Hawk Conservancy Trust newsletter Winter 20 Issue 86

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HAWKTALK WINTER 2020 ISSUE 86

HAWKTALK WINTER 2020 ISSUE 86

How can birds adapt to our changing planet? Climate change is one of the biggest threats affecting species and their habitats across the globe, and birds of prey are no exception. The rate of global warming is already having an impact on some birds, their prey, and their habitats. Over the coming decades, scientists predict that climate change could negatively affect up to a third of all known species on earth, with many species being lost, including many birds.

Closer to home There is a lot we still have to learn about how changes to the climate will affect British species, however we know that prey availability for our British species can be very dependent on climate. Barn Owls and Kestrels, for example, depend on small mammals, and fluctuations in prey populations can directly affect the birds of prey that rely on them. Extreme weather events like the ‘Beast from the East’ in 2018 had devastating impacts on many species, including birds of prey. Extreme low temperatures severely impact not only the survival of prey, but also their availability to predators.

Some species have already needed to adapt to changes in their environment. There has been a substantial change to the range of the Hobby in Europe, and scientists expect that warmer weather will push the species north to inhabit more areas in Britain as their usual breeding habitats in continental Europe become too warm and dry. Why is this important to humans? Birds of prey and nature as a whole have significant natural heritage value to people. It is well-documented that spending time in nature is extremely important for our well-being, and birds of prey are an important aspect of this for many people. Birds of prey are iconic species, with local significance in many areas. A fantastic example of this is the reintroduction of Red Kites in the late 1990s, in which the Trust played a role. People local to Hampshire and the Thames Valley now see this species as an important part of their cultural heritage as they witnessed the re-establishment of this British species over the past 20 years.

How does climate change affect birds of prey? Birds, like many other species, are adapted to their habitats. Changes to these habitats can make it more difficult for birds of prey to find food, or places to nest, and sometimes changes occur too quickly for them to adapt and survive. Some birds may be forced to find new and unfamiliar habitats in which to live, putting them at risk of starvation and exhaustion. These changes can have unexpected effects on food webs and ecosystem function. Changes to the environment where birds live contributes to habitat loss, for example more frequent and more severe wildfires will create changes to vegetation structure and species communities, which in turn can create opportunities for destructive invasive species. Milder winters will continue to lead to earlier growing seasons and the resultant effects on the breeding habits of some predatory birds. Fluctuations in local weather including the frequency of extreme weather events such as droughts and flooding can also have a huge impact. Extreme weather events can often be more catastrophic than the predicted effects from gradual changes to the climate. Scientists investigated how severe droughts might affect Lesser Kestrels and found that severe droughts can contribute to a decrease in survival of up to 12 percent in juvenile birds. This could seriously jeopardise the ongoing recovery of the European population of this species, which suffered significant declines in the second half of the 20th Century.

Arctic adapted species Changes to the environment can be especially problematic for species adapted to live in high latitudes. The Gyrfalcon is the world’s largest falcon and is adapted for living at high latitudes; it breeds in the Arctic tundra. Gyrfalcons face severe challenges in an Arctic environment that is changing rapidly. Due to their specialised ecological niche and reliance on specific prey such as ptarmigan (a medium-sized game bird), and small population size, the risk from a changing environment is very high. Gyrfalcons, and their main prey of ptarmigans, are well-suited to life in the harsh tundra conditions, but there are already indications that local populations of Gyrfalcons in Alaska and the Yukon Territory of Canada are in decline. Research has shown that the increasing temperatures will lead to a decrease in suitable habitat for Gyrfalcons and their prey. These changes in habitat availability and the distribution of species is at risk of causing a change in predator-prey dynamics, which could have cascading effects on other species, food webs and ecosystems overall. Changes in weather patterns, such as snowfall, can also create negative effects. Snow provides camouflage to some species of predator, for example Snowy Owls. Matching a white coat to a snowy background has obvious benefits for both predators approaching prey, but also for prey avoiding predators. As permafrost melts and snowfall decreases this could have negative effects on some Arctic species.

Gyrfalcon in the Arctic Tundra

WHAT CAN WE DO?

Climate change is already happening and its effects are predicted to get worse. The best thing we can do is reduce our impact on the planet. Even small changes can make a huge difference. Here are our top five ways for reducing your impact and helping to slow down climate change:

Consume less Reuse and re-purpose as much as you can.

Make ethical choices wherever possible Look for second-hand products, locally- made items and ethical, eco-friendly companies.

Reduce your meat and dairy consumption Where possible seek out food that is ethically and sustainably produced or sourced.

Waste less Only buy what you need, try planning meals in advance, avoid excessive packaging, and recycle where possible.

Ditch the car! Consider using

alternative transport ... walk, cycle or take public transport.

Juvenile Great Horned Owl in a burned out tree

Snowy Owls rely on snow for camouflage