Selling Noah's Ark? The collapse of Asia's bird biodiversity

From her base in southern China, ALERT member Alice Hughes gives us a perspective on the daunting challenge of the illegal wildlife trade, which seems to have a global epicenter in Asia.

Popular species: spectacular Twelve-Wired Bird of Paradise from Indonesia

Popular species: spectacular Twelve-Wired Bird of Paradise from Indonesia

If you have ever ventured into the forest you will know the whine of insects, and the ringing calls of birds that envelope you as you breathe in the humid air. 

Now, imagine that forest without the calls of the birds or the rustle of vertebrate life.  You are imagining the forests that are fast becoming a reality across much of Asia, under the relentless pressure of hunting for various forms of trade.

Indonesia is one such case.  As a global biodiversity hotspot for birds, it now finds itself a market for their extinction.  A TRAFFIC survey released this week found an incredible 19,000 birds of 206 species for sale -- at just three markets in Jakarta and in just three days.  And only 2 percent of these birds were legally harvested.

Among the birds found in Jakarta markets, 41 species are endemic (unique) to Indonesia.  Further, nine of the species are classed by the IUCN as vulnerable to extinction, four of which are Endangered or Critically Endangered.

The stunning number of birds found in just three days suggests that the annual sale of birds in Indonesia would involve hundreds of millions of individuals, including many globally endangered species.

Birds for sale in a Jakarta market  (Kanitha Krishnasamy/TRAFFIC)

Birds for sale in a Jakarta market (Kanitha Krishnasamy/TRAFFIC)

A Songbird Crisis Summit will be held in Singapore this week to highlight the illegal bird-trade crisis, and to seek strategies to secure a future for birds across the region.

Without rapid action to enforce existing laws and enact new regulations, we will undoubtedly witness the extinction of bird species from across the Asian region.  These forests may no longer ring with the calls of species found nowhere else on Earth.

For wildlife, huge difference between different kinds of agriculture

We live in an increasingly human-dominated world, where once-intact native habitats are being rapidly fragmented into smaller 'islands' surrounded by a hostile 'sea' of human land-uses.  But for wildlife, not all human land-uses are equal.

Bobcats like having trees overhead

Bobcats like having trees overhead

A recent study in southern California shows that the bobcat, an important but shy wildlife species, is affected very differently by different types of farming.

Like most species, bobcats must move to survive.  Animals trapped in small habitat fragments live in populations too small to be viable.  Bobcats are therefore far more likely to survive if human-dominated lands surrounding habitat fragments are 'permeable' to their movements.

One way to make fragmented landscapes more permeable is to create movement corridors linking the fragments together -- what some have called "bandages for wounded landscapes". 

Another way is to use less-hostile types of agriculture that pose less of a barrier to sensitive species.  For bobcats, it turns out that orchards pose considerably less of a barrier to movements than do intensively cultivated row-crops such as maize, soy, and sugar beets.

Bobcats used row crops only rarely, and even then tried to dash through them quickly, evidently feeling highly vulnerable.  However, their movements in orchards were much more relaxed and similar to those in native habitats.

Studies in the tropics have similarly shown that agriculture that retains tree cover is often much more benign for nature. 

In the New World tropics, for instance, birds, bats, and many other species tend to be much more abundant in shade-cacao plantations (used for producing cocoa), where larger trees are retained or grown to shade the cacao trees, than in more intensively used lands. 

Bare-eyed antbird, an understory specialist in New World rainforests

Bare-eyed antbird, an understory specialist in New World rainforests

Wildlife diversity is especially high when native tree species are retained in the shade-cacao plantations, rather than using exotic fruit or timber species.  Another big bonus for wildlife is having native forest nearby the shade-cacao plantation.

However, shade-cacao is not a panacea for tropical species.  The most sensitive wildlife, such as understory birds, rarely use cacao and are mostly restricted to native rainforest.

The bottom line: native habitats are always the best, but when agriculture is unavoidable, not all types of farming are created equal.  Understanding how different farming methods affect wildlife -- and which wildlife species are most vulnerable -- will give us a leg up for managing and conserving nature.


How does forest fragmentation affect birds?

ALERT member Dr Cagan Sekercioglu has just sent us an extremely interesting global meta-analysis of bird responses to habitat fragmentation.  It's a massive study, incorporating data on nearly 3000 bird species from almost 300 sites on five continents.

The paper is coauthored by Cagan as well as Tom Bregman and Joe Tobias, and was just published in Biological Conservation.  You can download it here.

Fragmentation is bad for tropical birds (photo by Susan Laurance).

Fragmentation is bad for tropical birds (photo by Susan Laurance).

Among the study's key findings:

- Fragmentation affects bird communities in tropical forests much more strongly than those in other ecosystems

- Among different types of birds, insect-eating species and large-bodied birds that eat fruit are most vulnerable

- The decline of birds in fragmented habitats can impact a number of important ecosystem functions, especially in the tropics

-Bill Laurance