Preventing Philippine Eagle hunting: what are we missing?

Ibañez, Jayson C.; Sumaya, Anna Mae T.; Tampos, Giovanne G.; Salvador, Dennis

doi:10.11609/jott.2301.8.13.9505-9511

Cited by 9 publications

(22 citation statements)

References 10 publications

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“…For the Philippine Eagle, GRIN includes nest locations from surveys on Mindanao conducted by the Philippine Eagle Foundation since 1978 to the present (Miranda et al . 2000; Ibañez et al . 2016), in addition to community science data from eBird (Sullivan et al .…”

Section: Methodsmentioning

confidence: 99%

“…We sourced Philippine Eagle occurrences from the Global Raptor Impact Network (GRIN, McClure et al 2021), a data information system for all raptor species. For the Philippine Eagle, GRIN includes nest locations from surveys on Mindanao conducted by the Philippine Eagle Foundation since 1978 to the present (Miranda et al 2000;Ibañez et al 2016), in addition to community science data from eBird (Sullivan et al 2009) and the Global Biodiversity Information Facility (GBIF 2021). Duplicate records and those with no geo-referenced location were removed and all occurrences were merged into a single range-wide database.…”

Section: Species Locationsmentioning

confidence: 99%

“…The Philippine Eagle is endemic to four islands in the Philippine archipelago (Mindanao, Leyte, Samar, and Luzon), sparsely distributed across lowland and montane dipterocarp forests (Salvador & Ibañez 2006). The population has declined drastically over the past 50 years, mainly due to habitat loss through deforestation (Kennedy 1977;Lewis 1986;Bueser et al 2003;Panopio et al 2021) and persecution (Salvador & Ibañez 2006;Ibañez et al 2016). Thus, the Philippine Eagle fulfils all three components of rarity, and along with its large body size and forest dependency would be associated with a higher risk of extinction (Kittelberger et al Most Philippine Eagle research has been conducted on the island of Mindanao (Miranda et al 2000;Bueser et al 2003), and thus occurrence data are biased towards this island.…”

Section: Introductionmentioning

confidence: 99%

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Priority conservation areas and a global population estimate for the Critically Endangered Philippine Eagle derived from modelled range metrics using remote sensing habitat characteristics

Sutton

Ibañez

Salvador³

et al. 2021

Preprint

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Many range-restricted taxa are currently experiencing severe population declines yet lack fundamental biological information regarding distribution and population size. Establishing baseline estimates for both these key biological parameters is however critical for directing long-term monitoring and conservation planning for at-risk range-restricted species. The International Union for the Conservation of Nature (IUCN) Red List uses three spatial range metrics that define species distributions and inform extinction risk assessments: extent of occurrence (EOO), area of occupancy (AOO) and area of habitat (AOH). However, calculating all three metrics using standard IUCN approaches relies on a geographically representative sample of locations, which for rare species is often spatially biased. Here, we apply model-based interpolation using an ensemble Species Distribution Model (SDM), correlating occurrences with remote-sensing derived environmental covariates, to calculate IUCN range metrics and a global population estimate for the Critically Endangered Philippine Eagle (Pithecophaga jefferyi). Our ensemble-averaged SDM had high predictive accuracy and was able to identify key areas of Philippine Eagle habitat across the species global range. We estimated an AOH = 49,426 km2 and from this metric calculated a maximum EOO = 609,697 km2 and a minimum EOO = 273,794 km2, with an AOO = 54,695 occupied cells. Based on inferred habitat from the AOH metric and territorial habitat area from home range estimates, we provide an updated global population estimate of 677 breeding pairs (range: 549-772 pairs), or 1354 mature individuals, across the entire Philippine Eagle range. We demonstrate that even when occurrence sampling is geographically biased, robust habitat models can be built which enable quantification of IUCN range metrics and a baseline population size estimate. In the absence of adequate location data for many rare and threatened taxa, our method is a promising spatial modelling tool with widespread applications, in particular for island endemics facing high extinction risk.

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Section: Methodsmentioning

confidence: 99%

Section: Species Locationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Priority conservation areas and a global population estimate for the Critically Endangered Philippine Eagle derived from modelled range metrics using remote sensing habitat characteristics

Sutton

Ibañez

Salvador³

et al. 2021

Preprint

Self Cite

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“…This was confirmed to be licensed under the terms of the cc-by-sa-2.0. Tagged as the "Haribon" or bird king, the Philippine Eagle is among the rarest and most powerful birds in the world whose species is endemic only to four islands of the Philippine archipelago, namely Luzon, Samar, Leyte, and Mindanao [51]. It is commonly known as the Monkey-Eating Eagle, but it can also prey on other vertebrates apart from monkeys, including mammals, reptiles, and other birds [52].…”

Section: Philippine Eagle (Pithecophaga Jefferyi)mentioning

confidence: 99%

Philippine Eagle Optimization Algorithm

2022

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We propose the Philippine Eagle Optimization Algorithm (PEOA), which is a meta-heuristic and population-based search algorithm inspired by the territorial hunting behavior of the Philippine Eagle. From an initial random population of eagles in a given search space, the best eagle is selected and undergoes a local food search using the interior point method as its means of exploitation. The population is then divided into three subpopulations, and each subpopulation is assigned an operator which aids in the exploration. Once the respective operators are applied, the new eagles with improved function values replace the older ones. The best eagle of the population is then updated and conducts a local food search again. These steps are done iteratively, and the food searched by the final best eagle is the optimal solution of the search space. PEOA is tested on 20 optimization test functions with different modality, separability, and dimension properties. The performance of PEOA is compared to 13 other optimization algorithms. To further validate the effectiveness of PEOA, it is also applied to image reconstruction in electrical impedance tomography and parameter identification in a neutral delay differential equation model. Numerical results show that PEOA can obtain accurate solutions to various functions and problems. PEOA proves to be the most computationally inexpensive algorithm relative to the others examined, while also helping promote the critically endangered Philippine Eagle.

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“…Extensive deforestation also reduced space for the Philippine Eagle's prey base (Kennedy 1985, Concepcion et al 2006) and has increased opportunities for human persecution. Although the Philippine Eagle receives legislative protection (Salvador and Ibanez 2006), its current estimated population decline remains at 2 -10% per year (Ibañez et al 2016).…”

Section: Priority Speciesmentioning

confidence: 99%

Movement Ecology of Philippine Birds of Prey

Concepcion¹

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Movement ecology is an emerging paradigm important to conservation biology and to the protection of global biodiversity. I used two common, but poorly known Philippine birds of prey as study tools in understanding movement ecology. One species is the migratory grey-faced buzzard (Butastur indicus), a raptor that which visits the islands in large numbers in winter. The other is the resident Philippine serpent eagle (Spilornis holospilus) which lives there at relatively high population density year-round. I used migration data at two terrestrial hawkwatch sites to assess how weather correlates influenced the movement behaviors of grey-faced buzzards. The grey-faced buzzard was the second most common raptor migrant using the Philippines as part of their migration route. My models show that they are more likely observed, either initiating or completing over-water crossings, in headwinds. I also created spatial models to understand how grey-faced buzzards overcome movement barriers (i.e. ocean). Modeled buzzard routes across the Philippines were between 1,582 and 2,970 km, and all repeatedly crossed water. Some of the routes overlapped at long and unavoidable over-water crossings. My models suggest that the optimal strategy for these birds is to find the shortest route to an exit point with the greatest possible access to stopover habitats and fewest over-water crossings under wind resistance. Additionally, I used road survey data to determine habitat associations of Philippine serpent eagle abundance across central and eastern Mindanao. My model showed that detection probability for the Philippine serpent eagle is relatively low, and the probability of occupancy was highest in near-pristine forests, especially low elevation dipterocarp forests. My road surveys helped establish the beginning of the breeding season for the Philippine serpent eagle. They also provided initial information on wintering habitats for grey-faced buzzards. This work is cutting-edge ecology and also provided natural history information about species for which there is almost no existing knowledge. vi Special thanks to Adam Duerr for all the help with setting up and interpreting some of my models. To my amazing field family, Pat Dumandan, Tracy Prado, Marvin Tancio, Perfecto Balicao, and Emiliano "Blacky" Lumiston. I am proud to call you my friends. You made the mud fun again. We should make all efforts to avoid the puddles. To all the communities who gave me a home, you are my people. You have all enriched my life with your generosity, support and love. I am grateful to my parents, Nap and Beng, who encouraged me to find my passion, whatever it may be. You cheered for your only daughter as she climbed mountains, lived in the middle of the forest, and even as she developed all sorts of allergies. You are my rock and inspiration. My brothers, Butch and Lance, are weird, but I love them. Thankfully, their wives, Jen and CJ, make them better. Lance gets half a bonus point for having fathered my adorable niece, Carra Isabelle. I thank my lola (gran...

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Preventing Philippine Eagle hunting: what are we missing?

Cited by 9 publications

References 10 publications

Priority conservation areas and a global population estimate for the Critically Endangered Philippine Eagle derived from modelled range metrics using remote sensing habitat characteristics

Priority conservation areas and a global population estimate for the Critically Endangered Philippine Eagle derived from modelled range metrics using remote sensing habitat characteristics

Philippine Eagle Optimization Algorithm

Movement Ecology of Philippine Birds of Prey

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