Friday, 27 May 2016

Wildfowl demography research - golden goose or lame duck?

Posted by Beth Roberts and Stu

The identification of research biases is vital in order to stem the current rate of biodiversity loss. Such identification will help to focus future research, thereby maximising its impact. In our new paper, just published in PLOS ONE (View paper here), Beth, Ed Harris (MMU), Geoff Hilton (WWT) and Stu investigate the taxonomic and geographic biases in wildfowl demographic research, and devise a simple metric that will help to focus research attention to 'plug the gaps' most effectively.

Identifying the biases

We conducted a systematic review of the published research data. First, we used strict criteria to search through two commonly used databases - Web of Knowledge and Google Scholar - for papers relating to wildfowl demography. Our review involved the screening of over 8,000 papers using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Of those papers, 1,586 met the search criteria. Following the screening, we proceeded to identify, in each paper: which demographic measures were recorded; the subject species; and the country of study.

The majority of demographic information for wildfowl is concentrated on just a handful of species. Best-studied is the Mallard, but Pintail Anas acuta, the second best-studied taxon, is far better looking (Photo: Dick Daniels)

We discovered significant research biases, with North America and Europe dominating the research output; species found in those regions accounted for over 90% of the research outputs. In addition, we found that over half (55%) of the research output concerned just 15 species from seven genera.

Geographical bias in wildfowl demography studies - little research has focused on the tropics.

Further, when we examined the distribution of research outputs across threat categories, we found that threatened species were poorly studied. Our research revealed that there were 21 species with no demographic research output at all, seven of which are globally threatened: the Critically Endangered Pink-headed Duck (Rhodonessa caryophyllacea) and Baer’s Pochard (Aythya baeri); the Endangered Campbell Teal (Anas nesiotis); and the Vulnerable White-headed Steamerduck (Tachyeres leucocephalus), Southern Pintail (Anas eatoni), Philippine Duck (Anas luzonica), and Swan Goose (Anser cygnoides).

Importantly, a task force has now been initiated to gather records and carry out survey work on the Baer’s Pochard. The Philippine Duck Project has also been started to gather abundance and demographic information.

The future for Baer’s Pochard Aythya baeri is bleak indeed (Photo: Graham Clarkson, WWT)

Redressing the imbalance in research 

Our aim was to provide a tool for the conservation community to prioritise and address these research gaps, using measures of research output, threat status and the availability of potentially useful surrogate information from congeneric species. According to the metric, the 25 highest priority species include thirteen threatened taxa and nine species each from Asia and South America, and six from Africa. For example, the Blue-winged Goose is classified as Vulnerable, has a restricted range (being found in the highlands of Ethiopia) and has no conspecific species. Our paper exposes the need to examine research gaps not just in isolation, but in conjunction with threat status.

The Ethiopian highland endemic Blue-winged Goose Cyanochen cyanoptera (Photo: Rod Williams, WWT)