While observing a local Purple Martin "condo" nest box this weekend I witnessed something for the first time. There were many young ones peeking out of the various holes waiting for the parents to return with food. On two occasions I noticed a parent approach a young one...not to feed it, but to forcibly pull it out of the nest hole:eek:. The surprised free-falling juvies had no choice but to fly and perch on the nearest pole! The parents then proceeded to feed them from there. Unfortunately no worthwhile images taken as both the sun and the wind (lack of both) were working against me.
Very cool behaviour that I thought would be interesting to share.:) I was also wondering if this was common with other cavity nesters?
As you say this is very interesting Daniel. I have not heard of this specifically before but it does bring a couple of points to mind. Parents often reduce or stop feeding their young to encourage them to fledge. This perhaps is analogous to what you saw. Why is this encouragement needed? It turns out that from an evolutionary standpoint, parents and offspring are in conflict at this stage of the life cycle. It is advantageous to the offspring to extract more investment from their parents in terms of care and food, but for the parents it is advantageous to stop investing in the current offspring because they need to save themselves for investment in future offspring. This whole topic is called "Parent-Offspring Conflict" and anyone who has had teenage kids will know what I'm talking about!!!!!
Last edited by John Chardine; 07-29-2008 at 09:40 PM.
In that case Fabs the male parent needs to get the murre (guillemot) chick to sea where the food is because the parents can no longer bring enough food to the nest to feed the growing chick. Murres are at the edge of flight capability and only bring one fish at a time back to the nest. When the young murre chick leaves the nest it is only half grown and spends the next few weeks with the male parent in the water, being fed, learning to feed itself and growing to adult size. In the case of murres at this stage of the life cycle there is no evolutionary conflict because it is in the interests of the chick and the parents to get to sea as quickly as possible. Thanks for bringing this one up!
Last edited by John Chardine; 07-29-2008 at 09:39 PM.
Purple Martin forced first flight.
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