First post-release documentation of Philippine Eagle 'Carlito' in MacArthur, Leyte

Rowell L. Taraya, Japheth Richa, and Jayson C. Ibanez, Phd

First in-situ photo of released female Philippine eagle 'Carlito,' three months after her release. Photo captured from the observation platfrom, 900 meters away from Carlito’s location in the riparian forest of McArthur, Leyte, on September 29, 2024.

Synopsis

The last known sighting of wild Philippine eagles in Leyte was in 2013. Despite several consecutive surveys conducted after Typhoon Yolanda, no Philippine eagles has been recorded since, leading to concerns that the species might have extirpated from the island.

On June 28, 2024, Carlito and Uswag became the first eagles to participate in the country's inaugural reintroduction program. Rescued from Mindanao, both birds symbolized hope for restoring the Philippine eagle population on Leyte Island. Tragically, just one month after the release, Eagle “Uswag” crashed into the sea and was found floating and dead off Camotes Islands in Cebu last July 2024. A necropsy revealed that Uswag died of drowning. The team suspected that a series of thermal updrafts brought Uswag closer to the shore line, and the gradual loss of these columns of hot air towards the sea and the inability of Philippine eagles to sustain power, flapping flights in the absence of thermal updrafts resulted to the bird crashing at sea.

Finally, for three months of scheduled painstaking search efforts, the team succeeded in locating Carlito. The following paragraphs of this report provide a detailed account of Carlito's rediscovery and the significance of this finding.

Methods

On September 24, 2024, a team from the Philippine Eagle Foundation (PEF), led by Senior Biologist Rowell "Ron" Taraya, along with Field Biologist Japheth Richa, and Field Technicians Rene Bacquiano and Christian Tan began a two-week expedition to monitor Philippine eagle "Carlito." Based on regular GPS readings from the solar-powered GPS transmitter installed on its back, the bird has settled in a thickly forested ravine about 3.2. kilometers North East of her release site.

Detecting Carlito and taking photographs of the bird were proven very difficult by the previous fieldworks that sought to locate her. While the GPS fixes from her tracking device showed that the bird is close to the team’s observation platforms, the eagle was very shy and secretive. She was detected only twice and only for brief moments. The primary objective of the team was to locate Carlito and assess her status in the forest, including getting decent photos and videos of her as a reference for assessment. On the morning of September 25, the team paid a courtesy visit to McArthur Municipal Mayor Rudin T. Babante. We also coordinated the expedition with DENR Region 8, the Provincial and Community Offices of the DENR, and the Barangay Local Government Units (BLGUs) surrounding the forests where Carlito has settled. Forest guards from Brgy Kagbana in Burauen town were also invited to help with the search.

Based on Google Maps (see map below), Carlito has established its territory within the forests of McArthur, Leyte, within the deep gorges and ravines of a river locally called “Valerie”. This area has been Carlito’s preferred habitat since August, 2024.

Google earth image of Philippine eagle Carlito’s habitat within the town of Mac Arthur, Leyte

To maximize the chances of detecting Carlito, four tree platforms with heights between 10 – 15 meters from the ground were established around Carlito’s activity area. The team employed the "Look-and-See" method (Bibby, Jones, & Marsden, 1998) to monitor Philippine Eagle Carlito, as well as other raptors in the area. The following field equipment were utilized: (i) three binoculars (two Nikon Monarch 8x42 and one Swarovski 8x30), (ii) one field scope (Swarovski Optik), (iii) two-way radios, and (iv) two zoom-lens camera sets (a Canon EOS 800D kit with a Tamron 150-600mm long lens, and a Canon R10 body with a Canon RF 800mm lens). From early morning to late afternoon, all observed raptors and other birds—whether calling, flying, or displaying—were recorded and photographed. The species and number of all raptors and other birds spotted were identified and listed. For species identification, we referred to A Guide to the Birds of the Philippines (Kennedy et al., 2000) and the Checklist of Birds of the Philippines (Jensen et al., 2019).

Finding eagle “Carlito”

Despite knowing Carlito's last known GPS location based on her September 22 GPS fixes, finding her from our tree platforms felt like searching for a needle in a haystack. She was neither soaring nor flying visibly despite the clear skies.

On September 26, the team began its observations at 0730 hrs and ended at 1600 hrs. From two observation platforms (Platforms 2 and 3), the team scanned each tree crown and the forest canopy for Carlito. However, no eagles were seen despite the sunny weather. Throughout the day, only a lone Southern Philippine Hawk-Eagle Nisaetus pinskeri was spotted.

To widen the search area, the team occupied three observation platforms on September 27:  Platforms 1 (the highest\tree platform), 2, and 3. Several raptors were seen, such as the Philippine Honey-Buzzard Pernis steerei, Brahminy Kites Haliastur indus, and the Southern Philippine Hawk-Eagles, but no Philippine eagle Carlito was seen. We had the same outcome on September 28—no sign of Carlito.

Finally, on the morning of September 29 (Sunday), at around 08:30, while scanning the canopy from platform 3, we spotted a large bird flying above the riparian forest until finally landing on a dead branch less that a kilometer away from our platform. The technicians who first saw the bird flying shouted "Eagle!" and everyone focused their binoculars to the direction of the bird. Upon closer inspection using our field telescope, the team confirmed that it was indeed Carlito - thanks to the GPS transmitter that was clearly seen strapped on her back.

Finally, after exactly 92 days (3 months and one day) since her release on June 28, Carlito had been finally observed closely and photographed in the wild.  

From 0830 to 0924 hrs, Carlito showed behaviors which suggest that she was feeding well and healthy in the wild forests of Leyte. The team observed her engaging in general maintenance behaviors such as preening (grooming her feathers), rousing (raising her feathers away from her body, shaking her body vigorously and then re-arranging its feathers), sunbathing (intentionally staying under the sun), and, most importantly, defecating or pooping. Popping suggest that she just had a meal. She also raised her crest or head feathers while looking intently at some portions of the forests. All of these are clear signs that she had been hunting successfully over the past three months.

In total, the team utilized four tree platforms as observation posts and logged 1,930 observation minutes over a period of four-days. Remarkably, Carlito was seen for only 54 minutes, or 2.8% of the total observation time, indicating that she is very shy and elusive in the wild. The team will continue monitoring the bird until October 6, 2024.

Philippine Eagle "Carlito" enjoying the morning sun from 0830 to 0924 from perch last Sept 29, 2024.

The following day, on September 30, the team relayed the good news to Mayor Rudin Babante of Mac Arthur who was very happy to learn about the development. He penned and released an official statement congratulating PEF on their admirable feat and showing his and his team’s support to the on-going monitoring and conservation of eagle Carlito within the town’s forests. He also expressed support to a plan to train and engage volunteer forest guards from three barangays around Carlito’s location to help in monitoring and protecting the bird.

“I am very happy and thankful about the current sightings of our national bird, Carlito, a Philippine Eagle….in Mac Arthur, Leyte", wrote Mayor Babante in Filipino in his official message to PEF. “I also want to express my heartfelt thanks to the Philippine Eagle Foundation (PEF) for their tireless efforts to protect our national bird and raise public awareness about the environment. Their close coordination with the Local Government Unit and with the MENRO is very important in giving a safe home for Carlito and other threatened species", said the message that was written in Filipino.

Acknowledgements

We extend our gratitude to the Mohammed bin Zayed Raptor Conservation Fund for the administrative and logistical support during the field expedition. We also thank McArthur Municipal Mayor Rudin T. Babante and MENRO Nhorly Gonzaga Lanza for their unwavering support throughout the expedition. Special thanks to Burauen Mayor Juanito E. Renomeron and MENRO Carla Ferrer for their steadfast support from day one. Our appreciation goes out to our partners at DENR Region VIII, PENRO Palo, CENRO Palo, and the Mahagnao Volcano Natural Park PAMB for providing the necessary consents and assistance for the expedition. We aldo tahnk the Rotary Club of Central Tacloban City for their logistical assistance.

We would also like to thank San Vicente Barangay Captain Joselito Abalos and Cagbana Barangay Captain Rudy Ecija for their valuable assistance to the team. Lastly, we thank the forest guards from Brgy Cagbana, Burauen, who served as field assistants during the expedition: Eddie Pocpoc, Dionie Banag-banag, Jero Roche, and Alven Caluser.