The Grey Currawong (Strepera versicolor)

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Currawong feeding chicks

Currawong feeding chicks

This #BeakoftheWeek focusses on a member of the Artamidae family.

The grey currawong is a large passerine species that is found in southern Australia and Tasmania (Xeno Canto links to a distribution map later in this article).  There are 6 distinct subspecies, which are so diverse in their colouration that they were originally split into 6 separate species.  They are found in a variety of habitats including arid shrub-land and temperate forests. Little is known about this species, but I will try my best to tell you everything that I have found out about them.

These guys spend a lot of their time foraging on the floor, using their strong beak to turn stones and break apart wood, to find tasty morsels. They are omnivorous and their diet is rather varied.  They are known to eat fruit and seeds, as well are partaking in the ingestion of lizards, small mammals and birds. Like their close relatives the Australian magpies (Cracticus tibicen) and butcherbirds, they are also fans of predating bird nests.

They are similar in size to ravens at about 50cm long, and one of their most distinguishing features, like other currawongs, is their striking yellow eyes.  Colouration in birds eyes can be caused by refraction and pigmentation, I like this article which goes into the reasoning and causes of eye colouration in more detail.

Grey currawong PC Donald Hobern

Grey currawong PC Donald Hobern

The female does most of the nest building and all of the incubating, although the male does assist with feeding the young.  They usually lay 2-3 eggs, which take about 23 days to hatch.  Whilst the female patiently waits for her eggs to hatch, her male companion helps attends to her dietary needs by feeding her on the nest.  Once the chicks fledge after around 32 days they stay with their parents until the next breeding season.

Currawong calls are pretty cool, and this species has some great ones which can be heard on Xeno Canto.  There is an extended version of the above gif here if you fancy watching a bit more chick feeding in action.  There is a also a nice video of some chilling out at their local watering hole here.

This species is listed as of least concern on the IUCN redlist, and birdlife describes its population numbers as stable, even though they have been described as falling across their range by other sources.

 

References

BirdLife International 2012. Strepera versicolor. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 27 May 2015.

BirdLife International (2015) Species factsheet: Strepera versicolor. Downloaded from http://www.birdlife.org on 27/05/2015.

Russell, E. & Rowley, I. (2009). Grey Currawong (Strepera versicolor). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/60624 on 27 May 2015).

Images and Videos:

BaseReality’s channel. 2015. Currawong feeding chicks. [Online]. [29/05/2015]. Available from: https://www.youtube.com/watch?v=DPdgedsmh8I

Image of Strepera versicolor” by Donald Hobern is licensed under CC BY 3.0 .

The Great Curassow (Crax rubra)

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A very handsome male great curassow (PC Alex Vargas: eol.org)

A very handsome male great curassow

One of our most recent #BeakoftheWeek‘s, the great curassow, is the focus of todays blog.

Curassows belong to the family Cracidae alongside the guans and chachalacas, and are the largest members of this group. The cracids are important seed dispersers in the Neotropical forests where the family is found. The great curassow is the largest cracid and can reach lengths of up to one metre from beak to tail. The male is a very striking bird with predominantly black plumage, a curly crest of feathers on his head, white under-tail coverts and a bright yellow knob (or cere) on his bill. The females exist in three colour morphs; a reddy-brown morph with barred tail, a dark morph and a barred morph. All lack the yellow cere of the male.

The great curassow is predominantly a frugivore, and perhaps unsurprising due to it’s large size, feeds mainly on fruits that have dropped to the forest floor, such as these guavas. Less frequently, it feeds in low branches and shrubs on attached fruits. It has also been reported to occasionally eat invertebrates and even small vertebrates (e.g amphibians) which are gleaned from the surface of leaves and amongst the leaf litter. It forages for food alone, in pairs or in small groups outside the breeding season, but can form large aggregations when trees such as figs are in fruit.

The calls of these birds vary from a low-pitched, deep, booming note to high-pitched peeping notes that are given in alarm. When escaping danger, the great curassow is more likely to run across the forest floor than it is to fly.

Great curassow chick (Victor Burolla, eol.org)

Great curassow chick

A monogamous pair bond is considered the norm in great curassows. Both members of the pair contribute to building the nest, which is placed 4-9 metres off the ground and is a platform made from sticks lined with leaves. The female lays 2 white eggs which take around a month to hatch. The chicks are buff coloured with black and chestnut markings and are precocial, being mobile soon after hatching. The female may carry chicks away from danger in their first few days of life. Great curassows are long-lived and one female in captivity was recorded to live to 24 years of age.

These birds have a wide but fragmented distribution and are found in the dense lowland forests of Southern Mexico, Central America down to Western Colombia and Ecuador. The great curassows’ population has been suspected to have declined rapidly over the past 30 years and was estimated at between 10,000-60,000 individuals in 2009. This species is particularly sensitive to hunting and habitat disturbance from the logging industry and settlement progression, and with population declines predicted to continue, it is listed by the IUCN as vulnerable.

A number of conservation schemes are currently in place with more being planned to reverse the population decline of the great curassow. You can find out more about them on BirdLife International’s website.

 

References

Atkinson, Jon, C. Rodríguez-Flores, C. Soberanes-González, and M.C. Arizmendi. 2012. Great Curassow (Crax rubra), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=81671

BirdLife International 2012. Crax rubra. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 28 May 2015

BirdLife International (2015) Species factsheet: Crax rubra. Downloaded from http://www.birdlife.org on 27/05/2015

del Hoyo, J. & Kirwan, G.M. (2013). Great Curassow (Crax rubra). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2013). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/53311 on 27 May 2015).

Images

The great curassow (Crax rubra) by Instituto Nacional de Biodiversidad Costa Rica (INBio) is licensed under CC BY-NC-SA 3.0

The great curassow chick (Crax rubra) by Victor Burolla is licensed under CC BY-NC-SA 2.0

The Keel-billed Toucan (Ramphastos sulfuratus)

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Keel-billed toucans perching. PC Patricia Jones

Keel-billed toucans perching. PC Patricia Jones

Another #BeakoftheWeek nomination, the keel-billed toucan is under the microscope today.

Although not quite as famous as the perennial Guinness mascot, the toco toucan, this species is quite the charmer.  Also known as the rainbow-billed toucan and the sulphur-breasted toucan, it is the national bird of Belize.  It ranges from southern Mexico to northern Colombia and north-western Venezuela.  They are usually found in pairs or family groups, sometimes in groups as large as 22.

Other than its vibrant bill, the keel-billed toucan has a few other things up its sleeve to impress.  One of my favourite things, is simply the fact that it has blue feet.  They are about 17-22 inches in length, and about 1/3 of this length is accounted for by their impressive bills.  Wouldn’t having such a large beak be rather cumbersome you ask? Well… Their beaks are made up of keratin and foamy or sponge-like bone structures, making it light weight, and unlikely to topple them over.  Their bills also have the added bonus of being very strong.  This article discusses this in further detail.

Another benefit to having this large bill is thermoregulation.  Toucans are able to use the blood vessels running along their beaks in order to regulate their body temperature.  This site has an excellent video of a toucan doing just that.

They also lend themselves to some pretty awful puns

They also lend themselves to some pretty awful puns

Keel-billed toucans have zygodactyl feet, with two toes facing forward and two back.  This interesting piece discusses different toe arrangements in birds, and what they are useful for.

This species is known to hang around in large groups, as mentioned earlier, and they also like to play, with reports of individuals tossing berries to each-other.  There are quite a few examples on youtube of toucans feeding, which are worth a look at, such as these (1) (2).  They are monogamous and both parents are known to take part in incubation duties and feeding their young. The keel-bill feeds largely on fruit, but also consumes arthropods and small vertebrates.

This article has been quite video heavy, but there are lots of great ones out there, and here’s a nice one of a male courtship calling.

Estimates of their longevity come from captive populations, where they are known to live for at least 15 years and 7 months.  In the wild this species is vulnerable when nesting, and they are targeted by snakes, mammals and bird species such as black hawk-eagles. Their population is decreasing due to habitat loss, being taken for the pet trade, and hunting. They are of least concern on the IUCN redlist however, due to their large population size and range.

Xeno Canto once again does a great job of showing us where they are found, and what types of calls they make.

 

References

BirdLife International (2015) Species factsheet: Ramphastos sulfuratus. Downloaded from http://www.birdlife.org on 26/05/2015.

BirdLife International 2012. Ramphastos sulfuratus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 26 May 2015.

Jones, Revee, and Carole S. Griffiths. 2011. Keel-billed Toucan (Ramphastos sulfuratus), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=303256

Short, L.L. & Sharpe, C.J. (2014). Keel-billed Toucan (Ramphastos sulfuratus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/56098 on 26 May 2015).

Images

Ramphastos sulfuratus by Patricia Jones is licensed under CC BY 3.0

The Pileated Woodpecker (Dryocopus pileatus)

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Figure 1 Pileated woodpecker looking for tasty treats

Figure 1 Pileated woodpecker looking for tasty treats

Time for a bit of info on one of our past #BeakoftheWeek candidates…

The pileated woodpecker is one of the largest woodpeckers in North America, being about the same size as a crow.  It is resident in coniferous, deciduous and mixed woodlands in Canada and the USA (see Xeno Canto link later for distribution map).  They are seen as a keystone species, playing a crucial role in forest ecosystems.  Amongst other things they excavate holes that can be used by other birds and mammals to nest in, as well as controlling some bug species populations.

When you go down to the woods today you may hear the thud thud thud of a woodpecker as it drums on a tree.  They are drumming in order to attract mates or advertise their territory.  If you or I were to repeatedly bang our head against something we’d get a pretty nasty headache, or even worse, brain damage.  The woodpecker is drumming away at a top speed of 6-7  metres a second, with a deceleration of 1000 g, so why don’t woodpeckers suffer the same fate?  Fortunately some lovely people have looked into this. The woodpecker’s skull is built in such a way so as to absorb the shock of the impact, something scientists are hoping will allow us to develop technology to help prevention of head injuries in people.  Here is a great link that explains this in greater depth.

Check out this video to see one of these guys looking for tasty treats.  It’d be great to see a slow motion video of the deceleration they experience, but I haven’t managed to track one down.  Carpenter ants make up the majority of this species diet, and given the structural damage these ants can do, it is a good job some of them are being taken out of the equation.

Pileated woodpecker (right) with downy woodpecker.

Pileated woodpecker (right) with downy woodpecker.

Pairs in this species defend their territory year round.  They could be seen as modern day parents, with the male getting hands on in all aspects of parental care.  The males don’t rest on their laurels, after doing most of the nest building, they also help with incubating the eggs, of which there is an average clutch size of four. With the male incubating at night and then sharing the responsibility with the female throughout the day.  Feeding duties are also shared between the parents.

If you are a fan of cuteness, then this video of some chicks being fed is for you.  The chicks are altricial, and leave the nest after about 25-30 days.

You’ll be pleased to know that according to the IUCN redlist, this species is of least concern.

Apparently these guys are where Woody got his voice

Apparently these guys are where Woody got his voice

So, down to the main reason you are reading this blog article.  Woody woodpecker’s characteristic laugh is supposed to have originated from this species, I think some artistic licence may have been taken here, but you can almost hear woody himself when listening to these guys on  Xeno Canto.  If you want to do a comparison, here’s woody after getting up to some mischief.

 

References:

BirdLife International (2015) Species factsheet: Hylatomus pileatus. Downloaded from http://www.birdlife.org on 08/05/2015.

Bull, Evelyn L. and Jerome A. Jackson. 2011. Pileated Woodpecker (Dryocopus pileatus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/148from http://www.birdlife.org on 08/05/2015.

The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 08 May 2015.

Winkler, H. & Christie, D.A. (2002). Pileated Woodpecker (Hylatomus pileatus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/56286 on 8 May 2015).

Images and videos

Pilieated woodpecker” from Freshwater and Marine Image Bank is licensed under Public Domain.

Martyn Stewart. 2013. Pileated woodpecker. [Online]. [25/05/2015]. Available from: https://www.youtube.com/watch?v=RNni2QLdLJo

The Hoatzin (Opisthocomus hoazin)

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Hoatzin chick climbing

Hoatzin chick climbing

I’m pretty excited to write about this week’s #BeakoftheWeek! The hoatzin, or stinkbird as it is endearingly known (due to a lovely stench it emits from its fermenting guts), is one of the most evolutionarily distinct birds in existence (lying in third, behind only the oilbird and cuckoo-roller) .  Check out this cool paper for more information.

It is the only member of the Opisthocomidae family, and ever since discovering this quirky creature whilst watching the life of birds I’ve been a big fan.  If you check out the gif to the left you’ll notice some pretty strange behaviour…

Their chicks have claws on their wings, unique in Aves, and they use them until their wings are strong enough to fly/ support them.  The presence of these claws historically led to people believing they were pre-historic, although I am of the belief that the shoebill has got to take the prize for looking like it should have walked with the dinosaurs.  I couldn’t reference Sir David Attenborough without a link to some of his work, so here he is talking about hoatzin claws in the life of birds.  Here is an interesting article on the evolution of wings.

Sir David's Life of Birds

Sir David’s Life of Birds

During the non-breeding season they will live in groups of up to 100, that is a lot of Hoatzin.  They are cooperative breeders, sometimes in groups with up to 6 helpers, which are known to help with nest building, care of chicks and some incubation duties.  The usual clutch size is two.  The chicks leave the nest after about 2-3 weeks, but are dependent upon adults for up to 3 months.  They vigorously defend their territory during the breeding season.

So, where does that stinkbird alias come from? They have been likened to flying cows due to their diet consists more or less entirely of leaves, which leads to their gut bacteria creating quite the smell when they break it down.  The large crop needed for food fermentation comes at a cost to flight ability, as it reduces sternum size, affecting flight muscles.  They are rarely seen to take to the wing because of this, but this does not mean they are unable to.  This video, although having an annoying high pitched ringing, does show one flying a short distance if you needed to see it to believe it.

Hoatzins chilling out. PC planetscott.com

Hoatzins chilling out. PC Planetscott.com

Predation is the primary reason for nest failure, with nests being preyed on by many creatures including: wedge-capped capuchin monkeys (Cebus olivaceus), tiger rat snakes (Spilotes pullatus) and toucans.  They nest over water alongside lakes and slow-moving rivers in trees and bushes, which allows their young, which are able to swim, to drop into the water to escape predators.

Endemic to the Americas, they are a widespread across in the lowlands of northern South America and the Amazon rainforest. Unfortunately population size is unknown, but they are described as common and easy to spot due to their behaviour, and probably their stench.  Could be easy to tick these off the list if you get to South America then!  They are described as of least concern by the IUCN red list, even if their population is in decline.

Once again, I recommend heading over to Xeno canto to get more of a feeling of where this bird lives and what it sounds like.

 

References:

IUCN of least concern The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 07 May 2015.

Billerman, Shawn. 2012. Hoatzin (Opisthocomus hoazin), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=201176

BirdLife International (2015) Species factsheet: Opisthocomus hoazin. Downloaded from http://www.birdlife.org on 07/05/2015.

Thomas, B.T., Kirwan, G.M. & Sharpe, C.J. (2014). Hoatzin (Opisthocomus hoazin). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved fromhttp://www.hbw.com/node/53530 on 12 May 2015).

Images and videos

Hoatzin (Opisthocomus hoazin)” by Scott Bowers is licensed under CC BY 3.0

TheHoatzin’s channel. 2012. Hoatzin claws. [Online]. [10/05/2015]. Available from: https://www.youtube.com/watch?v=87_shPJxdns

Sword-billed Hummingbird (Ensifera ensifera)

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Sword_Billed_Hummingbird

Sword-billed hummingbird in flight.

The sword-billed hummingbird is the only bird in existence that has a beak that is longer than its body.  It is from Andrean South America, ranging from Colombia in the north to Bolivia in the south.

At about 13g, which the internet reliably informs me is just over the weight of two bic biros, and 14cm in length, it is one of the larger hummingbird species.  This dwarfs the smallest bird species in the world, the bee hummingbird (Mellisuga helenae), which weighs about 2g (not even half a bic!) and is around 5.5cm long.

Unfortunately there is little breeding information available for these guys.  Here is the gif in video form, in slow mo, to stem your disappointment.

This species is typically a nectar feeder, although it also feeds on some insects.  Some species of passion flower, such as Passiflora Datura, depend upon this species for pollination.  When the hummingbird enters the flower to feed on delicious nectar they get covered in pollen, which they then carry to the next flower, pollinating it.  Not just a free-loader.

Population size for this species is unknown, but they are listed as of least concern on the IUCN red list.  Efforts to preserve this species with ecotourism should help prevent habitat destruction in its range and keep population numbers stable.  They are most commonly found 2500-3000m above sea level.

Xeno canto once again provides a great distribution map and a few call recordings.

References

BirdLife International 2012. Ensifera ensifera. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 08 May 2015.

BirdLife International (2015) Species factsheet: Ensifera ensifera. Downloaded from http://www.birdlife.org on 08/05/2015.

Chai, P., Kirwan, G.M. & Boesman, P. (2014). Bee Hummingbird (Mellisuga helenae). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved fromhttp://www.hbw.com/node/55653 on 8 May 2015).

Züchner, T. & Kirwan, G.M. (2015). Sword-billed Hummingbird (Ensifera ensifera). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2015). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/55570 on 8 May 2015).

Videos

Angela Drake. 2014. Sword-Billed Hummingbird (2x slow). [Online]. [08/05/2015]. Available from: https://www.youtube.com/watch?v=QU8FCtsYbpA

The Peregrine Falcon (Falco peregrinus)

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Figure 1 Peregrine falcon flying

Figure 1 Peregrine falcon flying

Where else to start but with speed.  This bird is the fastest animal on the planet, reaching speeds in excess of 200mph. To put that into perspective, Usain Bolt, the fastest man on the planet, can run the 100m in 9.58 seconds, and at 200mph the peregrine falcon can do that in less than 2 seconds.  It is also more than three times as fast as a cheetah.  You’d never see it coming.

There are estimated to be around 1.2million of them flying around, hunting down the pigeon population worldwide.  They have an extremely large range, extending from the tropics to the arctic, and it can be seen almost everywhere on the planet.  Head to xeno canto to see their distribution and hear some peregrine calls.

Looking at them you might expect that their most closely related family would be amongst the hawks and eagles.  However recent research has suggested that falconidae is closest to parrots (psittaciformes).  Here is a nice soundbite discussing it, and the original nature article.

Peregrine falcons are monogamous.  There is a noticeable size difference between the sexes, with females being up to 20% larger than their male counterparts.  Peregrines weight about 1kg, measure between 34 and 50cm in length and have a wingspan ranging from 80-120cm.  When nesting, this falcon does not build a nest, but instead usually lays its eggs in a scrape on cliffs (the eyrie).  They lay an average of about 3 eggs, which take around 30 days to hatch.  The chicks are semi-altricial and cared for by both parents for about 2 months.

Figure 2. Peregrines and chicks

Figure 2. Peregrines and chicks

Their speed and fantastic eye sight makes them majestic hunters, and the hunting ability of these birds did not go unnoticed, with people utilising them to meet their needs.  They have been used in falconry for thousands of years, and used in more modern ventures such as reducing bird collisions at airports.  Although sometimes the hunter becomes the hunted, with peregrines falling prey occasionally to gyrfalcons and great horned owls.  Nestlings and immatures can also fall victim to mammals such as wolves, foxes and cats.

I don’t think I can truly do justice to the peregrine’s hunting prowess, so I leave it up to youtube to portray this.  Check out this national geographic video of them hunting pigeons, and this BBC one featuring a peregrine cam.

As you can see from the videos, they have a penchant for pigeon as well as many other bird species, but they are also partial to the occasional mammal and fish.  It usually catches its avian prey in flight.  Once it has caught its prey, it takes it to its favourite plucking post to get rid of those pesky feathers before consuming it.

The IUCN lists this species as of least concern, and although it has had its problems in the past, its population is thought to currently be stable.  Bill Oddie has a marvellous voice, and here he is talking briefly about the effect of pesticides on this species a lot more eloquently than I could, for the BBC.

Last but not least, if you wish to see some young peregrines develop into supreme hunting machines, Sheffield University has some cameras set up watching a nest box on St Georges Church, where there are currently 2 chicks on a live feed.  Enjoy.

 

References

BirdLife International (2015) Species factsheet: Falco peregrinus. Downloaded from http://www.birdlife.org on 08/05/2015

BirdLife International 2014. Falco peregrinus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 08 May 2015.

RSPB. 2008. How fast can the peregrine falcon fly. [ONLINE] Available at :http://www.rspb.org.uk/makeahomeforwildlife/advice/expert/previous/peregrine.aspx. [Accessed 08 May 15].

White, C.M., Christie, D.A. & de Juana, E. (2013). Peregrine Falcon (Falco peregrinus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2013). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/53247 on 8 May 2015).

White, Clayton M., Nancy J. Clum, Tom J. Cade and W. Grainger Hunt. 2002. Peregrine Falcon (Falco peregrinus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:http://bna.birds.cornell.edu/bna/species/660

Images

Peregrine falcon flying” by Mike Baird is licensed under CC BY 2.0.

Peregrines and chicks” by Biodiversity Heritage Library is licensed under CC BY-NC-SA 2.0.

The Wrybill (Anarhynchus frontalis)

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We decided that it would be nice for us to give you some information on the chosen #BeakoftheWeek, so we are kicking things off with last week’s…

wrybill 1

Figure 1. Wrybill beak bend

Being amongst the strangest beaks that we have encountered during our scanning escapades, the wrybill, or ngutuparore, is a charismatic species endemic to New Zealand.   You’ll notice straight away from this picture and Fig 1 that there is something slightly awry with the morphology of this birds beak.  It is unique in being the only species of bird that has its beak always bent laterally, and exclusively to the right.  This specially adapted beak is used to sweep under stones in its hunt for invertebrates, such as mayfly and caddisfly.

The internet bird collection has a nice video of some wrybills in action.

The wrybill is a pale plover, of about 20cm in length, from the charadriidae family, which consists of about 60 species including dotterels and lapwings.  Similar species include the sanderling and banded dotterel.  Its breeding grounds are found solely on the braided riverbeds of New Zealand’s South Island, from where it migrates to over wintering grounds in the North Island.   They are known to form dense flocks at their wintering grounds (see Fig.2).

 

Figure 3 A sketch of the Wrybill from A History of the Birds of New Zealand (1888)

Figure 2 A sketch of the Wrybill from the A History of the Birds of New Zealand (1888)

This monogamous, ground nesting species has a life expectancy of about 5 years.  Chicks are precocial and clutch size consists of two eggs on average.  There is slight sexual dimorphism, with males having a black bar above their foreheads and a black breast bar.  Females have a slightly browner and narrower breast bar and lack the bar above the forehead.

 

 

 

The wrybill employs a few techniques to avoid predation.  As you can see from this picture of their eggs they blend nicely into the background of the riverbed, similarly to the pale appearance of the adults.  Camouflage is not the only method used as parents will also perform distraction displays to entice predators away from their nests.

This is a species in decline, with the IUCN redlist describing them as vulnerable since 1994.  Before the 1940s hunting was a cause for a major drop in their population, which has since recovered.  However, threats from predation by introduced mammals and native birds, as well as the flooding of nests and the loss and degradation of breeding grounds, are further putting this species under threat.  Population estimates from winter counts lie at about 5,000 individuals.

To fully immerse yourself in the world of the wrybill you can check out a distribution map and listen to some wrybill calls on Xeno Canto.

References:

BirdLife International (2015) Species factsheet: Anarhynchus frontalis. Downloaded from http://www.birdlife.org on 05/05/2015.

Dowding, J.E. 2013. Wrybill. In Miskelly, C.M. (ed.) New Zealand Birds Onlinewww.nzbirdsonline.org.nz

Hay, J. R. 1984. The behavioural ecology of the wrybill plover. Dissertation. Ph.D., Auckland University, Auckland.

The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 05 May 2015.

Wiersma, P. (1996). Wrybill (Anarhynchus frontalis). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/53856 on 5 May 2015).

Images

Sketch of Wrybill” by A History of the Birds of New Zealand, 1888 is licensed under Public Domain Mark 1.0.

Wrybill bill bend” by A History of the Birds of New Zealand, 1888 is licensed under CC BY-SA 3.0.