Fewer birds can be seen over summer

Bradford & Airedale RSPB bird survey identified 111 different species of birds in the district this year, however, no new species were reported for a couple of months over summer. Where had they all gone?

That time of year is not the best time to see birds. They seem to disappear - the dawn chorus gets quieter and quieter, and an odd silence takes hold in woodlands.

Birds sing for two basic reasons: to attract a mate and to defend a territory. By July, many baby birds have fledged, and even birds that have multiple nests per year have finished by early August.

Some birds may continue singing for a while to help their young learn their local song dialect. But many birds stop holding territories and start to join flocks - and territorial singing just isn’t compatible with flocking. One by one, each species drops out of the morning chorus.

Heavy foliage on trees and hedges makes sighting difficult and many birds are keeping a low profile, because they’re replacing their feathers. They look bedraggled, no longer sporting their bright breeding colours. A lot of us birders hang up their binoculars until the autumn migration.

A linnet. Picture by Paul Barrett

After breeding, the moulting season kicks in, heralding major changes in both the appearance and behaviour of birds. Moult is the systematic replacement of feathers. All birds do it, from hummingbirds to penguins. They must moult in order to survive, because feathers wear out from physical abrasion and bleaching from the sun. Once a year birds grow an entirely new set of feathers through a complete moult.

As birds grow new flight feathers, they are particularly vulnerable to predators. During wing moult, several of their flight feathers will be less than full length, producing gaps in their wings that render them less manoeuvrable and powerful in flight. To avoid attracting the attention of predators, many birds, such as sparrows, warblers, and thrushes, lie low, calling infrequently and hiding in vegetation.

Brightly coloured male ducks have an extra trick to avoid being conspicuous to predators during moult. Waterfowl lose all their primary and secondary feathers at once, rendering them flightless for about a month. To help them hide when they can’t fly, male ducks grow a special set of camouflaged feathers, called eclipse plumage. In July, you may notice the mallards in local parks looking scruffy and mostly brown, like they’re all females. Shortly after their wing feathers have regrown and they are able to fly again, drakes will regrow their brightly coloured body feathers.

An adult blue tit feeding its young. Picture: Paul Barrett

Ironically, the silence and secretive behaviour of birds make them harder to find in summer when birds are most abundant, because populations of adults are augmented by all the new young birds.

Avian Flu

An unprecedented outbreak of Avian Flu is killing thousands of wild birds in our country. Shetland is the latest area to be hit particularly badly, but there have been cases reported on many of Scotland’s islands and presumed cases in England too. The latest deaths follow the devastating outbreak on the Solway estuary last year which saw more than a third of the area’s wintering Svalbard barnacle geese population lost.

Avian Flu, or bird flu, is an infectious disease which spreads from bird to bird through contact with infected saliva and droppings. There have been several outbreaks of Avian Flu in the UK in recent years, but the vast majority have been in domestic poultry farms.

Britain's seabird populations are of global significance. For example, the UK is home to 56 per cent of the world’s gannet population and Scotland has 60 per cent of the world’s great skuas.

The avian flu which is causing these birds to die is a highly mutable and deadly new form which originated in poultry farming. Although most of the cases have been barnacle geese and seabirds, other species have been affected and there are concerns that the disease could spread. To help prevent the spread, good hygiene is key. Cleaning bird feeders and feeding stations weekly and changing bird drinking and bathing water regularly can make a big difference.

If you come across sick or dead birds, please do not touch them. If you find any dead waterfowl (swans, ducks, geese), any seabirds or birds of prey, please report them to the Defra helpline on 03459 335577.

A full list of birds sighted in the Bradford area can be found at group.rspb.org.uk/airedaleandbradford/news-blogs/blog/birds-in-the-bradford-area-2022/