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?