Название: Springwatch Unsprung: Why Do Robins Have Red Breasts?
Автор: Jo Stevens
Издательство: HarperCollins
Жанр: Природа и животные
isbn: 9780007498185
isbn:
So far so good, but then Gerald comes off the rails – as ever, scientific verisimilitude thrown out the window for the sake of a good yarn:
‘The toads killed him and ate him right up leaving nothing but his skeleton!’
Migrating toads often have to cross roads and passing cars can, inadvertently, cause carnage. If you would like to help you can find local toad patrols at www.froglife.org/toadsonroads.
I’m going to feature a special ‘Unsprung’ word for each season, and the one for spring is ‘guffing’. Male newts display to the females underwater and at the end of their display they sometimes come up close and blow a bubble of air at her as if to say, ‘I did all that and still have air to spare!’ This bubble blowing is called ‘guffing’.
Chris Packham and I went badger watching recently and it’s surprisingly exciting – as Chris says, you keep thinking something is going to emerge from the sett entrance in the next 30 seconds. Badger watching is especially rewarding in spring as the youngsters make their first appearance above ground and, having been stuck underground in the sett for many weeks, they tend to be particularly feisty. There are many local badger watching groups to be found at www.badger.org.uk/content/Living.asp.
Of course, spring wouldn’t be spring without mad March hares. I was once filming for Springwatch on Isla with Simon King and he suddenly said ‘quick, quick! Those hares over there – start filming them!’. Frankly I was bemused, it was interesting to see hares, there were six of them all together, but …? Gradually Simon, as only Simon can, revealed the real drama of what was going on. There was one female, just coming into season, and the other five hares were potential suitors. It was fascinating to watch the males chasing the female in turn and seeing her beat them off (and the fur really flies) until, finally, she made her choice. Fighting ‘mad March hares’ are generally females beating off unwelcome suitors, not males fighting each other.
The dawn chorus is one of the greatest wildlife experiences it is possible to have – no, honestly! – and it peaks in spring. Why not get up at first light, make a nourishing cup of tea and step outside into a magical world, a symphony of natural sound. I guarantee you’ll feel uplifted for the rest of the day. If you want to find out who’s making all the music there are organised dawn chorus walks up and down the country, look up your nearest one on: www.countryfile.com/countryside/top-10-dawn-chorus-walks.
The date I hear the drone of my first bumblebee of the year goes straight into the diary. It’s another joyful reminder that summer is on its way. In fact, we have no less than 25 different species of bumblebee. The first ones you see and hear will all be queens who, having hibernated all winter, are now prospecting to find a place in which to nest and start a new colony, often an old mouse hole. If it’s a cold morning and you hear a subdued buzzing sound coming from one place, have a look and you might see something curious. Bees have to ‘warm up’ flight muscles to a critical temperature (30°C) before they can actually take off. To do this they disengage their wings, then activate the muscles which warm up, without the wings moving (rather like pushing down the clutch in the car and revving the engine), then, once the critical temperature is reached, the wings are re-engaged and the bee takes off. Magic! There’s a lovely video of this on the BBC website: www.bbc.co.uk/nature/life/Bumblebee#intro.
Moths and other flying insects do this too.
To help bees, moths and butterflies in your garden why not plant flowers specifically to provide food and shelter for them? Best of all, plant a sequence of plants that will flower all year. There’s some useful advice on the best way to do this at: www.butterfly-conservation.org/93/give-time.html.
Finally, if you are really serious about helping wildlife, get in touch with your local rescue centre. This time of year they are often inundated with injured and abandoned baby animals, fox and badger cubs, deer and a host of birds. They often welcome volunteers and you will find yourself intimately involved in helping to care for wildlife. It’s an emotional roller coaster, though, once you get involved, so be warned!
At a Snail’s Pace
How long do snails live? Do they get slower with age? Nature Lover
Both the lifespan and speed of a snail vary according to the species. There are thousands of snail species worldwide but of those only about twenty are regularly found in our gardens. Whether or not they live to a ripe old age depends on how well they avoid parasites, disease or predators – and there are plenty of these around; thrushes in particular will readily make a meal of a juicy snail or two. Most snails will survive for only two or three years, but Edible or Roman snails (Helix pomatia) can live for several decades – the oldest known individual reached an impressive 35 years old.
As well as predators and parasites, snails also have to endure extreme weather conditions. They have adapted to survive several months of dry or cold weather by covering their shell opening with an epiphragm – a layer of mucus that dries out to form a barrier which prevents water loss. Some species, such as the Roman snail, can produce a much more substantial and solid epiphragm which is reinforced with calcium carbonate before the mollusc goes into hibernation. Snails can also protect themselves in winter by changing the composition of their blood, or haemolymph, to prevent it freezing. The common garden snail (Helix aspersa) can survive in temperatures down to minus 5 degrees Celsius.
Snails are renowned for their slowness, but they have no need to rush anywhere. The majority of species are herbivores, so they don’t have to chase after prey, and to escape most predators they need only to retreat within their shell. Snails may be slow but they are strong; when tested, one species was able to drag 50 times its own weight horizontally and nine times its weight vertically.
A snail moves by expanding and contracting its muscular foot in waves, and as it does so it secretes a slimy mucus that lubricates its path and reduces any friction on the surface beneath. You can watch how they do this by putting one on a clean drinking glass or windowpane. If you liquidise a little lettuce and smear some on the glass you may be able to see their tongue, or radula, in action too. While you’re there, you could test their speed. Garden snails can crawl up to 1.3 centimetres per second, equivalent to about 0.05 km/h. The fastest known garden snail was called Archie. ‘He’ (snails are hermaphrodites) slithered 33 centimetres in two minutes at the 1995 World Snail Racing Championships held in Norfolk. At the time of writing, Archie’s world record remains unbroken.
Archie’s racing days were numbered, though, because like most of us, he would have got slower with age. Scientists often use the common pond snail, Lymnaea stagnalis, as a model species for studying the central nervous system and investigating how brains change with age. Results so far show that older pond snails are more forgetful than young ones and feed more slowly. It seems that geriatric snails are generally more sluggish …
Flying the Nest