Steven S. Coles:
>Because one of the eagles had mottled markings we assumed this was not
>courting. Any suggestions on how we should view this behavior?

Hmm...it's beginning to appear as though talon-locking can be both
territorial and mating behavior in bald eagles.

However, just because one was immature don't assume it wasn't part
of a pair. Normally adults hog the breeding territories, but remember
that bald eagles have been increasing after a long-term, artificial
(caused by people) decline thus until recently there have been more
available territories than pairs to fill them. This is precisely
the situation that increases the likelihood of a non-adult-plummaged
bird breeding, as younger birds can fill territories not occupied
by adults until they get saturated by the increase in population.

Even when the population has reached a more-or-less stable level, as
bald eagles have Washington and Oregon, it's not at all unheard of
for occasional sub-adults to breed. When one partner dies, as happens
to a proportion of adults each winter, there's competition to fill
the empty slot, so to speak, and if there's not a convenient adult
of the right sex to do so, well, you get what you can.

- Don Baccus, Portland OR <donb at rational.com>