While the phrase “A little rain never hurt anyone” may be true for humans, it cannot be applied to birds, as rain, especially heavier downpours, presents some major risks to birds. Can birds fly in the rain, and just how dangerous can it be for them?
We take a look at the perils of flying with wet wings, and where birds go when the heavens open.
While most birds can cope with light showers with minimal harm or inconvenience, heavy rain poses some serious dangers to many bird species. Many avoid flying altogether during storms or downpours, seeking shelter in trees or undergrowth until the rain has eased.
Birds face the risk of hypothermia in periods of prolonged wet weather. In cold weather, birds stay warm by trapping small pockets of air beneath their feathers. But if exposed to heavy rain, these pockets quickly fill with water instead of air, lowering the bird’s body temperature to dangerous levels.
Long periods of rain also bring the risk of starvation, particularly in smaller birds. Birds need to forage for food regularly, and more often than not, this will involve periods of flight. If flight is not possible because of heavy rain, starvation becomes a very real outcome, especially when there is a nest of young chicks that need to be fed.
So, how do birds navigate this danger, especially in locations where storms and rain are not uncommon weather events? Read on as we look deeper into the topic of how birds fly in wet weather.
A Ruby Topaz hummingbird (Chrysolampis mosquitus) hovering in the rain
Light rain has a minimal effect on a bird’s ability – and willingness – to fly. However, birds will often avoid flying in heavier downpours and torrential storms as extremely wet weather can pose some serious issues for birds, including hypothermia and potential starvation.
Heavy rain, strong winds, and turbulent air currents can make flight and navigation difficult during storms. Flying in such conditions is not impossible, as birds’ feathers are coated in an oily, waterproof substance, and they have developed effective techniques to adapt their flight during such conditions.
During heavy rain, air is forced downwards by a birds’ wings, then, on the upstroke, birds can pivot their feathers to allow air to pass through them. On the downstroke they close their feathers, pushing against the air.
Birds’ eyes are equipped with a translucent nictitating membrane (effectively a third eyelid) which weeps their vision clear when rain is falling.
A very wet little owl flying through the rain
Birds waterproof their own feathers by preening, using oil from the uropygial gland near their tail. They use this waxy coating to cover the barbules in the feathers, meaning that their plumage is water-repellent, even in the wettest weather.
In heavy rain, the weight of the water may make it difficult to flap their wings and fly effectively. Where possible, many birds may choose to avoid flight until the weather has improved and the risk of becoming saturated has passed.
American Goldfinch preening its feathers
Where possible, birds will seek shelter in bushes, under cover of dense foliage, until the rain stops. Rain poses more of a risk to smaller birds, as their low body weight means they are likely to lose heat quicker than larger birds. Some hardy birds, such as turkey vultures may even be spotted, “rain-bathing” with their wings spread wide.
During showers, birds typically stay as still as possible, to conserve energy levels, due to the uncertainty of how long a period of wet weather may last. They commonly adopt a “rain pose”, effectively the opposite to fluffing up their feathers to keep warm in colder weather.
During showers, birds sleek their feathers, point their heads and bills towards the rain, minimizing their body surface area that is exposed to the water.
Bird sheltering away from the heavy rain
While birds are generally unaffected by light drizzle, prolonged, heavy rain is a different story. Where possible, birds will stay still and sheltered in bushes, trees, under eaves, and in hollow trees until the weather improves. However, when rains continue solidly for more than a day, the necessity of finding food becomes more urgent.
Braving the rain to avoid starvation, especially if a bird has chicks to feed, becomes a priority in wet weather that lasts longer than a few hours.
Birds have oily, water-repellent feathers that make some flight possible in rain, but the drop in air pressure in such conditions means more effort needs to be exerted and more energy is used, so many birds will choose to sit and wait for it to dry up.
If birds have been sheltering for some time, the need to feed and forage will be relatively urgent, especially if there are nestlings needing to be fed.
Rain brings worms to the surface of garden lawns, and once a shower has passed, large numbers of birds may be seen to quickly return to foraging to reap the benefits of the wet weather. The reappearance of insects after the rain has stopped will bring many birds out of their temporary cover.
Birds are also frequently heard to sing after the end of a storm, similar to the daily dawn chorus, although it is unclear as to exactly what – if anything – this renewed burst of vocalization might represent.
After a downpour, it's the perfect time for birds to hunt for worms!
Once a baby bird has reached the fledgling stage, and has mastered the art of flight, it will be theoretically equipped to fly in rainy weather. However, like adult birds, young birds may find it safer to shelter until heavier rain stops before testing this out, as they may quickly become waterlogged in wet weather.
Fledglings still need to eat, even in heavy rain, and those that are still being tended by their parents will quickly learn the art of storm survival. The feathers of young birds may quickly become saturated, even when they are sheltering in bushes or trees.
By the time birds have reached the fledgling stage, their feathers will have developed a degree of waterproofing functionality to give them some chance of making it through the storm safely, especially if they are able to shelter in shrubbery until the heaviest rain has eased.
Northern Cardinal still foraging for food in the rain
Pigeons can withstand light rains, but may choose not to take to the skies until extremely wet weather has passed. Stormy weather can dramatically impact a pigeon’s ability to navigate accurately.
Woodpigeons seem not to mind the rain, being observed to sit unsheltered on open grass, lifting one wing at a time, as if showering.
Hummingbirds are well adapted for flight in all weather conditions, and rain does not appear to affect their ability to fly. Light and medium rain showers do not seem to pose any challenge for hummingbirds, although in heavier rain they are observed to increase the number of wing beats per second to avoid becoming saturated by rainwater.
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