PHILIPPINES BIODIVERSITY CONSERVATION PROGRAMME

 

Conservation of Philippine Sailfin Lizards

Hydrosaurus pustulatus

 

A PROJECT FUNDING PROPOSAL

 

Introduction

The sailfin lizards of the Genus Hydrosaurus are the largest living agamids. They are notable not only for their large size (<1m) and rather spectacular appearance, but also because they are threatened throughout most of their remaining range by habitat destruction and over-hunting for food and the live animal trade – most of which is illegal at point of origin. In addition, the taxonomy of the genus is clearly unsatisfactory at present and is in urgent need of review; not least because this is certain to have important implications for our understanding of the distribution limits and, hence, the likely conservation status and future management needs of the various species and subspecies.

Sailfin lizards are essentially endemic to the Wallacean Region, which includes all of the Philippines except Palawan, though the range of the most widely distributed species, H. amboinensis, extends to New Guinea. Nonetheless, there is disagreement about the number of species, and the presumed or purported distribution of some of these species is inconsistent with expectations based on the biogeography of this region. A total of four species were originally recognised by Barbour (1911), but only three species by Kopstein (1924). Most recent authors, including Watkins-Colwell (1994), who conducted a major cladistic analysis of the genus, have gone further by synonomising H. weberi with H. amboinensis and therefore recognising only two species, i.e. H. pustulatus from the northern Philippines and H. amboinensis from the south Philippines, extending south and east through Sulawesi and associated islands to New Guinea. Even within the Philippines, however, the division between pustulatus and amboinensis remains unclear, or at least unsatisfactory, in that it is inconsistent with the country’s known biogeographic divisions and, hence, the distribution patterns of almost all other Philippine species’ groups. Moreover, few authors have bothered with subspecies, despite some seemingly spectacular variation in the scale patterns and skin colouration between neighbouring populations on different islands.

 

Recent and Current Research Activities

These concerns have been brought into sharper focus in the past two years during which wide ranging field status surveys on various threatened endemic species have been conducted in three of the world’s highest conservation priority areas, namely Southern Luzon and associated islands (including Marinduque, Burias, Catanduanes, Alabat and the Polillo Islands), Mindoro (including Ylin and Ambulong Islands) and key parts of the West Visayas, namely Cebu and large parts of southern Negros. These surveys have produced a great deal of new information on the distribution, habitat requirements, present threats, current conservation and likely future management needs of these animals. They have also resulted in the discovery of at least two, hitherto undescribed populations of sailfin lizards from Cebu and Panay Islands. Both of these populations are not only undoubtedly threatened, but also dramatically different in colouration and other features from each other and from sailfins from the intervening island of Negros and, indeed, those from all other islands seen thus far. Accordingly, it seems highly likely that these are new endemic species or subspecies, which will need to be described as soon as possible. Similarly, the surveys in South Luzon and Mindoro have also yielded data and descriptions of living sailfins that are different from other described populations from Samar. Leyte and Mindanao (J.C.T.Gonzalez, pers. comm.); thereby reinforcing evidence of much higher levels of inter- and intra-population variation than has been generally supposed or can be accounted for by the traditional splitting of the Philippine populations into northern (pustulatus) and southern (amboinensis) forms.

Mindful of these concerns, several leading herpetologists In Europe and USA have recently expressed interest in conducting mtDNA and other taxonomic studies. Unfortunately, little progress has been made so far owing to the absence of study specimens from many areas and the obvious logistic problems, costs and permit restrictions associated with the need to secure specimens of known origin from as many locations as possible. In theory, it is perfectly possible to obtain permits to capture specimens from the wild and/or export live or preserved specimens or parts thereof (including tissues for DNA studies), though this normally requires a new Memorandum of Agreement (MOA) between the relevant research institution/museum and the DENR. However, this may not be necessary if such studies are conducted in collaboration with a Philippine university or museum that already has an Academic Research Agreement (ARA) and no specimens have to exported for outside study. The obvious logistic difficulties and high costs involved in obtaining specimens from diverse locations/islands that are currently unrepresented in museum collections can also be overcome by establishing linkages with researchers in different regions and/or capitalising on opportunities presented by expeditions to target sites that are organised for other reasons (see below).

 

Current and Proposed Conservation Activities

Ironically, the extensive illegal trade in live sailfins has ensured that these animals are well represented in museums and captivity in the Philippines and elsewhere, but almost all of these animals are of unknown or uncertain origin, rendering them effectively useless for comparative taxonomic studies or conservation breeding purposes. However, specimens collected illegally for food or held in small private collections in the provinces are usually locally caught or their precise origins can be traced through local hunters or other suppliers. Thus, specimens of known origin can be acquired on an opportunistic basis over time and maintained alive for captive research, breeding and education purposes. This would also enable limited research funds to be directed towards the accession of specimens from other priority sites/populations that are unlikely to be acquired by these means. Such areas, where few or no museum specimens exist at present, but which are most likely to harbour new endemic taxa, include: Lubang, Romblon/Tablas, Sibuyan, Siquijor, Camiguin, Tawi-tawi and Sibutu Islands. As it happens, most of these areas are also likely to be visited within the next two to three years by experienced herpetologists attached to other projects being conducted under the aegis of the PBCP; thereby drastically reducing the number of locations needed to be visited for the specific purposes of this project.

As several sailfin lizards have been obtained (either donated or confiscated) by the three local rescue and breeding centres in Negros and Panay during the past few years, efforts are now underway to establish local breeding, research and education projects based around these animals. Several live specimens from Cebu have also been offered to project staff working on this island. All of these animals have been released in the absence of suitable facilities for the longer-term studies, captive management and breeding, but others could be obtained if such facilities can be established. Unfortunately, continued habitat attrition, hunting pressure and other, human-induced disturbances have not only reduced sailfin populations, but rendered these animals extremely difficult to study in the wild. Indeed, rather few field biologists can claim to have ever seen a wild sailfin, let alone had the opportunity to conduct studies at close quarters. However, these animals adapt well to captivity and most normal behaviours can be observed if the animals are maintained in spacious and appropriately landscaped and furnished enclosures. Needless to say, this is potentially far easier to achieve locally, than in temperate climates elsewhere.

Current Requirements

To these ends, perhaps the first-ever, purpose-built sailfin enclosure was constructed last year in the Biodiversity Conservation Centre of the Negros Forests and Ecological Foundation (NFEFI-BCC) in Bacolod City, with funding support from Adelaide and Melbourne Zoos.

sailfin enclosure 2000
This enclosure (c. 5 x 3 x 4 m) was specially designed and landscaped to meet the known biological requirements of these animals. It is therefore quite densely planted, but with exposed branches at high levels for basking. Other large branches overhang a pool to enable the animals to perform their usual escape reaction by dropping into water, where they immerse themselves or dash for the nearest bank. Surrounding rockwork and earthen banks provide additional hiding, and potential nesting sites. Particular care was taken to eliminate all mesh and other hazardous surfaces in areas accessible to the animals from the ground (i.e. to prevent snout impact damage) and terrestrial and avian predators (e.g. rats, feral cats, crows, etc.). Ventilation ‘windows’ were also built into the sides of the enclosures to promote air circulation and prevent heat build-up, Strategically positioned public barriers and planted verges help ensure minimal disturbance and intrusion of flight distances, whilst permitting clear observation through a viewing window at one end of the enclosure.

Such close attention to detail, and placing the needs of the animals before any other consideration, is entrenched in the philosophy of the NFEFI, which has long been established as the premier environmental NGO on Negros Island. The NFEFI-BCC is formally registered with the DENR as a ‘Threatened Species Rescue and Breeding Centre’, but it is being planned and developed as a ‘world class’ facility. Its primary objectives are therefore to the establish properly structured, collaborative breeding and research programmes for selected threatened endemic species, and to serve as a ‘centre of excellence’ for public education and promotion of environmental protection. The BCC now constitutes one of the NFEFI’s two major projects, the other being the protection and restoration of the Northern Negros Forest Reserve (c. 14,000 ha). The NNFR is the largest remaining forest block on this island and is therefore of immense local, national and international importance for biodiversity conservation. .

Thanks to a generous donation from ZGAP, a range of new enclosures for the maintenance and breeding of small groups of sailfins from Negros, Cebu, Panay and other selected locations has now been possible.

Range - 151990 Bytes

Interior view - not yet completed

Inswide
The new enclosures incorporate all landscaping and furnishing (environmental enrichment) features included in the first enclosure. However, these are designed as an interconnecting range of enclosures to facilitate the future management of these animals; whilst also providing a marvellous behavioural research and public education resource for their comparative study and display. Nonetheless, public viewing and caretaker/service access are confined to one corner of each enclosure to minimise disturbance to the animals. Smaller, ‘offshow’ enclosures will also be constructed in the rear service area for isolation and rearing purposes.

However, many more facilities and sponsorship assistance is required if the NFEFI-BCC is to realise its aspirations and its potential.

 


For further information about how you can help, contact:
William Oliver of FFI, Richard Perron of QC or Guntram Meier of ZGAP