The unusually mild winter temperatures in many areas this year has caused flowers to bloom early, trees to blossom and even produced some of the earliest crops of asparagus ever seen.

But the abundance of food and warm weather also seems to have been having an effect on squirrels too – by making them fat.

Sightings of seemingly overweight squirrels have been sweeping social media sites as the rodents take advantage of the mild conditions to cram in extra food in preparation for the cold weather, when it finally arrives.

Do I look fat in this? Mild weather conditions and crops of nuts have meant squirrels have been able to put on some extra weight this year before colder conditions finally arrive and they have to tighten their belts. Many fat rodents have been spotted in Cardiff's Bute Park (pictured) and elsewhere in the UK and US

Much like their distant human relatives, it seems squirrels are also prone to overindulging at this time of year.

In Cardiff’s Bute Park in Wales, grey squirrels puffed up with extra food and thick fur have been spotted scampering around, albeit a little slower than normal.

SQUIRRELS ARE FAST LEARNERS If you have ever hung a bird feeder in your garden only to find it emptied by a squirrel minutes later, you’ll already believe the pesky rodents are smart. Now scientists have shown the creatures really are fast learners, capable of adapting tactics to improve efficiency and reap the best rewards, which perhaps explains their ability to nibble even the most well-protected foods. The intelligence test, devised by the University of Exeter, test took form of a box with 12 sunken wells, four of which were hollow. Nuts were hidden in the four hollow wells diagonally across from each other, so that the least efficient way to look for them was by going from well to well in a clockwise or anti-clockwise sequence. Over a number of successive attempts, the squirrels - named Simon, Arnold, Sarah, Leonard and Suzy - worked out that if one well contained a reward, another nut would be located in the well diagonally opposite it. Researchers said they were surprised with the speed at which the squirrels solved the puzzle. Advertisement

According to the Met Office, last month was the warmest December on record in Britain, with temperatures of 7.9°C (46.2F), which is 4.1C (7.4F) above the average for this time of year.

This meant there are still plenty of nuts and seeds available to squirrels.

Although grey squirrels do not hibernate - they are active all year round - they usually pile on extra weight to help them survive the lean cold months of winter, when they must rely upon food they have stored.

Meanwhile in many parts of the US, including New York, Texas, Wisconsin and Boston, residents have also been posting pictures of their overweight rodent visitors.

Angela Palmer, a gardener in Boston, Massachusetts even tweeted a picture of one greedy squirrel that has gone to unusual lengths to reach some food – by climbing inside a bird feeder.

Others have expressed shock at the size of the squirrels they have seen in their own gardens.

Another photo of a fat squirrel making off over a woman's garden fence with an avocado it had also went viral, although the photograph was taken in 2014.

Nick Mason, project manager for Red Squirrels Northern England and Northumberland Wildlife Trust, said: 'Squirrels are opportunists and much like humans will take advantage of any food that is available.

'It is fairly typical for squirrels to put on weight through the year and this can vary depending on the stage of their breeding cycle and their life cycle.

A time of plenty: Squirrels normally look bigger at this time of year as they put on weight to help them survive the winter and have thicker fur, but experts said they may be larger than normal (pictured) due to mild weather

Guys I found the fattest squirrel #fatsquirrel pic.twitter.com/LD18rwkwP3 — Socks Fake (@fox_sake) December 24, 2015

the fattest squirrel I've ever seen in my life just stole an avocado from our trash can pic.twitter.com/zoeTV9dhAf — b (@brob3rts) December 2, 2014

'Grey squirrels can double their body weight in winter and the maximum weight ever recorded was 800 grams (1.7lbs).'

Wildlife TV presenter Iolo Williams told Wales Online it was normal for squirrels to look bigger at this time of year, but the extra food that is available had enabled many to put on extra weight.

He said mice and birds were also benefiting from the abundance of nuts, fungi and other food sources.

Cute, furry and fat: Squirrels in Bute Park, Cardiff, Wales, appear to have been making the most of the warm weather by over indulging in the abundance of nuts and other food sources (left and right) but similar fat rodents have been seen elsewhere around the UK and US

A new low for my favorite fat squirrel. He is now INSIDE the bird feeder. All hope is lost… https://t.co/XuvD5DI60c pic.twitter.com/UGwGGnQ3nK — Angela T. Palmer (@plantweenie) January 4, 2016

Here in Wisconsin, we even have a beer called Fat Squirrel Nut Brown Ale. Judging from my yard, not hard to see why. pic.twitter.com/NFhIF18opH — Stacy Merrick (@StacyMerrick) December 30, 2015

this glorious fat squirrel came really close to me and stuck this pose lol pic.twitter.com/uLl7J1PZ9A — Sarah Aspler (@saspler) January 2, 2016

However, he warned that the wet weather that much of Britain has experienced could increase death rates in animals like otters.

'Because of the mild wet weather there has been an abundance of food for squirrels,' he explained.

'There has been no shortage of nuts, seeds and fungi for them to eat and store.

'With the extra layers of fat and thicker winter coat this can make them look much bigger.'

Today, @SheltonStep and I saw a really really fat squirrel at the zoo and it was the best part of the trip �� pic.twitter.com/494IRDFqF8 — Greta Swift (@GretaSwift888) January 6, 2016