Regular readers of mine will know that I have a particular fondness for the common little wren.
Not only is this due to their appearance, with their tiny stature and rotund body, but it is also mostly in admiration of their industrious nature and willingness to protect their territory at all costs.
Like most gardens, mine sees fewer bird visitors during the winter. If you’re wondering where they get to as temperatures drop, read ‘Do Wrens Migrate’, for the answer.
The majority of British wrens are resident or sedentary. This means that they stay in one place and don’t migrate. In particularly harsh winters, the wren may travel distances of up to 150 miles in the hunt for a safe, sheltered place to roost.
If wrens don’t migrate, how do they survive prolonged winters?
The sad fact is that many of them don’t. During a severely cold winter, it is thought that the wren’s population is diminished by 25% – 75% as they struggle to survive the conditions.
The wren is a tiny bird with little space to store body fat. The only way to keep warm is to find a safe, sheltered spot and huddle together and prevent rapid heat loss.
This goes against the character of the wren. During the mating season, he is a very antisocial character, fighting off or angrily chatting at other males who dare to encroach upon his territory.
Yet when temperatures are low, male wrens actively encourage other wrens, both male and female, to snuggle and share what little body heat they have. He might call or go on short flying recces to invite other wrens to his generously-sized pad.
It is not uncommon for more than 30 wrens to group overnight in one roost. Wren’s don’t migrate, they just rely on each other for warmth and protection; there is safety in numbers.
If wrens struggle to cope with winter, why is there still so many of them
This is a good question. One of the main reasons that their population isn’t in decline is due to their high egg productivity. Each breeding season a female wren will hatch between 5 and 8 eggs. If the brood fledges successfully, it is very commonplace that the same mated pair will have a second brood immediately after.
Also, not every winter in the UK is harsh, so wrens don’t need to migrate. Milder winters are a huge contributing factor to the wren’s ability to survive. Sadly, this is probably directly linked to global warming.
Finally, more and more humans seem to be doing their bit to keep all of the garden birds well-fed through the cold months.
The wren has a particular fondness for finely grated cheese if he can’t get his beak on any insects or spiders. They don’t even mind digging in the snow for them.
Scattering a few crumbs on the ground near to some low cover can mean the difference between life and death for the wren in winter.
Of the 10,000 species of birds in the world, only about 1,800 of them are long-distance migrants.
Reading ‘Do Wrens Migrate’ will tell you that these charming little guys aren’t in that number. Instead, they choose to stay at home and pit their wits against our, sometimes unpredictable, climate. They only move from their territory when they’re on the lookout for a larger roost to accommodate more cold wrens.
Let’s all give them a helping hand by leaving them a few crumbs as the temperatures drop.