice:

  • Sponsor a dormouse: sponsoring a dormouse through Surrey Wildlife Trust will help to pay for new dormice nest boxes and maintain existing ones, which are important for both monitoring the species and giving them suitable nest sites for breeding.

Our national species is… the hedgehog?!

Hedgehog
Our national species

Germany has the magnificent Golden Eagle, Italy the wolf, India the Royal Bengal Tiger, and Uganda the proud crested crane. And our national animal? Perhaps the mighty red deer, or fearsome hunter the otter? Or beautiful barn owl? No. The people (or at least the readers of the BBC Wildlife Magazine) have spoken, and our national animal – the creature that represents Britain – is the humble hedgehog.

At first I was a bit taken aback by this. The hedgehog isn’t exactly top of the foodchain, and in looks, it’s more cute than beautiful or awe inspiring. Hedgehogs remind me of wombles, with their mobile noses. While they’re good at what they do, they’re not the cleverest creatures. They’re not even cuddly. Hedgehogs are more often the butt of jokes than anything else. (How do hedgehogs mate? Carefully.)

But on reflection, hedgehogs are a great choice. There’s something appealingly egalitarian about hedgehogs. You don’t need to live in a national park to stand a chance of seeing one – they live among us, even in urban areas. You don’t need to stake them out for days, in special hides with high powered binoculars. Most nights (when not hibernating) they happily stop and eat just 2 metres from our patio doors, and don’t mind the garden light.

They’re also very inoffensive. Our more impressive animals all have groups of people they’re unpopular with. For deer it’s people whose crops and trees they damage. Foxes are unpopular with poultry keepers, and otters and herons with fishermen and fish farmers. Badgers are meles non grata with cattle farmers, and game keepers often aren’t keen on birds of prey. But hedgehogs? Almost no-one dislikes hedgehogs. As Pat Morris recounts, in his excellent The New Hedgehog Book, a survey of over 1,200 WI members in 1990 found that 98% of respondents liked hedgehogs.

In fact, not only are hedgehogs hard to dislike, they’re positively popular. Gardeners love them because of their insatiable hunger for garden pests. One of my Dragons Den ideas is to start up a hedgehog farm, to sell to gardeners. Disappointingly, the ones that visit our garden seem remarkably uninterested in eating slugs (of which there are plenty). I’ve watched a hedgehog tucking into mealworms, carefully munching around a slug that has climbed into the bowl. But still, despite not pulling their weight in the slug devouring stakes, they’re always a welcome sight in our garden.

So, on reflection, I think the readers of BBC Wildlife Magazine have got it right. Hedgehogs are a great choice for national species. One everyone can get behind. And one that needs everyone to get behind it. According to the People’s Trust for Endangered Species, hedgehog numbers dropped by one third between 2003 and 2012. What was once a common sight is now becoming rarer, and many people I speak to have never seen a hedgehog in real life.

If you’d like to do something to help our prickly national species, there’s some good advice here. Better still, you could become a hedgehog champion as part of Hedgehog Street, and work with your neighbours to create a hedgehog friendly street. Let’s try to make sure that the British national species is around for future generations, and doesn’t become as rare as the Welsh dragon…

How to build a mini pond

Frog
Frog

As a kid, I loved the pond in my parents’ garden. It was brimming with frogs and newts (and leeches). My brother and I spent many happy hours catching frogs (the tiny, just-got-legs ones were the easiest to catch, and the cutest – poor little froggies being chased by curious kids). So when I finally got a garden of my own, I was determined to build one.

Building a pond is a great way of increasing the value of your garden to wildlife. It attracts invertebrates, amphibians (who eat slugs – horay!), and can be a vital water source for birds and mammals if it’s designed well. As I mentioned in my first post, our garden is rather small, and since Dr C objected to me turning the whole lawn into a pond, I had to content myself with a mini-pond. But even a tiny pond can be really valuable to wildlife.

Living in England’s equivalent to the Champagne region, the obvious container for our pond was half an old wine barrel, obtained from our local vineyard. Old tin baths, belfast sinks and other similar containers can also make good mini-ponds.

To make it easier for hedgehogs and frogs to access, we decided to recess it, so the top was about level with the decking. Dr C valiantly got on with the digging while I tried to clean up the barrel. After several scrub-outs, the water was still turning wine red, so as we didn’t want drunk frogs, we decided to line it with pond liner.

Once the pond was in place, we used old bricks and stones to create different levels within the pond. This is important so frogs and hedgehogs can easily climb out, and birds have a shallow bit to bathe in. When we had the landscaping sorted, we put the pond liner over the top and stapled the edges to the top of the barrel so they didn’t move.

Creating different levels in the pond
Creating different levels in the pond

We added a couple of handfuls of pond compost, and then filled it with water from our water butt (if you’re using tap water, you have to let it rest for 24 hours so all the chlorine can evaporate off, before adding any plants or creatures).

Picking plants for a small pond can be a bit of a challenge, as you need to find something that won’t spread too much. We managed to find a dwarf water lily for surface cover (most water lilies like to be planted quite deep), and then picked a couple of native oxygenating plants plus a small iris for the edge. Waterside Nursery have a good range of wildlife friendly pond plants.

Newly planted pond

Newly planted pond

I’ll save telling you how the pond has fared for another day, but here’s a sneak preview…

The mini pond
The mini pond

If you’re keen to have a go at creating your own pond, the RSPB provide some good guidance. Waterside Nursery’s website also contains lots of useful advice about building a wildlife pond and picking the right plants.

Welcome to the Wild South!

To start my blog, I thought maybe an introduction to my wildlife garden might be in order. We (Dr C, Fat Cat and I) live in a small town, and have a small garden (about 7.5m by 7.5m). Since we moved in (back in 2009) we’ve been gradually trying to turn it into a haven for bugs, birds and other beasts, and have had more success than I anticipated.

The RSPB have some brilliant resources for making homes for wildlife, and many of the ideas we’ve used have come from that.

When we moved in, the garden had a couple of decked areas, a lawn, a couple of borders and a small box hedge. A rampant buddleia has been an attraction for butterflies, bees and birds. Since then we’ve added a bird feeding station, a barrel pond, a small area of meadow, a hedgehog house, birdboxes, some small trees in pots, a wood pile, a raised vegetable bed, an insect log, a bird bath, and probably some more things I’ve forgotten.

Since then we’ve seen 25 species of bird in the garden, along with hedgehogs, a fox, mice, a slow worm, frogs, various pond life and numerous insect species. It’s been really satisfying seeing how quickly wildlife starts to make use of the things we’ve provided. Watching the garden has been a real source of pleasure to me, and I’ve learnt a lot along the way.

The meadow
The meadow
Raised bed & buddleia
Raised bed & buddleia
The mini pond
The mini pond
Bird feeding station
Bird feeding station