Humans are not the only ones enjoying a warm end to the year – everything from spiders to bumble bees are also relishing the relative heat.

Concern over bee deaths in Boulder, Colorado. Image by Ronald Saunders / CC BY-SA 2.0

Bees and other insects are enjoying a mild December. Image by Ronald Saunders / CC BY-SA 2.0

Winter usually marks the point where insects begin to hibernate or populations start to dwindle, but unfortunately for those with insect phobias, this year might be different, as temperatures have risen to about 10C above average for December. Insects can be very reactive to an increase in temperature, due to most of them having cold blood.

Dr Ed Turner, of the University of Cambridge’s Department of Zoology, said he had noticed certain species of bumble bees almost four months later than he would expect. He said: “Insects are exothermic, or cold blooded and, it being so seasonally mild, they are to going to stay. The other day I saw a buff-tailed bumblebee and I wouldn’t expect to see those after August or September.”

This can have a knock-on effect for the ecosystem and agriculture, he added, as insects can continue eating crops or pollinating. Warmer winters such as could be an indication that global warming is starting to have an effect, Dr Turner suggested. “I wouldn’t go as far as to say this is climate change, but this is the kind of warming we would expect,” he said. “Is the natural world being affected? Yes, it clearly is.”

Even the heat of a human body can be enough to stir some butterflies from a deep seasonal slumber. Dr Turner said: “If you go into an outhouse and turn on the heating, a butterfly might come to the window. “They go into torpor, which is a kind of hibernation, during winter – they shut themselves down and if you turn up the heat, even your body heat might be enough, they will get themselves active.”

(Press Association)