Tag Archives: Rattus norvegicus

Autumn Geese and a natural mystery

Autumn came in very slowly this year, but it turned quite cold quite quickly. However, now at last we are getting rain in proper autumn levels. We had proportionally very little rain all last winter, spring and summer. Finally the geese have started to arrive too. Here are two of the most common species, the Brent Goose (Branta bernicla):

and a flock of Greylag (Anser anser), with two Rooks (Corvus frugilegus) providing a sense of scale:

All of these birds are pictured at the famous Kilcoole Breaches and nature reserve.

There have been two noticeable trends this autumn – firstly there have been far less spiders than you would expect on average, particularly House Spiders. But all species seem to be lower in number than usual. The only spider species at normal levels, or apparently normal levels, has been the Garden Spider (Araneus diadematus), which is also the most obvious autumn spider:

    Conversely, there has been a population explosion of Brown Rats (Rattus norvegicus) which has been attributed to the long hot summer and the summer heatwave of May, June and July which almost led to a severe drought. The increased population of Brown Rats very likely has reduced the number of spiders, as rats and mice will happily eat large spiders. More rats equals less spiders.

However, from my own observations I disagree that the summer heatwave is responsible for the population explosion of rats – back in March, during the heavy snows, there was a massive surge in rat numbers. They were especially attracted to bird feeders. The winter had been very cold even before the snows arrived late, and it seems that this factor drew rats from the countryside towards human settlements in order to find food and warmth. But whatever the exact cause, there were a lot of them around, although numbers at last seem to be returning to normal:

A Very Crazy Spring – Winter Returns with a Vengeance

Only last week the weather was improving so much, and the spring flowers all blooming so brilliantly, that it seemed spring was truly here and here to stay. I even saw my first hoverfly, which was, unusually for our spring, a Drone Fly (Eristalis species):

But this week everything went crazy, with the arrival of the so-called “Beast from the East”, a fierce cold weather system bringing snow and freezing temperatures to all of Europe from Siberia. Just as I was winding down using the bird-feeders in my garden they suddenly became vitally important to birds in the cold weather, and were also getting the attention of many rodents, including one particularly handsome and determined Wood Mouse (Apodemus sylvaticus).  Here it is climbing out of the leaf litter next to the tree holding the feeders, just at sunset:

One night I even managed to get a video of the mouse climbing on a peanut-feeder, a tiny creature with huge eyes and ears, and a long tail:

However, there were also some less welcome visitors, such as two young Brown Rats (Rattus norvegicus), which were not quite so cute, and a lot bigger than the mouse, but equally interesting in their cheekiness:

   The cold weather inspired some incredible behaviour in some of the wildlife. Probably the most amazing thing I have seen in some years was a flock of desperate crows, Rooks (Corvus frugilegus) to be exact, who were managing to take food off the carefully-designed “crow proof” small bird feeders. One of them was even hovering like a hummingbird! Watch and be amazed:

The bad weather doesn’t end there though – tonight a huge rain storm from the Bay of Biscay, Storm Emma, collides with the Beast from the East and we have a Red Weather Warning, the highest level, only used once before and, ironically, only a few months ago when Hurricane Ophelia made for the island of Ireland. This time, it’s for snow drifts. Hopefully the wildlife will not suffer too much.