Unseen in PH for years, masked boobies start family in Tubbataha
PUERTO PRINCESA CITY, Palawan, Philippines — Believed to have disappeared in the Philippines for almost 20 years, a seabird family of the masked booby (Sula dactylatra) species has been reportedly spotted on an islet at the Tubbataha Reefs Natural Park and World Heritage Site in Palawan province.
“We have been on a roller-coaster ride of joy and despair as we watched our masked boobies build a family on Bird Islet,” the Tubbataha Management Office (TMO), which oversees the marine park, said in a statement on Monday.
For TMO personnel, the masked boobies represented “what we once lost—and what we hope to recover.”
Masked boobies are usually found in tropical oceans, from the Arabian Peninsula of the Indian Ocean to the western Australian coastline up to the Pacific, Caribbean and Atlantic oceans. With a lifespan of 15 to 20 years, they spend most of their adult life foraging in the open ocean.
The seabirds were first observed in “large colony” on Bird Islet by naturalist Dean Worcester in 1911, but their number significantly declined 70 years later, or in 1981 when ornithologist Robert Kennedy found only about 150 adults at the world-renowned park, and to only about 30 recorded in 1989.
In 1995, a lone seabird was photographed on Bird Islet and the species was declared completely gone in the Philippines a year later.
After almost 20 years, a lone masked booby was seen nesting on Bird Islet in May 2016. Three years later, marine park officials reportedly saw another seabird at the same spot.
The masked boobies, believed to be “partners,” were seen hanging around the “plaza” — the “unvegetated” area in the middle of the islet.
Being the only breeding pair known in the Philippines today, TMO officials said they were determined to provide them a “safe and nurturing space in which to start a family.”
The seabird’s sexual maturity is reached in three to five years, where breeding and courtship would usually begin. Pairs form a monogamous relationship over multiple breeding seasons.
“One of the peculiarities in nature is that even when these birds laid two eggs, only one chick will be raised as the younger or weaker one is kicked out of the nest to die. This focuses the energy of the parents on one offspring, increasing the likelihood of survival,” Angelique Songco, park superintendent, wrote in a previous East Asian-Australian Flyway report.
“These last few years, this masked booby couple has kept us in alternating strings of joy and despair, hope and discouragement, resignation and expectation. Are they home for good?” Songco said.
Last July, the TMO stepped up its efforts to save the seabirds at the country’s prime protected marine park after the Bird and South islets became “virtually flat” after losing their trees and shrubs due to guano overfertilization and past droughts.
The islets are also shelters to the black noddy (Anous minutus worcesteri), an internationally protected species, and red-footed booby (Sula sula).
The seabirds generally nest on a level platform, often created in the branches of trees by a series of dried leaves covered with bird droppings. One egg is laid each season and nests are reused in subsequent years.
In the last quarter of 2019, Songco said the TMO established a nursery of beach forest trees to revive coastal shrubbery in the islets. Last June, they planted at least 400 propagules or cuttings of “anuling” (Pisonia grandis) from Cagayancillo town.
Park personnel also built structures as nesting sites for the seabirds and even brought dried leaves to the islets as nest raw materials.
“Since we lost trees on Bird Islet, we had to create these structures. We had to do something if we are not to lose some of the very important species,” Songco said.
According to TMO officials, seabirds are “harder to monitor” because they occupy isolated locations and harsh habitats. BirdLife International says seabirds are “more threatened than all other groups of birds with similar numbers of species” as they suffer from bycatch in commercial fisheries, from loss of smaller fish due to overfishing, and from invasive species such as rats and cats.
The park rangers stationed in Tubbataha conduct a year-round regular seabird surveys to determine the soundness of their conservation strategies and actions.
They also check for illegal fishing and other damaging activities to ensure that a healthy ocean for the seabirds is provided. INQ