Characterizing the spatio-temporal threats, conservation hotspots and conservation gaps for the most extinction-prone bird family (Aves: Rallidae)

Abstract

With thousands of vertebrate species now threatened with extinction, there is an urgent need to understand and mitigate the causes of wildlife collapse. Rails (Aves: Rallidae), being the most extinction-prone bird family globally, and with one-third of extant rail species now threatened or near threatened, are an emphatic case in point. Here, we undertook a global synthesis of the temporal and spatial threat patterns for Rallidae and determined conservation priorities and gaps. We found two key pathways in the threat pattern for rails. One follows the same trajectory as extinct rails, where island endemic and flightless rails are most threatened, mainly due to invasive predators. The second, created by the diversification of anthropogenic activities, involves continental rails, threatened mainly by agriculture, natural system modifications, and residential and commercial development. Indonesia, the USA, the United Kingdom, New Zealand and Cuba were the priority countries identified by our framework incorporating species' uniqueness and the level of endangerment, but also among the countries that lack conservation actions the most. Future efforts should predominantly target improvements in ecosystem protection and management, as well as ongoing research and monitoring. Forecasting the impacts of climate change on island endemic rails will be particularly valuable to protect rails.

Threatened and extinct island endemic birds of the world: Distribution, threats and functional diversity

“…We also found that the orders including pigeons, rails, parrots and ducks have suffered disproportionate numbers of island extinctions (see Szabo et al, 2012; see also Lévêque et al, 2021 andSteadman, 2006, for discussions on island rail extinctions). Pigeons and rails are one of the small groups of birds known to be substantially negatively impacted by both introduced species and habitat loss (Owens & Bennett, 2000), which likely partly explains this observation.…”

“…When using all global species as the species pool, our analysis of taxonomic orders found that certain orders of island endemic birds are particularly threatened, such as those including pigeons, crakes and rails, parrots and owls. These orders tend to contain species that possess particular traits that place them at risk of extinction, including flightlessness and large body size, and in the case of parrots, colourful feathers that put them at the risk of collectors (Boyer, 2008; Lévêque et al, 2021; Spatz et al, 2017). Interestingly, the results for Gruiformes (which includes the rails) were non‐significant for Critically Endangered and Endangered species, which could indicate that the most sensitive species have already gone extinct; further evidence for this is provided in Figure 5, which shows that more Gruiformes have gone extinct since 1500 than expected based on our null model.…”

Dot-Winged Crake Porzana Spiloptera (Rallidae; Durnford, 1877) in Chile: New Records and a Review of the Status of Pacific Populations

“…Currently, rails seem to be undergoing con=nuous popula-=on declines, mainly due to invasive predators, natural system modifica=ons (Lévêque et al 2021), or habitat loss (Lehnert 2019). Two decades ago, Taylor & van Perlo (1998) stated that palustrine wetlands, where most rails inhabit, were threatened throughout the world and were disappearing at an alarming rate.…”

What passes through the extinction filter? Historical and contemporary patterns of vulnerability of the most extinction-prone bird family (Aves: Rallidae)

“…Globally, a third of extant rails are currently threatened or near-threatened (47 species). Island endemic rails are the most threatened rails (Lévêque et al, 2021) and have historically been observed in diverse situations of human contact, resulting in either extinction or coexistence. In the context of island rails, it is evident that their interactions with humans have varied substantially over time, offering a compelling lens through which to explore biogeographical patterns and processes.…”