Jboslerbirds
Masked/ Nazca Booby - Baja California
Masked-type Booby (Sula dactylatra/ granti), immature - Middle Rock, Coronado Islands, Baja California, MEX - 15 July 2014.
Conclusively identifying immature Masked-type Boobies in the eastern Pacific is likely an exercise in futility given what little is currently known, increasing hybridization in the northern breeding colonies and individual variation. This particular individual shows entirely gray-brown upperparts with a partial white collar which is typical of young Nazcas. This photo is deceiving in that it gives the bird a collared appearance (the back was acquiring a salt-and-pepper appearance typical of second-year birds while the head was extensively flecked with white). The second character worth noting is the rather large, deep bill which is more typical of S. d. californica Masked Booby. Images of the tail may also shed some light on a potential species ID, but alas I was unable to obtain any photos of the dorsal surface of the tail. This individual could very well be a hybrid from the nearest breeding colonies on Clipperton Island or Alijos Rocks, where researchers have observed mixed pairs.
Masked/ Nazca Booby - Baja California
Masked-type Booby (Sula dactylatra/ granti), immature - Middle Rock, Coronado Islands, Baja California, MEX - 15 July 2014.
Conclusively identifying immature Masked-type Boobies in the eastern Pacific is likely an exercise in futility given what little is currently known, increasing hybridization in the northern breeding colonies and individual variation. This particular individual shows entirely gray-brown upperparts with a partial white collar which is typical of young Nazcas. This photo is deceiving in that it gives the bird a collared appearance (the back was acquiring a salt-and-pepper appearance typical of second-year birds while the head was extensively flecked with white). The second character worth noting is the rather large, deep bill which is more typical of S. d. californica Masked Booby. Images of the tail may also shed some light on a potential species ID, but alas I was unable to obtain any photos of the dorsal surface of the tail. This individual could very well be a hybrid from the nearest breeding colonies on Clipperton Island or Alijos Rocks, where researchers have observed mixed pairs.