Wish you a Very Happy X'mas and New Year.
Have a wonderful time.
Next blogpost will be only on 1st of January
Friday, December 24, 2010
Thursday, December 23, 2010
Mammoths lived all over the world for thousands of years. It could be even millions of years. They became extinct about 10,000 years ago, which was around the time the climate started warming the last time. The extinction is still shrouded in mystery.
A path breaking research by University of Western Ontario researchers on the extinction of prehistoric elephants, lead them to postulate that adapted nursing pattern could have contributed to the prehistoric elephant's eventual extinction. The investigators believe that woolly mammoths north of the Arctic Circle during the Pleistocene Epoch (approx. 150,000 to 40,000 years ago) began weaning up to three years later than modern day African elephants due to prolonged hours of darkness. This adapted nursing pattern could have contributed to the prehistoric elephant's eventual extinction.
Jessica Metcalfe, an Earth Sciences PhD student working with Professor Fred Longstaffe, analyzed the chemical composition of adult and infant mammoth teeth. The scientists say the young ones didn't begin eating plants and other solid foods before the age of two to three. They add that predatory mammals like saber-toothed cats and a lack of sufficient vegetation could be the secondary reasons for delayed weaning.
Metcalfe, who examined fossil specimens alongside Grant Zazula of the Yukon Paleontology Program say that in modern Africa, lions can hunt baby elephants but not adults. They can't kill adults. But they can kill babies and by and large, they tend to be successful when they hunt at night because they have adapted night vision. "In Old Crow mammoths where you have long, long hours of darkness, the infants are going to be more vulnerable, so the mothers nursed longer to keep them close.
Metcalf says “Today, a leading cause of infant elephant deaths in Myanmar is insufficient maternal milk production,". "Woolly mammoths may have been more vulnerable to the effects of climate change and human hunting than modern elephants not only because of their harsher environment, but also because of the metabolic demands of lactation and prolonged nursing, especially during the longer winter months."
Most of the convoluted part of the paper went over my head. Here is a sample from the abstract.
This study investigates differences in the δ13Ccol, δ15N, δ13Csc, δ18Osc, Sr/Ca, and Ba/Ca values of juvenile and adult woolly mammoths (Mammuthus primigenius) from Old Crow, Yukon, Canada. The data indicate that nursing in woolly mammoths lasted at least three years, and was associated with minimal decreases in δ13Ccol (~ 0.2‰), large decreases in δ13Csc (~ 1.5‰), and large increases in δ15N (~ 2‰) and δ18Osc (~ 2‰) values. Sr/Ca and Ba/Ca ratios suggest that woolly mammoth juveniles began consuming plant foods between 2 and 3 “African Elephant Years” of age, much later than the initiation of weaning in modern elephants. We hypothesize that delayed weaning was an adaptation to increased predation risk and decreased food quality/quantity during the extended hours of darkness that occur in winter at high latitudes. Prolonged nursing and delayed weaning may have made mammoths particularly vulnerable to climatic stressors or human hunting.
Nursing, weaning, and tooth development in woolly mammoths from Old Crow, Yukon, Canada: Implications for Pleistocene extinctions
Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 298, Issues 3-4, 15 December 2010, Pages 257-270
Jessica Z. Metcalfe, Fred J. Longstaffe and Grant D. Zazula
Jessica Z. Metcalfe, Fred J. Longstaffe and Grant D. Zazula
Wednesday, December 22, 2010
I have always been fascinated by African elephants. So it was with utter fascination that I read the latest research paper on African elephants. The long standing dispute whether there are two species of African elephant has been finally resolved. Genetic studies by a team of scientists from the US, UK and Germany indicate that African Savannah and forest elephants are two distinct species. They are now the savannah (or bush) elephant, Loxodonta africana, and the forest species, Loxodonta Loxodonta cyclotis.
Savannah elephants weigh about twice the size of forest-dwellers.
The researchers also compared sequences of DNA from the nuclei of African and Asian elephants, and from woolly mammoths and the American mastodon. All are members of the Proboscidae order of mammals. They generated 39,763 bp of aligned nuclear DNA sequence across 375 loci for African savanna elephant, African forest elephant, Asian elephant, the extinct American mastodon, and the woolly mammoth. The authors say “Our data establish that the Asian elephant is the closest living relative of the extinct mammoth in the nuclear genome, extending previous findings from mitochondrial DNA analyses. We also find that savanna and forest elephants, which some have argued are the same species, are as or more divergent in the nuclear genome as mammoths and Asian elephants, which are considered to be distinct genera, thus resolving a long-standing debate about the appropriate taxonomic classification of the African elephants”.
Genomic DNA Sequences from Mastodon and Woolly Mammoth Reveal Deep Speciation of Forest and Savanna Elephants
Nadin Rohland, David Reich, Swapan Mallick,Matthias Meyer, Richard E. Green and Nicholas J.
PLoS Biology: Research Article, published 21 Dec 201010.1371/journal.pbio.1000564e
Tuesday, December 21, 2010
Here comes another post in between my break.
A new species of tropical mistletoe (Helixanthera schizocalyx) discovered on an expedition to Mount Mabu in northern Mozambique tops the list of Kew's botanical discoveries of 2010. The list includes a Vietnamese orchid and an exceptionally rare tree from Cameroon.
Paris japonica, a subalpine plant endemic to Honshu, Japan was found to have the largest genome of any living species studied so far. The genome is 50 times the size of the human genome. Kew site describes it as towering like Big Ben
Others in the list include.
Lustrous Vietnamese orchid (Dendrobium daklakense) discovered in the Dak Lak province of southern Vietnam
Cameroon canopy giant (Magnistipula multinervia) doscovered in the Korup National Park of Cameroon.
14 new species of Madagascan palms
Medicinal aubergine (Solanum phoxocarpum) discovered on an expedition to Kenya's Aberdare mountainous cloud forests.
Wild Irises from the Andes.
Ascension Island parsley fern
The rediscovery of extinct British fungi (Urocystis primulicola).
Click HERE to know more from KEW
Sunday, December 19, 2010
Here is another small post in between my spare time during the break.
I read this very interesting paper about the cognitive ability of dogs to tell another canine's size simply by listening to its growl.
The dogs can match this representation with other features provided by the visual modality. Dogs' growl is context specific and contains information about the caller's body size. A listening dog can find out exactly the other dog's size.
The fascinating piece of research was done by Tamás Faragó, Péter Pongrácz, Ádám Miklósi from the Department of Ethology, Eötvös Loránd University, Budapest, Hungary and Ludwig Huber, Zsófia Virányi, Friederike Range from the Department of Cognitive Biology, University of Vienna, Vienna, Austria and Clever Dog Lab, Vienna, Austria.
In conclusion the researchers say “we have shown for the first time that dogs can match cross-modal information between pictures and sounds and we provided evidence that dogs can assess accurately the size of a growling dog based on the acoustic information. Moreover, our results suggest that dogs are able to perceive species specific information based on pictures.”
Dogs' Expectation about Signalers' Body Size by Virtue of Their Growls
Tamás Faragó, Péter Pongrácz, Ádám Miklósi, Ludwig Huber, Zsófia Virányi, Friederike Range.
Friday, December 17, 2010
I am still in the midst of my break. I just read this interesting paper on human leopard conflict and thought it is worth an immediate post.
Translocation as a Tool for Mitigating Conflict with Leopards in Human-Dominated Landscapes of India
VIDYA ATHREYA, MORTEN ODDEN, JOHN D. C. LINNELL K. ULLAS KARANTH
A few years back, I was pilloried by self styled environmentalists for opposing vehemently the translocation of a leopard from Wayand to Parmabikulam. For the men at the top and for the uninitiated politicians it is a quick fix method for alleviating the man animal conflict. They never bother about the ecological impacts. A release without a comprehensive study of all factors involved is fraught with lot of imponderables.
VIDYA ATHREYA, MORTEN ODDEN JOHN D. C. LINNELL and ULLAS KARANTH have come up with an excellent paper on the impacts of translocation of leopards based on their study in the Junnar region (4275 km2, 185 people/km2), Maharashtra, India. The authors’ report that prior to the large-scale translocation program, there was an average of four leopard attacks on humans each year between 1993 and 2001. Surprisingly after the translocation program was initiated, the average increased to 17 attacks.
The attacks decreased when leopards were removed for releases far away. According to the authors potential explanations for the aberrant behavior include increased aggression induced by stress of the translocation process, movement through unfamiliar human-dominated landscapes following release, and loss of fear of humans due to familiarity with humans acquired during captivity.
The study emphasize the potential ineffectiveness of translocation to reduce human–carnivore conflict The authors suggest that making improvements to the administration of compensation programme for wildlife attacks and linking this to some form of insurance scheme that can be administered by local communities might help increase tolerance for low intensity, chronic predation on livestock by leopards. This is likely to decrease the demand for management action to remove leopards.
I feel this paper is a must read for the wildlife managers. So guys go ahead and read it.
I am thankful to Dr Ullas Karanth for sending me a copy of the paper.
Monday, December 13, 2010
Saturday, December 11, 2010
What do leaf-cutter ants do when their razor-sharp mandibles wear out? They let their more efficient sisters take over cutting, while still remaining productive. The cutting ants rest their blades and join the delivery staff, carrying the discs cut from the leaves into their nest.
The interesting piece of information comes from the research by a four-member team of researchers from the UO and Oregon State University led by Dr Robert Schofield, a scientist at the University of Oregon. Dr Schofield says “While division of labor is well documented in social insects, this is the first suggestion that some social insects stop performing certain tasks because they are no longer as good at them as they used to be. As social organisms, these ants have the luxury of being able to leave the cutting task to their more efficient sisters."
Leaf cutters carry pieces of leaves back to the underground nest where they grow an edible fungus on the resulting substrate. The foragers doing the cutting work are second in size to the majors, the large workers that protect the colony and do heavy clearing work. In addition to cutting, the foragers transport the cuttings and lookout for new resources.
The details will appear in the upcoming issue of journal Behavioral Ecology and Sociobiology. The study has appeared online ahead of regular publication.
Friday, December 10, 2010
Nature has given us lot of drugs from terrestrial vegetation. Now the sea promises to deliver new effective remedies for many of our health related problems. A sea snail has already formed the basis of a new painkiller.
Scientists in UK believe that Starfish could be the key to potential new treatments for inflammatory conditions such as asthma and arthritis.
The scientists are working on spiny starfish (Marthasterias glacialis). What they are interested in is the slimy goo that covers its body.
Dr Charlie Bavington, from GlycoMar, a marine biotechnology company based at the Scottish Association for Marine Science in Oban recently told BBC "Starfish live in the sea, and are bathed in a solution of bacteria, larvae, viruses and all sorts of things that are looking for somewhere to live. But starfish are better than Teflon: they have a very efficient anti-fouling surface that prevents things from sticking."
It is this non-stick property that has fascinated the medical scientists, particularly in the field of inflammation.
Inflammation is the body's natural response to an injury or infection. Inflammatory conditions are caused when the immune system gets skewered. White blood cells, which normally flow easily through our blood vessels, begin to build up and stick to the blood vessel wall. This in turn causes tissue damage.
The researchers believe that starfish slime could effectively coat our blood vessels in the same way the goo covers the marine creature, and this offers a clue for drugs for inflammation.
The team is now working on creating suitable drugs in the laboratory.
Thursday, December 09, 2010
I just read a good paper on conservation planning. The paper titled “Improving the viability of large-mammal populations by using habitat and landscape models to focus conservation planning” was authored by Yongyut Trisurat, Anak Pattanavibool, George A. Gale and David H. Reed.
The authors try to define suitable habitat for sambar (Cervus unicolor), banteng (Bos javanicus), gaur (Bos gaurus), Asian elephant (Elephas maximus) and tiger (Panthera tigris) in the Western Forest Complex, Thailand, and to assess their current status as well as estimate how the landscape needs to be managed to maintain viable populations.
The paper demonstrates a method for combining a rapid ecological assessment, landscape indices, GIS-based wildlife-habitat models and knowledge of minimum viable population sizes to guide landscape-management decisions and improve conservation outcomes through habitat restoration.
The researchers conclude that if managers wish to upgrade the viabilities of gaur, elephant, tiger and banteng within the next 10 years, park rangers and stakeholders should aim to increase the amount of usable habitat by ~2170 km2 or 17%of existing suitable habitats. The key strategies are to reduce human pressures, enhance ungulate habitats and increase connectivity of suitable habitats outside the current distributions.
The paper clearly provides a particularly useful method for managers and forest-policy planners forassessing and managing habitat suitability for target wildlife and their population viability in protected-area networks where knowledge of the demographic attributes (e.g. birth and death rates) of wildlife populations are too limited to perform population viability analysis.
I am indebted to Dr Yongyut Trisurat , Department of Forest Biology, Faculty of Forestry, Kasetsart University, Bangkok 10900, Thailand for sending me a complimentary copy of the paper.
Large numbers of woodcocks crashing in to windows is worrying conservationists in England.
Woodcocks migrate from places like Russia and Finland to the UK to escape harsh winters. Climate in UK is milder and finding food is easier. The birds migrate during the night at a low level.
Reports are pouring in from buildings close to rivers. In all probability the woodcocks are following the rivers on migration and crashing into buildings along the banks.Conservationists say the birds are failing to see buildings and windows, possibly because they are attracted to light. Another reason could be that they mistake reflections in windows for the open sky.
RSPB has advocated fixing an object to the outside of the glass to indicate the obstacle. According to experts of RSPB the most effective shape is likely to be a hawk. Self-adhesive bird silhouettes would do the job. Silhouettes of birds of prey create the instinctive reaction in small birds to avoid it.
Wednesday, December 08, 2010
Conservationists are elated by news emanating from Virunga Massif. A census carried out in the Virunga Massif, where most of the world's mountain gorillas live has come up with a figure of 480 individuals living in 36 groups.
The population has increased by over 25% in the last seven years. This is satisfactory against backdrop of scenario in Africa. Collaborative transboundary effort by organisations in the Democratic Republic of Congo, Rwanda and Uganda has acted as a primer. The mountain gorilla is the only one of the nine subspecies of African great apes experiencing a population increase.
30 years ago, only 250 gorillas survived in Virunga. 302 mountain gorillas are living in Bwindi. Thus the total population works out to 780 now.
Tuesday, December 07, 2010
The mysteries of nature never cease to fascinate me. Here is something amazing that I learned the other day.
Scientists have discovered that oriental Hornets (Vespa orientalis), are capable of harvesting solar energy. The discovery was made by a team of researchers working in Israel and the UK, led by Dr Marian Plotkin of Tel-Aviv University.
The fact that Oriental hornet workers, which dig out nests underground, correlate their digging activity with the intensity of sunlight had always puzzled the researchers. The late Professor Jacob S Ishay had proposed that the insects may somehow be capable of harvesting solar radiation.
The team led by Dr Plotkin's tested this hypothesis, with remarkable results. Using an atomic force microscope, the researchers examined the fine structure of the hornet's cuticle. The clue lay in the structure of the yellow part of the hornet's body. These structures had the ability to stop light being reflected off the hornet's body. The light is trapped, and harvested for energy. Within the cuticle there is a pigment that captures the energy of the sun's rays. This aids the hornets with their energy demanding digging activity, Wow
The details of the discovery appear in the journal Naturwissenschaften.
Monday, December 06, 2010
When one of the world’s rarest birds is sighted it is celebration time for conservationists. Recently some lucky birdwatchers were treated to a once-in-a-lifetime sighting when they observed the rare Peruvian long-whiskered owlet ( Xenoglaux loweryi ) for a lengthy time. Only a handful of people had seen it before. You can count the lucky people on your fingers.
The Owlet is mainly brown with a whitish belly and eyebrow. The large eyes are orange-brown in color. It is a nocturnal bird and is endemic to a small patch of forest in the Andes of northern Peru. Very little is known about the biology of the bird
The bird is so rare that it was discovered only in 1976. For a 26-year interregnum there were no confirmed sightings at all. The estimated population is between 250 and 1000 individuals in the wild. IUCN has classified the species as Endangered.
Saturday, December 04, 2010
Masai Mara ecosystem in Africa which witnesses the largest wildlife migration known to man, every year, is under threat from the noxious weed Parthenium (Parthenium hysterophorus). If left unchecked it will affect 5 million wildebeest, 500,000 Thomson’s gazelle and 200,000 zebra. Serengeti boasts 70 large mammal species and some 500 different bird species.
The new threat compounds problems from existing illegal hunting, land conversion, and fencing. Parthenium can grow from seed to maturity in 4-6 weeks and has an ability to produce 10,000–25,000 seeds. It produces chemicals which inhibit the growth of other plants. If left unchecked it can reduce carrying capacities of habitats of grazing animals by up to 90%.
Geoffrey Howard, IUCN’s Global Invasive Species Programme Coordinator says “Unless action is taken immediately to eradicate known infestations in the Masai-Mara it is not unrealistic to expect a drastic reduction in wildlife populations in the long term as the parthenium rapidly expands as an invading species,”
IUCN has urged international community to work together in support of the Kenyan government. This national and global treasure has to be conserved for our children's grand-children. Time to act is NOW.
Friday, December 03, 2010
World Atlas of Mangroves
This atlas authored by Mark Spalding, Mami Kainuma and Lorna Collins provides a global assessment of the state of the world's mangroves. The full colour atlas contains 60 full-page maps, hundreds of photographs and illustration and a comprehensive country-by-country assessment of mangroves. It covers 124 countries.
Changes in mangrove forest cover worldwide and at regional and national levels have been highlighted. The book also presents a global statistics on biodiversity, habitat area, loss and economic value.
Changes in mangrove forest cover worldwide and at regional and national levels have been highlighted. The book also presents a global statistics on biodiversity, habitat area, loss and economic value.
The book is a very valuable reference book. Highly recommended.
Dr Mark Spalding is Senior Marine Scientist at the Conservation Strategies Division of The Nature Conservancy, UK. Mami Kainuma is the Project Coordinator and a Senior Researcher for the International Society for Mangrove Ecosystems. Japan. Lorna Collins has worked as a research associate for The Nature Conservancy and is currently studying for an MRes in Marine Biology at the University of Plymouth.
Wednesday, December 01, 2010
Here is something interesting. Scientists Dr James E Palardy, and Dr Jon D. Witman of the department of Ecology & Evolutionary Biology, Brown University, USA have discovered that water flow has a net positive effect on the biodiversity of benthic invertebrate communities. Enhanced water flow treatments resulted in higher levels of species density (+56%) and richness (+74%).
The research was done in benthic marine communities of Palau, Maine and Alaska. The researchers wanted to test the following hypothesizes.
(1) Increased water flow velocities lead to increased local species density and species richness and
(2) Water flow generates increased species richness by promoting the increased recruitment of rare species.
The study clearly showed that the assembly and maintenance of diversity within the benthic invertebrate communities is strongly affected by flow. The communities exposed to higher water flow had greater species densities and richness. According to researchers a stronger current would increase the number of species whose larvae would land and settle on a particular area.
The researchers got identical results in two marine regions of the world separated by 4,000 miles with completely different regional diversities. The research clearly demonstrates that water flow is a really strong predictor of how many species are present in a particular area of the ocean.
Sunday, November 28, 2010
The spinoffs from wildlife conservation are enormous. We have only touched the tip of the iceberg. But in our inexorable push for “development” we give scant thought for wildlife conservation. Here is an example of a spinoff from marine conservation.
The low velocity associated with many tidal flows and the difficulty of extracting useful energy from low speed flows had put a damper on the effort to generate electricity from ocean tides. Now researchers from United States Naval Academy have taken a cue from whales to tackle this problem.
The researchers have designed a novel blade modification, which was inspired by humpback whale flippers. The new design has improved stall characteristics and aerodynamic performance .The turbines are very effective in extracting energy at low speeds. Hurray wildlife conservation.
Saturday, November 27, 2010
I read a very interesting paper in the British Ecological Society's journal Functional Ecology. The scientists describe how Whale sharks () use geometry to enhance their natural negative buoyancy. The research at Ningaloo Reef in Western Australia was headed by Dr Adrian Gleiss from Swansea University.
The scientists attached animal-borne motion sensors and accelerometers, to the free-swimming Whale sharks to measure their swimming activity and vertical movement.
The data collected revealed that sharks are able to glide without investing energy into movement when descending, but they had to beat their tails when they ascended. This is because sharks, unlike many fish, have negative buoyancy. The steeper the sharks ascended, the harder they had to beat their tail.
The Whale sharks displayed two kinds of movement modes. One was shallow ascent angles, which minimize the energetic demands of moving in the horizontal while the second movement of steeper ascent angles, optimized the energetic cost of vertical movement. The scientists conclude that geometry plays a crucial role in movement strategies of sharks. Movement geometry significantly affects power requirements in a manner similar to travel speed. Sharks are presumed to shift diving geometry with changing currencies and ecological context.
Moved by that sinking feeling: variable diving geometry underlies movement strategies in whale sharks
Adrian C. Gleiss, Brad Norman,Rory P. Wilson
Article first published online: 24 NOV 2010
Friday, November 26, 2010
Want to make a guess about the most bio-diverse forest on earth? Many people I put this question to said Western Ghats. They are wrong. It is Ecuador's Yasuni National Park. Yasunhas the highest number of species on the planet.one hectare of Yasuní, 644 different species of trees have been identified. ecords for amphibians, reptiles, and bats are also unprecedented.It covers about a million hectares. A single hectare of forest in Yasuní is projected to contain 100,000 different insect species. This biosphere reserve is also the abode of the indigenous Huaorani people.
Yasuni happens to sit atop Ecuador's second largest reserve of crude oil. There are 846 million barrels of recoverable oil reserves. This is a dilemma for the Government. Oil lobby has been eying the area for years. The researchers working in the area have waged an international campaign to protect the location.
It was in 2007 that the Ecuador President Rafael Correa offered the proposal in which his country would, in exchange for several billion dollars, keep the oil indefinitely underground. This proposal has started bearing fruit. United Nations has agreed to oversee a trust fund paid to Ecuador for the project. On August 3rd 2010 the Government of Ecuador and the United Nations Development Programme (UNDP) signed a historic deal establishing a trust fund. The funds would be used by the country to conserve its forests, develop renewable energy, and promote social development.
The Yasuni Initiative urgently needs more international funders .This is needed to offset the tremendous pressure from oil lobby.
Thursday, November 25, 2010
It is a known fact that dramatic increase in obesity has occurred among humans within the last several decades. I was fascinated to read in the journal Proceedings of the Royal Society B. about the increasing levels of obesity in research animals and others living close to humans.
David Allison, a statistical geneticist at the University of Alabama, Birmingham, and his colleagues gathered data on body weights of more than 20,000 adult animals from 24 populations of 8 different species from around North America. All 24 populations of animals, which ranged from primates housed in research facilities to feral rats living in the greater Baltimore area, showed measurable increase in body weight.
Average body weights of captive chimpanzees increased at a rate of 33 percent each decade. It was 9 percent per decade in captive marmosets. Laboratory mice got 12 percent increase every ten years. The average weight of cats increased by almost 10 percent each decade, while dogs' weights increased by 3 percent every decade.
In 23 out of the 24 populations animals were not just overweight, they were plain obese. Read this against the fact that records of exactly what research animals were fed and their housing conditions haven't changed much in the past 50 years.
Scientists suspect that Environmental toxins and viruses could be the causative factors for the aberration. Endocrine disruptors such as bisphenol A (BPA) and some tin-containing compounds have been shown to increase body mass. Adenovirus, have also been linked to significantly increased body mass.