Toward a predictive macrosystems framework for migration ecology

Abstract

Concern about the sustainability of intercontinental‐scale migration systems grows apace with global change. Traditional organism‐centred approaches to this problem have provided insights at the population level, but not at the systems level. We are sceptical that an accumulation of data from a species‐by‐species approach will yield an understanding of these systems in the near term. As an alternative, we advocate a new research programme that grows from an explicitly system‐based framework that leverages existing Earth observation infrastructure to make inferences directly at the macrosystem level. We illustrate how this approach can be used to generate and test system‐level predictions, using NEXRAD radar data as an example. We urge organismal ecologists to recognize that some of the most urgent migration questions are at the macrosystem scale and that tackling these questions requires an interdisciplinary approach if we are to make progress at a pace that exceeds that of climate change.

Generality and Causal Interdependence in Ecology

“…They start from particular, finely specified experimental results and attempt to generalize 'upwards' from them, with the hope of finding patterns across different systems. As before, the level of generality expected from this approach is usually quite constrained, as its scope is limited to variation within particular types of phenomena, such as disturbance (Peters et al 2006), plant-soil feedback (Casper and Castelli 2007) and migration (Kelly and Horton 2016). Occasionally, some ecologists seek to generalise further, by examining whether these patterns can be incorporated into pre-existing unifying theories (e.g.…”

Revealing patterns of nocturnal migration using the European weather radar network

“…Billions of mammals, birds, insects and other animals make seasonal round trips between their breeding and non‐breeding sites each year, with multitudinous effects on populations, communities and ecosystems (Bauer and Hoye , Hu et al ). Seasonal flows of extremely abundant migrants represent an enormous transfer of biomass, nutrients, propagules, pathogens and parasites, with effects on essential ecosystem services, processes, and, ultimately, ecosystem function (Bauer and Hoye ).…”

Mass seasonal bioflows of high-flying insect migrants

“…Such insect movements represent an underappreciated mechanism for redistributing nutrients and energy, and if the densities observed over southern UK are extrapolated to the airspace above all continental landmasses, highaltitude diurnal insect migration represents the most important annual animal movement in terrestrial ecosystems, comparable to the most significant oceanic migrations (21). Given the worrying declines in many migrants (8), developing global surveillance techniques (6) for long-term observation and 7 prediction of the impacts of mass aerial migrations at such macrosystem scales (22) should be a priority for ecologists. …”