Conservationists have been tirelessly working to prevent a rare bird species from vanishing entirely from the United Kingdom. Recent progress in safeguarding the Montagu’s harrier population in Britain can be largely credited to the exceptional breeding abilities of one male bird described as “absolutely prolific” by conservationist Mark Thomas.
This remarkable 10-year-old bird, known as AU, has fathered a total of 16 offspring, with 10 born in the last two years alone. According to Thomas, AU is playing a crucial role in sustaining the species in the UK single-handedly.
Montagu’s harriers are migratory raptors that winter in Africa and parts of Asia, returning to Europe each spring for breeding. While their global numbers are declining, with a classification of least concern on the International Union for Conservation of Nature’s Red List, the British population of these birds has been rapidly decreasing.
At their peak in the 1950s, there were approximately 30 breeding pairs in the UK, but this number dropped to zero in the ’70s before a partial recovery to 13 pairs in the mid-2000s. Another decline followed, with zero breeding pairs reported between 2000 and 2003. Thomas emphasized the importance of current conservation efforts to protect the existing bird population and highlighted the positive outcomes achieved this year.
AU’s successful breeding in 2025, resulting in four chicks, was followed by his return this year to engage in elaborate mating displays to attract female partners. This year, three females vied for AU’s attention, leading to successful nesting with two of them. AU fathered a total of six chicks, evenly distributed among two nests situated approximately one kilometer apart on a British farm.
Conservationists are optimistic that AU’s male offspring will eventually return to the UK for breeding purposes. Two male chicks from 2025 have already been sighted in the country, although they are not yet mature for breeding. To safeguard the hatchlings, measures have been taken to protect the nests, including constructing barriers to shield the chicks from predators.
The RSPB has affixed satellite trackers to two juvenile harriers for the first time, allowing researchers to monitor their migration patterns and potential return to the UK for breeding. This tracking effort will provide valuable data for future conservation initiatives aimed at ensuring the survival and prosperity of the Montagu’s harrier population in the UK.