At least 4,000 species of bird are known to be regular migrants, which is about 40 percent of the total number of birds in the world.
(Although this number will likely increase as we learn more about the habits of birds in tropical regions.)
Birds can reach great heights as they migrate.
Bar-headed Geese are the highest-flying migratory birds, regularly reaching altitudes of up to five and a half miles above sea level while flying over the Himalayas in India.
But the bird with the record for the highest altitude ever is the Ruppel’s Griffon Vulture.
The Arctic Tern has the longest migration of any bird in the world. They can fly more than 49,700 miles in a year, making a round trip between their breeding grounds in the Arctic and the Antarctic, where they spend their winters.
Over a lifespan of more than 30 years, the flights can add up to the equivalent of three trips to the moon and back.
The Northern Wheatear travels up to 9,000 miles each way between the Arctic and Africa, giving it one of the largest ranges of any songbird.
What makes this an especially amazing feat is that the tiny bird weighs less than an ounce.
The Bar-tailed Godwit has the longest recorded non-stop flight, flying for nearly 7,000 miles, over eight days, without food or rest.
To prepare for the extremely taxing effort of migration, birds enter a state called hyperphagia, where they bulk up on food in the preceding weeks to store fat, which they’ll later use for energy on their long journeys.
Some, like the Blackpoll Warbler, almost double their body weight before flying 2,300 miles for 86 hours without stopping.
Even birds that don’t fly migrate.
Emus, the large Australian birds, often travel for miles on foot to find food, and many populations of Penguins migrate by swimming.
Migration can be terribly dangerous for birds, and they often don’t make it back to their starting point.
Sometimes natural occurrences like harsh weather play a role, but human activities are the cause of many deaths.
In the United States alone, up to one billion birds die each year from window collisions,
seven million from striking TV and radio towers.
What is life?
It is the flash of a firefly in the night.
It is the breath of a buffalo in the wintertime.
It is the little shadow which runs across the grass
and loses itself in the sunset.
When the earth is sick and dying,
There will come a tribe of people
From all races . . .
Who will put their faith in deeds,
Not words, and make the planet
Green again . . .
— Cree prophecy
The idea of land being preserved for everyone to enjoy was first expressed in 1832 (that’s just 56 years after the birth of United States of America in 1776) and is credited to artist George Catlin. During a trip to the Dakota region in 1832, Catlin, best known for his paintings of Native Americans, pondered the impact the western expansion would have upon these civilizations, the wildlife and the wilderness. He wrote that they might be preserved “by some great protecting policy of government…in a magnificent park…a nation’s park, containing man and beast, in all the wild and freshness of their nature’s beauty.”
Though Catlin’s idea was seemingly impractical at the time and “had no immediate effect,” just 32 years later the “national park idea came to partial fruition in 1864” when President Abraham Lincoln signed an act of Congress to transfer the federally-owned Yosemite Valley and nearby Mariposa Big Tree Grove to the State of California on condition that they would “be held for public use, resort, and recreation . . . inalienable for all time.”
Two years ago, a research team led by the University of Oxford revealed that, when plucked like a guitar string, spider silk transmits vibrations across a wide range of frequencies, carrying information about prey, mates and even the structural integrity of a web.
Now, a new collaboration between Oxford and Universidad Carlos III de Madrid has confirmed that spider webs are superbly tuned instruments for vibration transmission.
Web-dwelling spiders have poor vision and rely almost exclusively on web vibrations for their ‘view’ of the world.
The musical patterns coming from their tuned webs provide them with crucial information on the type of prey caught in the web and of predators approaching, as well as the quality of prospective mates.
Spiders carefully engineer their webs out of a range of silks to control web architecture, tension and stiffness, analogous to constructing and tuning a musical instrument.
High-powered lasers were able to experimentally measure the ultra-small vibrations, which allowed the team to generate and test computer models using mathematical finite element analysis.
Professor Fritz Vollrath, Head of the Oxford Silk Group, added: ‘It is down to the interaction of the web materials, a range of bespoke web silks, and the spider with its highly tuned behaviour and armoury of sensors that allows this virtually blind animal to operate in a gossamer world of its own making, without vision and only relying on feeling. Perhaps the web spider can teach us something new about virtual vision.’
‘Tuning the instrument: sonic properties in the spider’s web’ is published in Journal of the Royal Society http://www.ox.ac.uk/news/2016-09-07-tuning-instrument-spider-webs-vibration-transmission-structures#
wade through black jade. Of the crow-blue mussel-shells, one keeps adjusting the ash-heaps; opening and shutting itself like an injured fan. The barnacles which encrust the side of the wave, cannot hide there for the submerged shafts of the sun, split like spun glass, move themselves with spotlight swiftness into the crevices— in and out, illuminating the turquoise sea of bodies. The water drives a wedge of iron through the iron edge of the cliff; whereupon the stars, pink rice-grains, ink- bespattered jelly fish, crabs like green lilies, and submarine toadstools, slide each on the other. All external marks of abuse are present on this defiant edifice— all the physical features of ac- cident—lack of cornice, dynamite grooves, burns, and hatchet strokes, these things stand out on it; the chasm-side is dead. Repeated evidence has proved that it can live on what can not revive its youth. The sea grows old in it.
Marianne Moore (1887 – 1972)
I am treading deeper and deeper into leaves and silence. I see more faces watching, non-human faces.
Ironically, I who profess no religion find the whole of my life a religious pilgrimage.
Loren Eiseley (1907 – 1977)
Study finds extremely slow reproduction rate unable to keep pace with deaths
African forest elephants have experienced serious poaching, driving an estimated population decline of 65% between 2002 and 2013.
Their low birth rates mean that it will take forest elephants at least 90 years to recover from these losses, according to researchers from the Wildlife Conservation Society, the Cornell Lab of Ornithology’s Elephant Listening Project, Colorado State University, and Save the Elephants.
These findings are from the first-ever study of forest elephant demography just published in the Journal of Applied Ecology.
“Female forest elephants in the Dzanga population typically breed for the first time after 23 years of age, a markedly late age of maturity relative to other mammals. In contrast, savannah elephants typically begin breeding at age 12.
In addition, breeding female forest elephants only produced a calf once every five to six years, relative to the three to four-year interval found for savannah elephants.”
Andrea Turkalo, a Wildlife Conservation Society scientist, collected the detailed data on the elephants over several decades, in spite of tough logistical challenges and political instability.
“This work provides another critical piece of understanding regarding the dire conservation status of forest elephants.”
George Wittemyer, a professor in Wildlife Conservation at Colorado State University said, “Legislation regarding ivory trade must consider the collateral effects on forest elephants and the difficulties of protecting them. Trade in ivory in one nation can influence the pressures on elephants in other nations.”
And the forest elephant is particularly susceptible to poaching.
Forest elephants also have critical ecological roles in Central African forests, and many tree species rely on the elephants to disperse their seeds.
Those forests are vitally important for absorbing climate change gases.