The Philippine Eagle – Keeping it in Flight

In flight Philippine Eagle

Philippine Eagle in flight. Source: Carmelo López

WHO AM I

 

 

 

 

 

The Philippine Eagle (Pithecophaga jefferyi) was discovered on the Philippines island of Samar in 1896 by British naturalist, John Whitehead. Like its name suggests, it is the national bird of the Philippines. This eagle is also affectionately known as ágila (“eagle”) and háribon (from haring ibón, “king bird”) among the locals.

It is a large bird-of-prey, with a long arched bill and strong claws. It stands at a metre tall with a wingspan of two metres and weighs approximately four kilograms. It also has striking blue-grey eyes and dark brown plumage. The most outstanding trait of the species is the crest of feathers around its head formed from elongated nape feathers.

TEST!

Which is the Philippine Eagle?

Golden Eagle 2

 

 

 

 

 

 

Source: (Left) Mike Atkinson (Right) Shane Bechler

Highlight this space to see if this is the one! –> Try again. This is the Golden Eagle (Aquila chrysaetos): Dark brown plumage with yellow to brown iris.

Harpy Eagle 2

Source: (Left) GuruG (Right) Thomas Marent

Highlight this space to see if this is the one! –> Try again. This is the Harpy Eagle (Harpia harpyja): Black and grey plumage with brown to grey iris.

Philippine Eagle 2

Source: (Left) Alain Pascua (Right) Vattaise Malazarte

Highlight this space to see if this is the one! –> You are right! This is the Philippine Eagle (Pithecophaga jefferyi): Dark brown plumage with crest around the head and blue-grey eyes.

Bald Eagle 2

Source: (Left) HDwallpapers (Right) Tony Hisgett

Highlight this space to see if this is the one! –> Try again. This is the Bald Eagle (Haliaeetus leucocephalus): Dark brown plumage on body with white head and yellow iris.

Distribution

P. jefferyi is only found in four out of more than 7,000 islands; Luzon, Samar, Leyte and Mindanao. There are only a few individuals remaining in Leyte and Samar, and the species is believed to have been extirpated in Luzon.


Source: BirdLife International (2014)

Population Size

Depending on the method used, numbers range from the most pessimistic of 40 individuals to 600. Currently, the best estimates, upon which the IUCN criteria is based upon, lists the number of adult birds at 226 and a total of 350 to 670 individuals including juveniles.

Diet

The eagles are apex predators in the habitat they live in, hunting individually or in pairs. Their diet comprises mostly mammals, such as flying lemurs, squirrels and civets (Table 1).

Diet content table

Reproduction

These eagles are monogamous and mate for life. The whole breeding cycle, including courtship through to the independence of the eaglet, takes around two years. Courtship and mating can occur in the air. This aerial display serves to mark their nesting area and to reinforce the relationship between the breeding pair.

Unson J (2013) Mating Philippine eagles sighted in Zambo Norte forest. Accessed 17 Apr. http-::www.philstar.com:.jpeg

Courtship displays of a mating pair. Source: John Unson

Following copulation, only one egg is laid. If the egg fails to hatch, or if the chick dies prematurely, the mating pair will nest again the following year. The eagles display strong parental care, with the mother incubating the egg and the male foraging for food.

Philippine Eagle feeding chick Nigge K (2014) www.art.com:.jpg

Philippine Eagle feeding its young. Source: Nigge Klaus

Lifespan

It lives up to approximately 40 years in the wild.

Vocalization

The call is a long, mellow whistle ending with an upward inflection, phonetically as “w-aū w-aū”.

TEST!

How does the call of the Philippine eagle sound like?

Source: Avian Vocalisation Centre

Highlight this space to see if this is the actual call! –> Try again. This is the call of the African Fish-eagle (Haliaeetus vocifer).

Source: Avian Vocalisation Centre

Highlight this space to see if this is the actual call! –> You are right! This is how a Philippine Eagle sounds like!

Source: Avian Vocalisation Centre

Highlight this space to see if this is the actual call! –> Try again. This is the call of the White-bellied Sea-eagle (Haliaeetus leucogaster).

Source: Avian Vocalisation Centre

Highlight this space to see if this is the actual call! –> Try again. This is the call of the Golden Eagle (Aquila chrysaetos).

Ecology

The eagle lives mainly in the primary and mature secondary dipterocarp forests in hilly areas at altitudes of 300 m to 2,000 m. They demonstrate a preference for forests with dense canopies that conceal nests more effectively. The size of their home ranges can vary from 25 to 100 km².

Current status and threats

 

 

 

 

Status

P. jefferyi has been granted the status of Critically Endangered by IUCN since 1994. This status is based primarily on the extremely small, and rapidly decreasing, population, which faces a very high risk of extinction in the wild. Its low population and reproduction rates, as well as its dependence on large tracts of mature forests, which is increasingly compromised, contribute to the status.Critically endangered.png

Source: Filipeanut (edited)

Main Threats

  1. Rampant hunting of the species for exhibitions and zoo trade, trophy hunting and even food
  2. Habitat destruction and fragmentation through deforestation from logging and agriculture
    • Continued growth in global population increases demand for timber, raising the pressure on the forests of the Philippines
  3. Lack of legislative protection and enforcement
    • Economic and political instability in the area makes attempts at conservation even more arduous.

The limited distribution, in addition to these growing threats, has led to it being considered as one of most endangered raptors in the world.

Reasons for their susceptibility

P. jefferyi has a low reproductive rate and the female only lays one egg every two years, leading to a low recruitment rate. As the parents spend a lot of time at the nest, they become easy targets for hunters. 

Their reliance on the forests for food and nesting also leaves them vulnerable to deforestation effects, which reduces the amount of remaining habitat. Furthermore, their inability to disperse across inhospitable habitats limits them within the forests fragments. 

Current conservation efforts

 

 

 

 

 

An important step towards the conservation of the eagles was in the recognition of its vulnerability at the IUCN Conference in Thailand in 1965. This created the impetus to form the Philippine Eagle Conservation Program (PECP, formerly Monkey-Eating Eagle Conservation Program), and later, the Philippine Eagle Foundation (PEF). The main conservation efforts have centred largely on a few strategies: research, captive-breeding and reintroductions, education, legislation and community-based activities.

Research

Research into the eagle’s life history and ecology is essential in garnering a better understanding, allowing for the formulation of appropriate strategies in the conservation of the species. An example includes the use of radio-telemetry activities to determine the range sizes and mortality rates of the eagles. PEF also paired up with The Peregrine Fund (TPF) to begin a programme–Philippine Eagle Conservation in Mindanao, Philippines–to conserve the remaining eagles’ nesting spots.

Captive-breeding and reintroductions

Research into the lives of the eagles may also aid in breeding among captive birds to maintain the genetic diversity of the species in view of dwindling wild populations. As of 2013, there are a total of 25 captive-bred eagles, the first of which occurred in 1992 when Pag-asa, which means ‘hope’, was born. In 2013, another milestone was achieved when Pag-asa produced a chick of its own, representing the first second-generation captive-bred eagle.

With successful breeding, some individuals were reintroduced into their natural habitats to augment wild populations. This was first achieved in 2004 when the first captive-bred eagle, Kabayan was released into the forests of Mt Apo. As of 2008, there have been three reintroduction events. In an extension to the captive breeding programme, there was also an introduction of an egg-and-chick-removal strategy in which newly laid eggs or hatched eaglets are removed from their nests to induce the parents to lay another egg the following year.

Education

Education is important to increase awareness and knowledge of the people who live in the closest proximity to the eagle. One such effort carried out by PECP was in the making of an educational film, which was broadcasted free-of-charge in Tagalog and English. The documentary chronicled the life of the eagles and results of the screening were thought to have led to a reduction in hunting activities among locals. Public lectures and exhibitions have also been conducted. Active campaigning in schools are also in place.

The sale of merchandise has helped to increase the awareness towards the plight of the eagles as well. These merchandise include stamps, postcards and t-shirts. There are even Transformer toys that can transform into the Philippine Eagle. Educational materials such as posters and pamphlets have also been produced. The simple message is simple: to save the Philippine Eagle from extinction.

Philippine Eagle stamp collage.png

Stamp collection to promote awareness of the Philippine Eagle.

Sources: Gurka.ch; Mountainstamp.com; Alfonso V. Divina; Peter Dickinson; Birdorable; Colnet.com

Coladilla, 2006. transformerph.blogspot.sg.jpg

Toy merchandise to promote awareness of the Philippine Eagle. Source: Azrael Coladilla

Legislation

Many different legislation, which serves to provide more teeth towards the protection of the species, were also implemented. The timeline below lists some of the notable laws that seek to protect the species. Click on the ‘>’ button to see the laws and their description!

Community-based activities

Locals stay in the closest proximities to the eagles and serve the greatest potential to protect the individual eagles. Those who report the presence of the nests as well as ensure the safety of the eagles, especially during the breeding season, have been rewarded. These community collaborations with tribes that stay in areas proximal to crucial eagle habitats in Central Mindanao, such as the Higaonon and Manobos tribes, seek to utilise local knowledge in the protection of the birds. These projects attempt to encourage proper usage of land and rehabilitation of the habitat. There are also plans to construct natural corridors to link isolated forest fragments and facilitate the dispersal of the eagles.

Individuals or corporations can provide for the husbandry and care for the eagles or nests by sponsoring 100,000 Philippine pesos a year, or the equivalent of roughly 2815 Singapore dollars, through the adopt-an-eagle or adopt-a-nest programmes as well.

 

Prognosis for conservation

 

 

 

 

 

Are the efforts working?

Research into the ecology of the eagles have been insightful and will provide better information as technology improves. For example, radio-tagging to detect the range of the eagles has been increasingly accurate. This would aid in the estimation of the number of individuals left in the wild. The tie-ups with commercial organisations would also serve to provide financial support to the cause while increasing exposure of the eagles to the public.

The captive-breeding programme has seen success stories with the birth of 25 captive-bred birds. However, great time and effort is required; it takes fledglings six months before they learn to hunt and an additional year to be adequately self-sufficient. Whether these skills can be imparted to captive-bred birds is another question. Moreover, even if the captive-bred birds are ready for release, they may not survive the threat of accelerating deforestation rates. This is evident from the premature demise of two released eagles–Kabayan, which was accidentally electrocuted, and Kagsabua, which was hunted and consumed. As Assistant Professor Frank E. Rheindt, an avian expert in the National University of Singapore (NUS) mentioned, captive breeding should be ‘the most pessimistic’ method to employ for the eagles as there are low chances of success of reintroductions for large raptors.

Education of locals and students may lead to a huge decrease in hunting rates and heightened awareness. However, the prevention of hunting may not be entirely useful in saving the eagles because even if hunting is totally removed, the eagles may not have a definite chance of survival.

This is the same situation in terms of legislation. Although there have been laws in place to protect the species, it may not be fully helpful to the eagles when the enforcement is found wanting.

Prognosis

In view that the most debilitating threat to the survival of the eagles–deforestation–sees no sign of abating, there may be a real possibility of the species disappearing from the wild very soon. Even if the captive-breeding programme is successful, without meaningful reintroductions, it may mean that the only individuals future generations can observe will be those found in the rescue centres.

Recommendations

The best bet currently may be to focus on the wild population and their habitat. Without a suitable habitat, there would be no real purpose to captive breeding and reintroductions. Hence, conservation of the habitats should be of the highest priority. There has been a plan to construct an Eastern Mindanao Corridor (EMC) to link eleven known eagle regions together. This corridor would prevent inbreeding depression and also facilitate access to patches of land that would otherwise be too isolated for inhabitation. This is critical in view of the poor dispersing ability of the eagles and rampant deforestation.

All these should be done with involvement from the local community so as to increase the ownership of the species. Known eagle habitats have to be preserved and the locals who stay in the closest proximity to the eagles are their ideal protectors. However, this bottom-up approach of community-based actions can only be successful if the conservationists have struck up good rapport with the locals.

How can you help?

Source: Philippine Eagle Foundation

Joining the roster of Philippine Eagle supporters (with a membership fee)

President’s Partners (corporate) P75,000 (≈S$2115)
President’s Associates (corporate) P20,000 (≈S$565)
Protector’s Club P10,000 (≈S$282)
Guardian’s Club P5,000 (≈S$141)
Keeper’s Club P1,000 (≈S$28)
Explorer’s Club P500 (≈S$14)

Adopt an Eagle or a Nest (for their food and husbandry)

Name-an-Eagle P125,000/year for 5 years (≈S$3525)
Adopt-an-Eagle P100,000/year (≈S$2815)
Adopt-a-Nest P100,000/year (≈S$2815)

Volunteer

Save us 3

Source: Draygyn

TEST!

Which four islands can the Philippine Eagles be found in?

Highlight this space for the answer! –> Mindanao, Leyte, Samar, Luzon

What is the main threat to the Philippine Eagle?

Highlight this space for the answer! –> Habitat loss (deforestation)

What is the name of the first captive-bred Philippine Eagle?

Highlight this space for the answer! –> Pag-asa 

Acknowledgements

The writers of this post would like to extend our deepest appreciation to Assistant Professor Frank E. Rheindt for generously sharing his insights. Sincere thanks as well to Dr. Mary R. C. Posa for her guidance.

Lee Wan Jia, Joan A0071838X;  Ng Boon Hong A0072243N

References

Agence France-Presse (2013) Pag-asa, the first captive-bred Philippine eagle, hatches her first offspring. Accessed 17 Apr. http://www.interaksyon.com/

Alvarez, J. B., Jr., 1969. A report on the 1969 status of the Monkey-eating Eagle of the Philippines. Papers and Proceedings of the International Union for the Conservation of Nature and Natural Resources. 11th Technical Meeting, New Delhi, India, 25 –28 November 1969, Vol. II: 68 –73.

Bildstein, K.L., W. Schelsky & J. Zalles, 1998. Conservation status of tropical raptors. Journal of Raptor Research, 32: 3–18.

BirdLife International (2001). Philippine Eagle: Pithecophaga jefferyi. In: Threatened Birds of Asia. Accessed April 14, 2014. http://www.birdlife.org/

BirdLife International (2014) Species factsheet: Pithecophaga jefferyi. Accessed 16 Apr. http/www.birdlife.org

Bueser, G. L. L., K. G. Bueser, D. S. Afan, D. I. Salvador, J. W. Grier, R. S. Kennedy & H. C. Miranda, Jr, 2003. Distribution and nesting density of the Philippine Eagle Pithecophaga jefferyi on Mindanao Island, Philippines: what do we know after 100 years? Ibis, 145: 130–135.

Coladilla, A., 2006. The foldabots and interview with comic creator Jomike Tejido. Accessed 17 Apr. http://transformersph.blogspot.sg/

Collar, N. J., 1996. The Philippine Eagle: one hundred years of solitude. Oriental Bird Club Bulletin, 24: 30–31.

Collar, N. J., 1997a. The Philippine Eagle on its hundredth birthday. Raptor, 24: 29–31.

Collar, N. J., 1997b. Species survival versus perpetuation of myth – the case of the Philippine eagle. Oryx, 31(1): 4–7.

Collar, N. J., Mallari, N. A. D. & Tabaranza, B. R., 1999. Threatened birds of the Philippines. Bookmark, Inc., in conjunction with the Haribon Foundation, Manila, Philippines, 559 pp.

Global Raptor Information Network, 2014. Species account: Philippine Eagle Pithecophaga jefferyi. Accessed 17 Apr. http://www.globalraptors.org

Harder, D. S., R Labao & F. I. Santos, 2006) Saving the Philippine Eagle: How much would it cost and how are Filipinos willing to pay for it? Environment and Economics Center for Studies, Inc., Quexon City, The Philippines. 59 pp.

Ibañez, J. C., H. C. Miranda Jr, G. Balaquit-Ibañez, D. S. Afan, & R. S. Kennedy, 2003. Notes on the breeding behavior of a Philippine eagle pair at Mount Sinaka, Central Mindanao. The Wilson Bulletin, 115(3): 333–336.

IUCN, 2012. IUCN Red List categories and criteria: Version 3.1. Second edition. Gland, Switzerland and Cambridge, UK. 32 pp.

Kennedy, R.S., 1977. Notes on the biology and population status of Monkey-eating Eagle of the Philippines. The Wilson Bulletin, 89: 1–20.

Maala, C. P., 2000. Endangered Philippine wildlife species with special reference to the Philippine eagle (Pithecophaga Jefferyi) and Tamaraw (Bubalus Mindorensis). Journal of International Development and Cooperation, 8(1): 1–17.

Mesina, S. R. & Manipon, A. J. N., 2009. Communities, conservation and the Filipino environmentalist. Philippines Foundation for the Philippine Environment, Quezon City, The Philippines. 241 pp.

Miranda, H. C., Jr, D. I. Salvador, J. Ibañez & G. B. Ibañez, 2000. Summary of Philippine eagle reproductive success, 1978-1998. Journal of Raptor Research, 34: 37–41.

Mohamed bin Zayed Species Conservation Fund, 2014. Strategic action plan 2009-2013. Accessed 17 Apr. http://www.speciesconservation.org/

Philippine Eagle Foundation, 2007. The Philippine Eagle. Accessed 20 Feb. http://www.philippineeagle.org/

Philippine Eagle Foundation, 2008. Strategic action plan 2009 – 2013. Accessed 15 Apr. http://www.speciesconservation.org/

Posa, M. R. C., A. C. Diesmos, N. S. Sodhi & T. M. Brooks, 2008. Hope for threatened tropical biodiversity: Lessons from the Philippines. BioScience, 58(3): 231–240.

Salvador, D. J. I., J. C. Ibañez, 2006. Ecology and conservation of Philippine eagles. Ornithological Science, 5: 171–176.

Seth-Smith, D, 1910. On the Monkey-eating Eagle of the Philippines (Pithecophaga jefferyi). Ibis, 52(2): 285–290.

Tacio, H. D., 2013. A chick at last for ‘Pag-asa’, first Philippine eagle bred in captivity. Accessed 17 Apr. http://www.gmanetwork.com/

The Peregrine Fund, 2014. Philippine Eagle Conservation. Accessed 16 Apr. http://www.peregrinefund.org/

Unson, J., 2013. Mating Philippine eagles sighted in Zambo Norte forest. Accessed 17 Apr. http://www.philstar.com/

 

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