Alien invader taking over River Mole

The day had been sweltering and, even in the relative cool of early evening, people were picnicking on the river bank and kids splashing in the water. They had no idea that just metres away lurked an alien invader, laying siege to the River Mole, and threatening to take over completely.

Like Scarlet Johannson in Under the Skin, this alien’s danger was disguised by a pretty face. The pink flowers of Himalayan Balsom distract from its invasive nature. The plant can grow up to 2.5m tall, and forms dense swathes. When the seed pods are ready they explode dramatically, firing seeds into the river, where it can be swept for miles downstream, before settling on a new stretch of river bank.

Himalayan Balsom

As well as crowding out other species of plant, the shallow roots of Himalayan Balsom can cause erosion of riverbanks. Thick stands of it may also increase the risk of flooding.

Luckily, although it spreads quickly, it’s easy to pull up. Further downstream in Leatherhead volunteers with Surrey Wildlife Trust have done quite a lot of clearance work. But because it spreads downstream so easily, it’s hard to eradicate it permanently from a small stretch of river.

Himalayan Balsom is one of the non-native invasive species I look out for during my Riversearch surveys. And unfortunately I found quite a bit on my latest survey.

Once again the river bank has changed dramatically with the seasons. This time much of the river was inaccessible, as shoulder high nettles formed a barrier I wasn’t willing to test in light trousers and short sleeves.

The river level was low, and apart from the Himalayan Balsom there was little new to report. I did find a rather intriguing stash of fruit between some tree roots. Any idea what could have hoarded that?

Whose secret stash is this?

Advertisement

Photo special: Lundy Island

Lundy is a small British island, marking the point where the Atlantic becomes the Bristol Channel. It’s a lovely destination for wildlife lovers, as it’s a breeding site for many seabirds, including puffins. The waters surrounding it have been protected for 40 years, making it one of the best spots for diving in the UK.

Here are a few photos from my trip there a few years ago.

 

The ferry departing from the small harbour on Lundy

The sheltered east coast of Lundy

Sika deer

Sika deer

Seabirds (including puffins) nesting on the sheer cliffs of the west coast of Lundy

Seabirds (including puffins) nesting on the sheer cliffs of the west coast of Lundy

Dormousing: July

It was hot and humid in the woods on Saturday. There was none of that delicious freshness you usually get in the shade of the trees on a summer day. It felt like a tropical rainforest, and I half expected to hear the cries of chimpanzees.

It was strangely quiet. Perhaps all the birds and animals decided that the best way to deal with the humidity was to stay quiet and still. I must admit that if I hadn’t had a good reason to be out in the woods that morning, I would probably have been sitting near a fan, trying not to do anything.

But each month there is a ten day window to carry out the dormouse box checks, and this was the only day I could do. I was helping to check a site I haven’t done before, which is always a bit of a challenge. When you don’t know where the boxes are it’s a bit like geochaching or letterboxing. Dormice boxes are often away from the beaten track, which means you have to fight your way through brambles, wade through waste high nettles, and scramble over fallen trees.

We didn’t have much luck on this check. No dormice, or signs of new nest building. Just a solitary wood mouse, a wren’s nest, and a couple of bees’ nests. We did glimpse a deer in the distance, but I think everything else was staying hidden away from the heat.

Hopefully I’ll have better luck next time.

Box Hill and The Lark Ascending

My walk on Box Hill the other day was lovely. The sun was shining and the slope alive with butterflies. But I felt that something was missing. There was no skylark song.

I recommend you listen to this YouTube video while reading the rest of this post. You’ll thank me for it!

Skylarks are plain-looking brown birds, smaller and duller to the eye than starlings. But to hear them sing is to have your ear filled with molten silver, and your thoughts lifted to the heavens.

Patrik Åberg, XC27004. Accessible at http://www.xeno-canto.org/27004.
Creative Commons Attribution-NonCommercial-ShareAlike 3.0

Skylarks are ground nesting birds, found mostly in farmland. A few years ago we visited Lundy, which seemed to be bursting with skylarks. Elsewhere in Britain skylarks are a rarer sight. Their numbers halved in the 1990s, and continue to decline.

The main reasons behind the plummet in skylark numbers seems to be changes in farming practices. The move from spring to winter sowing of crops, overgrazing and a shift from hay making to silage have dramatically reduced the habitat available for skylarks to breed in.

I missed skylarks on Box Hill because it felt like the right sort of habitat for them. But I think there was also a sub-conscious expectation that there would be skylarks there, because of its links to skylarks in poetry and literature.

The 19th century writer George Meredith lived on Box Hill, and wrote the poem The Lark Ascending that inspired one of my favourite pieces of English music, by Ralph Vaughan Williams. Vaughan Williams lived in Dorking, the town Box Hill protects and shelters. His The Lark Ascending is said to describe the English landscape in musical form, as well as capturing something of the soaring beauty of the lark’s song. While I love this piece, I hope it isn’t the closest our next generation gets to hearing skylarks.

British Animal Challenge: July update

Progress on my British Animal Challenge slowed somewhat in June, mainly due to me being distracted by football, tennis and music.  I have seen (and heard) a couple of new bat species, thanks to my new bat detector. But I’m not quite sure which species, as I find it hard to distinguish them. This month I have a bat walk planned with an expert, so hopefully I will pick up some tips.

In addition to bats, I am also hoping to see a yellow necked mouse, and maybe some other small rodents when I go out dormousing.

Chalk grassland: Europe’s rainforest?

Sometimes places that look barren or dull can be full of diverse wildlife, on closer inspection. I am a bit of a tree fan, so it’s always been the woods of Box Hill, with their rare box trees, that have excited me. While the grassy slopes of the hill have appealed to me aesthetically, I assumed that the real wildlife was elsewhere.

The grassy slope to the summit of Box Hill

A recent walk up the hill on a sunny day made me suspect I might be wrong.  What, from afar, looks like boring old grass, is actually a huge variety of plant species, including many different flowers. And these plants were buzzing with insect life.

Chalk grasslands are home to a huge range of plant and insect species

A bit of reading up on the subject has confirmed that my earlier assumptions were well wide of the mark. Chalk grassland, grazed by sheep and unfertilised, is one of the UK’s richest for plant and insect diversity. The poor, thin soil, and regular grazing, means no single species can dominate.  A square metre of chalk grassland may have up to 40 different plant species, leading to some calling it Europe’s answer to the rainforest.

The chalk grassland slopes of Box Hill, looking towards the woods

This diversity of plants gives food and shelter to a wide range of insects.  41 different types of butterfly have been found on Box Hill, including some of the rarest in the UK. I didn’t even know there were that many butterfly species in Britain.

Chalk grassland is in itself quite rare. It is an internationally important habitat and is a priority in the UK Biodiversity Action Plan.Besides the North and South Downs there aren’t many other large areas of chalk grassland left. Much has been lost in the last 50 years due to changes in farming, (intensification including use of fertiliser and over grazing), encroachment of scrub where grassland isn’t grazed, and development of land for other purposes. Only 1% of the Surrey Hills has remnant chalk grassland cover.

Looking south from Box Hill

There’s been quite a lot of controversy locally about a recent Court of Appeal judgement allowing some chalk grassland to be turned into an exclusive golf club. Neatly manicured, fertilised and herbicided greens and fairways are deserts compared to natural chalk grassland.

While it may not have the immediate feel of the wild that you get in woods or at the coast, chalk grasslands are rich habitats, and need protection. Losing chalk grassland means losing a unique and fragile ecosystem, which we will be poorer without.

Looking from Box Hill towards Dorking

Fascinating wildlife fact #7: Grass snakes play dead

Grass snakes sometimes play dead when they feel threatened. The roll onto their backs, release a smell that makes it seem like they are decaying, and even bleed from their eyes and mouth.

Sleeping like a dormouse

After years of monitoring dormice, I have now had a taste of what it’s like to sleep in a dormouse nest. Last week we went camping, and stayed in a remarkable tent, suspended from oak trees.

The tent was made of a spherical wood and aluminium frame, covered in canvas. The design was inspired by harvest mouse nests, but I prefer to think of it as a dormouse nest, since dormice live in trees.

It was an exciting experience. The tent had two windows, looking into the branches. Every so often we could feel the tent move gently, like being in a boat.

It was also a comfortable experience, as it comes with proper beds and a tiny woodburner.

The campsite itself is a wildlife haven. The pitches are mown areas of grass in a meadow. There’s a pond, and the site is surrounded by woods. The owners are keen to keep it wildlife friendly. Later this month they are hosting a wildlife weekend with Sussex Wildlife Trust.

We didn’t have any dormice visit us during our stay, but it was lovely watching (and listening to) the common pipistrelle bats as we sat by the campfire after dark.  We also saw three deer at dusk, crossing into the woods. And there are plenty of bunny rabbits, birds and bugs around.

 

Have you come across any particularly wildlife friendly campsites you would recommend?