Cormorants. Bright blue throat pouch and white at base of bill. Large numbers of these were present on the island.
San Diego County, California, US
BAMONA record
http://www.butterfliesandmoths.org/sighting_details/1019883
San Diego County, California, US
BAMONA record
http://www.butterfliesandmoths.org/sighting_details/1000688
This must have been a young bird, it would not fly, but keep hopping through the rocks and grass.