It's not trails that disturb forest birds, but the people on them

November 12, 2018, Frontiers
Credit: Wikipedia.

The first study to disentangle the effect of forest trails from the presence of humans shows the number of birds, as well as bird species, is lower when trails are used on a more regular basis. This is also the case when trails have been used for many years, suggesting that forest birds do not get used to this recreational activity. Published in Frontiers in Ecology and Evolution, the finding suggests the physical presence of trails has less of an impact on forest birds than how frequently these recreational paths are used by people. To minimize the impact on these forest creatures, people should avoid roaming from designated pathways.

"We show that are quite distinctly affected by people and that this avoidance behavior did not disappear even after years of use by humans. This suggests not all habituate to humans and that a long-lasting effect remains," says Dr. Yves Bötsch, lead author of this study, based at the Swiss Ornithological Institute, Sempach, Switzerland and affiliated with Institute of Evolutionary Biology and Environmental Studies, University Zurich, Switzerland. "This is important to show because pressure on natural habitats and nature protection areas is getting stronger and access bans are often ignored."

Many outdoor activities rely on infrastructure, with roads and trails being most common. Previous research has shown that trails cause habitat loss and fragmentation, where larger areas of habitat are dissected into smaller pieces thereby separating wildlife populations. However it has been difficult to say for certain whether it is the presence of trails or humans that have the most impact on forest birds.

Bötsch explains, "Previous studies provide conflicting results about the effects of trails on birds, with some studies showing negative effects while others do not. We thought differences in the intensity of human use may cause this discrepancy, which motivated us to disentangle the effect of trails from the presence of humans."

The researchers visited four forests with a similar habitat, such as the types of trees, but which differed in the levels of recreation. They recorded all birds heard and seen at points near to the trails, as well as within the forest itself, and found that a lower number of birds were recorded in the forests used more frequently by humans. In addition, they noticed certain species were more affected than others.

"Species with a high sensitivity, measured by flight initiation distance (the distance at which a bird exposed to an approaching human flies away), showed stronger trail avoidance, even in rarely frequented forests. These sensitive species were raptors, such as the common buzzard and Eurasian sparrowhawk, as well as pigeons and woodpeckers," says Bötsch.

He continues, "Generally it is assumed that hiking in nature does not harm wildlife. But our study shows even in forests that have been used recreationally for decades, birds have not habituated to people enough to outweigh the negative impact of disturbance."

Bötsch concludes with some advice, which may help to minimize the adverse effects on forest birds by people who use forests recreationally.

"We believe protected areas with forbidden access are necessary and important, and that new trails into remote forest areas should not be promoted. Visitors to existing trails should be encouraged to adhere to a "stay on " rule and refrain from roaming from designated pathways."

Explore further: Improving 'silvopastures' for bird conservation

More information: Frontiers in Ecology and Evolution, DOI: 10.3389/fevo.2018.00175 , https://www.frontiersin.org/articles/10.3389/fevo.2018.00175/full

Related Stories

Improving 'silvopastures' for bird conservation

September 19, 2018

The adoption of "silvopastures"—incorporating trees into pastureland—can provide habitat for forest bird species and improve connectivity in landscapes fragmented by agriculture. But how do silvopastures measure up to ...

Human traffic threatens urban forests

August 28, 2014

A study investigating the affect of recreational trails in endangered urban forests has found that their expansiveness and unmethodical planning is increasing fragmentation and impacting biodiversity.

How can forests regenerate without birds?

April 30, 2018

Human activity continues to shape environmental systems around the world creating novel ecosystems that are increasingly prevalent in what some scientists call the Anthropocene (the age of humans). The island of Guam is well ...

For tropical forest birds, old neighborhoods matter

February 15, 2018

Old, complex tropical forests support a wider diversity of birds than second-growth forests and have irreplaceable value for conservation, according to an Oregon State University-led exhaustive analysis of bird diversity ...

Recommended for you

What happened before the Big Bang?

March 26, 2019

A team of scientists has proposed a powerful new test for inflation, the theory that the universe dramatically expanded in size in a fleeting fraction of a second right after the Big Bang. Their goal is to give insight into ...

Probiotic bacteria evolve inside mice's GI tracts

March 26, 2019

Probiotics—which are living bacteria taken to promote digestive health—can evolve once inside the body and have the potential to become less effective and sometimes even harmful, according to a new study from Washington ...

Cellular microRNA detection with miRacles

March 26, 2019

MicroRNAs (miRNAs) are short noncoding regulatory RNAs that can repress gene expression post-transcriptionally and are therefore increasingly used as biomarkers of disease. Detecting miRNAs can be arduous and expensive as ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.