Imagine you are at your local pond and all the ducks are out and about. You scan through a flock of Mallards with your binoculars.
Mallard…mallard…mallard…wait, what is that?
You spot a duck that looks…strange. It kind of looks like a Mallard, but something is not quite right. It’s possible that you found a hybrid.
Hybridization is common in birds, but especially so in waterfowl. When two birds of different species mate they can produce a hybrid offspring. The hybrids will usually display characteristics of both parents to some degree. Two of the most common hybridizing species in North American waterfowl are the Mallard and Wood Duck. In fact, scientists have identified around 400 different waterfowl hybrid combinations.
In general, many hybrid offspring are infertile. This is not always the case. Sometimes a hybrid can reproduce, but usually with not as much success as a pure-breed duck. This may occur in species that are more closely related in the same genus. The more evolutionary distant two species are, the more likely their hybrid will have low fitness (relative success of an individual in passing along their genes) or be sterile. Female hybrids are more likely to be inviable than males, due to the fact that sames have two different sex chromosomes and males have two of the same sex chromosomes (the opposite of mammals).
Hybrids actually tend to be rarer than people think. This is because there are many barriers to reproduction between unique waterfowl species. Examples of these barriers include songs/calls, habitat preference, physical attributes, and courtship behaviors. However, when everyone arrives at the breeding grounds and all those hormones get going, well….just about anything can happen.
It’s pretty interesting seeing a hybrid duck. It’s fun to try and figure out what species the parents were. Although interesting, unfortunately sometimes hybridization can lead to a decline in population of a species. Let’s use our Mallards again as an example. Over time, habitat changes in some duck species has led to Mallards expanding their range. In the case of the American Black Duck, their shrinking range has been encroached by Mallards and since these species interact more often, they result in more American Black Duck x Mallard hybrids. Species threatened by Mallards also include the Mottled Duck of Florida and the Hawaiian Duck.
There’s also the good possibility that the odd duck you saw at the pond could be a domestic duck. It’s not uncommon to find domestic ducks mixed into the waterfowl flock. If a strange duck seems comfortable with/approaches people or has large white patches where you don’t expect it, then it is most likely a domestic duck. We have seen plenty of these domestic ducks at Haddon Lake over the years.
And last but not least, my favorite: Puff Duck ( aka “Puffy”, R.I.P. You can read his story, “The Tale of the Three Amigos”, here).
Keep an eye out for strange ducks! Happy duck watching!