Believed to be locally extinct in the Philippines for almost twenty years, a family of Masked Booby (Sula dactylatra) was reportedly seen in the Tubbataha Reefs Natural Park and World Heritage Site in Palawan province.
For marine park officials, the Masked Boobies represent “what we once lost – and what we hope to recover”. “We have been on a roller coaster ride of joy and despair as we watched our Masked Boobies build a family in Bird Islet,” the Tubbataha Management Office (TMO) said in a statement Monday afternoon.
The seabird was first observed in “large colony” within the Bird Islet of Tubbataha by naturalist Dean Worcester in 1911. The population significantly decreased seventy years later that in 1981, ornithologist Kennedy observed only about 150 adults at the world-renowned park.
The number of Masked Boobies continued to drop with only about 30 adults recorded in 1989, until a lone seabird was photographed at the Bird Islet in 1995. The species had been previously declared extirpated in the Philippines after its disappearance from the island in 1996.
In May 2016, believed to be locally extinct in the Philippines for almost 20 years, a lone Masked Booby was seen nesting at the Bird Islet. Three years later, in November 2019, the marine park officials reportedly saw another seabird at the exact spot the lone individual used to occupy in its previous visits to the islet. The Masked Boobies, believed to be “partners”, were seen hanging around the “plaza”—the unvegetated area in the middle of Bird Islet.
Complex mating rituals and conservation efforts
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 most of their adult life foraging in the open ocean.
The seabird’s sexual maturity is reached in three to five years, where breeding and courtship would usually begin. Masked boobies form a monogamous relationship with pairs remaining together over multiple breeding season.
“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,” park superintendent Angelique Songco wrote in an earlier East Asian-Australian Flyway report.
In July 2020, the TMO has turned its efforts to save the seabirds at the country’s prime protected marine park after the Bird and South Islets became “virtually flat” when the trees and shrubs died because of guano overfertilization and past droughts.
The islets are also a shelter 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 re-used in subsequent years.
In the last quarter of 2019, Songco said they established a nursery of beach forest trees to revive the coastal shrubbery in the islets. In June this year, they planted cuttings of anuling (Pisonia grandis) imported from Cagayancillo town – with at least 400 propagules transported aboard their boat.
The TRNP personnel also came up with several other strategies such as making temporary structures where the seabirds may nest—to a point that they also even brought dried leaves to the islets as nesting raw materials for the birds.
“Since we lost trees in 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 park officials, seabirds are “harder to monitor” because they occupy isolated locations and harsh habitats. Birdlife International claimed that 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 monitor the efficacy of the 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.
Being the only breeding pair known in the Philippines today, the Tubbataha Management Office (TMO) said they are determined to provide them with a “safe and nurturing space in which to start a family”.
“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 concluded.