The changing weather brings a variety of challenges for our Solent birds.
Birds that migrate to the Solent every year have a lot to contend with. Firstly, some have flown 3000 miles from places like Siberia and Northern Canada.
They use a variety of methods to migrate, varying from using a geomagnetic sense to sun, star or landmark navigation. The journey for any bird is never a straightforward matter of travelling from one place to another, it’s fraught with dangers such as storms, exhaustion and starvation. When you consider that many of the birds return to the same location every year, this feat of navigation is almost inconceivable.
Once safely arrived, wonderful waders, such as the ringed plover and black-tailed godwit, need to settle in to their new surroundings quickly and get down to the business of re-energising.
For this to happen the birds need to spend their time feeding, foraging and resting. Their diets will change throughout year, but during the colder months many will eat worms, shell fish, crabs and invertebrates to fatten up. Others will eat grass and plant matter to gain essential nutrients. However, when the temperature drops, and the wind increases the challenges multiply for our feathered friends.
In extreme weather, invertebrate species living in the mudflats, sand and saltmarshes often become less active and thus become less detectable to a beak in the sand. Low temperatures and high winds also mean that potential meals lie deeper under the surface to take refuge from the elements. The effect of this can be that the birds’ energy use increases as they fly further to find food.
With the temperature below zero, the energetic costs of thermoregulation are also raised. The birds then rely on their fat reserves to survive and the smaller birds usually find this most difficult, simply because they don’t have as much fat.
With all this considered, it’s tough being a migrating coastal bird. Mercifully the elements are now changing and with February here it means in a few weeks the birds should be in terrific condition, having confronted all the challenges winter has thrown at them.
Next comes the small matter of flying back 3000 miles to start the process all over again.
Keep an eye out in future for an article covering some of the challenges our birds face at their summer breeding grounds.