How Birds Cope With Heat Waves

How Birds Cope With Heat Waves

Courtesy of Sam Bark, Unsplash

In a recent blog, we covered the ways in which birds have adapted over millennia to deal with hot days, offering advice on how you can help them manage to avoid heat stress. As the months go by, more evidence builds that shows how heat waves are becoming the norm in places that had fared well in the past, and their intensity is only increasing. In today’s blog, we look at what this means for the wild birds out there.

Courtesy of pxfuel

The heat waves of 2022 in northern Africa, southern and central Europe and North America made headlines around the world as wildfires raged and thousands of people were displaced or made homeless, and temperatures reached their highest in recorded history in many parts of the world, with an estimated 60,000 heat-related deaths. At the time of writing, it is now mid-summer 2023 and those very same records have been broken again and wildfires rage once more, the heat causing havoc, destruction and death in Spain, Italy, Greece, China, Algeria and California for starters.

Courtesy of Malachi Brooks, Unsplash

It is now widely accepted this will be an annual event. Whilst we wait for stalling governments to make the biggest decisions of all, we need to learn how to prepare at the same time as understanding the mechanisms behind climate change and what we can do in the long-term to mitigate the issues in the hope it can be reversed; or altered at least, by literal degrees. That is a topic for another blog entirely, but if you want to know more, here is a good place to start.

The heat waves

The mechanisms of temperature regulation in birds have been studied for decades and were largely thought to be well understood — panting, gular fluttering, urination on the legs, all connected to the relief achieved from evaporative cooling, as well as the traditional methods that you or I would engage in — keeping out of the sun, finding a cool spot where there is a breeze, taking a dip and drinking and eating cool or cold liquids and foods and so on.

Whilst many of us have the luxury of heading indoors, even into an air-conditioned environment (which, in a bitter twist of irony, contributes to climate change), birds need to find external suitable habitat to hide away from the hottest part of the day, and water sources soon dry up, so we know we can play a significant part in helping birds survive excessive heat by providing shelter in the form of native plants in our yards and gardens and leaving out fresh water on a daily basis.

Photo taken with Bird Buddy

Understanding the consequences

But these temperatures are pushing the boundaries of coping mechanisms, as there is little relief at night and the persistence of the heat across several days or even weeks is leading to some disastrous outcomes. In June, the hot ocean currents caused by the weather-system changing event known as El Niño were responsible for a mass die-off of seabirds along Mexico’s Pacific coast.

Sooty Shearwater. Courtesy of Gregory Smith, Wikimedia Commons

Population numbers have already been gravely affected by avian flu, but here was another creeping and invisible enemy. Hundreds of Sooty shearwaters, pelicans and gulls were found to have perished through starvation, as warming surface waters on the seas were driving the fish and other food sources deeper into cooler temperatures, and far out of reach of hungry bills. Inland, goldfinches and curve-billed thrashers who only live in desert areas lack the ability to find shade and water and fears for their numbers are increasing. The heat-coping mechanisms that have taken eons to evolve are looking like they could almost be redundant as the world heats up faster than the birds can adapt.

American goldfinch. Photo taken with Bird Buddy

Red-bills, warm heart

But it can be said that problems exist in order to find solutions. Ignoring that we have been warned for decades for a moment, to our eyes these changes are new, shocking and visceral; seen to be believed, as it were. But animals may well have been quietly adapting in the background for a number of years, picking up on the subtle changes as they repeat themselves and intensify; as best they can, given the scale and speed of change.

Scientists have already witnessed migration patterns shifting; whether this may be for the worse or better is yet to play out, but understanding how animals try to compensate for grave situations is how we can understand what the impacts of climate change may eventually be, therefore we can work towards heading off some issues.

Red-billed quelea. Courtesy of Charles J. Sharp. Wikimedia Commons

The domestic chicken is the most populous bird on the planet at around 3 billion individuals, and of course it holds that place because of our industrial-scale population boosting. Coming in second at 1.6 billion, however, is one species of bird that has now confounded scientists when it comes to handling heat. The red-billed quelea is a small songbird from the Weaver family, and their success is a huge bane to farmers and other crop managers in sub-Saharan Africa where they cover a vast range across a large proportion of the continent, from sea level to 3,000m up.

Queleas have been likened to biblical locusts for their flocks of millions moving from field to field of cereal crops, their voracious decimation provoking culling techniques as brutal and abrupt as firebombing colonies at night while they roost. But it turns out that these ‘pests’ may be one of many species who hold a key to understanding how heat affects different birds. A study conducted in 2022 explored how various species tolerate heat, and it found that the behaviors we have long thought universal are anything but.

Flock of Red-billed queleas. Courtesy of Chris Eason, Wikimedia Commons

Birds as climate change indicators

Like all organisms, birds have a maximum tolerable body temperature before things start to shut down and fatality ensues. After the large-scale deaths of cormorant chicks in Patagonia in 2016, Magellanic penguins in Argentina in 2019 and swift chicks killed in the 2022 heatwaves in Spain, researchers at the University of Pretoria studied 53 species of southern African birds and found that the way they cope with heat stress varies greatly, depending on their natural environments. Astoundingly, red-billed queleas showed no ill effects as the air temperature increased to 48˚C, previously thought physiologically impossible. Until this study, all research had assumed that all birds reacted to extreme temperatures in a similar way.

Red-billed quelea, South Luangwa National Park. Courtesy of I've Got It On Film, Wikimedia Commons

If that assumption had continued to be extrapolated, then predictions on how vulnerable all species of birds are would be wildly off-mark, which means that conservation efforts and mitigation plans would not be suitable. It is not contested that these feathered locusts are a major problem for food producers, but perhaps their existence can help us understand how to prevent further calamities on earth.

Facing the heat

At the moment, it all sounds like bad news, where the metaphorical rays of sunshine through dark times are actually not what we need more of right now, and to modify a popular phrase, you can’t nectar-coat bird poop. All many avian scientists can do at the moment is research what is happening and use that data to help form the arguments that something needs to change and change quickly.

Courtesy of Harshakamanuru, Wikimedia Commons

Predictions long-cited are now coming true; the time to act is passing us by at this very moment. Understanding how to act will be part of the solution, and finding that out requires studying what happens to birds. These amazing creatures have acted as indicators of the health of the planet throughout history, and if all we can currently do is watch them suffer, then the very least we could do for them is learn from that suffering.

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