- Apr 16, 2009
- Posted By: Clive Schaupmeyer
- Tags: none
If you pay attention, sometimes you will see ducks and geese dropping into a pond, twisting and turning as they come down. This is called whiffling. When I first noticed whiffling, I assumed they were merely twisting sideways to lose “lift” and allow them to drop faster. I was surprised four years ago when I took some pictures and saw that one or two birds were completely upside down. Interestingly, their heads were upright. When they slip sideways, they indeed lose lift, but when they turn upside down, there is actually a downward pull (Bernoulli in reverse) and they drop fast for a fraction of a second.
I have done some rough measurements and, based on the camera taking five frames per second, have determined that these birds can drop 2 or 3 meters in a fraction of a second.
Whiffling has been associated with hunting (waterfowling) and I think this is highly unlikely. I found this comment, “Descending rapidly from a height once the decision to land has been made, involving fast side-slipping first one way and then the other. The term is usually applied to geese … whose flocks whiffle spectacularly, especially when wishing to avoid a long, slow descent over an area where wildfowling is practiced.” I think this is completely unfounded. My observations over the past two or three seasons would indicate otherwise. Here are some reasons why I believe this flight process is an inborn and natural response primarily to wind.
1) I have seen them glide in low one day and then whiffle the next day in the same location.
2) The whiffling is almost always on windy days only when the natural “lift” is high and they need to lose height faster.
3) I have seen them whiffle over land.
4) I have seen entire goose families whiffle just days after the young birds have learned to fly, in an area where there is no hunting and well before hunting season. There was no reason whatsoever for the parents to teach the young birds to whiffle. This has to be an innate behaviour in response mainly to high winds. (It is a complex behaviour and unlikely that parents could ‘train’ young birds that have be flying for mere days.) This is almost certainly an innate behaviour mainly in response to high winds when they need to drop faster than with normal gliding. I think this has nothing at all to do with hunting ... just a natural flight response.
I have seen geese whiffle on calm days and once saw some do this with a slight tail wind, so conditions and response are not consistent.
Most interesting! ☺
Coaldale, Alberta, Canada
PS: Some of these pictures are heavy crops and not the best quality.