Northern royal albatross on the Chatham Islands. Photo / Canterbury Museum
Northern royal albatross on the Chatham Islands. Photo / Canterbury Museum
In a world first, Kiwi and British scientists have used satellite images to calculate the number of endangered albatrosses living on remote and inaccessible islands.
Researchers from the British Antarctic Survey and Canterbury Museum have shown that the highest resolution satellite imagery is capable of "seeing" these birds from space,allowing researchers to count them on remote islands without ever having to go there.
The study used the new WorldView-3 satellite, which can see objects larger than 30cm.
The team developed and tested the accuracy of the satellite-method by counting individuals on a well-studied colony of wandering albatross on South Georgia, a remote island southeast of Argentina in the southern Atlantic Ocean.
They then applied it to the northern royal albatross, a species that only breeds in New Zealand.
Northern royal albatross on the Chatham Islands. Photo / Canterbury Museum
"This is a major conservation concern for this globally-endangered albatross species," said Professor Paul Scofield, Canterbury Museum's senior curator of natural history.
"This technique will be an invaluable global conservation resource that can give us near-real time information about the status of endangered species.
"The ground-breaking image resolution of the newly-available satellite will provide a step change in our ability to count albatross, large birds and other wildlife directly from space without disturbance, at potentially lower cost and with minimal logistical effort."
People with a slender lower face are about 25 percent more likely to be left-handed, scientists say. Photo / 123RF
People with a slender lower face are about 25 per cent more likely to be left-handed, according to the unexpected results of three national US surveys that covered 13,536 participants.
Scientists say this association may shed new light on the origins of left-handedness, as slender jaws have also been associated with susceptibility to tuberculosis, a disease that has shaped human evolution and which today affects 2 billion people.
Slender jaws are a common facial feature and past surveys measured the prevalence of this condition by evaluating how the upper and lower teeth come together.
People with slender jaws typically had a lower jaw which bites a bit backward, giving them a convex facial profile and what's commonly called an overbite.
"Almost 2000 years ago a Greek physician was first to identify slender jaws as a marker for TB susceptibility, and he turned out to be right," said the University of Washington's Professor Philippe Hujoel, author of the just-published study.
"Twentieth-century studies confirmed his clinical observations, as slender facial features became recognised as one aspect of a slender physique of a TB-susceptible person."
Hujoel said the finding raised the hypothesis that the genetics that shape facial features and tuberculosis susceptibility also increased the likelihood for left-handedness.
Such a hypothesis may explain curious geographical coincidences: the UK was described as the tuberculosis capital of Western Europe, and also had a high prevalence of left-handedness and people with slender faces.
Other populations, such as the Eskimos, were in the 19th century described as tuberculosis-resistant, having robust facial features, and typically depicted in art as showing right-hand dominance with tools and instruments.
Whether this is more than a coincidence needs further exploration, Hujoel said.
Can we thank Medieval Christians for the egg-laying machines that are today's chooks? Photo / 123RF
Can we thank medieval Christians for the egg-laying machines that are today's chooks?
Chickens were domesticated from Asian jungle fowl around 6000 years ago and, since domestication, have acquired a number of traits that are valuable to humans, including those concerning appearance, reduced aggression and faster egg-laying.
It's been a mystery as to when and why these traits evolved, perhaps until now.
An international team of scientists has combined DNA data from archaeological chicken bones with statistical modelling to pinpoint when these traits started to increase in frequency in Europe.
"Ancient DNA allows us to observe how genes have changed in the past, but the problem has always been to get high enough time resolution to link genetic evolution to potential causes," said the new study's lead author, Dr Liisa Loog of Oxford University.
"But with enough data and a novel statistical framework, we now have timings that are precise enough to correlate them with ecological and cultural shifts."
To their surprise they found that this happened in High Middle Ages, around 1000 AD.
Intriguingly these strong selection pressures coincided with increasing urbanisation and Christian edicts that enforced fasting and the exclusion of four-legged animals from the menu.
Could medieval religious rules have increased the demand for poultry and thereby altered chicken evolution?
With the new method, scientists could see that the time of selection coincided with an increase in the amount of chicken bones in the archaeological records across Northern Europe.
Intriguingly, they also coincided with several socio-cultural changes, including a general increase in the popularity of Christian beliefs, new religious dietary rules and increase in urbanisation.
While the researchers could not say which one of these was most important, it was most likely a combination of all the factors that affected selective pressures on European chickens and consequently their evolution.
How young mongooses avoid being killed by their own
If your kids complain about how tough they have it, just tell them about young mongooses, which scientists say may conceal their identity, even from their own parents, to survive.
Killing of pups is common in mongoose social groups, and UK researchers believe offspring may do best if they hide which adults they are related to.
Concealing identity reduces the risk of attack by less-related adults, the researchers say.
But it means mothers may not be able to tell pups apart and, therefore, cannot pay special attention to their own young.
"In most species we would expect mothers target care at their own offspring, but mongooses seem unable to do this," said Dr Emma Vitikainen, of the Centre for Ecology and Conservation at the University of Exeter.
"We think this is because mothers synchronise birth to the same day, and pups may have evolved to conceal their identity.
"In the banded mongoose infanticide is common, and it might be too dangerous for the pups to advertise which adults they are most closely related to, as this could expose them to spiteful behaviour by less-related group members."
A system of adult "helpers" operates in mongoose groups, with adults often looking after pups that are not their own.
They do not choose which young to care for based on relatedness, the researchers said.
Dr Vitikainen added: "Intriguingly, we also found that female helpers tend to pair up with female pups, and male helpers with male pups."
The study also found that females become more likely to act as helpers after they have given birth.
