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Name: Jim S.
Status: other
Age: 40s
Location: N/A
Country: N/A
Date: 7/4/2003


Question:
We visit a lake near the Kalamazoo river every year. Every year we see at least one pair of swans, every year they start off with six to ten young, and every year they lose several or all of their young.

This year we had one pair with seven cygnets, soon to be six. One night two disappeared, one of which we found washed up on a sand bar. The next day the parents were obviously driving away or trying to kill one of the cygnets. It was very dark and difficult to observe the exact behavior but they had obviously separated the one from the other three, he (she) was screaming either in pain or bewilderment, and the adults appeared to be trying to drown it. The next morning the cygnet was alone on the shore and as I understand from my in-laws it dead. They found it with a severed foot and broken wing. Do you have any idea what is behind this behavior?


Replies:
Jim,

As a former field biologist, the first thing you need to think about is exactly what did you see? Predators are the number one problem with geese and swan success in rearing young. What you may have witnessed is the parents attempting to protect a cygnet. Of course, I do not know for I was not there. Snapping turtles, owls, hawks, snakes, raccoons, etc. are always looking at young birds as meals. The missing foot may have been the work of a snapping turtle. Common! It is a hard life out there on the pond and you may not have seen the entire picture. As for parent behavior toward their young, usually the adults gradually abandon their broods, but only after a point that they can survive on their own. At this point in time, chasing away offspring may be observed.

Steve Sample


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