Natural England has published a statement outlining the impact that this summer’s avian flu outbreak has had on wild bird populations on a number of its NNRs, with one site reporting that 80-85% of all wild bird chicks have died.
The UK, along with continental Europe and North America, is currently experiencing the largest outbreak of avian flu on record, according to the regulator, with poultry, captive birds and wild birds all affected.
While the virus occurs seasonally every year, normally in between autumn and spring, this year the strain is more infectious and has continued to impact bird populations during their breeding seasons.
“The scale of mortality is unprecedented with significant losses of adult birds and even larger mortality of chicks being reported,” read the Natural England statement, which added that the regulator has “a number of NNRs that have been affected.”
Summer reserve warden and county bird recorder Neil Lawton, from Scolt Head NNR in north Norfolk, said that a total of 805 dead adult sandwich terns – an amber listed species – had been collected and removed from the site, with a further 200 birds collected elsewhere along the coast.
This, he said, had resulted in 10-15% of the adult population of the species in north Norfolk believed to have died.
“The actual number of dead birds could be significantly higher with many believed to have died at sea. Mortality amongst chicks has been huge, with around 80-85% of all chicks dying and several thousand (around 500kg), mostly terns, removed from the site,” he added.
The crisis has affected nature reserves belonging to other bodies such as the RSPB and the National Trust, and the former has called in recent weeks for more leadership from DEFRA to help manage the outbreak and prevent a conservation crisis.
“On and on this relentless tragedy goes”, the RSPB’s chief executive Rebecca Speight said this week on Twitter, adding that the continued deaths of wild birds “makes the need for a proper recovery strategy dealing with the multiple threats they face all the more urgent [...].”
The NGO has said that a number a measures should be taken by the government, including the setting up of a task force to develop a national response plan for avian flu in wild birds, the development of “clear guidance on wild bird carcass removal and disposal in high risk areas”, and the undertaking of a “rapid risk assessment on whether it is prudent to release large numbers of non-native gamebirds when [avian flu] is present across the country”.
This week, DEFRA said its approach to tackling the outbreak “continues to be led by international best practice and the latest evidence, which suggest that mitigation measures are not very effective in reducing transmission within seabird colonies”.
The statement added that the government does not generally recommend that wild bird carcasses are removed, due to “limited evidence” to indicate whether their removal reduces transmission risk within seabird colonies. This, the government said, is because the levels of environmental contamination remain significant in the area even after dead birds have been removed.
DEFRA said that Natural England has set up a “seabird reporting system to collect data on seabird mortality at key sites”, in order to assess the impact on populations and inform recovery programmes. It has also commissioned the regulator to “assess the vulnerability of seabird species in light of the pressures they are facing, including avian influenza, and propose actions to address them”.