how many swan 's cignets die in the first year of life?

Answer 1

The survival rates of course vary from species to species, within populations of specific species and from year to year depending on conditions.

Also most survival research on cygnets is from hatching to fledging rather than for the first year.

The Seney National Wildlife Refuge Trumpeter Swan Monitoring Project reports various survival rates (hatching to fledging) between 20-80% for the period 1991-2005. 2005 survival rates were the lowest ever at 20% for the total population but averages over the total period appear to be about the 60% mark.

"Reproductive success of exotic mute swans in Connecticut" reports figures of about 40% and qoutes, including citation,s similar figures from Chesapeake Bay and England.

"Prefledging survival of Mute Swan Cygnus olor cygnets in the Lothians, UK", reports figures from 1981-1998 ranging from 57%-82% across a range of habitats.

Connecticut Dept of Environmental Protection Mute Swan Factsheet states survival after fledging is high, with 7 year survival rates of about 50%.

All the previous figures are for survivals from hatching. The articles also indicate that only about 40-60% of eggs hatch.

Answer 2

I am not sure exactly. It will depend on how well the nest is located and on how good the weather is that year. However, I am afraid the answer is most of them.

I went to a uni that had a lake with a resident pair of swans. They would have about half a dozen cygnets each year. Most of them would tag along behind them throughout the Summer (begging food from the students). Perhaps four would be left. But only one or two would be about the next spring, before the parents drove them away. So lack of food in the winter was probably the major cause of death. Also, many cygnets have fatal accidents when they learn to fly, specifically in that they fly into power lines.

Overhead electicity cables are a major cause of death for swans, as are fishing lines. It was sad once or twice to see a cygnet on the uni lake with its foot hopelessly entangled in nylon line.

Answer 3

It depends on the breed of swan. Quite a few of them die but if he/she considers them worth nurturing, then she tends to look after the cYgnet that gives the most sign of surviving in what is basically rough territory.

Answer 4

Not sure about that but one pair of mutes on the river dee in aberdeen had a full clutch of 7 and all survived :)

Answer 5

If you spell that "cygnets" wou would be able to look it up on the internet.