Life’s Oddities: The Pigeon

The Pigeon (Columba Livia)

Although not a conventional oddity, you will look at Pigeons in a different light after this, enjoy.

Imagine a town, city or park without our little chappy the Pigeon. They are the birds that humans have utilised for thousands of years for food, fertiliser, and messengers but they are not always met with the thanks they deserve.

City Pigeons, Carrier (or Homing) Pigeons, Domestic Pigeons raised for meat, and Racing Pigeons are all the same species, descended from the Rock Dove of Europe, North Africa, and South Asia and are all members of the same species “Columba Livia”
 

The Feral pigeon is derived from domesticated pigeons that have returned to the wild. The domestic pigeon was derived from the rock dove that inhabited sea cliffs and rocky outcrops near the sea.  Since the instinct to roost in high crevices and holes is still strong, they choose the next best thing, the buildings within cities and towns.

Pigeon Eyes

Pigeons have the ability to see literally millions of different hues and have around 15 times the amount of cone cells compared to a human. http://wiki.answers.com/Q/What_is_the_receptor_in_the_retina_that_allows_you_to_see_color this allows them to see food opportunities, predators and recognise subtle changes in the environment.

Another feature of the Pigeon is that they their brain and eyes work at a much higher FPS http://en.wikipedia.org/wiki/Frame_rate meaning they see life much slower than we do, meaning they can fly with ease through the tightest spaces, land on the most precarious ledges and evade oncoming threats such as cars and Peregrine falcons… sometimes.

As a rather unorthodox clarification example I will try and explain a pigeons FPS rate, as no articles exist online; say you took a pigeon into a cinema and watched a film, you, the human, would see the film as a smooth seamless movie and would not be able to identify the join between each individual frame and the next; a pigeon however would see the movie quite literally like a rather boring “PowerPoint” presentation,  with each frame taking around 4 seconds relative to the human mind to “flick” to the next.

See here for more on the eyes of a bird http://www.backyardnature.net/birdeyes.htm

Pigeon wings

Have you ever seen a Pigeon take off and have you ever wondered what that slapping noise was? Some thought it was the noise created by Pigeons as they rapidly respire http://answers.yahoo.com/question/index?qid=20080211153911AAtAbQs drawing in masses of oxygen for their muscles during takeoff (anyone interested in the avian respiratory system see here) http://www.peteducation.com/article.cfm?c=15+1829&aid=2721 . We now know that the sound is generated by the “Scapulars” http://birding.about.com/od/Bird-Glossary-S-T/g/Scapulars.htm or http://www.taxidermy.net/forums/BirdTaxiArticles/04/k/047B3FB5C6.html,  “Primary” and “middle primary covert sections” http://www.infovisual.info/02/057_en.html  of the wing striking the other wing when they are in the fully raised position above its head like so: http://www.flickr.com/photos/jackabob/3296372305/ see this video for clarification http://www.youtube.com/watch?v=uviWnggSHDg .

This is an article about the structure and strength of birds wings compared to their function: http://jeb.biologists.org/content/46/2/219.full.pdf .

Some Quick facts about the Pigeon

Pigeons can fly at altitudes of 6000 feet or more and  cruise at speeds of  to 77.6 mph but have been recorded flying at an astonishing  92.5 mph!

Pigeons can fly between 600 and 700 miles in a single day, with the longest recorded flight in the 19th century taking 55 days between Africa and England and covering 7000 miles.

Pigeons are thought to navigate by sensing the earth’s magnetic field and using the sun for direction. Other theories include the use of roads and even low frequency seismic waves to find their way home.

Pigeons (and all the “Columbidae” family) drink by sucking water and using their beaks like straws. Almost every other bird collects water in the mouth and utilises gravity to drink.

Pigeons have lived alongside man for thousands of years with the first images of Pigeons being found by Archaeologists in Mesopotamia (modern Iraq) and dating back to 3000 BC.

There are many theories as to how homing pigeons navigate, from iron deposits in the eyes to following landmarks and even smelling! Every one of them having a positive and negatives.

So why do they bob their heads you ask?

The Twitchers’ amongst us may know that pigeons are not the only bird to bob their head while walking, chickens, Parrots, Magpies, Quails, Cranes and many more Birds also bob their heads while walking but we simply see the pigeon more often.

Birds, in particular pigeons, bob their head as an “Optokinetic http://en.wikipedia.org/wiki/Optokinetic_reflex reflex” to movement around them. The head bobbing is much more precise that what it first seems, there are two stages to the head movement, the “Thrust” phase where the head is literally thrust forward, then there is a “Hold” phase where the head is again literally held stationary enabling the bird to focus on an object   http://www.youtube.com/watch?v=IgaH8lES39E . This only occurs when the bird is in motion and the objects appear to move accordingly.

Pigeons were placed on a tread mill to prove this theory and were encouraged to walk, scientists suggested that they would not bob their head as the surroundings remained stationary and to everyone’s astonishment, they were right!

Here is some more information on the “Optokinetic reflex” http://www.biomotionlab.ca/bobbing.php

Thank you for the messages and do not forget to comment on what you think about my Pigeon post, any advice for next time, any opinions and any questions, I reply to everyone.

I said you would not look at Pigeons the same way again.

Elliott

 

Life’s Oddities: The Peregrine Falcon

 The Peregrine Falcon (Falco peregrinus)

(Image)

http://en.wikipedia.org/wiki/File:Peregrine_Falcon_profile_shot.jpg

(Wiki article)

http://en.wikipedia.org/wiki/File:Falco_peregrinus_-Nova_Scotia,_Canada_-eating-8.jpg

The peregrine Falcon is the fastest animal in the world and can be found right here in sunny England. Peregrines are a cosmopolitan species and you can find them on all continents apart from the high Arctic and Antarctica.

The fastest recorded speed was 275mph and they regularly reach speeds of around 231.25mph.

The peregrine falcon can see prey up to 7 miles away making it an extremely effective hunter.

The Peregrine nasal cavities are shaped like jet engine inlets with a retractable stopper inside to stop its lungs exploding during free fall. http://www.bbc.co.uk/nature/collections/p00hldcc#p00715hq

They adapt extremely well to city environments and the developing world, including the challenges of pollution, diseases and glass. Glass is a serious threat to every bird as at the correct angle; it can appear to be completely transparent causing them to fly into the window panes.

The link at the bottom is the best coverage of the peregrine falcon I have seen to date and i highly recommend viewing. It explains the challenges of the city environment, raising chicks and hunting as well as providing excellent shots of the Peregrine in action.

http://www.youtube.com/watch?v=eK1Ezg5gaq4

This post concludes the four Holiday special min-posts, normal blogging will resume Next Tuesday.

Elliott

 

Life’s Oddities: The Lion’s Mane Jellyfish

The Lion’s Mane Jellyfish (Cyanea capillata)

Before I begin visit this image:

http://simbania.files.wordpress.com/2011/04/lionsmanejellyfish.jpg?w=535

The Lion’s mane jellyfish is the largest know species of jellyfish and is found in the arctic, northern Atlantic and northern pacific oceans.

The “Bell” or body of the Lion’s mane can reach a diameter of 6 metres and the trailing tentacles over 50 metres long.

The tentacles are arranged in eight bunches, of over 100 tentacles each and covered with millions of stinging capsules that these predators use to catch zooplankton, small fish and moon jellyfish.

They have a very severe sting, which is potentially fatal to humans (though generally not). Stings can produce blisters, irritation, and muscular cramp and may even affect respiratory and heart function. Detached tentacles, left on buoy ropes for example, retain their stinging power.
However, since this species mostly lives in very cold waters, contact with humans is not very common.

They have outlived the dinosaurs by 65million years and were alive long before them so in actual fact they have outlived them for much longer.

They were one of the first living things on the planet and the fact that we are still studying live specimens pays tribute to how adaptive they really are. They have coped with extremes from the dinosaur extinction, ice ages, constant attacks from predators and the latest edition, humans.

We trap millions upon millions of jelly fish in nets to control their numbers, http://www.youtube.com/watch?v=bnAQHWsPqio&feature=related .

The Jelly fish is possibly the most successful animal in the world, making it an excellent study point and real interest to investigate.

See link for more information:

http://en.wikipedia.org/wiki/Lion’s_mane_jellyfish

Elliott

 

 

 

 

 

Life’s Oddities: Birds of Paradise

The Lyre bird  (Menura novaehollandiae)

http://en.wikipedia.org/wiki/Lyrebird

Found in the forests of southeastern Australia the Lyre bird is possibly the most famous when it comes to its calls.

It can mimic the calls of hundreds of different birds, it does this listening to its surroundings and remembering the tone, pitch and tempo of the noises, then repeats them later on to attract a mate.

These calls can be so effective and accurate that they can even fool the original generator of the sound, as seen in the link at the bottom.

The way the lyre bird captures its vocabulary means that some interesting anomalies can arise. It has been reported that the Lyre bird has been seen mimicking the noise made by a camera shutter as someone takes a picture, a car alarm and a chainsaw that was demolishing its habitat.

See the link below for further details.

http://www.youtube.com/watch?v=VjE0Kdfos4Y

 

The Vogelkop Bower bird (Amblyornis inornata)

http://en.wikipedia.org/wiki/Vogelkop_Bowerbird

Found on the Vogelkop Peninsula at Western New Guinea, Indonesia.

This is another example of a bird that is simply excellent at mimicking other noises, be it the beat of a pigeons wings, or another birds mating call, the larger and more varied the repertoire, the more attracted the female will be.

The Bower bird displays weird some even weirder behaviours, this attracts a mate by constructing an ornate “house” made from fine woven twigs, carpeted with fine black moss on the floor. The house is constructed around a single sapling that provides the structural support for the house. The focal point of the house is the guardian filled with colour orientated objects, be it flower petals, plastic, leaves and in one case, deer droppings. E very male has his own personality and preference in colours and design, allowing great variation to occur throughout.

The males live in what we would call a street, they live within close distance of each other, this area is no larger than a football field and there is never more than 5-6 males per “street”. Each street has its own female and every male in the street competes for only that one female. She visits them all individually to inspect their craftsmanship before making her decision.

The link is for a “David Attenborough” documentary on the “Vogelkop Bowerbird” and I highly recommend you watch.

http://www.youtube.com/watch?v=E1zmfTr2d4c

Elliott

 

 

 

 

Life’s Oddities: The Giraffe-Necked Weevil

This is part one of four mini-posts I will be publishing every day from now till the 28th as part of the holiday special, so remember to get reading.

The Giraffe-Necked Weevil

 (Trachelophorus giraffa)

http://en.wikipedia.org/wiki/File:Trachelophorus_giraffa_male_01.jpg

The giraffe weevil is a giant insect that belongs to the family, “Attelabidae” http://en.wikipedia.org/wiki/Attelabidae. It is found on Madagascar and large islands off the east coast of Africa.

The long neck is an adaptation for nothing more than fighting with other males for the right to mate with a female. The longer the neck the more chance they have of being accepted by the female.

The Giraffe Weevil is sexually dimorphic http://en.wikipedia.org/wiki/Sexually_dimorphic , the males and females differ from each other in the length of their neck and leg development. The males have the characteristic long giraffe necks, where as the females have a shorter, stubby neck.

The females also have immensely powerful legs able to fold and manipulate leaves many times their own size and weight.

The females use their mandibles to snip grooves into the leave’s stem so that when folded over it stays in position. The leave is then cut from the connecting stalk and falls to the floor to hatch. The process is then repeated up to 15 times.

See for further details:

http://www.youtube.com/watch?v=CN-WjdA6uUo

Thank you to very much to:

Lizabeth Kiah, Adolfo Hadnott and Clara for commenting.

Elliott

 

 

Life’s Oddities: The Pistol Shrimp

The Pistol Shrimp

The Pistol Shrimp is a small, harmless looking animal. It looks no different from your average shrimp, apart from a weapon so unique and innovative; it reaches a temperature that is as hot as the surface of the sun.

The Pistol Shrimp is found all over the world, with over 600 species it is not hard to see why. The Pistol shrimp belongs to the “Alpheidae” family who are classified due to their Asymmetrical claws and have the ability to produce a snapping sound.

The shrimp uses its weapon for two purposes, to either stun or kill prey for it to eat, or to ward off predators that might want a shrimp sized snack.

The “Pistol” on the Pistol Shrimp works by forcing water out of the cavity in the modified claw at over 60 kilometres an hour, this instantly vaporises the water making a bubble of super heated gas, travelling at 60 kilometres an hour that is hotter than the sun, not bad for a little Shrimpy.

This is a link to the Pistol Crab, with slow motion footage of the pistol in action, the mechanism of the Pistol is identical to that of the Pistol Shrimp it is merely to demonstrate the Pistol mechanism in greater detail.

http://www.youtube.com/watch?v=1jvcgz-BiHs&feature=related

Here is another link to the Pistol Shrimp in action:

http://www.youtube.com/watch?v=uQ7Ztmcf0Cc

Elliott

 

 

 

 

 

 

Life’s Oddities: The Giant Squid

The Giant Squid

It is a fact that we know more about the moon that the bottom of the ocean, we have been to the moon more times than the bottom of the ocean and until recently, we knew verry little about the creatures at the very bottom of the ocean.

The giant squid is a member of the “Architeuthidae” , “Architeuthidae” are the largest (in terms of weight), known cephalopods, the largest known molluscs and probably the largest invertebrates ever known to exist in the oceans.

Giant Squids are found in almost every ocean, each dot represents a giant squid that was caught or stranded on a beach. http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/IMAGES/architeuthis_map.gif

Giant squid’s anatomy is about as far from human anatomy as you can get, they have 3 hearts, jet propulsion, deadly sexual reproduction and blue blood! What’s not to love!

The giant squid has three hearts in a line, one larger on in the middle (systemic heart), and two smaller ones on either side that cope with the high demand for oxygen when using the jet propulsion on the underside of its body. (33.18 minutes on the link at the bottom)

The octopus and the squid are very similar, an interesting fact about the octopus, is has a donut shaped brain and an oesophagus that runs straight through the middle (50.15 minutes at the link at the bottom)

The sexual reproduction of Giant squids makes you glad to be human, first the male creates darts consisting of sperm, the 3 inch darts them move down one of its arms (via peristaltic contractions), the male then finds a female and latches onto the female squid, the male then uses his penis to stab the semen darts into the females body.

There are many more interesting facts about the Giant Squid that I simply did not have enough time to include, I suggest watching the whole video, it’s a bit long but who cares!

http://www.youtube.com/watch?v=JieznnvQHhI

Elliott

 

Life’s Oddities: The Mudskipper

The Mudskipper

http://www.flickr.com/photos/pfenya/2636647982/

The Mudskipper lives  in equatorial Africa, Madagascar, Arabia, south-eastern Asia, Japan and Australia, frequently in Mangrove swamps .The Atlantic mudskipper can grow to 9.8 inches, and has about a 5 year life span.

Mudskippers are classified into the subfamily “Oxudercinae” from the family “Gobiidae” http://en.wikipedia.org/wiki/Gobiidae

Some mudskippers live in Mudflats, resulting in extraordinary behaviour. They create a U shaped burrow to escape the tides under the mud, the burrow displays features of the u-bend in a toilet as it has one end open, allowing the water to enter, and the other end of the U is covered, resulting in an air pocket from which the Mudskipper breathes and survives the rough tides.

The U shaped burrow also serves as a nursery, the adult Mudskipper lays eggs up the side of the U shaped burrow in the air pocket, as there is more oxygen in the air compared to the water; however, it is an air pocket and therefore not an infinite supply of oxygen, if this supply runs out the eggs and therefore the Mudskippers young will die. The Male Mudskipper solves this by going to the open side of the burrow at low tide and taking in a huge gulp of air, he then swims to the closed end of the burrow and breathes the air out, he does this hundreds of times until the air in the burrow has been replenished, when the carbon dioxide begins to build once again, he repeats the process.

The Mudskipper walks on strengthened fins and spends most of its life out of water.

The Mudskipper breathes by gulping in a mouthful of air, and storing it in sacks near its head where its gills are (much like a scuba divers oxygen tanks), meaning the Mudskipper can always have a fresh supply of oxygen.

Any comments or questions you have feel free to use the comment bar at the bottom or drop me a message.

Here is a 4 minute documentary of the Mudskipper by my hero, Sir David Attenborough.

http://www.youtube.com/watch?v=KurTiX4FDuQ

Elliott

 

Life’s Oddities: The Platypus

Before I begin I will introduce my new site, in this blog I will talk about life’s strange and weird creatures that I find just as, if not more interesting to learn about than domesticated animals.

The Platypus

The Platypus has been described as the bits left over in God’s animal parts bin that he just “stuck” together , displaying features from a beaver (tail), a duck (bill and feet) and a small mammal (fur), however the Platypus displays other features apart from the ones we are taught in first school.

The platypus is one of only 3 mammals to lay eggs and belongs to a family called Monotremes, http://en.wikipedia.org/wiki/Monotreme , the other two being the long and short nosed Echinda (an anteater), http://en.wikipedia.org/wiki/Echidna  . This egg then develops and a small foetus-like undeveloped Platypus emerges, following a similar reproductive theme to that of Marsupials.

The young Platypus is different to an adult however in the sense that it has an egg tooth to break through the eggs leathery surface that drops off after a week or so, something that is more commonly seen in birds. Once the egg hatches the young develops in a pouch in the parent’s underside (like some Marsupials).

Once inside the parents pouch, the mother produces the mammalian specialty, milk, for which to feed its young. This milk is not delivered via the conventional means of a teat like in most mammals but instead, milk oozes from pores in its skin where it is channelled via hairs and folds in its skin into pits where the young can lap up the milk.

The Male platypus also has two venomous barbs at the bottom of its hind legs that some say are used in some way to display dominance during the mating season. The venomous barbs are present in both male and female platypus, but the barb falls off in females during development into sexual maturity. The poison is deadly to small animals such as dogs and cats but causes only severe pain to humans, and Oedema rapidly forms around the wound that can spread to a larger area if untreated. The poison is comprised mainly of DLP’s (Defensin-like proteins) http://en.wikipedia.org/wiki/Defensin  three of which specific to the Platypus.

I find the platypus fascinating, as you can tell it displays traits and behaviours from many species and many different types of animals making it an excellent animal to study.

There is more information on the Platypus here if you wish to learn more, such as the way in which the Platypus find its food to how it keeps warm in the cold waters, for you AS-Biology students out there, you will know that being a smaller mammal this increases their surface area to volume ratio resulting in a more rapid heat loss compared to larger mammals making it a complication for prolonged exposure to cold temperatures, especially in water as it conducts heat away from the body 1.2 joules faster than in air (25 times faster).

http://en.wikipedia.org/wiki/Platypus#Venom

Elliott

I will have more information on what next week’s animal will be closer the time