Sunday, 15 September 2013

Save our birds - stick to the speed limit!

Clever old crow!
Have you noticed how some birds are so much better at getting out of the way of cars than others? The Crow family seem to be particularly good at avoiding cars, whereas Pigeons, doves and Pheasants seem to be particularly dozy! Well, some interesting new research has thrown some extra light onto this – read this extract:
Scientists tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individual's ability to respond adaptively to local speed limits.
Birds such as Carrion crows, House sparrows and Blackbirds all took flight earlier after spotting their car in areas where the speed limit was higher. Curiously, the birds did not seem to pay attention to the car itself. "They reacted the same way, no matter the speed of the car," the researchers said.

The scientists speculate that some combination of two things might be happening. First, it may just be a case of natural selection in which individuals that failed to take off quickly enough are killed. As a result, only those birds with traits that help them successfully escape oncoming traffic go on to reproduce. Another possibility is that the birds are actually learning to adapt to different traffic speeds.
But why did the birds seem to ignore the speed of the scientist's car itself? It's possible that the birds might have just learned that it's simpler to react the same way for any given section of road. "This way, they are not spending a lot of time being vigilant by looking at the speed of each car."  

So, don’t speed - especially in restricted areas with speed limits, as you may well kill lots of birds as well as the possibility of knocking a human over!! 

1 comment:

  1. Hi Peter,

    Interesting that you should bring up this study as I posted up a comment in response to it on my naturestimeline Facebook page below. Re: my comment about a Magpie, I wasn't going in excess of about 40mph at the time, but I do agree with your sentiments, slow down guys n gals.