Exploring and discussing the ways through which anthropogenic activities have had -and are having- an impact on the nature, populations and species diversity of birds.
I was hoping to get another post or two in before this but sadly time is short and there are essay that need writing (I had promised someone I would write something on the endangered Gurney's Pitta, but he's going to have to forgive me for now).So, this will be my last post here at Goodbye, birdsong... at least, for now it is. Thank you all for sticking this through with me, and I hope you enjoyed the posts! I've really enjoyed writing this blog, so I'm hoping to post now and then when I have the time, though my future posts will probably have a wider focus upon all animals, and plants included, rather than just birds.
The bird whose name sounds like an item from a lunch menu; a male Gurney's Pitta from Thailand - image by Michael Gillam on Flickr.
That's not to say I don't find birds interesting any more; I've learnt a lot whilst carrying out this assignment, and it's made me love them even more. Did you know there's a bird that hatches with claws, so that the young can climb back up to the nest if they need to? That's the Hoatzin, a really cool looking bird that I didn't know about it until I started this project.
I also didn't know so many of our birds were threatened, but a whopping 13% (BirdLife, 2013) (New York Times, 2012) are and much of that is due to anthropogenic actions. Climate change, pollution, habitat destruction... all of these things, and more, are harming ecosystems around the globe. Unless we start looking after our planet better, the future it faces may not be a happy one.
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!
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.
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).
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.
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).
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.
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.
Thoughno 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.
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...
