Masked Boobies at Molokini – First Verified Sighting

Mike Severns Diving Maui - History/Events, Molokini Crater Leave a Comment

Last August we reported the first verified sighting of Red-footed boobies at Molokini. During the 20 years prior to that the only large seabirds that we had seen roosting on Molokini were Great frigatebirds, so it was very exciting to see the Redfoots. They stayed for about two weeks and then were gone. The frigatebirds too left for the winter.

In a normal year we would see the return of the Great frigatebirds in the spring. This year, because of Covid-19, we were not operating at the time they would have returned. So, when we did begin going out to Molokini again in August the full congregation of Great frigatebirds was already there. It wasn’t until Sept. 4 that we thought to look for the Red-footed boobies and sure enough, there they were, mostly sitting on the same two shrubs they had been roosting on last year.

Three red-footed boobies perch on a small tree on the inner slope of Molokini. Sept. 11, 2020.
Red-footed boobies returned to Molokini for second year. Sept. 11, 2020. Photo by P. Fiene.

THIS time, however, there were also two birds sitting on the ground that looked a little bit different. They were a brighter white and the black on the edges of the wings was darker. They were up on the slope, and it was hard to get a good look at them through binoculars from the moving boat. A week later we came back with a camera. They were sitting in the same place, just the two of them, as they were the week before. When we saw the photos we knew right away that it was a pair of Masked boobies (Sula dactylatra. Hawaiian name is ‘ā).  

Two masked boobies roosting on the inner slope of Molokini. Sept. 4, 2020.
A pair of Masked boobies are seen roosting on the inner slope of Molokini for the first time on Sept. 4, 2020. On a perch to their right is a Red-footed booby. Also in the photo are three Great frigatebirds. Photo taken Sept. 11, 2020. Photo by P. Fiene.

In the Hawaiian Islands Masked boobies are found most commonly in the northwestern Hawaiian Islands where there are an estimated 2,500 breeding pairs. Another estimated 450 pairs nest on Moku Manu off O‘ahu, and on Ka‘ula off Ni‘ihau. They are rare elsewhere in the Hawaiian Islands, but according to Dr. Eric VenderWerf, Director of Science, Pacific Rim Conservation, they have been seen on a couple of the islets off the north and east sides of Maui. They have never previously been recorded on Molokini.

The first Masked boobies recorded at Molokini on Sept. 4 are still there as of this photo taken the morning of Sept. 18, 2020. Photo by Andy Schwanke.

We were so lucky that we had gotten out to Molokini early because after the sun rises they – and the redfoots and frigatebirds – take flight and head out to sea to feed. We would not have known they were there if our captain hadn’t required a punctual meeting time. These two individuals have been sitting together in the same spot every Friday for three weeks now.

The pair of Masked boobies at Molokini were grooming each other when we visited in the morning of Sept. 18, 2020. Photo by Andy Schwanke.

And on Sept. 18 we even got to see them grooming each other. Unfortunately male and female Masked boobies have identical plumages so we can’t tell their sexes. However, according to Dr. VenderWerf, “It would be strange for two birds of the same sex to behave that way (at least in boobies).”  

They are still there as of Oct. 27, 2020.

We will keep you posted about these two Masked boobies in the weeks ahead. 

Written by Pauline Fiene. Photos as credited.

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http://hbs.bishopmuseum.org/birds/rlp-monograph/pdfs/03-PHAE-GRUI/MABO.pdf

Harrison, Craig S. 1990. Seabirds of Hawaii. Ithaca, N.Y. : Comstock Pub. Associates.

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