The Blackpoll Warbler's truly amazing migration understood with the use of light-sensing geo-locators.
March 2015
Scientists have recently documented how this songbird weighing 12 grams completes an arduous nonstop flight over the Atlantic Ocean from forests in New England and eastern Canada to Caribbean Islands as it migrates each Autumn towards its South American wintering grounds. They determined the birds flew on average 2540 km over two or three days. No other bird this size migrates for this long in one go. They land in Puerto Rico and Hispaniola, resting for a couple of weeks before flying to Columbia and Venezuela. The Spring return flight follows a more overland route through Florida and up the US East Coast. Most migratory songbirds that spend winters in South America fly a safer overland route through Mexico and Central America. Before migrating these little birds gorge themselves to build strength. They also shrink many of their digestive organs to minimise any part of the anatomy not required during their extended flight.
Source: Reuters Washington.
Source: Reuters Washington.
A Selection of weird Bird Houses from around the World.
Wednesday 14th April 2014
Wednesday 14th April 2014
Leucism and Albinism.
Monday 3rd March 2014
In Leucism the affected plumage lacks melanin pigment due to the cells responsible for melanin production being absent. This results in white feathers, unless the normal plumage colour also comprises carotenoids (yellows) which remain unaffected by this condition. Although leucism is inherited, the extent and positioning of the white colouration can vary between adults and their young, and also skip generations if leucistic genes are recessive. The reduced pigment in leucistic birds causes feathers to weaken and be more prone to wear. It can even hinder flight, which can further heighten risk of predation. Other plumage irregularities include progressive greying and dilution.
Albinism also results in white feathers, but true albinos are thought to be rare in the wild. It is a genetic mutation causing an absence of tyrosinase in pigment cells. An albino is unable to produce melanin pigments. This leads to a good diagnostic feature with which to distinguish between the two conditions - the colour of the eye.
Albinos have pink eyes while the iris pigmentation in leucistic birds remains dark. Most albino birds die soon after fledging, primarily as a consequence of poor eyesight, and are not thought to progress to adulthood in the wild.
British Trust for Ornithology
Monday 3rd March 2014
In Leucism the affected plumage lacks melanin pigment due to the cells responsible for melanin production being absent. This results in white feathers, unless the normal plumage colour also comprises carotenoids (yellows) which remain unaffected by this condition. Although leucism is inherited, the extent and positioning of the white colouration can vary between adults and their young, and also skip generations if leucistic genes are recessive. The reduced pigment in leucistic birds causes feathers to weaken and be more prone to wear. It can even hinder flight, which can further heighten risk of predation. Other plumage irregularities include progressive greying and dilution.
Albinism also results in white feathers, but true albinos are thought to be rare in the wild. It is a genetic mutation causing an absence of tyrosinase in pigment cells. An albino is unable to produce melanin pigments. This leads to a good diagnostic feature with which to distinguish between the two conditions - the colour of the eye.
Albinos have pink eyes while the iris pigmentation in leucistic birds remains dark. Most albino birds die soon after fledging, primarily as a consequence of poor eyesight, and are not thought to progress to adulthood in the wild.
British Trust for Ornithology
The colour of bird eggs.
Tuesday 11th February 2014
The colour and colour pattern of bird eggs varies enormously from species to species. (even between individuals of the same species, and even between eggs from the same female)
Eggs are made from calcium carbonate which is white, therefore white is the default colour for eggs.
Colouration of bird eggs can be explained by their biology and behaviour. The eggs of ground-nesting birds need to be well camouflaged to avoid discovery by predators. They are usually coloured and patterned to match the substrate which they are laid upon. Tree-nesters on the other hand usually have blue or green eggs. Birds eggs that are hidden from view ( in hollows, burrows, or deep nests) or who sit on their eggs continuously during incubation, tend to have white eggs.
The patterns on eggs have developed via natural selection. The better the camouflage the more likely the eggs are to survive so offspring can pass on their genes to the next generation. Colour is also thought to act as a sunscreen, protecting the developing foetus from UV light. In addition it strengthens the egg shell.
Specific colours are incorporated into the shell in the final stage of egg development. Blue and green comes from a pigment called biviverdin, which comes from bile. The red and brown colour comes from protoporphyrins, which comes from blood.
Egg patterns have style names : Splashed, blotched, spotted, dotted, marbled, streaked, scrawled, overlaid, capped and wreathed by way of example.
Source: Museum Victoria 2012
Tuesday 11th February 2014
The colour and colour pattern of bird eggs varies enormously from species to species. (even between individuals of the same species, and even between eggs from the same female)
Eggs are made from calcium carbonate which is white, therefore white is the default colour for eggs.
Colouration of bird eggs can be explained by their biology and behaviour. The eggs of ground-nesting birds need to be well camouflaged to avoid discovery by predators. They are usually coloured and patterned to match the substrate which they are laid upon. Tree-nesters on the other hand usually have blue or green eggs. Birds eggs that are hidden from view ( in hollows, burrows, or deep nests) or who sit on their eggs continuously during incubation, tend to have white eggs.
The patterns on eggs have developed via natural selection. The better the camouflage the more likely the eggs are to survive so offspring can pass on their genes to the next generation. Colour is also thought to act as a sunscreen, protecting the developing foetus from UV light. In addition it strengthens the egg shell.
Specific colours are incorporated into the shell in the final stage of egg development. Blue and green comes from a pigment called biviverdin, which comes from bile. The red and brown colour comes from protoporphyrins, which comes from blood.
Egg patterns have style names : Splashed, blotched, spotted, dotted, marbled, streaked, scrawled, overlaid, capped and wreathed by way of example.
Source: Museum Victoria 2012
World's Smallest Bird.
Thursday 6th February 2014
The male Bee Hummingbird from Cuba has this distinction. It weighs approx. 1.8 grams and has a length of about 2 inches.
It has about 1000 feathers compared with up to 25 000 in larger birds.
It flies with a wing beat of 80 per second, and during courtship the male wing beat can reach 200 per second.
They eat half their total body mass and drink 8 times their mass every day.
It is crucial in ensuring the pollination of several plant species.
Source: Softpedia News.
Thursday 6th February 2014
The male Bee Hummingbird from Cuba has this distinction. It weighs approx. 1.8 grams and has a length of about 2 inches.
It has about 1000 feathers compared with up to 25 000 in larger birds.
It flies with a wing beat of 80 per second, and during courtship the male wing beat can reach 200 per second.
They eat half their total body mass and drink 8 times their mass every day.
It is crucial in ensuring the pollination of several plant species.
Source: Softpedia News.
Fastest Bird in level Flight.
Tuesday 4th February 2014
Peregrines use a specific flying technique - the stoop. Flying high they close their wings and enter into a downward dive. Stooping Peregrines reach speeds of up to 200 mph. This is gravity assisted however, and their level flight speeds are recorded at 40 mph.
Many Swift species reach high speeds during their display flights, with speeds recorded up to 69 mph. These speeds are reached in level and ascending flight so it could be argued they are the holders of the title. However their normal flight speeds during migration or en route to roosting sites is 22 - 26 mph.
The humble Eider has the right to be the known as the fastest bird in steady flight.
Despite the difficulties of recording the speed of level flight in many species, so far the Eider has come out on top at 47 mph.
They have a very small wing area relative to body size. (highest wing loading) Due to this ratio, speed is vital for the eider to produce enough lift to keep it in motion. This amazing species can be seen along the east coast of Scotland and n England.
Pigeons, waders, and other wildfowl are all capable of hitting speeds over 40 mph. As more sophisticated technology becomes available, more accurate flight speed analysis will be possible. New contenders will then emerge for the title.
Source: RSPB article July 2010.