Agricultural Expansion and Habitat Loss

Since 1700, there has been a six-fold increase in the global extent of agricultural land (Birdlife - Agriculture, 2008). In 1700, only 6% of global land area was being used for agriculture yet in 2011, this figure sat at 37.6% (WorldBank, 2013). The area of land used for agriculture is predicted to rise further as global population increases and with it the demand for commodities such as coffee, soy bean, palm oil and sugar-cane (BirdLife - Crop Expansion, 2013). The expansion of agriculture most often involves the transformation of natural habitats and a loss of biodiversity. In 2008, agriculture contributed to the declines of 87% of threatened bird species on the IUCN Red List.

The pressures of agricultural expansion are felt globally, but let us look at Brazil in more detail. Brazil is home to not only a large portion of the Amazon rainforest, but it is also home to the "forgotten" Cerrado; the worlds most wildlife rich savannah, which covers 21% of the country (WWF - Cerrado). The Cerrado once covered 2 million km², but has since been reduced to 43% of its former size and is being lost at a rate of 1% per year (Birdlife - Cerrado, 2008); if the rate of destruction continues, then the Cerrado is projected to be lost completely by 2030 (Mongabay, 2010).

The Cerrado; the  Brazilian savannah in the height of the summer dry season, which lasts approximately from May to September - image by Christoph Diewald on Flickr.

The Cerrado is extremely important for wildlife (WWF - Cerrado), and is home to over 10,000 species of plant and more than 1600 species of animal; including 935 species of bird. Amongst these animals is the incredibly gorgeous and fluffy Maned Wolf (Chrysocyon brachyurus - Near Threatened), Kaempfer's Woodpecker (Celeus obrieni - Endangered) and the Cone-billed Tanager (Conothraupis mesoleuca - Critically Endangered). New species are still being discovered, with one bird species among the 13 new species found in 2008 (Mongabay, 2010).

The majority of the loss of the Cerrado is due to highly mechanised soya farms (most of much is used for animal feed), but land is also cleared for cattle ranches and other farms. Models have shown that in areas converted into planted pastures, precipitation may be reduced by up to 10% and surface air temperature may increase by 0.5*C (Klink & Machado, 2005). Were all endemic bird species in the Cerrado to go extinct, then Batalha et. al. (2010) predict functional diversity (Tilman, 2001) to decrease by 27%.

Only 7.5% of remaining Cerrado is currently under protection, yet an estimated 20% of threatened animal and plant species live outside of the protected areas (Klink & Machado, 2005). That said, the future of the Cerrado need not be grim. State governments are focusing on creating new protected areas, extending existing protected areas and establishing ecological corridors. There are also NGOs promoting alternative economic activities to support the livelihoods of local communities, such as ecotourism, the sustainable use of fauna and flora products, and the use of plants for medicinal purposes (Klink & Machado, 2005). Sustainable farming may also help to slow down, and possibly eventually reverse, the decline in biodiversity in Brazil.

A male Bobolink (Dolichonyx oryzivorus) by Kelly Colgan Azar on Flickr.

To finish, I will leave you with an example of successful sustainable farming; the story of "bird friendly" Bob-o-Link Coffee. The brand is named after a migratory American blackbird, the Bobolink (Dolichonyx oryzivorus), whose species had experienced a 75% decline (Science for Brazil, 2013) in the last decade due to habitat lost to make way for sugar-cane plantations in the Cerrado. 

One of the reforested Bobolink Coffee plantations;
growing the coffee beans in the shade is said to improve
their taste and quality. 

Bob-o-Link Coffee have restored much of the forest on their 700 acre organic farm, through the planting of trees so that they can grow their coffee beans in the shade. Alongside producing higher quality coffee, this reforestation has restored habitats for the Bobolink and several other animal species (Science for Brazil, 2013). 

Bob-o-link coffee also encourages its farmers to keep beehives on their farms; this not only helps with pollination of the coffee plants, but if more farmers turned to bee-keeping then it might help slow the decline of bee populations in many countries (Bob-o-Link Coffee).