Conservationists warn that the number of seabirds in the UK is rapidly declining due to an outbreak of bird flu. This decline is considered to be “catastrophic.”
The United Kingdom has seen a decrease of over 75% in its population of great skuas on monitored areas since the outbreak of bird flu. This is the first documented report that measures the effects of the H5N1 virus on seabird populations.
The deaths have happened over two years, since the outbreak of H5N1 in 2021. The UK is internationally important for seabirds, home to most of the world’s 16,000 pairs of nesting great skuas.
Jean Duggan, a policy assistant at the Royal Society for the Protection of Birds (RSPB) specializing in avian influenza, expressed concern about the severe decline in a population that the organization is responsible for protecting. This level of loss is considered catastrophic on an international scale.
She stated that this has a major impact globally and can affect populations all over the world.
The United Kingdom is home to over 50% of the global population of northern gannets. However, a report from the RSPB, the British Trust for Ornithology, and other conservation organizations revealed that these birds have decreased by 25% in surveyed locations.
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The nesting population of northern gannets in Wales decreased by 54% due to their tendency to live in a few large colonies, making them more susceptible to diseases.
According to Duggan, the situation for gannets and great skuas is worse than previously believed.
According to the report, the virus has resulted in a 21% decrease in the population of roseate terns in the UK. The roseate tern is considered the rarest breeding seabird in the country, with only one known nesting colony.
Seabirds are known for their longevity and typically do not reach reproductive maturity until about five years of age. Due to their low number of offspring, it can take longer for their populations to rebound from a widespread illness like avian influenza.
The outbreak of H5N1 is believed to have caused the death of numerous wild birds and has recently been observed among penguins in the Antarctic. According to the report, H5N1 poses a significant conservation threat to various seabird species in both the UK and continental Europe.
The number of great skuas, northern gannets, and roseate terns were on the rise until the outbreak of avian flu. This allowed researchers to determine that the decrease in population was caused by the bird flu. The report also revealed that the decline in sandwich and common tern populations, by 35% and 42% respectively, was most likely due to bird flu as well.
Out of the 13 species mentioned in the report, nine had experienced a decrease of over 10%. However, it is uncertain to what extent the bird flu was responsible for this decline as many of these species were already declining prior to the outbreak.
Conservationists monitored seabirds for this latest report from May to July 2023. Even more birds died later in the summer, with black-headed gulls, guillemots and kittiwakes particularly badly hit.
The report cautioned that the impact of bird flu could potentially be more severe than what was initially suggested. Additionally, the researchers noted that there is a possibility of ongoing consequences as the disease continues to spread.
According to the most recent Seabirds Count study, released in November, approximately 62% of seabirds in the UK were experiencing a decrease in population. This decline was attributed to various factors such as unsustainable fishing methods, the effects of climate change, the presence of offshore wind farms, and the introduction of invasive mammal species. It should be noted that the survey did not account for the potential impact of bird flu.
According to Katie-Jo Luxton, the director of conservation at RSPB, a recent study has revealed that bird flu is yet another threat to our already vulnerable seabird populations.
The RSPB is urging for measures to be taken to decrease additional stressors on seabirds in order to improve their population and make them more resilient against H5N1. Duggan stated: “We have completed the census and now we are faced with this issue. We must take action immediately; it is crucial to strengthen their ability to withstand challenges.”
Scientists have recently announced that certain wild birds have gained resistance to avian flu. By analyzing blood samples from northern gannets, they discovered that 30% of the birds had developed antibodies. Similarly, approximately 50% of shags had also acquired immunity. However, due to the limited number of samples, it is still uncertain how long the immunity will endure.
Source: theguardian.com
