The hunt for Philippine Ducks

Posted by Beth Roberts and Carmela Española

Beth has just returned from Philippines where she attended the Wildlife Conservation Society of the Philippines conference, and, together with Carmela Española, started a project looking at distribution, abundance and hopes for the little-studied Philippine Duck.

Conversion of wetlands to agriculture is placing many species under increasing threat of extinction (Photo: Beth Roberts)

The Philippines is among 25 megadiversity hotspots in the world and has been placed within the two ‘hottest of hotspots’ owing to its high levels of endemism (>47% of vertebrates and >76% plants). However, this rich biodiversity do not translate into increased measures of conservation action, and 33% of the country’s 181 endemic birds are threatened, the second highest total of any country. One such species is the threatened Philippine Duck Anas luzonica. My PhD research to date examines the biases in published wildfowl demographic research (see http://stuartmarsden.blogspot.co.uk/2014/01/macro-demography-and-conservation-of_18.html) and highlights the importance of conducting studies in areas with limited knowledge, such as the Philippines.

Philippine Duck Anas luzonica (Photo: Arman Asilo)

To gather vital basic ecological and habitat requirements of the Philippine Duck, I visited the Philippines with funding received from two MMU awards (Careers and Development award and an RKE Conference award). Dr Carmela Española and I visited four wetland habitats, two of which are Ramsar sites. Hunting continues at all sites; however, at the Ramsar sites, prosecutions for Philippine Duck hunting had been made.

Candaba Bird Sanctuary (Photo: Beth Roberts)

We first visited Candaba Marsh, Luzon (categorised as an IBA); an important wetland site for resident waterbirds and migratory species with recorded sightings of Baer’s Pochard Aythya baeri (Critically Endangered) and Streaked Reed-warbler Acrocephalus sorghophilus (Endangered). Candaba Bird Sanctuary, a 100-hectare private property of the former mayor Jerry Pelayo, acts as a wetland fragment in an agricultural landscape and is under threat from agriculture expansion.

Other species, such as Clamorous Reed-warbler Acrocephalus stentoreus

are found in the wetland habitats (Photo: Beth Roberts)

Large numbers of Wandering Whistling-duck Dendrocygna arcuata and Philippine Duck were present, along with many other wetland bird species. We recorded over 300 Philippine Ducks at the site and, whilst interviewing local farmers, we observed a man standing on a water buffalo collecting eggs, possibly Philippine Duck eggs.

Man stood on a carabou collecting birds’ eggs in the marsh (Photo: Beth Roberts)

The ducks were flushed from the disturbance (Photo: Beth Roberts)

We also conducted a site visit to the river mouth at Subic Bay, Luzon, which has historically recorded 400 Philippine Ducks congregating in a large group in the mangroves. We found no ducks, but we gathered valuable nesting and habitat data from local people.

The mangrove area at Subic Bay (Photo: Beth Roberts).

Our third site was Naujan Lake (14,568 ha) in Mindoro, designated a Ramsar site, and the fifth largest lake in the Philippines. The lake supports large numbers of ducks and other waterbirds.. The duck may occur at low densities due to the availability of many suitable wetland habitats or as a consequence of increased hunting pressure from the local people that live next to the lake. 

Naujan Lake, Mindoro Island (Photo: Beth Roberts).

The final site was Las Piñas-Parañaque Critical Habitat and Ecotourism Area (175 ha), a coastal wetland within Metro Manila, and designated a Ramsar site. The area supports large numbers of resident and migratory birds (including the ‘Vulnerable’ Chinese Egret Egretta eulophotes) and is a breeding site for the Philippine Duck. We found 25 Philippine Ducks using the shallow lagoons within the mangrove forest.

The area consists of many small lagoons, with dense vegetation surrounding the pools. Permits are required to visit the area (Photo: Beth Roberts)

 The Asian Waterbird Census (AWC) has been conducted in the Philippines since 1990. Totals of 24,585 Philippine Duck were counted at 71 sites in 2013, 17,491 at 67 sites in 2012, and 20,337 at 65 sites in 2011. One criterion for Ramsar designation is that a wetland site supports 1% of a given bird’s global population. Using this criterion, many more Philippine wetlands should be designated as Ramsar sites. It is critical to: 1) assess the accuracy of the AWC data; 2) determine whether better wetland protection translates into better species protection; 3) conduct surveys at key wetland sites to assess the abundance and habitat use of the Philippine Duck and other wetland bird species; 4) gather information on other threatened species, such as the Vulnerable Sarus Crane Grus antigone and Chinese Egret, the Near Threatened Spot-billed Pelican Pelecanus philippensis, and the Data-Deficient species such as the Brown-banded Rail Lewinia mirifica; and, 5) assess hunting pressure and egg collection rates.

Chinese Egrets (Photo: Drakesketchit)

We plan to raise funds to conduct research on Philippine wetland bird species to provide information on abundance and habitat requirements and evidence to support better protection for important wetland sites throughout the Philippines. We are applying for small research grants and also doing crowdfunding- Please see our campaign at - http://igg.me/p/753968/x/7124691, if you would like to make a private donation.

If you would like to know more about the project please contact – Beth Roberts at b.roberts@mmu.ac.uk. Collaborating on the project are Dr Carmela Española, University of the Philippines, Dr Stuart Marsden, Manchester Metropolitan University and Dr Matt Geary, University of Chester.