Reader Bruce Lyon sent what he calls a “wood duck fairy tale.” Well, like the old timey fairy tales, it’s not all beer and skittles, but does have a happy ending. And there’s some nice biology included. The story stars a beleaguered mother wood duck (Aix sponsa), some predatory California scrub jays (Aphelocoma californica), and a protective California quail (Callipepla californica).
Bruce’s notes are indented.
My colleague John Eadie and I observed a bizarre natural history event at a wood duck nest. John has been studying within-species brood parasitism in several populations of these ducks near Davis, California for the past decade. Some background before the bizarre observation. Wood ducks lay eggs in each others’ nests with reckless abandon and we are trying to figure out the adaptive basis (if any) of this ‘conspecific brood parasitism’. Parasitism is so common that most nests seem to have eggs from more than one female and some nests with 40 or 50 eggs are not that uncommon.
John Eadie checks a duck box at a site near Butte City, California:
A hen incubating in a box:
Example of a large clutch that results when several females lay in the same box. The different colored eggs were laid by different females so the parasitism in this nest can be seen with the naked eye:
Wood ducks nest in tree cavities (and nest boxes) and the ducklings are famous for leaping from the high nests the day after they hatch. Because we were monitoring nests closely, we knew for many nests when the ducklings hatched, and we decided to stake out one nest and watch the little jumpers in action the day after hatch. This nest was right beside our cabin, so we were able to sit in our cars and watch the nest departure without disturbing the hen or her ducklings.
The mother duck was very cautious about having the kids leave the nest (the kids seem to wait for a signal from mom before jumping). She came to and from the nest box three different times, each time sitting in the entrance for at least five minutes time scanning the surroundings carefully. Unfortunately, the local scrub jay pair had learned that a duck box is a lunch box and had been around earlier in the morning checking things out, so perhaps they jays had made her cautious. She finally flew to the ground, walked around quietly for a bit and then must have called to the ducklings because they suddenly started coming out of the box like popping popcorn.
Female flying to the ground to finally call the ducklings out:
Out they came!
The ducklings seem to get a bit of lift from their webbed feet:
The ducklings came out in batches—three or four in a pulse, then a break for few minutes, and then another three or four. Unfortunately, we don’t know if this pulsed departure is a normal departure pattern because as soon as the first duckling hit the ground one of the scrub jays swooped in, snatched the duckling and took it off and killed it. The jays grabbed a couple of the first ducklings to jump. We suspect that this freaked out the female because she took the ducklings away into the woods when only only eight of the total of 18 ducklings had left the nest. Ten ducklings remained in the box.
The scrub jays show up:
The scrub jay dispatches a duckling:
Many of the ten ducklings in the box did eventually jump but since Mom was not there to give them instructions, they just sat under the nest box peeping their heads off. After a few minutes they started wandering about aimlessly:
The jays got two more ducklings, but then something astonishing happened. A male California quail rushed in and started defending the ducklings—he attacked the jays three times when they came in for a duckling and prevented them from getting any. The ducklings then followed him around for 45 minutes as he fed at the edge of the woods. The quail was clearly conflicted about the situation because, in addition to chasing off the jays, he also frequently pecked at the ducklings. After about half an hour, the quail and the ducklings went into the woods and the ducklings eventually stopped peeping. We could hear the female duck in the woods not far off, calling to ducklings, so our best guess is that she came back and got the remaining ducklings.
Male quail with his temporary adoptees:
John and I were pretty stunned by this interaction and we do not have a good explanation for what happened. Male quail defend their own chicks them against predators. One possibility is that the duckling distress calls were similar enough to the distress calls of baby quail that they triggered his defensive response. That he pecked at them, however, suggests that something was not quite right to him.
There are a few bizarre examples of ‘misdirected’ parental care like this in the literature. My favorite example is the textbook classic shown below: a male cardinal photographed feeding goldfish (from the web by unknown photographer). The gaping fish may have resembled begging baby birds.