Sea Eagles - talon clasping
Taken from the ship as it passed close to the land, this is a sequence of shots taken of two sea eagles. Talon clasping is a pair bonding behaviour practised by adult mates and also by female birds and their young juveniles. It's hard to tell, but I think these are both adult birds. In birds of prey, the larger bird is invariably the female.
"One explanation for the females' larger size suggests that it protects them from aggressive males that are well equipped with sharp talons and beaks, and the killer instincts to go with them. According to this theory, over evolutionary time, females have preferred to mate with smaller, safer males -- in fact, the female may have to be able to dominate the male for proper pair bonding to occur and for the male to remain in his key role as food provider to both female and young. Such a system would involve sexual selection for smaller size in males. Bird-hunting raptors are assumed to show aggression most suddenly, and to represent the greatest threat to their mates, and they are the ones exhibiting the greatest size difference.
Another hypothesis proposes that the size differences allow the two sexes to hunt different prey and thus reduce competition for food. Competition is thought to be more severe among bird hunters than among other hawks, since their small agile prey are able to flee in three dimensions and are thus effectively scarcer than, say, carrion or ground squirrels. Indeed, there are data indicating that the hunting success of bird-chasing raptors is only about half that of raptors preying on mammals, and only a sixth that of raptors eating insects. Tom Cade has suggested that, for bird eaters, available food supply in the nesting territory can become limiting, making it adaptive for the male to specialize on small prey and for the female to specialize on large prey. The male feeds the female and young at the beginning of the nesting season; the female becomes an active hunter when the nestlings are larger, and the adults then tend to partition the prey resource in their territory."
The quotation is taken from 'Size and Sex in Raptors' by Paul R. Ehrlich, David S. Dobkin, and Darryl Wheye, 1988.