MOURNING DOVE TALES 36

So far this spring and summer (2007) we have had four nests of mourning doves (Zenaidura macroura) in three different hanging flower baskets in our patio. The hanging basket which was occupied twice was the one nearest (and very near) the patio door. It would appear to me that in the trade off between being wary of humans versus the protection of their eggs and hatchlings from predators by having their nests near humans, the mourning doves have chosen the latter. Are their little “bird brains” capable of making such intelligent decisions? Whether by instinct or conscious choice, it would appear these avian folks are sufficiently sophisticated to effectuate the proper course of action.

What I can say by virtue of observation is the following: Building the nest is a cooperative effort between the male and female mourning doves. The one bird (presumably the male) brings small sticks, twigs, and what other building material he can find to the female who, mostly using her beak, weaves these into a nest. Of course these nests were in hanging baskets so they did not have to be outstandingly structurally sound. Still they were constructed with interlaced materials without the use of proper five fingered hands – remarkable. I don’t know where the male got his material, but it must have not been far away because he made round trips in just a couple of minutes or less. The whole nest building activity was completed in a couple of hours. A short time later the female sat in the nest and must have laid her eggs soon after.

In the last mourning dove brood there were two eggs (as there were in the other three) which took 15 days to hatch. This is a bit tricky to determine as the parent birds not only sit on the eggs, but sit on and conceal the squabs, as they are called after they are hatched. I detected when the two eggs were hatched by getting so close to the nest that the parent bird flew away. Not to worry. After I moved away from the nest the adult bird returned in less than one minute.

The encyclopedia states that the male bird incubates the eggs from the morning to the afternoon; the female at night and the rest of the day. I observed that the first change occurs an hour so after sunrise, again circa an hour after noon, and an hour or less before sundown. The timing was so consistent from day to day that I almost suspected they both possessed Rolex timepieces. The changing of places on the nest contained a bit of variability. Sometimes the bird on the nest would fly away a second before the other came to the nest. More frequently the incoming bird would land on a ledge above the patio door and wait for the nesting bird to depart – usually in less than one minute. Only rarely did the incoming bird land directly in the nest before the other departed. Perhaps how soon the bird on the nest left was a function of how cramped he/she felt. I listened carefully, but could not hear any recriminations about “Where have you been all this time?” But that may have been because I don’t understand mourning dove talk.

The chicks are fed by both of the adults with what is called pigeon’s milk (dove milk) which is partially digested food (the diet of mourning doves is normally 99% seeds) in the adult bird’s crop. This food which has the consistency of cottage cheese, is regurgitated (Medieval Latin regurgitatus meaning to engulf) into the beaks of the chicks, ugh! It makes the human mammary system of feeding babies downright civilized and sanitary by comparison.

Mourning dove chicks are altricial (from Latin altric meaning nourish) at birth as opposed to precocial (from Latin praecoci, the same root as the word precocious); that is to say they are born blind and helpless instead of being capable of defending themselves or fleeing. The parents do not voluntarily leave the chicks alone for one minute until they are eight or nine days old. During this rapid growth period the chicks become too big to be concealed by the adult bird sitting on the nest and also the chicks appear to be curious about their immediate environment so they want to see what is going on. As the chicks mature they are left alone for an hour, then for a couple of hours and an increasing number of times per day until they are two weeks old. At that point the chicks were left alone all night for the first time after being on their own almost all that day. The next day (the 15th day after being hatched) first one, then several hours later, the other chick left the nest. An adult mourning dove (probably the mother) was perched nearby watching and seemingly encouraging the chicks as they left the nest. Even a couple of days later the mother was with the chicks as they appeared to be hanging around our enclosed backyard although they were fully capable of flying.

It takes a certain amount of courage for the chicks to attempt to fly out of the nest after being confined there during their maturing stage. In the first brood the chick stood on the edge of the hanging basket for several minutes before trying out his wings all the while the adult bird was perched on the backyard fence as if to say “come on youngling, you can make it.” The second chick in the last brood actually flew up to the ledge above the patio door before flying down to the patio floor. The mother mourning dove was on our house roof where the chick soon joined her. With seemingly simple minded mourning doves being so solicitous and protective of their offspring, what is the excuse for a few humans who carelessly or deliberately endanger their children?