Nature was the first in terms of hybrid models

Posted Jan 26, 2012 By Michael Runtz

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EMC Lifestyle - Hybrid cars have recently become the all the rage.

With fossil fuels soaring in cost, the hybrid strategy offers savings over the long term.

While the designers of this technology are undoubtedly receiving accolades galore for their brilliant designs, in Nature hybrids are nothing new. Ever since plants and animals began to genetically drift apart into new species, hybridization has occurred.

The more closely two species are related, the greater the chance of successful crossing between them.

Perhaps the best example is that of Mallards and American Black Ducks.

Separated during the last glaciation, these two ducks look very different yet are very closely related.

So much, so that when Mallards began their great range expansion and infiltrated the territory of Black Ducks, the hybridizing was rampant, with female Black Ducks preferring male Mallards to their own species.

Thus, in our region, hybrid Black-Mallards are frequently more common than pure American Black Ducks.

Last weekend I was looking at waterfowl at Cobourg Harbour, a fantastic place in winter for seeing northern ducks up close.

There were dozens of Long-tailed Ducks (formerly called "Oldsquaw"), the males looking sleek and dapper in their black and white winter coats complete with long thin tails.

There was also a spattering of other species, including Common Goldeneye, Red-breasted and Common mergansers, Greater Scaup, and a lone male Redhead.

Then I spotted a small duck among the thousand or so Canada Geese that crammed the sheltered harbour.

At first glance, the little duck looked like a female Hooded Merganser because it had a puffy brown head and gray sides and back.

However, there were a few features wrong for that species: there was a vertical white stripe on each side of its breast and the bill was thicker than normally possessed by that minnow- and invertebrate-eating duck.

When it swam closer, I could make out a pale area near the base of its bill. I realized it was a cross between a Common Goldeneye and a Hooded Merganser.

Now, for those who know ducks, this might sound like an unlikely cross.

However, hybrids are known between the two species and I suspect one reason lies in their nesting habits. Both are cavity adopters, which means they lay their eggs in hollows in trees (or nest boxes).

They also perform "egg dumping," a behaviour in which one duck lays or "dumps" an egg in another duck's nest.

Often the egg ends up in a nest belonging to another of the duck's own species but cross-laying also can occur.

Perhaps a goldeneye that is raised by a merganser or a merganser that is raised by goldeneye might just be a little confused when it matures and goes mate searching.

Alternatively, perhaps their genetic relatedness allows them to hybridize on occasion.

Regardless, this little odd duck was on its own. It will be interesting to see which species it chooses to socialize with once it matures.

Whatever its choice, it is bound to produce some interesting offspring!

The Nature Number is 613-387-2503, email is mruntz@start.ca




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