Fascinating wildlife fact #13: Slavemaker ants enslave other ants

Slavemaker ants raid the nests and enslave brood of other ant colonies to strengthen the workforce of the slavemakers’ colony. They trick the other ants using pheromones.

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Fascinating wildlife fact #12: dormice spend three quarters of their life asleep

Not only do dormice hibernate for around half the year, they also spend a large part of early summer in a state called ‘torpor’. Torpor is somewhere between sleep and hibernation, and helps them save energy on cooler days. They also sleep through most of the day, even at the height of summer.

torpid dormouse
Torpid dormouse

 

NB. for pedants - hibernation is different from sleep, as is torpor. But it's not such as punchy fact if I try to explain that in the headline.

Grrrreat tiger news!

It’s January, so (if you live in the Northern hemisphere) I’m sure you could do with some good news to cheer you up. You’re in luck! Figures released this week show that the tiger population in India has gone up by 30% in the last 4 years.

Tigers are an endangered species, and their numbers have plummeted by 95% over the last century. They now live in just 7% of their original range. Habitat loss and poaching are the main reasons behind this decline. India is home to around 70% world’s remaining wild tigers, so an increase here is very encouraging.

A few years ago I was lucky enough to see tigers in the wild in India. It was an amazing experience. Tigers have to be my favourite animal – they’re so powerful. And stripy. Stripes just look great on any animal (that’s why zebra are cooler than other antelopes), but in burning amber and forest black on a tiger they’re hypnotic.

Bengal tiger

While in India we saw 5 individual tigers (two mothers, and 3 almost fully-grown cubs). That came to about 0.2% of the world’s population of tigers. 5 individuals should not make up that large a proportion of any animal species.

With numbers that low, it’s easy to assume the tiger’s time is up. But the latest news from India is not the only good tiger news there’s been recently. According to the World Wildlife Fund, the number of tigers in Nepal has increased by 60% since 2009. These two success stories show that, with enough political will, effort and funding, the decline can be reversed. They’re not a reason to be complacent – the population is still fragile, but all is not lost yet. It’s not inevitable that tigers will become extinct. We need to do more to protect these wonderful cats.

Bengal tiger

Alien invaders: the grey squirrel

Few British animals are as divisive as the grey squirrel. While its red cousin is universally popular, the grey squirrel seems to be loved and loathed in equal proportion.

History and spread

While red squirrels are native to the UK, grey squirrels are a north American species. They were first brought into the UK in the late 19th century , and have since become firmly established in Wales and England. They are very common, with several million in living in the UK, mostly in England. They are at home in urban areas and gardens as well as rural woodland. They now outnumber red squirrels 67 to 1 in England, and 32 to 1 in Wales, while in Scotland red squirrels still outnumber greys.

The case for grey squirrels

Grey squirrel in a park
Grey squirrel in a park

Say what you like about the down side of grey squirrels, they are attractive with their bushy tails and dextrous front paws. They’re also great fun to watch. They’re agile climbers and watching squirrels chase each other up trees is a delight. They spend a lot of time on the ground, hunting for food, or burying nuts, so they’re easy to see. For many people, the grey squirrel is the only British mammal that they regularly encounter. In some urban areas they can become very bold. I used to live in a suburb of London, and the squirrels in the park would happily take food from your hand. That kind of encounter with a wild animal is a rare pleasure, and the charisma of the grey squirrel may hook people (especially children) to be more interested in wildlife.

(Grey squirrelIn fact the grey squirrels in that particular park were so bold that I sometimes worried about being mugged by them, when walking through with shopping bags. It was surely only a matter of time before they carried a toddler to the treetops.)

Grey squirrels have adapted well to life in the UK. They thrive because they’re suited to the environment we’ve got.

The case against

The case against grey squirrels can be split into two main types: vandalism and their impact on red squirrels.

Grey squirrel
What? Me cause damage?

Grey squirrels are capable of inflicting quite a lot of damage. They have very strong teeth, and can easily wreck a standard bird feeder (hence the number of complex, expensive squirrel-proof feeders on the market). Unfortunately for us dormousers, they seem to like the glue used in the plywood that dormice boxes are often made of, gnawing great big holes that makes the box unusable. Over the course of a season the costs of this can add up to significant amounts. They also damage trees by eating bark, causing between £6 and £10million worth of damage to UK woodlands every year, according to the Forestry Commission. And you really don’t want grey squirrels moving into your attic.

The most serious charge against grey squirrels is their impact on red squirrels. Greys are bigger and less specialist than red squirrels, and soon out compete them (they may also outcompete dormice when there are limited supplies of hazelnuts). Greys can also carry a virus (that they’re immune to) that has wiped out large numbers of red squirrels. Grey squirrels are probably not the only factor that has contributed to the demise of the red squirrel in much of England and Wales. Habitat loss of woodland is also likely to have played a part. Grey squirrels are much better adapted to an urban lifestyle, and can get by in a more fragmented landscape than red squirrels need.

Red squirrel
Red squirrel

 

What’s to be done?

Every few years plans to do a huge cull of grey squirrels surface. The number of grey squirrels makes getting rid of them from the UK pretty much impossible, even if it was desirable. And culling in one area is unlikely to do any good, unless there are geographical boundaries that mean grey squirrels from neighbouring areas can’t just move in to fill the gap.

In places where red squirrels maintain a foothold, with good squirrel boundaries, keeping grey squirrels out is important. But we’ve missed the boat for the rest of the country. I’m following the progress of a red squirrel reintroduction programme on the Lizard peninsula in Cornwall with great interest. At the moment they are trying to get rid of the grey squirrels before releasing captive bred red squirrels. The Lizard isn’t an island, although it pretty cut off from the rest of the mainland by a river. Whether that’s enough to keep the greys at bay remains to be seen. Other reintroductions have tended to be on islands which have a more squirrel-proof border (like Tresco). It’s unlikely we will see red squirrels returning to most of England.

So there’s not much else that can be done, except for try to make the most of the grey squirrel as a charismatic ambassador for wildlife in our towns and cities. And enjoy watching their exploits.

Weasel words (or in praise of weasels)

Weasels have a bad press. Their name has come to mean some sly, sneaky and treacherous. Their most prominent depiction in popular fiction is (together with stoats) as a gang of vicious, mean ruffians, taking advantage of poor Mr Toad’s foolishness to take over Toad Hall.

With their pointy teeth and carnivorous diet, they are certainly fearsome predators, but I think their reputation is rather unfair. If they were bigger, perhaps people would respect them more. The larger members of the mustelid family (badgers and otters) are (generally) regarded with affection. Compare how they’re portrayed in The Wind in the Willows with the poor stoats and weasels. Yet otters are no gentler than weasels.

While weasels are pretty common in the UK, and active both day and night, people are largely unaware of them. I remember being amazed how small they are, the first time I saw one. In fact, a sub-type of the common weasel is the smallest carnivore on earth. The type we get here in the UK measures just 18cm (females) or 22cm (males) in length, and weighs just 70g (females) or 125g (males).

Despite their diminutive size, weasels are effective hunters. Their diet is largely made up of small rodents (voles and mice), but they can also dispatch rabbits. A weasel can run carrying prey that weighs half their own body weight. Pretty impressive.

Last weekend I attended a fascinating course on smaller mustelids, run by the Wildwood Trust. Before now I’ve not spent much time thinking about small mustelids. I was amazed by how little we know about stoats and weasels, which are both pretty common and widespread. This lack of knowledge may partly be down to their poor reputation. The difficulties of surveying them doesn’t help, either.

The limited data we do have suggests that, while they are common, their numbers have been declining in recent decades. They’re not a protected species, so can be trapped and killed by gamekeepers. Secondary poisoning from eating poisoned rats is also a problem, along with predation by cats, foxes and birds of prey. They’re also vulnerable to parasites. Starvation is probably the biggest cause of death for weasels, and they are very dependent on the population of small rodents.

At least now, with the advent of cheaper DNA tests and camera traps, we may be able to find out a bit more about them. I’d certainly love to learn more, as they’re fascinating creatures.

Bird nerd part 7: blackcap’s back

I’m not a fan of winter, but it does make watching the birds in my garden a little more exciting. This week I was thrilled to see a blackcap for the first time since 2012. Blackcaps are a pretty type of warblers, with soft grey feathers and a striking black (if it’s male) or brown (if it’s female) cap.

Male blackcap
Male blackcap

Blackcaps aren’t the only unusual visitor I’ve seen in the garden recently. I saw a female chaffinch the other day. I’d only seen chaffinches in the garden twice before, both times back in 2013.

While few days go by without a visit from woodpigeons, feral pigeons are much rarer in my garden. But I have seen them twice in the last couple of weeks, having not seen them since 2013.

Obviously the food we put out is attracting more customers, despite the relatively mild and calm winter we’ve had so far. Better make sure I keep the feeders topped up!

December Riversearch: nothing to see here

In all the excitement of Christmas, I haven’t had a chance yet to tell you about my latest Riversearch. For those of you who are new to this blog, Riversearch is a scheme run by Surrey Wildlife Trust, where voluntary River Wardens regularly survey their stretch of river. We look out for (and report) pollution, non-native invasive species, and more positively, signs of river wildlife like otters and water voles.

I did my most recent survey just before Christmas. It was quite a contrast to the same stretch a year ago. On Christmas Eve 2013 the River Mole flooded, hitting the national news. When I surveyed it in early January (once the water levels had receded enough to get near it), the meadows along it were like lakes.

Christmas 2014 was different. In fact, the remarkable thing was there was nothing remarkable to see, for the first time. No storm-felled trees. No burst banks. No dumped rubbish. No invasive species. No kingfishers. No deer prints. No people paddling. No intriguing cache of fruit. Nothing. Just the river at a normal level, doing what rivers do best.

Still, even this rather dull data is useful, I’m assured.

Photo resolution

2015 arrived while I was sleeping. Happy new year, everyone! A new year, time for a new challenge. Obviously there’s plenty to keep me busy with the British Animal Challenge. But I’ve also resolved to take more photos.

Preparing for the craft fair in November made me realise most of my best photos are years old. But I also got some really encouraging feedback. Not only did people give me lots of complements, they put their money where their mouth was and bought some of my photos.

Going to the Wildlife Photographer of the Year exhibition was humbling.  It also reminded me there are loads of photographic techniques that I could try out.

Reflecting on those things made me decide to do more photography in 2015. That’s easy to say, but I know if I left it at that I would soon run out of ideas and lose interest. So, to push myself, I am going to set myself a new challenge each month. Hopefully this will encourage me to try new techniques, and actually get out more with the camera.

The list of challenges may well change a bit over the course of the year, as I get new ideas and opportunities. But here’s the first draft.

  • January: winter nature
  • February: still life
  • March: birds in the wild
  • April: spring nature
  • May: garden
  • June: insects
  • July: summer nature
  • August: woodland
  • September: seascapes
  • October: autumn leaves
  • November: landscapes
  • December: portraits

There’s also a number of techniques I want to experiment with over the year, including:

  • Using flash
  • Low-light / night
  • Macro
  • Using my 50mm prime lens
  • Using my USB microscope
  • Timelapse
  • Motion blur
  • Black & white

I’ve put these into my calendar, and hopefully it will spur me on to improve my photography skills and boost my portfolio. I’ll try to post any good photos I manage to take…