Winter is Coming

The scarves and gloves are coming out, the days are getting colder, and the nights are getting longer.  It can only mean one thing! Winter is coming, and it's that time of the year where all the shops start trying to sell us fruit pudding, gaudy knitted sweaters and gift-sets of soap, and every café is playing Christmas songs three weeks too early for my liking. If  hear 'Rudolph the Red-nosed Reindeer' one more time, I might have to scream.

A European Robin, Erithacus rubecula, with it's feathers puffed up for warmth - image by Jean-Daniel Echenard on Flickr.

The only thing I don't mind seeing everywhere (other than cheap chocolates) are the cute little animals that are usually associated with Christmas here in Europe; Deer, Polar Bears and the proud little Robin. The European Robin (Erithacus rubecula), that is; I discovered whilst writing this that the American Robin (Turdus migratorus) is very different in appearance. There are even Australian Robins, with all the species belonging to the genus Petroica.

The American Robin, Turdis migratorus - image by
 KellyColgan Azar on Flickr.

Though the Robin seems to have been tied to the festive season, it's actually a bird you can see all year round in the UK. My parents often have one hopping around below the bushes in the back garden, and during a hike along Dorset's 'Jurassic Coast' in late September, I saw between 6 and 10 single Robins in a 1-hour stretch. We stopped counting after Robin number 5, to be honest...


Robins are cool little guys, though. Like many migratory birds, Robins have an inbuilt magnetic compass in both of their eyes (Hein et al, 2011)(Deutschlander & Muheim, 2010), though not all of the UK's Robins are migratory. Both males and females of the species are also aggressively territorial birds (RSPB, 2011). And some good news, for once! The population levels of Robins are doing well; since 1970, the Robin population has increased by 45% (RSPB, 2011).

The Flame Robin, Petroica phoenica, one of the many
species of Australian Robin - image by Leo on Flickr.

But this isn't to say they've escaped the effects of urbanisation. Anthropogenic noise pollution has been found to alter the singing behaviour of male Robins and causes them to move away from areas with high levels of noise (McLaughlin & Kunc, 2013), or to sing at night (Fuller et al, 2007); an argument to stop playing all those Christmas tunes? Light pollution in urbanised areas has also been show to alter the behaviour of European Robins, causing them to begin singing earlier before sunrise (Kempenaers et al, 2010) (Hasan, 2010).

All that aside; why are the little Robins associated with Christmas?

There are a few theories bouncing around in the internet, but the most common theory is that the association originated in the early to mid 1800s, when postmen were known as 'redbreasts' due to the scarlet uniforms they wore. With more postmen seen around Christmas time, the European Robin Redbreast apparently began appearing upon cards and postage stamps goods as a representation of the postmen (FoHBCP) (YPTE) (Wikipedia, 2013).

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). 

Climate Change 2. - Biological Invasions Seminar Summary

First off, I'm going to apologise for the crazy amount of posts this week. I just wanted to post this whilst everything was still fresh in my mind. Secondly, this isn't 100% related to birds, as you'll see, but I thought it might interest those studying Geog3057.

On Wednesday I attended a small seminar given at UCL by Franck Courchamp, a specialist in population dynamics and conservation biology from Université Paris Sud. The talk was on 'Interactions between Climate Change and Biological Invasions' and here I'm giving a quick summary of what was said.

Myrmica rubra; the European Fire Ant (aka. Common Red Ant) - by Tim Keppens on Flickr.

Biological invasions are the second greatest threat to biodiversity; they also impact upon the economy and society. Will climate change effect biological invasions? Will it make them more, or less, of an issue in the future?

Courchamp's research can be roughly divided into two sections; the effect that climate change will have on invasive ant species, and the effect it will have upon the IUCN's 100 of the World's Worst Invasive Alien Species.

Climate Change and Invasive Ant Species

• Over 200 of the ~1200 described species of ant (family; Formidae) are found outside of their native range. Some of these species can be classed as 'exotic' (i.e. not native, but not invasive). 19 of these species, however, are classed as highly invasive; 5 of them are present of the '100 of the World's Worst-' list.
• Ant invasions have important consequences for biodiversity; they may remove native species and other arthropods. They also effect mammals, birds, and other animals, and can impact seed dispersal and pollination by doing so. They also affect us; Red Imported Fire Ant (Solenopsis invicta) causes a total economic loss of around $1 billion per year, as well as roughly 100 deaths from anaphylaxis (severe allergic reaction).

Using climatic models, will invasive ant species increase their range and 'invasive-ness'?

• Some ants (5 species) will benefit from climate change, and will become more able to invade new regions. Amongst these are the Asian Needle Ant (Pachycondyla chinensis), Singapore Ant (Monomorium destructor) and European Fire Ant (Myrmica rubra).
• HOWEVER, many species are projected to freeze or decrease in their invasiveness (7 decreases and 3 remain 'stable'). 3 of the decreasing species are amongst the 'World's Worst'. 
• So, overall, the general global trend seems to be that future climate change will decrease the invasiveness of ants. 
• But don't start the party just yet! When we look at and compare the regions that these invasions are decreasing and increasing in, we get a more grim picture. Though the global trend in the future is to decrease, two-thirds of species show a strong increase in the world's Biodiversity Hotspots which, though they only cover 2.3% of the Earth's land area, contain high numbers of endemic species. 

Climate Change and the 100 of the World's Worst...
Having looked at invasive ants, Courchamp and his PhD students repeated the models, but this time did so for all of the '100 of the World's Worst-'. Would the results be worse, or better?

•  Aquatic and terrestrial invertebrates, as well as terrestrial plants, amongst others, showed an increase in their invasive range. Europe and South America in particular showed a greater risk of being invaded with future climate change.
• Amphibians and birds, amongst others, showed a decrease in their invasive range with climate change. As with the ants, their was a general global decrease in invasiveness. 
• However, as it had been with ants, the picture was different when Biodiversity Hotpsots were focused upon. With climate change, these hotspots were more likely to be invaded in hue he future, and some are more susceptible than others. Polynesia, for example, is at risk from 35 of the 'World's Worst'. 

In the words of Franck Courchamp, the overall pattern is "a lot of invasions everywhere". Even though some species show a decrease in their distribution, as most are predicated to increase their distribution in the places that are most at risk we can be fairly confident in saying that climate change will not suppress biological invasions. 

Journals referenced in the talk:

• Increase in Quantity and Quality of Suitable Areas for Invasive Species
• Impacts of Climate Change on the Future of Biodiversity
• Will Climate Change Promote Future Invasions?