Animal Movement Disruptions Threaten Biodiversity

Animal movement changes are the result of human disruption of ecosystems. Discover why these changes pose a threat to species survival and to global biodiversity.

A few years ago, a mother fox moved in under our storage shed at the cottage. She must have done this early in the spring before we started heading up there for the tourist season. 

We didn’t mind. In fact, we enjoyed discretely peeking under the shed to see how the little family was progressing. Our dog, Lucky, however was much too curious.

He didn’t mean any harm, but he started working most of his body into their den entrance and barking at them. It wasn’t long before mama fox, and her kits decided to pack up and find a quieter den somewhere.

Human Activity Affects Animal Movement

That was a straightforward example of how human activity affects animal movement and behaviour. The little space under our shed seemed like a perfect shelter to our motherly vixen until humans started showing up and ruining the neighbourhood.

We’ve known for some time that human activities like logging, urban development and mining are significant causes of species migration and extinction. Now, a new study in the journal Nature Ecology and Evolution shows that isolated events like hunting, war and tourism spark even more profound changes in animal behaviour.

This is the first global study on animal movement ever conducted. A team of researchers from the University of Sydney and Deakin University in Australia pored through 208 previous papers to measure how human activity affected animal movement.

Humans Increased Animal Movement by Over 50%

The papers covered 167 animal species over 39 years. They all provided data on how human activity disturbs animal movement. In one out of every three case studies, humans increased animal movement by over 50%. 

The literature covered all kinds of animals, including birds, mammals, reptiles, amphibians, fish, and insects. The cases covered the movements of animals ranging from the tiny Sleepy Orange Butterfly to the massive Great White Shark.

These changes in animal movement are more than an academic curiosity. Altering where animals live, and travel is a threat to individual species survival and to global biodiversity.

Threat to Species Survival and Global Biodiversity

Wildlife ecologist Dr. Tim Doherty is the lead author of the study. He explained, “It is vital we understand the scale of impact that humans have on other animal species. The consequences of changed animal movement can be profound and lead to reduced animal fitness, lower chances of survival, reduced reproductive rates, genetic isolation and even local extinction.”

The researchers have concluded that animal movement patterns throughout the global biosphere are shifting dramatically. Those movements are being disrupted by humans, damaging animal populations, species and ecosystem processes.

Dr. Doherty explained why the impact of human activity on animal movement matters. “Movement is critical to animal survival, but it can be disrupted by human disturbances. Animals adopt behavioural mechanisms to adjust to human activity, such as by fleeing or avoiding humans, travelling further to find food or mates, or finding new shelter to avoid humans or predators.”

Changes Due To Human Activity Happen Frequently

The research team came up with several broad findings. One was that changes in animal movement because of human activity happen frequently.

Beyond that, irregular activities like hunting, flying planes, army maneuvers and tourism are more significant environmental threats than we realize. They provoke more extensive changes in the distances animals travel than land-use changes like logging or agriculture.

The article cites cases from around the world. For example, in Norway, military manoeuvres caused an average 84% increase in moose’s home ranges. 

Every Continent Showed Similar Effects

Back-country skiers next door in Sweden caused moose to move 33 times faster within an hour of being disturbed. Examples from every continent showed similar effects.

Putting some global figures behind this, episodes like these drive a 35% overall animal movement change. In contrast, ongoing changes to animal habitat only trigger a 12% movement change.

As well, human disruption to the environment is more likely to increase animal movement than reduce it. Overall increases average 70%, while decreases were 37%.

More LIkely to Increase Movement than REduce It

Readers may wonder why the distance travelled would decrease. Reductions result from food availability where people live and from obstacles to animal movement due to habitat destruction or barriers like highways or walls.

Beyond the direct disruption, shifting animal movement also has a multiplier effect on the web of life. Dr. Doherty explains, “As well as the direct impact on animal species, there are knock-on effects. Animal movement is linked to important ecological processes such as pollination, seed dispersal and soil turnover, so disrupted animal movement can have negative impacts throughout ecosystems.”

The researchers pointed to the policy implications of their findings. Their main suggestion is that governments need to acquire and legally protect wild spaces, both on land and in the sea.

Acquire and Legally Protect Wild Spaces

In places where land-use change is unavoidable, planners should look for ways to conserve animal movement patterns using more supportive landscape design and management.

Dr. Doherty wrapped things up, saying, “Further research is needed to better understand the impact of habitat modification on animal movement in rapidly developing parts of the world.”

We always have more to learn if we dare to know.
Learn more:
Human activity forces animals to move 70 percent further to survive
Human disturbance causes widespread disruption of animal movement
Nature Emergency – Time to Make It Official
Biodiversity Always Wins
Biodiversity Targets – Canadians Need Actions Not Words

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