Sir JC’s R.O.X .Thursday Talk “Avian Farmers of the Philippine Rainforest : Saving the Walden’s Hornbill from Extinction”
by Nikdye Realubit-van de Ven
R.O. X. holds a weekly, sometimes monthly, talk on Thursday nights about different outdoor sports related topics the most recent being bike safety. Last August 31, 2017 bird watching was the week’s highlight as Dr. Juan Carlos T. Gonzalez gave his talk on “Avian Farmers of the Philippine Rainforest : Saving the Walden’s Hornbill from Extinction”. Sir JC for those who don’t know him is one of the leading experts in ornithology in the Philippines, who graduated from the prestigious University of Oxford, a self declared bucerotiphile, has a 25-year track of teaching at University of the Philippines-Los Baños, director at the UPLB- Museum of Natural History (MNH), and a proud long-time member of the Wild Bird Club of the Philippines (WBCP).
Starting off after the cheers from the rowdy first row audience, Sir JC started with a primer on Philippine bird diversity. The total of 565 bird species in 1991 is now 683 species in the current WBCP 2017 checklist. The focus of the talks are birds that belong to Family Bucerotidae, that has a lot of local names ranging from Kalaw in Tagalog to Talusi for Bisaya. Bucerotidae can be broken into two words: bous which means “cattlehead” and keras which means “horn.” Two words combine to point to one of the most distinguishing characteristic of the hornbills, their large helmet-like bills, also know as casque. For newbies, there are popular movie/pop culture sightings of hornbills. Examples include Sazu of Lion King which is a ground hornbill, Professor McGonagall in the Harry Potter movie transfigures a hornbill into a cup, and in Katy Perry’s Roar MTV there was the Great Pied Hornbill. Take note, the bird on the Fruit Loops cereal box design is NOT a hornbill but a toucan which is very similar and most often confused with the hornbill.
Much ado about hornbills
For the hornbills of the world, there are currently 61 species in 88 taxa, distributed from east Africa going across the globe to Solomon Islands. Hornbills, like all birds, have four toes. As an aside, if you see a bird with five toes, RUN AWAY. The third and fourth toe of hornbills is fused, technically referred to as syndactyl. Other birds with same feet are kingfishers (Coraciformes). Other birds have casques too, like cassuaries but it is really the nest plastering behavior of the hornbills that is unique to them. Locals refer to hornbills as selosong ibon because the females are sealed off inside the cavity throughout breeding season. But actually it is the female that plasters herself in, and the males just bring the materials to her.
For hornbill evolution, hornbills are of the tropics but historically, a long long time ago, there were hornbills in eastern Europe when it still had a tropical climate. At present, we have 32 species of Asian hornbills that DO NOT eat people but may eat snakes and lizards during their breeding season. There are four clades of Philippine hornbills, including 15 species & subspecies. Tarictics or Penelopides dwarf hornbills are mostly found on the eastern side of the country, except for the Mindoro Hornbill that has a blue face for females. The Basilan species is quite distinct. We have lost the Ticao Hornbill which cannot be found anywhere else in the world but is closely related to the Masbate populations. For the Rufous Hornbill, or the Buceros clade, there are three different subspecies –the Luzon, eastern Visayas, and Mindanao populations. For the two pied Anthracoceros of Palawan and Sulu these are small populations within a small distribution facing bigger threats. This is even more felt in that there are no Sulu Hornbill specimens in the Philippines except in the natural history collection of Mindanao State University-Marawi.
To get an in-depth look on why hornbills are farmers of the rainforest, in 2009 Sir JC went into the Northern Sierra Madre National Park (NSMNP) in Palanan. Forest hornbills can serve as bio indicators because they are charismatic canopy frugivores (majestic bills, raucuous calls, and unusual nest-sealing behavior), forest-dependent, and important seed dispersers. They can also be easily heard because they lack underwing coverts and have very distinct and loud wing beats. For the field study at NSMNP, the sympatric (co-existing in the same area) occurrence of two hornbills (Luzon Tarictic and Rufous Hornbill) in Luzon was investigated. Such field study is good for weight loss, when Sir JC went into Palanan he was 95kgs, when he returned after four months, he was 75kgs. The field expedition team sifted through 16 hectares of three different types of forests: primary, secondary, and degraded. Primary forests had large trees, with >60cm in diameter sometimes needing four people to measure the trunk. Results showed that the larger Rufous Hornbills do not appear in degraded forests, while smaller Luzon Tarictics persisted across the different forest types. The Luzon Tarictics preferred a wider food choice, also including palms and non figs. For the Rufous Hornbill, they have a preference for dispersing large-seeded fruits like Myristica collinridsalei. This species of Myristica is a nutmeg, that is an endangered nutmeg fed on by an endangered hornbill. There is no other animal that can disperse it, you need something like a tweezer to the remove the fleshy aril then it has to be regurgitated. The fruit itself is bigger than a flowepecker, the seed is bigger than a bulbul head. Even if hypothetically, crows would feed on it, it definitely won’t come down on the other end, and the kwaaaak of the crow will be very different.
What is being done to protect the Dulungan?
For the star bird of the talk, Walden’s Hornbill or the Dulungan which used to have a scientific name of Aceros. Except Aceros means “no horn”, but the species has a horn. So now it is currently Rhabdotorrhinus waldeni. It has a staccato call, a Tarictic tic tic kind of call. The species has a distinct oil gland, which is basically “hornbill make-up” that ensures the vibrant colors of the bird. Females have a blue face while the male has a yellow face. Their historical distribution covered Panay, Negros, and Guimaras, before the mangoes were there. The name Rhabdotorrhinus, reminds us of the fuschia-red joke, it is definitely easier to spell Aceros. The name is divided into rhabd-rod, doto-endow, rhinus-nose. It was named after Viscount Walden, Marquess of Tweeddale, head then President of Zoological Society and was a Scottish ornithologist.
The same bird, with three names, has the behavior of sentinels: while the flock is feeding just under the canopy, one individual is on top to watch out for the flock. Dulungan was derived from the Hilgaynon term for “watching from a vantage point”. WBCP member Gina Mapua mentioned that dul-ong in Hiligaynon means “deliver.” Sir JC also shares at this point that hornbills were culturally known to deliver spirits to the gods.
The Dulungan was officially discovered in 1877; it was actually discovered before the Philippine Eagle. The holotype or the first specimen was collected in the Tweeddale expedition. Tarictic hornbills are most related to the Dulungan. There are probably more people in BGC than Walden’s Hornbill. This is based on the number of nests by the study of PhilinCon. The Dulungan has been assessed as Critically Endangered (CR) by IUCN Red List. It is also an EDGE ZSL species. For in situ conservation, they are functionally extinct in Negros, but ironically there are more ecological studies on the species than other hornbill species. Ex situ conservation was spearheaded by Mari-it Wildlife Conservation Park and Talarak Foundation, where they were able to captive breed a few individuals. What can a person do to help? Awareness is the first step, it is amazing that there are people interested to come to a talk on hornbills. Supporting the conservation programs of both government and non-government organizations is also encouraged. Joining bird clubs and helping record bird counts are a great help. Lastly, refusing to buy live wild birds and their products is a must.
Current fundraising efforts for the Dulungan and PhilinCon by Wild Bird Club of the Philippines
After the talk, WBCP President Willem van de Ven, as coached by Mike, announced that the Club has already raised Php50,000 for the species through the NGO. Next month there will be shirts released by R.O.X. featuring hornbills so everybody is encouraged to buy as this will also add to the fundraising. There is also currently a bird photo exhibit at R.O.X. , and the photos are for sale.
Thank you very much to everyone who braved the long weekend traffic to attend the R.O.X. Thursday Talk. We hope to see everyone in the future club activities and encourage non-members to sign up!