A Green Energy Dilemma?

The demand for energy has increased by 3.6% in the past 30 years (Saidur et al, 2011). Renewable energy sources are consistently proposed as ways of meeting this demand whilst reducing our CO2 output, thus slowing down our contribution to climate change, and also of halting our unsustainable use of fossils fuels. All renewable energy sources have their critics, though, and Wind Turbines often generate protest when someone proposes constructing a wind farm.

There's the NIMBY (Not In My Back Yard) groups who claim they're a blot on the landscape, and there is large concern that homes near wind-farms lose up to a third of their value (Express & Echo, 2013). It is no surprise that recent plans to construct turbines in Ireland (Telegraph, 2014), Wales (WalesOnline, 2013) and Scotland (BBC, 2013) have been opposed. Personally I find wind-farms a pleasant site, though that might have something to do with having grown up in the industrial north with Teesside power-station, the former ICI (now Syngenta) chemical works, and the Hartlepool nuclear power-station sandwiching my home-town. If they're being built out at sea, there are still groups who claim they're aesthetically unappealing, and then there's the issue of cloud formation behind the turbines, that may reduce visibility and pose threats to sea-faring vessels (Emeis, 2010).

My focus upon both onshore and offshore wind-farms, however, will be the apparent threats they pose to bats and birds. Are the number of fatalities of flying animals really as high some groups make them out to be? And do wind-farms result in more or less deaths than other methods of energy production?

Saidur et al (2011) proclaim that wind energy "is the energy source that is most compatible with animals and human beings in the world". Though bird mortality does occur, wind turbines have been demonstrated to kill fewer birds (~20 times) than fossil fuels, and many more times less than human activities. Amongst anthropogenic causes, building windows largest cause of bird mortality with 97-976 million deaths a year. Pesticide poisoning causes a further 72 million deaths, direct hunting more than >100 million deaths, and collisions with cars and trucks around 50-100 million fatalities. (Sovacool, 2013)

A recent study by Sovacool (2013) estimated that whilst fossil fuel power stations are responsible for roughly 5.2 deaths per gigawatt-hour (Gwh) of electricity, wind farms and nuclear power stations only account for between 0.3 and 0.4 fatalities. In the USA alone, this estimate means that an estimated 20,000 birds have been killed by wind farms in 2009, but over 14 million by fossil fuel power plants.

The number of avian deaths per year in 2009 in the United States - from (Sovacool, 2013).

There are direct and indirect ways in which electrical generation can impact upon birds and other wildlife. Wind farms pose threats during their construction, and the construction of associated infrastructure; large areas of land, roughly 2.5 acres per turbine, are also required (Katz, 2010). Fossil fuel stations post the same threats, and even more. Emissions such as mercury, which is especially a threat to water birds, may lead to fatalities. Acid rain pollution is another threat, causing an estimated 0.5 deaths per GWh, and climate change as a result of CO2 equates to around 4.98 deaths per GWh.

The number of bird and bat collisions with turbines has been show to correlate with weather conditions, with poor weather leading to a greater number of fatalities (Saidur et al, 2011)(Sovacool, 2013). Poor visibility, rain and high winds may lead to birds flying at lower altitudes, becoming disorientated, and birds may become attracted to lights around the wind farms, thus increasing the chances of collision. (Saidur et al, 2011). Older turbines also pose a greater risk as turbines are often spaced more closely and have blades rotating at higher speeds. The lattice-shaped towers of older turbines may also attract nesting birds (Saidur et al, 2011).

Though collision is an issue, the greatest risks to bats appears to be the rapid reduction of air pressure around wind turbines, which leads to fatal barotrauma; the rupturing and internal haemorrhaging of bats' lungs. Barotrauma is not an issue for birds, as their lungs are more adapted to sudden changes in pressure (Sovacool, 2013).

Overall, it is undeniable that Wind Farms pose a threat to birds and other avian animals, but the threats are much less than those of Fossil Fuel plants. I think it important that instead of fighting against protests against wind power, that we instead focus upon ways to reduce the risk to birds and bats, and ways to decrease their offensiveness towards people.

Wind turbines on the Isle of Lewis, Scotland - image by Lews Castle UHI on Flickr.

Minimising motion smear, the blurring of the tips of the turbine blades because of their high speed, has been proposed by Hodos et al (2001) as a way to reduce avian collisions with turbines. They suggest that patterning the blades of the turbines will help birds see turbines more clearly.

Active damping systems may help neutralise the low buzzing noise that wind turbines give off, thus allowing them to be operated at a full load whilst not disturbing local residents (Alternative Energy, 2008). An alternative to building traditional turbines may be instead to use existing infrastructure for wind turbines, such as placing them inside of electricity pylons. By locating the turbines in or on existing structures, complaints that they are an eyesore may be reduced (Alternative Energy, 2009). In China, street lights have been erected in PingQuan with small wind turbines (and two solar panels) atop each structure (Urban Green Energy, 2012); small scale projects like this may be useful for powering local infrastructure, thus reducing the amount of energy required from other sources.

Merry Christmas, and a Happy New Year!

[image source]

Climate Change 2. - Where are the sandeels?

Over the summer I spent two weeks as a residential volunteer on the RSPB reserve at South Stack, Holyhead. During that time, I lost count of how many times I was asked 'Where are the puffins?'. Only once, however, was I asked 'Where are all the sandeels, then?'.

Until mid-to-late July, South Stack cliffs host to around 10,000 breeding birds; mostly guillemots, but approximately 1,500 razorbills too, along with a handful of other birds such as puffins, kittiwakes and fulmar.

Who are you calling a penguin?! Razorbills (Alca torda) on South Stack Cliffs. The guillemots and razorbills spend their lives at sea, and only venture onto land to breed. 

A large part of the diet of these seabirds during the breeding consists of sandeels; several species of slim, eel-like fish that occur in shoals that are important in linking together many trophic levels of the marine ecosystem. The primary species fed upon by bird colonies in the North Sea are the adult lesser sandeels (Ammodytes marinus) which, like all sandeels, burrow into soft sandy substrates with which they are closely associated. Their distribution is therefore restricted to areas in which such substrates are found, and as a result these fish are unable expand their ranges into deeper waters to deal with the threats they may face (Scottish Gov, 2010).

A reduction in the sandeels available with not only effect species of seabirds -Kittiwakes in particular-, but also marine mammals such as harbour porpoises (MacLeod et al, 2007) and up to 10 species of predatory fish (van Deurs et al, 2009). Sadly, sandeel populations have been declining in number, and this in turn has been linked to a reduction in sea-bird populations which struggle to feed themselves and their young. Between 1986 and 2011, the number of seabirds breeding around Scotland decreased by 53%, and the decline is believed to be due to a drop in sandeel availability (Herald Scotland, 2012).

So, where are all the sandeels going?

The population decline of the sandeels has been linked to two anthropogenic causes:

• Climate change, resulting in a warming of the UK coastal waters since 1980 of up 1°C per decade (Wanless et al, 2010).
•  Over-fishing for commercial purposes, such as for fish-meal feed and fertiliser.

Sandeel population decline has been correlated with rising sea temperatures by several authors (Wanless et al, 2010) (Heath et al. 2012). As the seas warm, the cold-water zooplankton that the sandeels feed upon are replaced by less nutritious warm-water varieties (Wanless et al, 2010). Though the cold-water species are still found in cooler, deeper waters, the habitat restriction of the sandeels means they cannot follow the cold-water zooplankton as they migrate (Heath et al. 2012). As a result, the sandeel populations experience a decline.

Rising sea levels are also thought to be posing a threat to the sandeels, though overall the effects of anthropogenic climate change on Ammodytes is not fully understood, and research is still ongoing as a result.

Whilst over-fishing is not thought to be the primary cause of sandeel decline, it makes it harder for the climate-hit sandeels to fight back. In turn, this affects seabirds; Sandeel exploitation has been linked to declining kittiwake colonies near to fishing grounds.

Plans were announced in November 2012 to halt the decline in seabird numbers (Scottish Seabird Centre). One of these plans involved the inclusion of sandeel habitats in the Scottish Government's Marine Scotland agency's network of Marine Protected Areas where there are imposed fishing limits. It is hoped that these fishing limits will halt the decline in sandeel numbers, which in turn is anticipated to stem the decline in seabird populations.

The Orange-bellied Parrot - Colourful but Endanged Aussies

Before starting up this blog I had no idea that so many parrot species (well, just birds in general) were classed as Endangered or Critically Endangered. Partly it's because I never knew there were so many different species out there, and partly because -in the case of parrots- you can walk into pet shops and see them lined up in cages. I used to assume that if they were being sold to the general public, they were clearly in abundance in the wild.

How wrong I was; of the popular cage bird species, several are classified as 'threatened' on the latest IUCN Red List. Amongst those that are Vulnerable is the African Grey Parrot (Psittacus erithacus), and several others are classed as Endangered, amongst them being the Hyacinth Macaw (Anodorhynchus hyacinthinus) and the Red-fronted Macaw (Ara rubrogenys).

The Orange-bellied Parrot (Neophema chrysogaster) (BirdLife, 2013) is an example of a Critically Endangered parrot, but as far as I'm aware these little guys aren't available as pets. It could argued that such a thing is as good as it is bad; a lack of demand for the pet trade means that nest poaching is much less likely, but it also means that there are few people breeding these birds in captivity. The gem coloured birds are incredibly rare; found in Southern Australia and Tasmania, their population in the wild estimated to be lower than 50 individuals, with a decreasing trend. Between 2000 and 2008, there was an observed 12% decline in the number of adult birds at breeding grounds. This is thought to be due a lack of female parrots attempting to breed, which in turn results in a decline in the recruitment of juveniles to the species' population (Holdsworth et al, 2011).

The Critically Endangered Orange-bellied Parrot (Neophema chrysogaster) - image by Ron Knight on Flickr.

A number of factors are believed to be behind the declining population, and the majority of these are anthropogenic. Agriculture and urbanisation, along with industrial developments, fragment and degrade the important overwintering habitats of Southern Australia. Salt-marsh habitat degradation is also classified as a large threat, and worries have been voiced that proposed mining in Tasmania at Melaleuca could significantly damage breeding grounds. Looking at invasive species, various introduced seed-eating finches compete with the parrots for available winter food, and common starlings (Sturnus vulgaris) take-over nesting sites previously used by the parrots.

Random events also impact upon the species' population, though some of these events may become less random in years to come. Death from storms during migration may rise if storm frequency and intensity increases with future climate change. Disease is another danger, especially when the population is so small. Between 2005 and 2006, 40 birds bred in captivity died due to a suspected viral disease. The population was quarantined to prevent any disease spreading to the wild population, but things may not be as lucky in future. Other threats proposed by BirdLife Australia (2012) include the risk of predation by cats and foxes, inbreeding, deaths from collisions with structures such as wind turbines, and threats from noxious weeds.

It all paints a pretty grim picture for the Orange-bellied Parrot, doesn't it? Nonetheless, things may be looking up for these Aussies!

A breeding programme has been in place since 1986, which aims to increase numbers in the wild by releasing birds bred in captivity into the wild (Tasmania Parks & Wildlife Service, 2013). In 2006, $3.2 million was committed to help expand and protect the population and habitat of the parrots. The conservation attempt encompasses many things, including enhancing the captive breeding program in place, conservation of the breeding and nesting habitat in Tasmania, expansion and protection of the winter nesting grounds in Australia, and control of predators in breeding, migratory and wintering habitats (BirdLife Australia, 2012).

21 young birds were taken from nests in 2011, from where they were transferred into a captive 'insurance population' that currently numbers over 200 individuals. To boost the numbers in the wild, 23 members of this population were released this year. It's hoped that these newly released birds will integrate into the wild population and breed in the following years, thus reserving the population decline (Stephen Garnett, 2013). Hopefully this means we'll be seeing some good news regarding orange-bellied parrot in the next few years to come!

Bird Friendly Tuna?

Many albatross and petrel deaths attributed to pelagic long-line fishing for tuna and similar species in the southern hemisphere. In a study of seabird deaths due to pelagic longline fishing in the southern Atlantic Ocean between 2004 and 2008, Yeh et al. (2012) estimated that between 3446 and 6083 birds were killed per year. These deaths lead to many breeding-site populations reducing in number (Roberston et al, 2013).

A shoal of Skipjack Tuna (Katsuwonas pelamis) - image
from Wikipedia Commons.

There are ways to reduce mortality, such as setting lines at night, but this method -and several others- may mean that industries are unable to set their lines at times that optimise catch rates.

Robertson et al. (2013) suggest that focusing on branch-line weighting may be a way of reducing mortality rates of seabirds in the Australian fishing industry. Weights are not a new innovation in longline fishing, but Robertson et al. (2013) carried out experiments that differed from previous weighting methods. In their tests, weights were positioned differently upon the lines; in the first test, a 120g weight was placed ≤ 2m from the hook, and in the second test a 40g weight was placed directly at the hook. The purpose weighting the lines is to reduce time it takes for the hook and its bait to sink, thus reducing risks to seabirds by reducing the exposure of bait at the surface where birds may become caught.

Concern is often expressed that weights reduce catch, but Robertson et al. (2013) found no reduction in catch rates of Yellow-fin tuna; rather, catch rate correlated with bait type. For the other species caught, neither weighting or bait type seemed to have an effect on catch rates.

Though the heaver weighting method had faster sink rates, the authors acknowledged the implications of the extra weight in the gear bins. For this reason, they suggest using the lighter weighting method. They also indicate concerns for the loss of lead weights through shark bite-offs. Though not so much an economic problem, there is some concern that lead weights will become deposited on the seabed, or that they could be swallowed by sharks which may be later caught for human consumption. A way round this dilemma would be the replacement of lead with another substance.

Robertson et al. (2013) also state that loss from bite-offs may be minimised by placing weights on shorter leads; having the weights nearer hook is also safer for members of the fishing crew, as their experiments show such placement to reduce 'fly back' of the weights when hooks are bitten off. Other benefits they raise are reduced labour times for fishing crews due to less tangling and less like breakage (and therefore less repairs) of lines, as well easier line deployment.

New weighting regimes therefore seem like a win-win situation for both seabirds and the fishing industry. I just don't think the tuna will be all that happy...

To Plant, or Not to Plant? - A Reforestation and Afforestation Dilemma?

There's a great post covering deforestation over at Harmonising Humans & Nature, so I won't bore you with the facts. There's no way we can deny that deforestation is unsustainable and having a vastly negative impact upon the Earth's ecosystems; 70% of the worlds land organisms live in forests, yet deforestation destroys the habitats of these plants and animals (National Geographic). With all this said, it seems that right thing to do would be to stop cutting down the trees and re-plant them; either where they once stood, or elsewhere.

Sadly, things are never as straight forward. Planting trees or letting natural succession take place until areas once wooded long ago are reforested may, in some areas, impact negatively on biodiversity. Planting forests where there were once no forests (afforestation), to replace those lost elsewhere, can also have detrimental effects - often more so than reforestation.

We humans have been shaping and leaving our footprints upon this planet for tens of thousands of years, and animals have partly evolved to coexist with us. Landscapes have been anthropogenically modified in Western Europe, through deforestation and agriculture, for at least 4000 years; in Asia this modification is likely to have been going on for even longer (Anson Mackay, 2013). This causes a dilemma, as though many argue for returning habitats to their 'pre-human' state, the animals now living in these 'new' habitats may have adapted to them, or may not be the original organisms that previously lived in the area.

 Rannoch Moor, Scotland; A natural peat-land, though many bogs are present due to human modification and management of the landscape in the northern hemisphere  - image by Martin Sojka on Flickr.

Reforestation and afforestation are generally beneficial; both can increase biodiversity, have economic benefits (such as providing timber), can reduce soil erosion and run-off, and reforestation can help restore natural habitats (Reino et al, 2010). However, both may also have negative impacts on plant and animal species that have adapted to a woodland-free environment. 

After the abandonment of traditional mountain agriculture in many regions, natural reforestation can lead to a loss of open spaces which has been linked to a decline in grassland plant species that are vulnerable to landscape fragmentation (Sitzia et al, 2010). Though reforestation is beneficial for alpine birds whose species often experience population increases, Sitzia et al, (2010) noted that landscape fragmentation can act negatively upon species unable to live in small, patchy habitats.

Two studies into the effects of anthropogenic afforestation of Mediterranean farmland in the Iberian Steppes of Spain show the negative effects that afforestation may have in certain regions, including the direct loss of habitat for species of conservation concern, and increase in the abundance of predators (Reino et al, 2009)(Reino et al, 2010).

Whilst the planting of forests may lead to an overall increase in bird abundance and diversity in farmlands adjacent to forest patches, the overall increase is at the expense of grassland specialists (Reino et al, 2009). Steppe birds show strong negative edge effects, with the abundances of Calandra Larks and Short-toed Larks in particular depleted in grasslands directly adjacent to forest plantations. The abundances of these species increased further away from the edges of the plantations, and the highest species abundance and richness were observed in large arable patches. Though both species were listed as 'Least Concern' in the latest IUCN Red List report, their populations are in decline (BirdLife, 2013 - Calandra Lark)(BirdLife, 2013 - Lesser Short-toed Lark); habitat loss due to afforestation, which has already been accredited to regional declines of Lesser Short-toed Larks, may lead to greater pressure upon both species.

As the number of forested patches increased, Reino et al (2010) also documented an increase in the abundances of generalist predators, such as foxes and corvids (crows, ravens, magpies...); the increases of which have been associated elsewhere to population declines of ground-nesting birds (Fletcher et al, 2010).

Increased nest predation by predators such as foxes may lead to significant population declines of ground nesting birds, such as Eurasian Curlews in Scotland and Northern England (Douglas et al, 2013) - image by Jans Canon on Flickr.

A recent paper by Douglas et al (2013) on upland land use and declining waders populations highlights another case where afforestation and the fragmentation of moorland has been linked to increased predation rates, this time leading to a decline in breeding populations of the Eurasian Curlew (Numenius arquata), a bird listed as 'Near Threatened' in the latest IUCN Red List due to a 20-30% global population decline in the last 15 years (BirdLife - Eurasian Curlew, 2013). Both Douglas et al (2013) and Fletcher et al, (2010) also noted that predator control can help prevent population declines in species of conservation concern; for Lapwings, Curlews, Red Grouse and Golden Plovers, predator control lead to an observed population increase of ≥14% per annum, whilst a lack of predator control saw populations decrease by ≥17% per annum (Fletcher et al, 2010). 

The Eurasian Curlew, Numenius arquata - image by Davis Kwan on Flickr.

Though in the study by Reino et al (2010) it was concluded that nest predation rates (on artificial nests) showed no relation to predator abundances in the Iberian Steppes, they suggest that landscape composition and configuration may instead have a stronger impact due to edge density effects.With this, they recommend that afforestation in the Mediterranean -and other areas inhabited by ground-nesting birds of conservation concern- be avoided where possible. Where afforestation is unavoidable, they insist that populations be monitored closely for signs of declining numbers due to predation. They also suggest aiming to reduce habitat fragmentation and edge effects by afforesting a smaller number of large patches, rather than planting many relatively small patches (Reino et al, 2009).

References:

• Biodiversity and Landscape Change (Lecture) - Anson Mackay, 2013

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?

Happy Halloween!

Thriller playing in the background would be suitable considering the holiday, but oh well! The Mannequin bird never fails to make me smile. This guy has to be one of the grooviest little animals out there.

I was thinking it'd be cool being a bird on Halloween; no teeth = no cavities from so much sugar. Then I remembered this from Series B of QI and decided it probably wouldn't be such a great idea after-all...

"Birds do not like chocolate. It is poisonous, and birds have only 20-30 taste buds, so they could not taste it anyway. A Smartie would kill a small songbird. Chocolate is also poisonous to humans, but the lethal dose is very high (22 pounds). Humans have 9-10,000 taste buds, but new ones grow every five days." (QI - Series B, Episode 2)

Sucks to be a bird then, I guess. Though most of them do have the awesome ability to fly, so I guess it's not all bad, right?

Fun Feathery Facts:
1. The earliest known bird is thought to be the fossil specimen, Aurornis xui.
2. Feathers didn't originate in birds; it is now believed that proto-feathers originated in dinosaurs, and were probably present in Velociraptors... Jurassic Park probably wouldn't have been as terrifying as if they'd known that back-in-the-days.
3. Some birds, such as the Hooded Pitohuis (Pitohui dichrous), are known to be toxic to touch or eat; they produce these toxins from food in their diet.

Toxic and appropriately coloured for this frightful day; the Hooded Pitohuis (Pitohui dichrous). He'd look really cool perched a-top some pumpkins (I wouldn't eat them afterwards, minds) - image from Top5's

4. All birds lay eggs; no living bird species is known to give birth to live young.
5. There is some debate over which bird has made the longest recorded flight, depending upon whether you go by days spent airborne or distance covered. This year, three Alpine Swifts are reported to have spent a non-stop total of 200 days airborne, whilst a female Godwit in 2007 reportedly flew non-stop from Alaska to New Zealand, a journey of 7145 miles (11,500km).
6. The Peregrine falcon (Falco peregrinus) has the fastest dive speed of any bird at a speed of around 200 mph (320 km/h). In 2005, one particular falcon was recorded diving at a top speed of 242 mph (389 km/h).
7. Owls are excellent hunters and can fly more slowly than other birds, and do so almost silently thanks to noise muffling feathers in their wings. Their eyes are large relative to their small skull, but cannot be moved in any direction. Instead, owls can rotate their head 270° to look around.
8. The Potoo (Nyctibius spp.) is another nocturnal bird which relies heavily on their fantastic camouflage. In the day, they sit on tree stumps to avoid detection. They're also pretty comical looking, don't you think? 

"But I don't wanna go to school!" - image from fanpop.

9. The smallest known bird, the Bee Hummingbird (Mellisuga helenae), also produces the smallest eggs of any bird species. The eggs are no bigger than peas, and are lay in a tiny cup-shaped 1 inch (2.5 cm) nest. 
10. Whilst most nocturnal birds have evolved brilliant eyesight, the Kiwi might as well be blind. What it lacks in sight, however, it makes up for in it's ability to smell. Whilst most birds have little or no sense of smell, the kiwi bird's is highly developed. 

Taken from imgur.

Critically Endangered - The Philippine Cockatoo

I stumbled across an interesting article by BusinessMirror (2013) on the Red-Vented Cockatoo (Cacatua haematuropygia)  (IUCN, 2012) during a coach-trip back from visiting friends. Sometimes called the Philippine Cockatoo or Katala, this clever bird is one of the few bird species capable of mimicking human speech. Sadly, the population of these beautiful birds has plummeted rapidly (a decline of 60-90%) (Katala Foundation, 2013) in the last two decades due to anthropogenic activities.

The Red-vented cockatoo is listed as critically endangered on the IUCN Redlist with an estimate of roughly 1000 remaining in the wild, and with the remaining populations fragmented and dispersed across the Philippine islands  (IUCN, 2012). 

The Red-vented Cockatoo, by Edmond Sham on Flickr

Destruction of their natural coastal habitat poses one threat; deforestation and destruction of mangroves has been particularly extensive throughout their range, leaving the remaining populations vulnerable to typhoons (IUCN, 2012). The cockatoos are also persecuted for being agricultural pests, and are sometimes hunted for food (Birdlife, 2013).

Illegal trade of the birds for sale as pets, however, has probably been the largest impact that humans have had upon the species. The Red-vented Cockatoo is highly demanded as a cage-bird, as reflected in the price these birds can reach on the market (US$300 in Manilla, in 2006) (IUCN, 2012), and as such illegal trappers will remove any chicks from nests they come across  (Katala Foundation, 2013). 

Thankfully, things are being done to try and stop the decline of this species through the Philippine Cockatoo Conservation Program (PCCP). The PCCP has proposed protecting nests from poaching, restoring destroyed habitats, education and involvement in the community and conservation breeding for re-release as some of their conservation methods. 

Climate Change 1. - The Big Picture

Being perfectly honest, this is really just an overview; were I to address every impact that climate change has had upon birds, I would be here for a long, long time. Whilst I can and will focus on the finer points in my future posts, here I simply aim to provide a stepping stone. The topic of Climate Change is a long debated one, and the effect that our activities have had upon the climate is one of the reasons why many believe we're entering a new geological time; the Anthropocene.

What is Climate Change, and how do we know it is happening?
In short, Climate Change is a large-scale, global change in patterns of weather and temperature trends over time. As a result of shifting climate zone boundaries, climate change also results in a shift of biodiversity over time.

Athabasca Glacier in Canada is just one of the world's many retreating mountain glaciers that make it hard to deny that our planet is has been warming over the last century - by Maggie T on Flickr

Climate Change can be natural; the earth has experienced both cool periods where ice has been present over the poles, and warmer ice-free periods. Whilst the exact mechanisms for natural climate change are not fully understood, it is believed changes in the earth's orbit (Milankovitch Cycles) (British Geological Society) (Wikipedia, 2013) play a large role. This sort of climate change, however, takes place over thousands of years. Since the beginning of the 20th century global temperature has risen 0.8°C (1.4°F) (UK MetOffice) (US EPA) (Koronowski, 2013). This rapid change is above and beyond natural climate change (IPCC, 2007) and has been attributed to human activities; primarily an increase in atmospheric CO2 (from 280ppm before the industrial revolution (IPCC, 2007) to the present value of over 390ppm)(CO2 Now) through the burning of fossil fuels.

This rise in temperature has in turn caused a shift in global precipitation pattens (US EPA). Whilst there has been increased rain observed in the northern hemispheres mid-latitudes, other areas of the globe have suffered increasing drought  (UK MetOffice). Climate change has also brought with it a rapid retreat in mountain glaciers (Oerlemans et al, 1998) (Kaser et al, 2003) , a decline in sea ice and continental ice sheets, and a rise in sea level (Rockström et al, 2011).

Threatened by climate change and stronger, more frequent El Niño cycles; the critically endangered Waved Albatross (Phoebastria irrorata), a migratory sea-bird who's population is believed to have declined by up to 19% in the past 84 years (BirdLife, 2013) - image by Victor Burolla on Flickr

How does climate change impact upon birds?
There is compelling evidence that Climate Change has had a large impact on the behaviour, breeding patterns, breeding ranges (Araújo et al, 2005) and migration patterns of birds (Nature Canada). Earlier springs in northern hemisphere have been associated with an earlier arrival and breeding of birds, and in turn an earlier autumn and winter migration of juveniles (Crick, 2004).

For those birds that don't migrate to warmer climates, the harsher, colder winters may pose the threat of starvation and freezing as they require an increased energy expenditure for birds to keep warm (Crick, 2004). In turn, this could impact breeding success.

Other threats posed to birds, both migratory and non-migratory, include the loss of habitat and food (National Geographic, 2013). Whilst some areas of the world are becoming dryer and suffering from drought, other areas are becoming more 'hospitable'; in Alaska trees are now appearing on the formerly tree-less tundra, and deciduous trees are beginning to replace mountain conifers (O'Hara, 2011) . Whole ecosystems are changing rapidly, and populations of birds unable to adapt to these changes may decline rapidly.

Two Wings of Terror

I present to you a creature that sounds like it was plucked straight out of a legend. A giant raptor believed to have had a wingspan of roughly 3m (10ft) (Wingspan, 2012)(Warne, 2002), it is a bird that would be perfectly at home in the Lord of the Rings universe.

Though no longer soaring through our skies, Haast's Eagle (Harpagornis moorei) (Wikipedia, 2013)(Holdaway, 1991) was as real as could be, and is possibly the source behind the Maori legend of the monstrous man-eating Pouakai aka. Hokioi (ICR, 2009) (Wehi et al, 2009) (Wingspan, 2012). So, not the sort of creature that would be found flying over the mighty peaks of the Iron Mountains and rescuing Thorin and company from goblins, or plucking Gandalf from the top of the Isengard.

An artists depiction of the Haast's Eagle attacking the New Zealand Moa - image via Wikipedia Commons

I mentioned these amazing birds briefly in my last post, Bird Extinction: The Pre-Industrial Picture. Until humans colonised New Zealand, the only predator of the giant Moa (more than ten-times the eagles' weight) were Haast's Eagles which inhabited the South Island and went extinct at the same time as their primary source of food (Wingspan, 2012).

As is the case with many extant birds of prey, the females were believed to be the larger of sexes with a standing height of almost a metre (Brathwaite, 1992). With a weight of over 14kg for females (Brathwaite, 1992), this monster predator is believed to have been capable of reaching top speeds of approximately 50mph (80 km/h)(Wikipedia, 2013) at which it "...could hit its prey with the force of a 35-pound concrete block dropped from an eight-story building" (Warne, 2002). At such speeds, it would grasp its prey at the rear, as indicated by claw marks on Moa pelvic bones (Holdaway, 1991), and deliver a killing blow to head or neck. 

As a result of it's size, it has also been suggested by scientists that the Haast's Eagle was very near the threshold for flapping flight (BBC); had they been much larger, they would probably have had to rely on gliding. By keeping their wings relatively short and their tails long for their size, the eagles were able to maintain the ability to navigate swiftly through the forests as they hunted (Holdaway, 1991)(Brathwaite, 1992)(Wingspan, 2012). So, good news for a hungry Haast's Eagle, but bad news for any Moa or the unfortunate human...

Bird Extinction: The Pre-Industrial Picture

Extinction as a result of anthropogenic activities is not something that can be confined to the last century or two; as humans have expanded their reach across the globe, they have been contributing to a loss of biodiversity on Earth for at least 50,000 years (Braje & Erlandson, 2013). Human induced animal extinction rates are believe to be up to a thousand times higher than the natural background rate, and are associated with the loss of around 8500 species of bird since 1600 AD alone (Braje & Erlandson, 2013).

Whilst a loss of species diversity can be seen across the globe, some of the most prominent examples are on the many islands of the South Pacific, where Polynesian expansion across the pacific led to the extinction of many animal species (Pimm et al, 2006). Island populations are especially vulnerable to extinction, as their populations are often small, and may be confined to a minimal area of land. Their isolation also often results in the loss of adaptability to pathogens, predators and competitors that may be introduced, and to the rapid environment change often brought about by humans (Grayson, 2001).

The extinction of endemic flightless birds alongside plants and mammals in Australia coincides with the arrival of humans (Braje & Erlandson, 2013), which may have been visiting the country as early as 22,000 years ago (Flannery & Roberts, 1999), as suggest by a rise in charcoal and a change in tree pollen in the sedimentary record. This has been contributed to anthropogenic deforestation through fire, and not down to climate change (Flannery & Roberts, 1999).

The same applies to New Zealand, which wasn't colonised until much later in the 13th Century (Irwin & Walrond, 2012). Prior to humans living in New Zealand, it was home to many species of endemic birds that are now extinct. 21 species of small landbird are no longer with us today, and alongside them were 11 species of Moas (Braje & Erlandson, 2013) (Grayson, 2001). The only birds known to be totally wingless, the enormous Moa were a family of herbivorous flightless birds. The two largest species, Dinornis robustus and Dinornis novaezelandiae weighed over 200kg, and could reach a height of 3.6m (12ft) if they stood with their neck outstretched (Wikipedia, 2013).

Published in 1879; a photograph of Richard Owen, the director of London's Natural History Museum, standing beside a reconstructed skeleton of Dinornis novaezelandiae - Image via Wikipedia Commons

The only natural predator of the Moa was the Haast's Eagle which was also driven to extinction when the Moa were wiped out completely in just over a century since the Maori populated the islands. Their extinction is believed to be a result of multiple factors, but all are attributed to human activities (BBC, 2009) (Grayson, 2001). Before the arrival of our species it is estimated that up to 90% of New Zealand was covered in forested, yet within a few hundred years almost all of the lowland forest had been destroyed, and with it vanished the habitats of the Moa and other animals (Grayson, 2001). Human predation, evidence of which has been gained from many archaeological sites, was another large factor in the Moas disappearance (Holdaway & Jacomb, 2000). Lastly, the unintentional introduction of Polynesian rats (Rattus exulans) is believed to have played a large role in the extinction of birds not only in New Zealand, but across the whole of the South Pacific (Pimm et al, 2006). Whilst it's doubted by many archaeologists that there was direct predation of Moa eggs by the rats, the rodents are likely to have caused competition for food and impacted the vegetation on which the Moa and other landbirds depended (Grayson, 2001).

Madagascar suffered similar losses following human colonisation roughly 2300 years ago; it too was home to two genera of large flightless bird (Mullerornis and Aepyornis) that are often referred to as Elephant Birds which went extinct between 1600 and 1700 AD (Braje & Erlandson, 2013). Aepyornis was the larger of two, and is believed to have reached weights of up 400kg and a height of 3m (10ft). The causes of extinction are less clear, but signs of butchery from archaeological sites suggest humans played a primary role (Burney & Flannery, 2005).

The birds of other remote islands didn't fare much better. Grayson (2001) suggests that, alongside anthropogenic predation, predation by invasive dogs, pigs and Polynesian rats brought to the islands by humans may have been largely responsible for the disappearance of endemic Hawaiian species. Of 17 species of landbird known from archaeological deposits, only four remain on Hawaii today (Braje & Erlandson, 2013). Rats are also believed to be partly responsible for the loss of 6 species of landbird and several seabird colonies, alongside much of the vegetation (through eating nuts and seeds and thus impairing the ability of the plants to reproduce) on Easter island, which in turn contributed to the breakdown of human society on the island (BBC, 2009)(Braje & Erlandson, 2013).

Grayson (2001) raises the possibility that anthropogenic activities may have, in some instances, created habitats for some subsets of bird species which would not be present were it not for such changes. Despite this, the general consensus is that the increased colonisation of Oceania by humans correlates with an increase in avian extinctions. The past extinction of island fauna paints a grim picture; it shows how easy it is for anthropogenic activities to lead to a loss of biodiversity. Unless we try to minimise our impacts and attempt to preserve and conserve the species that have so far survived, many more species of bird may join the mighty Moa. 

New Zealand by Steve Taylor, on Flickr

Cited:

• Extinctions in Near Time: Causes, Contexts and Consequences - Chapter 10: Late Quaternary Extinctions in Australia (T.F. Flannery & R.G. Roberts, 1999)