It’s raining again…

I’m sitting here this morning watching the rain and the old Supertramp song went through my head and brought up a question that my mother asks me a lot:  what do birds do when it rains?  This question is both really simple and really tough to answer at the same time.  I’ll start with the simple version, first.

What do birds do?  In a heavy rainstorm, birds will find a place to roost, they may perch on a protected branch in a tree or bush, flush up their feathers and just sit.  Feathers are excellent insulator and their structure keeps birds dry.  Both the keratin that makes up feathers (and your fingernails and hair) and the physical structure of the feather, itself, provide the waterproofing capabilities.

Yang, S-h.; Y-c, Xu; and D-w. Zhang.  2006.  Morphological basis for the waterproof characteristic of bird plumage.  Journal of Forestry Research 17:  163-166.

So a bird, sitting under a branch, is actually pretty well-protected from the rain that’s coming down.  Now that answer is the easy one. The next version is the more complicated version of an answer.  What really happens to birds during a severe storm?  The answer is that we don’t really know.  There are all sorts of reports of changes in bird population density after hurricanes.  There are a fair number of reports of birds being moved around on their migratory flights (I’ll come back to this topic in other post).  There don’t seem to be too many reports of what actually happens to birds that are perched during a severe weather event.  Some events certainly result in bird mortality.  A hail storm, for instance, can definitely knock a bird out of a roost.

Hall, D.W. and T.M. Harvey.  2007.  Mortality at a night roost of Great-tailed Grackles and European Starlings during a spring hail storm.  Wilson Journal of Ornithology 119:  309-312.

These severe events, however, aren’t usually that common and that fact is part of what makes them difficult to study.  In order to know how birds are affected by a rain storm, a researcher would need to know how many birds are in a particular place before a storm hits, then count the number of deaths and injuries during and immediately after the storm event to be able to get a good estimate.  If you’ve ever watched the weather channel, you should already be aware that it’s very hard to know exactly when and where a storm is going to hit.  As a result, we don’t seem to have very good data on the actual impacts of storms on birds.

As a result, the complicated answer also comes out as sort of unsatisfying, which takes me back to the basics.  What happens to a bird during a storm?  Not much.  They just find spots to perch and let their feathers protect them.  So (Mom), there’s not much need to worry about the birds during these rainstorms that we’ve been getting.  They should be just fine.


About thomasbiology

I'm an Associate Professor of Biology at Queens University of Charlotte with a background in animal behavior with an emphasis in bird song. I've got two secret goals with this blog (well, since I'm sharing them, they're not so secret): 1. To encourage people to look at the natural world around them- not just as a hiking destination, but to notice all the little things moving around them all the time; and 2. To show some of the science that relates to these little things moving around. There's some really fascinating research out there that so few people get to see.
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