Pat's made some interesting observations on Hooded Mergansers. Here are a
few ideas that relate to her questions. Besides tending to their own nests,
Hooded Mergansers commonly lay eggs in the nests of other cavity-nesting
ducks, including Wood Ducks as well as other Hooded Mergansers. (Wood Ducks
also return the favor.) You can think of it as a bet-hedging strategy -
literally, don't put all your eggs in a single basket (nest). If something
happens to your nest, maybe a few young will survive from another nest. So
it's possible that the young mergansers with no parent actually hatched in
someone else's nest, such as a Wood Duck. Or perhaps the mother was killed
after the young hatched. Both of these possibilities seem more likely than
the mother abandoning the young at a very early stage.

While Hoodies usually nest right near a pond, suitable cavities aren't
always available so females sometimes have to nest away from water. In that
case, the mother will lead the ducklings to water after they hatch -
distances of more than a kilometer have been recorded. So the 1/8 of a mile
between neighbors' ponds seems pretty reasonable for a duckling to travel,
even if they seem ungainly out of the water.

Survival of ducklings is pretty low, even with the protection of the female.
(The fact that females commonly lay 9 or 10 eggs each year gives an idea of
how risky it is for ducklings.) However, young can feed themselves, and
presumably the older and larger they get, the better their chances of making
it are. I suspect that from an evolutionary standpoint, females wouldn't
invest the energy required to lay eggs in the nests of other duck species if
their young had no chance of making it on their own. So the duckling still
may have a chance!

  -- Scott Schwenk
     South Burlington

On Wed, Jun 29, 2011 at 1:10 PM, Pat Folsom <[log in to unmask]> wrote:

> Hi Birders,
> I'm hoping some of you can give me some insight into this Hooded Merg
> mystery (to me).  I live on East Warren Rd in Waitsfield and have a small
> pond in my backyard.  My neighbors also have a pond that is actually a
> dammed up part of a brook and at least 1/8 of a mile away (as the duck
> waddles).
> On June 17, my neighbors had three baby ducks on their pond, no mom with
> them.  They were there for a few days, dwindled to two, one, none.
> June 23 - I found a single baby duck on my pond, I knew it was a merganser
> and determined it was a Hooded after looking at photos online and some
> advice from friends.  Baby was active, feeding, preening the next two
> days.  Two years ago I had a baby Wood Duck on the pond for four days, but
> mom came back one day with four sibs and they all waddled off into the
> woods together.  I thought the same thing might happen this time.
> June 26 - A single female Hooded Merg on my pond early in the morning,
> then I had to leave, so I don't know how long she was here.  The first and
> only time I've seen her or any Hoodie on my pond this year.  I did not see
> the baby with her and she was gone, but the baby still here when I
> returned home.
> June 27-28 - Baby continues to live alone in the pond, growing bigger.  In
> the afternoon of June 28 at 3 PM, he disappears.  At 6 PM I receive a call
> from the neighbor - there's a baby on her pond.  I went over to take
> photos, seems to be the same bird, definitely the same species and age.
> Here are my questions:
> Do mother Hooded Mergansers sometimes abandon their newborn?
> What is the likelihood that the female was the mom that then rejected the
> baby?
> How likely is it that this baby has moved from the neighbor's pond to mine
> and back again on his own?
> Does this baby have a chance of surviving to adulthood on his own?
> Thanks for any insight you can give,
> Pat