Text by Jayson Ibañez; Illustrations by Cheno de Guzman
Come October of each year, revelers from all over explore the uplands to attend the colorful and vibrant Indigenous festivals. But up in the mountains of Mindanao, some Philippine eagle couples take the crisp blue skies and their spacious nests as staging areas for their seasonal courtship performances.
An integral part of eagle pre-breeding rituals, romantic flights and nest-based courting mark the start of eagle reproduction on the island.
We at the Philippine Eagle Foundation (PEF), a conservation NGO based in Davao City, have documented the breeding and nesting behavior of eagles on Mindanao for years. Research showed that our country's feathered national symbol, like humans, have their romantic side, too.
In order of increasing intimacy, below are the ten courtship moves by our country's top forest predator.
Philippine eagle couple in mutual soaring and dive chase. Illustrated by Cheno de Guzman
1. Mutual soaring
Without flapping their wings, the couple rides the rising columns of hot air (thermals) together. They glide and soar above the nest site until they reach the clouds.
2. Dive chase
With wings folded close to the body, the female eagle drops from great heights and plunges at high speed towards the forest below. Doing a similar dive, the male eagle chases the female.
Talon presentation or grappling of a Philippine eagle couple. Illustrated by Cheno de Guzman
3. Talon presentation or grappling
At the end of a dive chase, the male catches up and extends its legs and talons towards the female. The female then turns its body to face the male in pursuit and stretches its legs and claws towards her mate. In some instances, the birds grab talons in mid-air and spiral down until they lose altitude and release grip.
Male Philippine eagle delivers branches and twigs to the nest. Illustrated by Cheno de Guzman
4. Sprig collection and delivery
The male eagle gathers fresh branches and twigs and flies them to the nest. But apart from re-building the nest, collection and transfer of greeneries in full view of the female is also a strong visual cue of the male's readiness to mate and raise a chick with the female.
Nest building stimulates the female Philippine eagle. Illustrated by Cheno de Guzman
5. Nest building
Depositing and fixing greeneries provides a lining of soft cushion on the nest bowl but seeing the male nest-building also excites the female. If she joins in, it means she is warming up to his sexual advances.
Billing is the Philippine eagle's way of reciprocating intimacy, it is somewhat allegorical to the human act of kissing.
Illustrated by Cheno de Guzman
6. Billing
An apparent display of reciprocal intimacy, the touching of the beaks while on the nest helps renew the pair's romantic bonds.
When eagles clean up or groom themselves, it is called preening. As part of their breeding and courtship, they may sometimes groom their partner Philippine eagle. Illustrated by Cheno de Guzman
7. Allo-preening
The male run his beak along the female's wing feathers several times to groom her, which the female reciprocates.
Philippine eagles ensure that their partner who stays in the nest is always fed. Illustrated by Cheno de Guzman
8. Courtship feeding - the male delivers fresh prey to the female which she consumes. Frequent food transfers allow the female to store the extra fat she would need to burn while sitting on the egg, and the chick once its hatched. But repeated food rations also signals male fitness, and that adequate food will be delivered while the female focuses on her incubation and chick rearing duties.
Philippine eagles emitting mating vocals in chorus. Illustrated by Cheno de Guzman
9. Vocalization
Loud and audible call exchanges that intensify prior to mating (sex-solicitation vocals).
Philippine eagle copulation takes only a few seconds but happens several times in a day. Illustrated by Cheno de Guzman
10. Copulation
Successful rituals eventually lead to the male mounting the female to copulate. Although eagle sex lasts only seconds, it happens several times a day and may occur even after an egg is laid.
Because they do it more than what seems to be necessary to fertilize an egg, experts think the extras is a pleasurable reward to a diligent male. This, in turn, motivates the male to remain loyal to his female and faithfully hunt and deliver food to her while she is confined to the nest.
ABOUT THE CONTRIBUTORS
Dr. Jayson C. Ibañez is currently the Director of Research and Conservation at the Philippine Eagle Foundation.
John Cheno G. de Guzman is a registered architect with a passion for artistic expression, utilizing various mediums like graphite, charcoal, watercolor, acrylic, and digital art to merge architecture with illustration. He has a history of winning awards, including first place at the On-the-spot manual rendering competition during National Architecture Week 2018 and second place at Defining Spaces 2019, showcasing his talent and dedication to illustration. Beyond his architectural work, he enjoys sketching and painting urban scenes, photography, and exploring diverse creative outlets.
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