For more than three months we have been writing about Fabio, the masked booby, and his strange adoption.

Lynn Fowler has spent two consecutive Thursdays watching the nest in search of an answer: Who feeds Andrea, the frigate chick on the ground? We all believe that it must be its real parents. But we have no evidence. Nor is there any proof that Fabio feeds it.

The only thing we can be sure about is that this masked booby is behaving in a very peculiar way, especially since we saw how it practically left Andrea to "adopt" a different frigate chick in the neighboring tree.

We stayed near the visitor site for about an hour. During that time, Fabio was on the tree, in the nest of his new frigate chick friend. It seems that this young one, which rejected the masked booby presence three weeks ago, is now used to sharing its nest with such a creature.

We are certainly not short of theories about this unique course of action. Every week at Prince Philip's Steps on Tower island, we wait for a new surprise. We may never understand Fabio's motive, but ours is to learn from observing our surroundings. Nature is there for us to discover, understand and then protect.