Seabirds spend their entire life in the open ocean, hence, they are a good indicator of coral reef health. Their nutrient-rich droppings fertilize roosting grounds and the surrounding water to the benefit of other marine life. Seabirds are one of the most highly threatened species of animals. Although they have a relatively long life span, they breed much slower and have fewer offspring than other birds in general.
Partly supported by EAAFP Small Grant Fund for Working Groups and Task Forces, this year, the Tubbataha Management Office (TMO) use seabirds as an indicator to assess of how well – or how badly – the site are conserving Tubbataha Reefs Natural Park, A Flyway Network Site (EAAF 123) in the Philippines. We monitored the population of the seven species that breed in the Park, the: Red-footed Booby (Sula sula), Brown Booby (Sula leucogaster), Masked Booby (Sula dactylatra), Great Crested Tern (Thalasseus bergii), Sooty Tern (Onychoprion fuscata), Brown Noddy (Anous stolidus), and endemic Black Noddy subspecies (Anous minutus worcesteri).
We use various monitoring methods and integrate results for a more accurate estimate of the populations. Distance counts are conducted once a month, while direct counts are done once a quarter. In-flight counts are done late in the afternoon, and dawn counts are made before the birds leave the islet to forage for food. When called for, we would do night counts of birds that come to roost after sundown.
Adults, subadults, juveniles, pullus, eggs, and nests of each species are counted. Two teams conduct the count of the various species in various life stages. In all, it took a total of 39 teams to complete the survey.
In May each year, we join the marine park rangers (MPR) for quarterly monitoring. The Covid 19 situation interposed several complications that delayed our trip, with interesting results. Together with WWF-Philippines staff, and volunteers, we were finally able to set sail on 2 June 2021. This year’s survey was funded by the East Asian-Australasian Flyway Partnership (EAAFP), Department of Environment and Natural Resources (DENR), and Pilipinas Shell Foundation, Inc. (PSFI). Report of the surveys will be shared by the end of 2021.
Tubbataha Reefs Natural Park is both a Ramsar site and a Flyway Network Site of the EAAFP. Located 92 nautical miles southeast of Palawan, it is a 97,030-hectare marine protected area which was established on 11 August 1988. It is the largest no-take marine protected area in the Philippines. Its two islets are among the last known safe breeding habitats of seabirds in Southeast Asia.
Article prepared by Tubbataha Management Office.
The Tubbataha Reefs Natural Park is in the middle of the Sulu Sea. It is composed of two atolls and a reef. The Bird Islet is in the North Atoll and the smaller South Islet is located in the South Atoll.
Marine park rangers construct the ‘Tubbataha Hilton’, our shelter from the sweltering heat in Bird Islet. Photo © Segundo Conales Jr
Our team from Puerto Princesa City met with MPRs at the ranger station upon arrival. Research Officer Retch Alaba gave a briefing on the work at hand and assigned tasks for each person. Photo © Rowell Alarcon
Our first task before setting foot on the islets was to do a distance count. Park Ranger Jeffrey David (in blue) leads the count in Bird Islet, where 80% of the total seabird population of Tubbataha reside. Photo © Rowell Alarcon |
In the following days, the teams got busy with their respective tasks. Here, one group counts the eggs of the Great Crested Tern. Photo © Kymry Delijero |
Showing off their EAAFP hats, Angelique Songco and Rowell Alarcon count Brown Noddies. Photo © Kymry Delijero |
Marine Park Ranger Segundo Conales Jr., (with umbrella) counts the eggs, nests, and adults of Black Noddy in the structure while John Eric Magbanua, Bantay Dagat of Local Government of Cagayancillo (LGU), serves as recorder. Photo © Retch Alaba |
From left: MPR Noel Bundal, SN2 Paul Balonsay PN, and Joan Pecson, WWF-Philippines, start the in-flight count at 4:30, when birds begin to arrive from the day’s foraging. Photo © Kymry Delijero |
The team doing a night count of the Sooty Tern population that landed after sundown. The estimate was 6000 individuals! Photo © Kymry Delijero |
From left to right: Marine Park Rangers Segundo Conales Jr, SNDP Paul Balonsay PN, SN2 Francis Lim and Noel Bundal (in blue shirt) with tallies their day’s count in the native dining table inside our hut. Photo © Kymry Delijero |
We observed lesser seabirds, probably because we arrived at the end of the breeding season when most of the adults have left. We also counted lesser eggs because most of the birds were already in the pullus or juvenile stages. Photo © Kymry Delijero |
Black Noddies continue to occupy the artificial nesting structures we built in 2017. Last year, we added new structures made of PVC and steel pipes (above), which are designed to last longer. Photo © Gerlie Gedoria |
We planted saplings of native trees in the islet in 2020 but most did not survive. Marine Park Rangers Amado Cayabo (LGU) and Cris Caranay (TMO) construct bamboo guards around a sapling so birds would not build their nests on the saplings and use their leaves as nesting materials. Photo © Kymry Delijero |
The only known breeding Masked Booby in Philippines lain an egg for the fourth time (!) since 2019. A second egg appeared a week later. Photo © Retch Alaba
We used the WWF-Philippines research vessel, M/Y Navorca for the survey. Here, the team disembarks for the survey in South Islet. Photo © Rowell Alarcon
This year's seabird survey team. Photo © Rowell Alarcon