Volume 28 No.1

Spatial ecology of a male and a female leopard cat (Prionailurus bengalensis heaneyi Groves 1997) in Aborlan, Palawan, Philippines

The spatial ecology of Palawan leopard cats (Prionailurus bengalensis heaneyi) was studied using live trapping, radio telemetry, and small mammal trapping from May 2013 to July 2014 in Aborlan, Palawan, Philippines. One adult female and 3 adult male P. b. heaneyi were captured. Radio-collars were attached to one adult male and one adult female individual then released in their respective capture sites. Radio telemetry was conducted for 32 days per season. Non-volant small mammals were captured using box traps and released to determine prey species availability. Results showed that the habitat types utilized by the 2 P. b. heaneyi include: forest (71.09%), mixed brushlands (25.78%), coconut plantations (2.60%), and built-up areas (0.52%). The mean 95% minimum convex polygon (MCP) home range of the male (6.2917 km2) was larger than that of the female (3.9236 km2). An increase in mean home range size from dry season (3.5658 km2) to wet season (4.0611 km2) for both sexes could be related to the decrease in small mammal abundance during wet season. Small mammal species captured in the area included Rattus exulans, Rattus tanezumi, Sundasciurus steerii, Maxomys panglima, and Tupaia palawanensis. When prey availability decreases, leopard cats may be driven to occupy larger ranges in search of food.


Ecological implications of domestic cat ranges on the Calayan rail in the forest sanctuary of Calayan Island, Cagayan, Philippines

Studies show that domestic cats are considered as one of the biggest threats to wildlife. They have been implicated in species decline on islands and on continents, and affect mammals, birds, reptiles, and amphibians. A preliminary assessment of the threats to the Calayan rail (Gallirallus calayanensis) showed that introduced domestic cats have effects on its conservation status from being vulnerable to being extinct. This study aims to determine domestic cat diet and ranges on Calayan Island; confirm if there is an overlap between cat and G. calayanensis habitat range; identify human perceptions on the possible impact of domestic cats on G. calayanensis; and provide basis for future management options. Results showed that cats traveled an average distance of 112.38 m and overlapped with the habitat of the G. calayanensis. Although cats were not perceived to be threats to local wildlife by the respondents, the cats sampled in the study were able to cross buffer areas into the wildlife sanctuary, implying a possible impact on species vulnerable to predation. Calayan Island, because of its size and importance to biodiversity, can be a possible model for island conservation through the control of introduced predators and management of pet ownership.



Conservation milestones of the critically endangered Philippine crocodile (Crocodylus mindorensis Schmidt 1935)

Conservation efforts to save the rarest crocodile species in the world, the Philippine crocodile (Crocodylus mindorensis), were exerted through the years from 1891 to 2016. This study aimed to provide insights for the conservation management of the species by documenting the milestones that could form part of future conservation programs. The review of historical accounts and published scientific articles identified species milestones in a timeline format. Results showed that C. mindorensis became known to science as early as 1891, based on specimens collected from the island of Mindoro (FMNH 11135), and was originally described by Karl Schmidt as Crocodylus mindorensis in 1935. It was later considered as a subspecies of the New Guinea crocodile (Crocodylus novaeguineae mindorensis) until Philip M. Hall provided new evidence for its designation as a totally separate species in 1989. Wild populations severely declined in the early 1940s to 1980s due to human persecution and indiscriminate hunting for skin trade. This triggered distribution studies to locate and estimate the abundance of extant wild populations. Upon the conclusion of these studies in the early 1990s, the International Union for Conservation of Nature (IUCN) declared the species as critically endangered in 1996. Ex-situ conservation breeding program was deemed the only hope for the species in the late 1990s to early 2000s. The successful initiation and continuous development of the collaborative breeding programs have resulted into a restocking of the species to form nucleus populations in its natural habitat from 2009 to 2016. Over the course of 125 years, wild populations have been unearthed and the species was finally released in protected sanctuaries starting in the year 2009.


Odonata communities and habitat characteristics in Mount Kanlaon Natural Park, Negros Island, Philippines

A study on the diversity, abundance, and habitat preference of odonates on different habitat types and altitudinal gradients in Mount Kanlaon Natural Park was conducted from May 18 to June 2, 2015 using line transect, visual searching techniques aided by sweep nets, hand catching, and photo documentation. A total of 72 plots with a size of 10 x 10 m each was established in the study area for habitat assessment. Eleven species, in which 8 are Philippine endemics, were recorded. Highest diversity (H’=2.05) and endemicity (70%) were recorded in secondary lowland forest. Areas with low elevation had the highest species richness (S=10). Furthermore, all species found in high elevation were considered endemic. The Philippine endemic Cyrano unicolor was the most abundant species. Canonical Correspondence Analysis showed that height of understory level seems to influence the abundance of Drepanosticta cf. pistor, canopy cover and elevation might influence the abundance of Heteronaias heterodoxa, and stream depth might affect the abundance of Neurobasis subpicta. Multiple Regression Analysis identified water pH as an important factor influencing the occurrence of C. unicolor while occurrence of Risiocnemis rolandmuelleri might be dependent on tree density.


Review and update of the 2004 National List of Threatened Terrestrial Fauna of the Philippines

In 2004, the Philippines' Department of Environment and Natural Resources issued the National List of Threatened Fauna Species. Between 2015 and 2017, this was reviewed by assessing 1994 taxa, including 57 mammals, 683 birds, 355 reptiles, 115 amphibians, and 784 invertebrates, using the threatened categories specified in the 2001 Wildlife Resources Conservation and Protection Act. Another group evaluated the initial assessment if the criteria were properly applied and the taxa were assigned to their appropriate categories. Fifty-five percent or 1105 species were placed under four threatened categories: Critically Endangered (CR) – 61; Endangered (EN) – 40; Vulnerable (VU) – 439; Other Threatened Species (OTS) – 545. For the first time, invertebrates were included in the assessment and accounted for nearly 70% of species listed. Among the vertebrates, an increase in the number of taxa in all categories was notable and most pronounced in birds in all threatened categories. For reptiles, the number doubled but half of these were under OTS. For amphibians, the increase was due to species classified under CR and OTS. For mammals, the number of threatened species also increased except under VU. The number of threatened endemic species increased to 168 species, representing 15% of all threatened taxa.