Birds of a feather need better weather

Migratory birds are having a tough time at the moment. Those that haven't contracted bird 'flu are finding themselves under threat after the coldest March in a decade has helped delay the traditional signs of spring.

Only last month there was snow on the ground, and Grainne Greene of the Royal Society for the Protection of Birds, says there has been a noticeable difference in the species at West 

"We have a nest box camera in place, so people can have a look at the birds while they are nesting," she says.

"We usually have blue tits or great-tits, but we haven't had any come in yet, that's a difference we have noticed compared to other years."

Earlier this week the RSPB warned that the cold weather had led to a delay swallows arriving in England from Africa, and late frosts have killed frogspawn. The breeding of frogs has also been delayed, meaning that their young could be at risk by the summer sun when they are born later than normal.

A decade of mild winters has meant birds breeding in January and February has been a common sight, but there has been a delay this year.

The average temperature in March was 3.9 deg C (39F), more than one degree C below the 30-year average, and 2.5 deg C lower than March last year. This has wiped out many of the insects which many of the birds depend on for their food supply.

"Little birds like blue tits and great-tits need to wait for peak levels of insects, and it is possible that they are delaying breeding," says Miss Greene. "Migrant birds coming to us from Africa are struggling at the moment because of a lack of insects.

"They have lost all their fat on the journey, and the shortage of food means they are going hungry. They need to double in weight before they go back," says Miss Greene.

Birds that nest in the undergrowth in Sandwell Valley, such as the lapwings, are also suffering, and seem to be delaying their breeding.

"I can imagine if the cold weather persists their chicks would get cold, so they might be holding back a little."

All this sounds bad news for the Black Country bird population, but Miss Greene says one cold spring alone will not make much of a long-term impact. But what if it is cold again next year?

"It wouldn't help, it would have an impact, although it is difficult to gauge how much," she says.

Miss Greene says there has also been a reduction in the number of butterflies seen around the park, which may be due to the fact that they are taking longer to pupate, although the trees and flowers seem to be unaffected by the weather.