Wildife struggle in an increasingly noisy world

We live on an ever more-populous planet, pulsating with human-generated noises of every description.  As the din of humanity grows ever louder, what will this mean for wildlife?

White-crowned sparrow: stressed-out by noise

White-crowned sparrow: stressed-out by noise

It's an important question.  Across the U.S.A., for example, nearly nine-tenths of the population experiences artificially elevated sound levels.  In the world's oceans, noises from commercial shipping alone have risen an estimated 16-fold in recent decades.

The most ubiquitous noise-making structures humans create are traffic-laden roads, which already crisscross the Earth and are projected to increase in length by some 25 million kilometers by mid-century—enough to encircle the planet more than 600 times.

A recent study by Heidi Ware and colleagues used an innovative ‘phantom road’ to assess how road noise affects migrating bird species.

Working in Idaho, USA, the authors laid out an array of loudspeakers to mimic road sounds, which they turned on and off periodically to judge the birds' responses.  They also captured birds using mist-nets to assess their overall body condition.

The authors found that bird abundance declined by about a third near the phantom road, with some some noise-sensitive species avoiding the area.

In addition, even birds that remained near the phantom road often fared poorly, having lower body weight and worse overall condition than birds captured elsewhere. 

The authors attributed this to the fact that the birds were often startled by sudden road noises -- and so spent more time looking around for predators and less time feeding. 

A graph (sonogram) of road noises, above a logging truck.

A graph (sonogram) of road noises, above a logging truck.

This is particularly bad news for migratory birds, which are already stressed out by the huge exertions of migrating vast distances.  More noise disturbance could mean that more birds will starve to death while trying to migrate.

In an independent perspective piece on this article, ALERT director Bill Laurance emphasizes that the rapidly expanding footprint of roads and other infrastructure across the planet is invisibly degrading habitat quality for noise-sensitive species.

Laurance suggests that many kinds of species could be affected by human-generated noises. 

For instance, might sensitive marine species, such as echolocating whales or migratory fish, avoid noisy regions such as high-volume shipping lanes or areas where naval vessels regularly pierce the oceans with high-intensity sonar?

Could echolocating bats be distressed by roaring airplanes or even by the steady whine of wind farms or other infrastructure? 

For that matter, might even hiking trails frequented by ecotourists or researchers reduce local wildlife activity, as has been observed in protected areas in California and Indonesia?

The oceans are getting noisier too.

The oceans are getting noisier too.

The findings of Ware et al. suggest that human-generated noises can be serious stressors for some wildlife.  This is an alarming prospect in a world ever more beset by human-induced noises.

For instance, nowhere in Costa Rica’s iconic La Selva Biological Reserve can one avoid hearing the incessant thrum of a nearby highway.  Many other nature reserves are suffering a similar fate, underscoring the urgency of limiting new roads in protected areas and devising strategies to limit noise disturbances where roads already exist.

For wildlife and for humans too, quiet places on the Earth are becoming increasingly rare and precious.

Protected areas do far better when governments work to make them succeed

Why do some protected areas do a good job of protecting their biodiversity whereas others struggle to keep the poachers and illegal loggers out?

Protecting biodiversity takes effort -- but it's worth it  (photo by William Laurance)

Protecting biodiversity takes effort -- but it's worth it (photo by William Laurance)

In a new analysis published in Biological Conservation, ALERT members Corey Bradshaw and Bill Laurance, along with colleague Ian Craigie, argue that it largely comes down to national commitment.

When you factor out national-level variables like population size, socioeconomic differences, and the like, one big conclusion jumps out at you. 

Nations that are serious about protecting their protected areas -- and by that we mean they designate most of their reserves into IUCN categories I-IV, which enjoy the greatest legal protections -- their reserves and biodiversity fare a lot better.

In many nations -- China being an obvious example -- few reserves are fully protected.  Rather, the reserves can also support a range of human uses, such as limited hunting, natural-products harvests, logging, and land clearing.  Such reserves fall into the IUCN categories V and VI.   

However, reserves that are nominally fully protected include things like national parks, World Heritage sites, and wildlife preserves, where conservation of nature is the top priority.

In their analysis, Bradshaw and colleagues tried to factor out all the complicating factors that can bedevil such national-level comparisons.  The result was that the "high-protection" nations did a lot better overall than the "lower-protection" nations in terms of maintaining the biological health of their reserves.

The answer is appealing intuitively and makes sense.  The more you invest in protecting nature reserves -- and that means not only defending the reserves but also striving the limit the threatening land-use changes immediately around them -- the better their biodiversity fares.

Conserving nature is often not cheap.  For that reason, nations that make a real commitment to protecting their imperiled reserves and biota should be recognized and heartily applauded.

 

Brazil funds world's biggest reserve network

Conservationists get used to hearing bad news.  But once in a while, there's a big win and really great news.  Today is one of those days.

News worth shouting about...

News worth shouting about...

Brazil has just committed to permanently fund its massive ARPA reserve network--a total of 128 million acres (58 million hectares) of protected areas stretching across the Amazon basin.

ARPA--the Amazon Region Protected Areas program--was originally sustained in part by funding from the World Bank and other overseas donors, but without permanent Brazilian funding it was far from secure. 

ARPA was initiated with a vision to consolidate and interconnect Amazonian protected areas, to create large reserve networks that will hopefully be resilient to future land-use and climate change.

Now, with a permanent commitment to fund the network--with US$215 million this year--the ARPA reserves are guaranteed financial support, theoretically in perpetuity.

The importance of the ARPA network and Amazon rainforest generally--for biodiversity, the global climate, and scores of indigenous cultures--is highlighted in this nice 5-minute video.

The great news about ARPA comes on top of a sharp drop in deforestation in the Brazilian Amazon--which is nearly 80% lower than in the early 2000s.  The ARPA reserves and other protected areas, such as indigenous lands, are clearly partly responsible.

So, break out a bottle of bubbly.  Tomorrow it's back to the battle but today, conservationists can celebrate a huge milestone and well-deserved victory.