The Effects of Humans on animal behaviour

[Sully]

Human disturbance causes widespread disruption of animal movement

Abstract:

Disturbance and habitat modification by humans can alter animal movement, leading to negative impacts on fitness, survival and population viability. However, the ubiquity and nature of these impacts across diverse taxa has not been quantified. We compiled 208 studies on 167 species from terrestrial and aquatic ecosystems across the globe to assess how human disturbance influences animal movement. We show that disturbance by humans has widespread impacts on the movements of birds, mammals, reptiles, amphibians, fish and arthropods. More than two-thirds of 719 cases represented a change in movement of 20% or more, with increases in movement averaging 70% and decreases −37%. Disturbance from human activities, such as recreation and hunting, had stronger impacts on animal movement than habitat modification, such as logging and agriculture. Our results point to a global restructuring of animal movement and emphasize the need to reduce the negative impacts of humans on animal movement.

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Fig. 1 | The global extent and magnitude of the impacts of disturbance on animal movement. a, Study locations, with each point representing an individual case (N = 208 studies and 719 effect sizes). b, Histograms of effect sizes (percentage change in movement in response to disturbance). Bin size is 25%. Five movement distance and six home range effect sizes >500% are not shown. c, Photos of representative taxa included in our database, left to right: sleepy orange butterfly (Eurema nicippe), southern leopard frog (Rana sphenocephala), tawny owl (Strix aluco), red-eared slider turtle (Trachemys scripta), diademed sifaka (Propithecus diadema) and great white shark (Carcharodon carcharias). Photos adapted from Flickr under Creative Commons license CC BY 2.0.

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Fig. 2 | Effects of disturbance on animal movement distances and home range size according to taxonomic groups. Positive effects represent increased movement in response to disturbance, and the opposite for negative effects. Symbols represent posterior means and coloured bands represent 95%, 80% and 50% CIs. Silhouettes adapted from PhyloPic under Creative Commons licenses CC0 1.0 and CC BY 3.0.

*This image is copyright of its original author

Fig. 4 | Effects of different disturbance types on animal movement distances and home range size according to taxonomic groups. Positive effects represent increased movement in response to disturbance, and the opposite for negative effects. Symbols represent posterior means and coloured bands represent 95%, 80% and 50% CIs. The black box encloses the results for mammals. Silhouettes adapted from PhyloPic under Creative Commons licenses CC0 1.0 and CC BY 3.0 Reply