Trends and missing parts in the study of movement ecology

Abstract

Movement is important to all organisms, and accordingly it is addressed in a huge number of papers in the literature. Of nearly 26,000 papers referring to movement, an estimated 34% focused on movement by measuring it or testing hypotheses about it. This enormous amount of information is difficult to review and highlights the need to assess the collective completeness of movement studies and identify gaps. We surveyed 1,000 randomly selected papers from 496 journals and compared the facets of movement studied with a suggested framework for movement ecology, consisting of internal state (motivation, physiology), motion and navigation capacities, and external factors (both the physical environment and living organisms), and links among these components. Most studies simply measured and described the movement of organisms without reference to ecological or internal factors, and the most frequently studied part of the framework was the link between external factors and motion capacity. Few studies looked at the effects on movement of navigation capacity, or internal state, and those were mainly from vertebrates. For invertebrates and plants most studies were at the population level, whereas more vertebrate studies were conducted at the individual level. Consideration of only population-level averages promulgates neglect of between-individual variation in movement, potentially hindering the study of factors controlling movement. Terminology was found to be inconsistent among taxa and subdisciplines. The gaps identified in coverage of movement studies highlight research areas that should be addressed to fully understand the ecology of movement.dispersal ͉ foraging ͉ migration ͉ navigation ͉ physiology

Non-random gene flow: an underappreciated force in evolution and ecology

“…There are enough empirical studies to make it clear that non-random dispersal happens, and arises from a wide variety of sources. However, we know little of the cognitive, physiological, or genetic basis of non-random dispersal in most species [68]. Neither do we know how widespread non-random dispersal is in nature, its typical effect size, or its evolutionary effects, although there is ample reason to think that they are important.…”

Construction of energy landscapes can clarify the movement and distribution of foraging animals

“…incline, substrate-and vegetation-type) [12] will be responsible for varying movement costs and this variation translates into an effective energy landscape for animals foraging through, or in, it [7]. Ultimately, the costs of moving in particular landscapes should prove important for informing movement ecology [13] and help us understand why and how animals distribute themselves in space [14]. We expect variability in the energy landscape to exert selection pressure on animals to modulate their foraging strategies accordingly although to our knowledge this has not been examined explicitly in an optimal foraging context.…”

When the going gets tough: behavioural type-dependent space use in the sleepy lizard changes as the season dries

“…heat stress). Yet, the factors shaping spatial dynamics in natural systems remain poorly understood, presumably because animal movements result from complex feedbacks between the state and traits of focal individuals and their environment [1,2]. Well-known environmental factors include the local distribution of resources and competitors [3,4], but the effects of consistent behavioural differences among individuals within a population, remain elusive [5,6].…”