There has been a Merlin roost discovered in central Iowa over the last few weeks where 6 of the birds routinely gather in open deciduous trees in a fairly small area in late afternoon to early evening. Then after a few hours they slip into nightly hiding places in nearby coniferous trees. So far the IDs seem to be 2 female/juvenile richardsonii ("prairie"), 1 male richardsonii, 1 female/juvenile and 2 male columbarius("taiga", "boreal"). I saw a female prairie come in first. Then a male prairie came in and swooped her and went to a different tree and then a male taiga swooped in and took her spot. These birds are predators of birds and at the top of the food chain but can be taken by large hawks and owls. They can also be killed by gulls during over water migration. They have been described as a fairly tame to tame raptor and these 6 are pretty cooperative birds. They can also be very antagonistic harassing large raptors and birds too large to kill.