During the winter months it is not uncommon to see large numbers of birds, all seemingly getting on with each other unlike the spring and summer months when birds become very territorial. But why do they do this?
The main reasons for birds grouping together are safety in numbers and warmth at night. Most birds’ arch enemy are raptors. Particularly sparrowhawks, peregrines and merlins, which will chase single birds.
However, when birds are in large groups the raptors get easily confused and struggle to home in on a single bird unless there is an older, weaker, injured or ill bird, which gets left behind. Some birds will also group up at night to snuggle up together and share body heat but again, the stronger birds will be in the middle and the weaker birds pushed out towards the edges where there is less protection from the elements.
If you are boating through an urban area there is the chance that there is a pied wagtail roost nearby. They are very similar to long-tailed tits in that they roost together for warmth and protection with the weaker birds being pushed out to the edge.
During the winter months lapwings flock together and can be seen feeding in fields or along waters edges and they can be seen in groups of several thousand. However, take a closer look at the flocks, especially inland, and there’s a good chance of finding golden plover or maybe ruff.
These birds can form vast groups sometimes in excess of 5,000,000 individuals. This is called a murmuration and it is a stunning site to see as they cartwheel in the air creating amazing shapes and yet they never seem to crash in to each other. If you have the technology search for it on the internet with Hams Wall RSPB being one of the largest murmurations in the UK.
Long-tailed tits are small but quite vocal birds, always chirping as they go on their way feeding along hedgerows and trees. However, look closely and you’ll see other species of small bird too. Blue, great and coal tits, goldcrests and, if you are very lucky, firecrests. Long-tailed tits are also known to roost in large numbers especially in town centres where there are lights that offer warmth.
As a rule birdwatchers do not get excited about geese during the summer months as they are usually all canada and greylag geese with the odd population of barnacle geese. However, during the winter months the UK becomes home for thousands of pink-footed, white-fronted, barnacle and bean geese, which can pass over in groups or skeins in their thousands. Sometimes a handful of wild geese can turn up anywhere with the feral flocks so canada and greylag geese are still worth checking out in winter.
Duck numbers swell in winter thanks to migrating ducks. Our resident ducks - mallard, tufted duck, shoveler and gadwall are joined by goldeneye, teal, wigeon and smew. These can be found on canals, rivers and lakes in large groups.
Mute Swans gather in large numbers to spend the winter feeding on crops in fields but there are two other swan species that can be found with the mute swans, whooper and bewick’s swans. Bewick’s can be distinguished from mute swans by their yellow beaks (rather than orange). However it is a bit trickier to tell the difference between a whooper and a bewick’s swan.
Vast flocks of finches can be found in many locations with several species of finch found flocking together. They include the chaffinch, greenfinch, bullfinch and goldfinch but are also joined with linnets. If you are lucky you may also find a brambling, a winter visitor.
So the next time you see a large flock of birds do not just assume they are all the same species you most probably will find other species as well and you never know, you might find a rare beauty.