5 Red-tailed Tropicbird This species increased in number 257% from 7 in April to 25 in May. There was a minor concentration of these birds in the northwestern corner of the grid area, where on two occasions courtship flight was observed. White-tailed Tropicbird Numbers of this species increased 500% from 4 in April to 24 in May. Twelve of these were seen along the coast of Maui where the species is known to breed. Blue-faced Booby This species increased 125% from 4 in April to 9 in May. All were immature or sub-adult birds. All were seen in the southwest corner of the grid area. Brown Booby Two of this species were seen within sight of the coast of Oahu where it breeds. Red-footed Booby This species increased 52% from 71 in April to 108 in May. All but one of these were seen within 60 miles of Oahu where they breed. One bird, an immature, was seen in the northwest corner of the grid area. Great Frigatebird Eleven of this species were seen in the grid area, 2 at the southern end and the remaining 9 near Oahu, where they roost.