Species Update
Buzzard numbers in have increased dramatically in the UK since the 1990s, but will this trend continue?
Kate Risely on the buzzard, whose population has boomed since the nineties
IOFTEN SEE BUZZARDS near my home; small groups soaring in clear springtime skies, or single birds sitting impassively in the roadside trees. British Buzzards are resident, occupying territories roughly a kilometre across all year round, so the birds I see must nest nearby; it’s exciting to think that in a tree very close to home there will be a massive Buzzard’s nest, at least a metre across. There aren’t actually that many large trees here in the open, arable landscape at the edge of the Fens, and I often look through the small copses, wondering where they might be nesting. For 10 years now, Buzzards have been Britain’s commonest bird of prey, with a population estimated to be in the range of 57-79,000 breeding pairs. This makes them even more abundant than Kestrels and Sparrowhawks, with populations of 46,000 and 35,000 pairs respectively. Bird Atlas maps show that they are present in 90% of 10km squares in Great Britain, absent only from large urban centres, and more sparsely distributed in areas with few trees for nesting, such as the Scottish Highlands and in East Anglia. They are less common in Ireland, found only in eastern parts. The recovery of the population to these high levels has been one of the most complete and extraordinary success stories of any bird in recent times. Once widespread, they were wiped out from large parts of the country due to persecution during the 18th, 19th and 20th Centuries, loss of their Rabbit prey following the Myxomatosis outbreak of the 1950s, and poisoning by organochlorine pesticides in the 1950s and 1960s. They were driven back to strongholds of Scotland, Wales, the South West and Cumbria. By the end of the 1960s, all of these pressures were lifting, and Buzzards started to make a comeback. Since 1990, numbers have skyrocketed. According to the Breeding Bird Survey, their population has increased by 80% across the UK over the last 20 years; this overall figure includes a 182% increase in England, while numbers in Scotland and Wales have remained relatively stable. Their incredible recovery, once released from persecution, is testament to the adaptability of this species. As I have seen for myself at home in East Anglia, they can thrive in intensively managed The BTO runs volunteer surveys to monitor and explain changes in bird populations. To find out more about the Waterways Breeding Bird Survey visit habitats; like Red Kites, they are relatively generalised in their diet, taking their food where they can find it. They primarily feed on mammals such as small Rabbits and voles, but they will take a very wide range of other foods such as birds, snakes, frogs and earthworms. They hunt prey on the ground, and the birds they take tend to be fledglings or ground-dwelling species; they will even take Wrens, presumably due to their mouse-like appearance. In Northern Ireland, there are no Bank Voles, and Buzzards here take a much higher proportion of birds, particularly crows. Overall, however, Rabbits are by far the most important component of their diet, and fluctuations in Buzzard numbers can often be linked to outbreaks of Myxomatosis or other Rabbit diseases. Perhaps contrary to the general perception, results from the Breeding Bird Survey, which also covers common mammals, show that numbers of Rabbits in the wider countryside have declined over the last two decades. For now, the increase in Buzzard numbers shows no signs of slowing, but it remains to be seen whether this adaptable predator will reach the limits of food availability.
Kate Risely is the British Trust for Ornithology’s Garden Birdwatch Organiser
Their incredible recovery, once released from persecution, is testament to the adaptability of this species