Feathers Solve Migration Mystery

Article excerpt

Byline: By Tony Henderson

Measurements by North-East experts of metal found in bird feathers could unravel mysteries of their migration patterns and help predict the arrival of avian carried diseases such as bird flu.

Concerns about the spread of bird flu means there is an urgent need to find better ways of monitoring the movements of migrating birds.

Dr Laura Font and a team at Durham University have developed a technique which can measure very low concentrations of strontium isotopes in bird feathers. The team measured strontium isotope levels in the feathers of the sedge warbler, and mapped how this changed with geographic location.

Dr Font said: "The routes of migrant birds have previously been studied using a variety of techniques, such as marking individuals with metal leg rings, radio or satellite tags, or simply counting bird numbers at migratory stop-over points.

"But these labour intensive methods generate relatively little data and often do not reveal the origin of individual birds."

Migratory birds regularly renew their feathers, often prior to migration ( and the feathers tend to reflect the unique "isotopic signature" of the region in which they were grown.

Although analysis of carbon, nitrogen, hydrogen and oxygen isotopes can give a rough idea of the birds' origin, strontium isotope ratios in the bones, claws and egg shells of birds tend to provide a much more precise location.

Bone analysis is too invasive for routine use. But Dr Font's technique has finally made accurate analysis of strontium in feathers a viable option for tracking birds.

Dr Font said: "By determining migration pathways, the arrival of potential diseases from infected areas can be anticipated.

"Knowledge of migratory routes also helps evaluate the likelihood that individual avian influenza outbreaks could be related to migratory movements rather than activities, such as poultry movements, which are believed to be the main vector of avian influenza in most outbreaks."

FORESTRY Commission wildlife rangers are setting out to attract more Ospreys to new locations in Cumbria.

A number of potential new breeding sites have been identified at secret locations around the county and will undergo a facelift in the coming weeks.

A team of wildlife rangers from Grizedale Forest have joined forces with the Lake District National Park forestry team to construct a series of artificial osprey "supernests" to appeal to the migrating birds as they fly back over the county this spring.

Each osprey nest will be the size of a single-bed and take a day to construct.

The timber platform base will be covered by a cocoon of wire-mesh to give added strength and branches, twigs and moss will be painstakingly applied by hand to re-create the appearance of a real osprey nest and to withstand the worst that the Cumbrian weather can throw at them. …