Aeroconservation for the Fragmented Skies

Abstract

From birds to bacteria, airborne organisms face substantial anthropogenic impacts. The airspace provides essential habitat for thousands of species, some of which spend most of their lives airborne. Despite recent calls to protect the airspace, it continues to be treated as secondary to terrestrial and aquatic habitats in policy and research. Aeroconservation integrates recent advances in aeroecology and habitat connectivity, and recognizes aerial habitats and threats as analogous to their terrestrial and aquatic counterparts. Aerial habitats are poorly represented in the ecological literature and are largely absent from environmental policy, hindering protection of aerial biodiversity. Here, we provide a framework for defining aerial habitats to advance the study of aeroconservation and the protection of the airspace in environmental policy. We illustrate how current habitat definitions explicitly disadvantage aerial species relative to non-aerial species, and review key areas of conflict between aeroconservation and human use of the airspace. Finally, we identify opportunities for research to fill critical knowledge gaps for aeroconservation. For example, aerial habitat fragmentation may impact biodiversity and ecosystem function similarly to terrestrial habitat fragmentation, and we illustrate how this can be investigated by extending existing methods and paradigms from terrestrial conservation biology up into the airspace.

Perspectives and challenges for the use of radar in biological conservation

“…Such reserves could benefit migratory birds and bats moving through geographic and seasonal bottlenecks (Rydell et al 2014, Bayly et al 2017, Panuccio et al 2018, Sherry 2018 or more locally, roosting birds and bats or foraging waterfowl and raptors that use the same airspaces on a recurring basis. Airspace protection does not need to be absolute: dynamic aerial reserves would offer protection at critical points in the season and allow human use at other times (Davy et al 2017). Radar-based detection of high concentrations of flying animals moving through a particular airspace could prove useful for identifying key areas of habitat and assist in delineating future aerial conservation areas.…”

“…Currently, our ability to envision airspace reserves is ahead of our ability to actually identify airspaces that might be critical for species conservation. However, the legal and policy apparatus presumably necessary to establish aerial reserves is still unclear and in need of development (Davy et al 2017). Furthermore, radar data can efficiently highlight key areas for the protection of aerial animals on the ground.…”

“…The 'airspace' in question here primarily concerns the lower parts of the troposphere where an organism's presence indicates use of some airborne resource, from flying insects as food to favourable winds aloft supporting movement (Diehl 2013). It is habitat for incredible numbers of microorganisms, wind dispersed seeds and fungal spores, arthropods, bats, and birds , Womack et al 2010, Drake and Reynolds 2012, Diehl 2013, Davy et al 2017, Reche et al 2018. Hahn et al (2009) calculated, for example, that some 2.1 billion songbirds and near-passerine birds migrate from Europe to Africa in autumn, and recently Dokter et al (2018) estimated from radar data that 4.7 billion passerine-sized birds leave the USA southward in autumn and 3.55 billion birds return northward in spring.…”

National contributions to global ecosystem values

“…Indeed, for bird communities, migrants may consume up to 78% of all energy in northern areas and drive many ecosystem process (Fristoe 2015). Protection targets for breeding grounds and migratory routes (Davy et al 2017) link domestic policies to globally important ecosystem values associated with migratory species. The relative importance of breeding areas for other migratory, aerial species (e.g., bats and insects) are less well understood but likely follow similar patterns of accrual in nations with larger land area.…”

Environmental Stewardship: A Conceptual Review and Analytical Framework

“…The idea of stewardship based on an underlying ethic has been examined extensively in environmental philosophy (Welchman 1999;Fernandes and Guiomar 2016). Take, for example, the classic "A Sand County Almanac" wherein Aldo Leopold argues eloquently for a "land ethic" (Leopold 1966) and similar volumes focused on the marine environment such as "The Sea Around Us" (Carson 1951) and "Values at Sea" (Dallmeyer 2003). These and similar texts suggest that an ethic of care, which is rooted in connections to non-human species, environments or special places, will motivate people to take stewardship actions.…”