City centre gulls could help plan drone flight paths

 The issue of gulls in cities is an interesting one, as populations of Herring Gulls and Lesser Black-backed Bulls are declining in many rural areas, while increasing in many urban locations.

The reasons are likely multiple, among them easy access to nesting sites and food, and a learned tolerance of humans. However, in our recently published study, we raised the possibility that ease of flight might also make city centres an attractive option for these birds.

Turbulant skies

As terrestrial animals, it can be difficult for humans to imagine what it is like to travel in a medium that is also moving. If you swim in a pool alone, it feels easier to slip through the water because it hasn't been churned up by another swimmer. This is just small-scale turbulence: add on top of this how it feels to swim in the sea, where the tide can pull you back as you try to return to the shore, and you will begin to understand what it is like to be a bird.

Now imagine that you have to swim through the sea to get to work every day. Sometimes the currents would be with you, sometimes they would be against you, this and the choppiness of the water will have a huge effect on how hard you have to work. If you had to do this every day, you would get pretty good at predicting the sea state and current direction. Flying animals face this all the time: the air is hardly ever still and this has a profound effect on flight behaviour.

In our study, we looked at how gulls use the rising air generated by buildings to fly without flapping. Using the seaside city of Swansea as our research location, we found that gulls actually alter their flight paths in certain wind conditions, to take advantage of updraughts occurring around a line of hotels bordering the bay.

Such energy-saving strategies are already well-recognised in birds that are undertaking their vast annual migrations, but are less well-studied for birds moving around on a daily basis.

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Bad breeding year for Cumbria sea birds

Cumbria Wildlife Trust has reported that seabird chicks are in decline in the county.

After analysing the breeding success of several species across three of its coastal nature reserves, the charity found that the numbers of birds to have fledged over the summer has seen a dramatic decline in some instances.

At South Walney Nature Reserve on Walney Island, the number of breeding Herrings and Lesser Black-backed Gulls was estimated at 4,500 breeding pairs in spring 2014, compared to 6,000 the previous year.

Lesser Black-backed Gulls are on the Amber list of conservation concern, as the UK is home to 40 per cent of the European population, and more than half of these are found at less than 10 sites across the country.

Herring Gulls are also found at fewer than 10 sites in the UK, and are in a slightly more worrying situation on the Red list. They have experienced a moderate decline in their numbers over the past 25 years.

Cumbria Wildlife Trust protected the breeding colonies from predators by erecting electric fencing, and believes that had this not been done then the decline in the population of both bird species would have potentially been much worse.

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High court challenge over cull backing

Published on the 13 May  2014 

A High Court challenge has been launched against Government backing for the culling of thousands of seabirds on the Lancashire coast.

The Royal Society for the Protection of Birds (RSPB) is concerned that the cull is setting a dangerous precedent for bird conservation in the UK.

The RSPB is asking a judge to quash the Environment Secretary’s decision last May to sanction the cull in the Ribble Estuary on the Lancashire coast, at the request of aerospace firm BAE Systems.

BAE said a reduction in the population of lesser black-backed gulls and herring gulls was required because of fears over birds being sucked into the engines of jets taking off at the airfield at its nearby Warton site.

Consent was for the killing of 552 pairs of lesser black-backed gulls and for further operations to maintain the population at the reduced level for 10 years, provided the overall population was not reduced to lower than 3348 pairs.

There was also consent for further measures to be taken to maintain the herring gull population at the reduced level that followed an earlier cull.

David Forsdick QC, for the RSPB, told a judge sitting in London: “As far as we are aware this has never happened before in the UK and that is why the RSPB is so concerned to have the decision set aside.”

Asking Mr Justice Mitting to order a re-think, he said the culls threatened to undermine the conservation purposes of European Directives for birds and habitats.

The populations of lesser black-backed gulls were in “substantial decline” across the UK and in need of protection.

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