Vulnerability of megapodes (Megapodiidae, Aves) to climate change and related threats

Abstract

Aspects of species life histories may increase their susceptibility to climate change. Owing to their exclusive reliance on environmental sources of heat for incubation, megapodes may be especially vulnerable. We employed a trait-based vulnerability assessment to weigh their exposure to projected climate variables of increasing temperatures, fluctuating rainfall and sea level rise and their biological sensitivity and capacity to adapt. While all 21 species were predicted to experience at least a 2°C increase in mean annual temperature, 12 to experience a moderate or greater fluctuation in rainfall and 16 to experience rising seas, the most vulnerable megapodes are intrinsically rare and range restricted. Species that employ microbial decomposition for incubation may have an adaptive advantage over those that do not and may be more resilient to climate change. The moderate microclimate necessary for mound incubation, however, may in some areas be threatened by anthropogenic habitat loss exacerbated by warmer and seasonally drier conditions. As with many avian species, little is known about the capacity of megapodes to adapt to a changing climate. We therefore recommend that future research efforts investigate megapode fecundity, gene flow and genetic connectivity at the population level to better determine their adaptive capacity.

Breeding and feeding habitat selection by an island endemic bird may increase its vulnerability to climate change

“…Although Micronesian Scrubfowl are not threatened by direct anthropogenic habitat loss in the RISL, sea level rise may reduce breeding habitat by the end of the current century. The strand forest scrubfowl use for breeding is vulnerable to future scenarios of eustatic rise predicted by the Intergovernmental Panel for Climate Change (IPCC) (Church et al., 2013; Radley et al., 2018). Terrestrial vertebrate species of Oceania may be the most impacted by rising seas and are predicted to lose up to nearly a quarter of their current ranges (Wetzel et al., 2013).…”

“…Endemic landbirds in the tropical Pacific are thought to be the most vulnerable bird species due to their relatively small populations, which are often located on small, isolated islands (Jetz et al., 2007; Taylor & Kumar, 2016; Wetzel et al., 2013). Species‐specific habitat preferences, biology, and geographic range make some groups, such as mound‐nesting scrubfowl, particularly sensitive to climate change (Radley et al., 2018).…”

“…The Micronesian Scrubfowl ( Megapodius laperouse senex ) of Palau is listed as endangered by the International Union for the Conservation of Nature (IUCN) (Birdlife International, 2016) and is threatened by habitat loss due to rising sea levels (Radley et al., 2018). This sub‐species also experiences anthropogenic challenges related to increasing tourism and introduced rats throughout its core range (Radley et al., 2020).…”

“…Species-specific habitat preferences, biology, and geographic range make some groups, such as mound-nesting scrubfowl, particularly sensitive to climate change (Radley et al, 2018).…”

“…While little is known about habitat selection for mound sites by Micronesian Scrubfowl, much less is known about their foraging habitat preferences. This is a common discrepancy in published research on scrubfowl, with little habitat use data originating from locations away from incubation sites (Radley et al, 2018). The data available regarding foraging habitat preference tend to lack detail (e.g., Broome et al, 1984;Göth & Vogel, 2003;Sivakumar & Sankaran, 2012).…”