Thursday 30 June 2016
Water of beki river ( near manas national park)
the beutiful water jumping in near manas national park beki river..we cupture this pic some moment ago.
Non-governmental Organisation (NGO) · Barpeta Road, India
love the nature ngo....a non goverment oranagaition estabilished 2010.this ngs mission is save the birds and save nature.the ngo many more social work..live update next post Wednesday 29 June 2016
Tuesday 28 June 2016
Beutiful look at manas national park
the beutiful look at manas natiomal park..this pic shote last winter session. we are ovserve some special moment in birds so capture
Assam Villagers fishing point
Assam Villagers fishing point...the villagar whol day doing hard work and afternoon selling the fish,
the are hard work poupil...tody i am click this beutifull movment......
the area are near manas national park,baksa dirstick katajhar gaon.the are love natura finnaly
KAZIRANGA NATIONAL PARK
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about of manas national park
manas national park is the best park in assam baksa diristic ,at btad.they are many pepule are come for out of india par year. and visit the manas national park..Manas is the closest I have come to seeing paradise on earth in my life - but that was 25 years ago. Today, Manas looks like an aged diva wearing rags, though I think I still caught the familiar sparkle in the eye.
The focus point of Manas National Park is the enchanting Manas River, named after the serpent goddess Manasa. It is the largest Himalayan tributary of the mighty Brahmaputra. Coming down the Bhutan Hills from the north, the crystal clear waters of the Manas river runs through the heart of the 500 sq. km core area of Manas Park. The main tourist spot of Mothanguri, on the northern border of Manas with Bhutan, is situated on the banks of this river.
Situated in the north bank of the Brahmaputra river, in Assam, Manas lies on the international border with Bhutan. It is bounded on the north by the Royal Manas National Park in Bhutan, on the south by populous North Kamrup district and on both east and west by buffer forest reserves which are part of 2,840 sq. Km Manas Tiger Reserve.
Sunday 26 June 2016
jungal run,
100%Saturday 25 June 2016
GREAT TIT TELOMERES, BABY TALK, BRAINY BIRDS
Great Tit Telomeres, Baby Talk, Brainy Birds
This morning, I have three interesting scientific findings related to bird for you. First, birds may age more quickly in urban environments. Maybe everything ages more quickly in urban environments. Second, baby birds learn, or perhaps are taught, song as adults alter the way they produce the song around babies, chirping slowly and clearly, as it were. Third, which we already suspected, bird brains are adjusted to provide extra smartness in a way not seen in mammals.
CITY GREAT TIT (PARUS MAJOR) TELOMERES SHORTENED.
Every time a gene is replicated, or really, a chromosome (during cell division), a bit of the end of a gene may be lost, owing to the way this process happens. Telomeres are repetitive sequences of genetic material sitting at the ends of genes. The Telomere does not contain useful genetic information, but rater, acts as a buffer. A bit of the telomere part of the gene can fall off without a problem. But as cells replicated again and again, you eventually run out of telomere, and the gene may become broken. This is part of the process of aging.
So, aging can be observed by measuring telomere length. The less telomere, the more aging, independently of time.
Scientists studies the telomeres of city dwelling Great Tits (Parus major). They used Great Tits from non-urban and urban areas, and mixed them up through breeding, to rule out any possible family history of telomere length. They found that cit dwelling Great Tits aged faster than expected.
ABSTRACT
Urban environments are expanding rapidly, and with urbanization come both challenges and opportunities for wildlife. Challenges include combating the anthropogenic disturbances such as light, noise and air pollution and lower availability of natural food sources. The benefits are many, including the availability of anthropogenic food sources, breeding boxes and warmer temperatures. Thus, depending on the context, urbanization can have both positive and negative effects on fitness related traits. It is well known that early-life conditions can have lifelong implications on fitness; little is however known about development in urban environments. We reciprocally cross-fostered urban and rural nestling great tits (Parus major L.) to study how growing up in an urban versus rural habitat affected telomere length (TL)—a suggested biomarker of longevity. We show, for the first time, that growing up in an urban environment significantly shortens TL, independently of natal origin (i.e. urban or rural). This implies that the urban environment imposes a challenge to developing birds, with potentially irreversible effects on lifespan.
That’s from Urban environment shortens telomere length in nestling great tits, Parus major by P. Salmón, J. F. Nilsson, A. Nord, and S. Bensch, C. Isaksson, Biology Letters, Royal Society.
BABY TALK
In humans, adults (probably mainly mothers) do this thing called “motherese” which is talking in a way one would normally not talk to another adult, to a baby. You are certainly already familiar with this. Research done quite a while back suggests that this is adaptive. Babies learn certain aspects of langauge better if they get exposure to motherese.
Turns out that adult birds also alter their vocalizations to facillitate learning by baby birds.
Jon Sakata, a professor of neurobiology at McGill, says that songbirds learn vocalizations like humans learn speech. “Songbirds first listen to and memorize the sound of adult songs and then undergo a period of vocal practice–in essence, babbling–to master the production of song.”
Researchers have been studying song learning in birds for some time. But the degree to which social interaction with adult birds contributes to that learning has been unclear. That’s because, unlike this current work, past studies didn’t control for the time exposed to song and the presence of other birds.
In this study, published in the journal Proceedings of the National Academy of Sciences, a group of juvenile zebra finches was allowed to interact with an adult. Another group simply heard adult songs played through a speaker. After a brief period of “tutoring” the juveniles were house individually for months as they practiced their tunes.
Sakata and his team found that avian pupils who socialized with an adult learned the adult’s song much better. That was true even if the social tutoring lasted just one day. In analyzing why this would be so, Sakata and his team made a surprising discovery.
Adult zebra finches change their vocalizations when singing to juveniles. Sakata says just as people speak more slowly and repeat words more often when speaking to infants, so do these birds. “We found that adult zebra finches similarly slow down their song by increasing the interval between song phrases and repeat individual song elements more often when singing to juveniles.”
What’s more, the researchers found that juvenile birds pay more attention to this “baby talk” compared to other songs. And the more the juveniles paid attention, the better they learned.
More on this here, as well as some audio examples for you to listen to.
BIRD BRAINS PACKED WITH NEURONS
Here’s the problem. Neurons are picky and inefficient. Had cells or organelles evolved, way back when, to handle “intelligence” rather than simple information signaling, they may have turned out differently, but that didn’t happen. A result of this evolutionary constraint is that later organisms that build complex neural processing organs (brains) to do advanced brainy things have to work with a cell type that is only fed with one kind of sugar, that requires a fair amount of coddling to operate, and that takes up a lot of space (one cell per bit of information). In humans, which have large brains, the brainy tissue uses up a disproportanate amount of our energy. In an infant, with a devloping brain that is out of proportion in size to it’s body compared to an adult, the total energy required to maintain the brain can be something close to half of the infant’s energy input. This is rather remarkable, when you think of it.
Bird, at least the ones that fly, can’t afford this kind of waste, so bird brains have evolved to be much more efficient than mammal brains. For example, some of that brainy tissue needed to be a singing, territory defending, mate seeking male bird is added during breeding season, and removed later when not needed. Can you imagine what it would be like if mammals could grow brain when needed, discarding it when not needed? Think about that for a moment …
ROBIN EGG BLUE
I recently took a walk off-trail at Papscanee Island in Rensselaer County, New York, taking advantage of deer trails to find my way through the thick brush. I was startled by an American Robin flushing from directly in front of me, not more than three feet away. A closer look at the location the bird flushed from revealed this:
After quickly taking a couple of pictures while the robin cluck-clucked her displeasure I retreated and waited for a few minutes, guarding against cowbirds, until the robin returned to the nest.
Good luck, egg!
RED-SHAFTED NORTHERN FLICKERS FEEDING NESTLINGS
My nestling Red-shafted Northern Flickers (Colaptes auratus) are around two weeks old now and the adults are still entering the nestbox to feed them. According to Birds of North America Online:
“Nestlings huddle at the bottom of the nest until about 11 days old, then for about 1 week they array themselves around the circumference at the bottom of the cavity with their chins and throats pressed against the wall; at 17–18 days they are strong enough and claws sharp enough to cling to cavity walls. At approximately 16 days, tips of bills can be seen at the nest hole, and heads at 21 days.”
I saw no tips of bills at the nestbox entrance but this is what the nestlings looked like in the box.
The female and male were both feeding the young birds, then sometimes eating the nestling’s excrement and sometimes carrying out the fecal sacs.
GUIRA CUCKOO
You could be forgiven for thinking that I only ever post about birds from Costanera Sur in Buenos Aires. TheGuira Cuckoo will make an even dozen galleries from the reserve, but I surprise myself that it has taken this long.
They are common and confiding birds that form small flocks and roost together in a cuckoo knot. The birds that frequent the promenade at Costanera Sur are especially bold and will even try to stare a birdwatcher down rather than give way at the parilla (pop-up café).
They undulate back and forth between the reed beds and the light woodland on the reserve and the wall that lines the promenade. The promenade has been marooned half a kilometre inland after land reclamation created the wetland on the banks of the Rio Plata. The wall provides a convenient place to tick-bathe. The birds raise the feathers on their backs to allow the UV rays to penetrate to the skin. This deters parasites and must just feel good.
Though they disperse a little during the day, the cuckoos form up again during the late afternoon as the sun comes inland and lights the Laguna de los Copios to the east of the promenade.
This is when the Guira Cuckoo looks its best. It can look scruffy and drab in poor conditions, but the evening sun shows up the subtle colour variations and catches details that are otherwise easily missed.
“THANK YOU” IS ALL YOU NEED
Birders are utterly suspicious characters. By Greek law enforcement officers, I had already been taken for a spy. But, seen from the opposite angle, I do not look spylike, more like – a policeman!
A month ago I visited this site, right at the edge of Belgrade for the first time, only to discover that I cannot get into the overgrown area in my low-clearance city car. Hence, I sat, parked in the last street – where the city ends, a coffee mug in my hand, binoculars around my neck, observing anything that flies.
A black VW Touareg 4×4 with darkened windows approaches and I politely offer to move aside, to free the parking spot. A guy is curious what am I doing; watching birds; which birds; these, see that green-and-blue one (a European Bee-eater conveniently sitting on a wire); are you a cop; no, I’m not a cop (laughing at a guy who drives a way too expensive car for this neighbourhood); you’re suspicious, he concludes. Then he adds: No, you’re not a cop, they always come in pairs, they’re pussies, don’t you agree? Yes and no, I said, smiling all the time.
He is puzzled: a policeman watching his house would not offer him a parking spot, yet, he does not know what to make out of me. Cops are all corrupted, he continues (that car vs. this neighbourhood – he probably knows what he is talking about), but I don’t think you’re a cop. Still, you’re suspicious.
The other day, I came at 5.40 am with an ornithologist friend of mine by his Lada 4×4. The Touareg is parked, but no one is to be seen. Over a few obstacles, we follow the dirt track into an abandoned and overgrown claypit.
Although quite a few species will have a second brood (European Starlings among them), in the lowlands, mid-June is the end of the breeding season for many small passerines. I am using one of the last days available for a proper census of the colony of European Bee-eaters.
500 m / 1650 ft long clay buttress in front of us, filled with many holes. Bee-eaters are diggers and they do not use an old nesting cavity, but dig a new one every year. Yet, Starlings cannot dig and are happy to use abandoned cavities.
Tall grass is slowly turning wheat-yellow. One European Hare sits frozen, believing that he is invisible if he doesn’t move. We are sitting in the Lada, having coffee and observing clay cliffs. Bee-eaters spend a lot of time on the wing, balancing in the wind before they enter their holes. Starlings move in flocks, many brown fledglings from the first brood among them.
Calling Eurasian Hoopoe, also a Little Owl… singing Ortolan Bunting… One Eurasian Magpie waits for a Bee-eater to land at the entrance of its nest, only to land on its back, hit it with its beak and pull the unfortunate Bee-eater down into tall grass that hides the gruesome part.
Section by section, we count the new holes and the birds flying in or out, estimating the number of occupied nests and the percentage of Bee-eaters vs. Starlings per each section.
Without slowing, a Common Swift quickly flies into one of the holes! They normally breed inside roof spaces of tall buildings and neither of us has observed them using clay cliffs. Five to six holes (possibly a few more) are occupied by Swifts – the fastest flyers in the bird world, making 110 km / 70 mi per hour actively flapping wings in horizontal flight. Checking the data later, I will find this type of nesting sites recorded in Serbia in the mid-20th century and probably becoming rarer afterwards, although it is currently observed at at least one more site in the country.
Three hours later, the census is done. What to do next? We follow a dirt track uphill, criss-crossed with ravines, to reach the saddle between two hills, with a great view of the claypit and the river Danube in the background. One threatened European Turtle-Dove is in front of us, taking flight as we go further along the ridge towards the higher hill (it is in human nature, I guess – does anyone ever chooses to go for the lower hill?).
A European Honey-buzzard disappears as we enter surprisingly dense and mysterious pine forest overgrown with lianas – a climbing shrub Clematis vitalba, oddly called the Traveller’s Joy. In the south of Europe, pines do not normally appear at this altitude – a mere 260 m / 850 ft – and these ones were clearly planted, some half a century ago. Birds are singing from every direction: Common Nightingales and Chaffinches, Eurasian Blackcaps and Golden Orioles, Great Tits…
We do not know which overgrown track to choose, nor how to get to the nearest forest edge without more deep puddles (I jumped in my seat enough to rip off the page from my notebook), but the general idea is, let’s go downhill and we should find a track leading to the nearest village. Easier said than done, it will turn out to be…
While forest tracks are mostly used by hunters in 4x4s, as we go into the more open areas of peach orchards with Red-backed Shrikes, singing Common (Greater) Whitethroats and Yellowhammers, dirt tracks are now used by farmers driving tractors and cutting deep mud traps. We almost made it, but before the day was over, we needed one such tractor – merely 5 km / 3 mi from the edge of the city!
A farmer who towed us refused to take any money for his assistance, saying that “thank you” is all he needs.
Bee-eaters Belgrade city birds Serbia starlings swifts
WHAT’S IN A NAME: BREWER’S BLACKBIRD
Blackbirds, as a family, often have those simple descriptive names that are easy to mock (Yellow-rumped Warbler, ugh) until a non-birder comes describing such a species to you and asking for an ID. Then you bless the folk wisdom that gave the Red-winged Blackbird, Yellow-headed Blackbird, Brown-headed Cowbird, and even the Rusty Blackbird their names.
Which is not to say that the creeping hand of ornithological nepotism has never touched the blackbirds. TakeBrewer’s Blackbird. It is a bird, and it is indeed black, so that part of the tag is accurate enough. “Brewer’s”, however, comes not from any affinity for barley or baseball but from a buddy of John James Audubon.
Thomas Mayo Brewer was younger than Audubon but less iternant, spending all his life in Boston. There he dedicated himself to his dual passions of science and publishing, combining these interests in work on a number of important books realted to ornithology and oology: afficiandos of books about birds may know his name as the joint author, with Spencer “Baird’s Sparrow” Baird and Robert “Buff-Collared Nightjar” Ridgway, of the three-volume A History of North American Birds published in 1894. The blackbird wasn’t Audubon’s only venture into naming things for the guy; there was also a Brewer’s Duck, but that proved to be a hybrid resulting from the notoriously incontinent habits of Mallards, and it fell by the wayside.
Audubon greatly and sincerely admired Brewer, by all available evidence. After Audubon’s death, however, Brewer managed to put some serious scratches and dents in his own ornithological reputation, first by advocating for the introduction of the House Sparrow to Boston and later by vehemently opposing those who wanted the invasive species eradicated. He was even suspected by his opponents of using his standing with the Boston press to print scurrilous anonymous editorials about them. In the long run, all of this proved to signify nothing, as the sparrows were more than able to take care of themselves.
Spare a thought also for Johann Georg Wagle, assistant to Johann Baptist “Spix’s Macaw” von Spix. He described the Brewer’s Blackbird for science more than a decade before Audubon. As a result, while Brewer still has the distinction of the bird’s common name, he was removed from the binomial in favor of Wagle’scyanocephalus: a nice, plain, blackbird-worthy description of the blue gloss on the male’s head.
Friday 24 June 2016
Birds of manas natinol birds
24th junary Big birds day we are participation the day. we are count manas national park bird
the credit goes to Debobroto saika director wwf north east..thank you,
we are 4 member participet this day.me, Humayun Islam,Gulam Ahmed, and Forhad Ali,and specaly thanks
DFO sir Dhoroni dhar Boro.
Tuesday 21 June 2016
World Birding Destination
One New Years resolution is to blog more. Let’s see if we can kick some life into this great blog. In order not to leave any loose threads, here is the Gran Finale of the somewhat impossible challange to choose what destination (usually a country) is the best in the world for birders. The criteria varies for different people. For some the exoticness of the species one encounters is the main thing, for others the diversity or sheer numbers are more important. And for many travellers simply safety, accessibility, infrastructure and logistics are paramount. What is your key feature to rate a birding destination as the best in the world. You could cast your vote on a destination you have been to or one that you are dying to go to.Saturday 18 June 2016
Male sandpipers do better by choosing sex over sleep
The need to sleep has long plagued scientists. Why do we—and in fact every other animal with a nervous system—spend such large portions of our day sleeping? After all, there are so many other aspects of life that need our attention. Studies have suggested that sleep may function to consolidate memories, help us solve difficult problems, and boost our immune system. However, there’s still no conclusive answer to why sleep is so vital.
This week, one hypothesis is gaining ground. It suggests that sleep is a “state of adaptive inactivity”that conserves energy when activity is either not required or is not particularly advantageous.
In the most recent issue of Science, a group of scientists from the Max Planck Institute for Ornithology tested this theory by looking at a system where near-constant activity, and therefore a lack of sleep, might benefit fitness. In pectoral sandpipers, male fitness is determined by access to females, and at the high Arctic latitudes in which these birds live, extremely long days enable males to engage in near-constant mating displays during periods of high female fertility. If giving up sleep to spend more time wooing potential mates increases the reproductive success of males, sleep in this species might depend more on the value of wakefulness, rather than the benefits of resting.
The researchers recorded electrical activity from the brains and the muscular systems of several male sandpipers via electroencephalogram and electromyogram dataloggers, in order to determine the amount of time the males spent sleeping each day. The sleeping patterns of males varied greatly; some males slept as little as 2.4 hours per day, while others slept more than three times as much. Males that spent the least time sleeping during periods of high female fertility were rewarded; those that slept less interacted with more females, sired young with more females, and sired greater numbers of young overall than males that slept more.
Because male pectoral sandpipers generally return to their breeding grounds yearly, it was possible for the scientists to assess survivorship by using return rates as a proxy; males that didn't return the next year were likely to have died. If sleep deprivation during the breeding season is detrimental to long-term health, males that give up sleep might be less likely to survive until the next year. However, the researchers found that males that were successful in breeding the previous year—those that slept less—were ten percent more likely to return the next year than other males. This suggests that males were not rendered less healthy over the long term by giving up sleep; in fact, they actually returned to breed at greater rates than birds that took more time out of their breeding season to sleep.
The take-home message is surprisingly simple: self-imposed sleep deprivation is positively correlated with both reproductive success and survival in male arctic sandpipers. Furthermore, this study lends some credence to the theory that sleep may not be particularly beneficial when animals have something better to do.
However, the period during which females are fertile is a relatively short three-week window. So males may be able to “catch up” on their sleep after the breeding season when females are not fertile. Additionally, the study did not test any short-term health risks of this strategy, or whether sleep deprivation in these males led to any type of reduced cognitive performance. It is possible that there are ramifications for sleep loss. But, in the grand scheme of biology, reproductive success is what matters, as it determines what traits are passed on to the next generation. And for male pectoral sandpipers, sacrificing sleep for sex appears to be a good strategy.
Male sandpipers do better by choosing sex over sleep
The need to sleep has long plagued scientists. Why do we—and in fact every other animal with a nervous system—spend such large portions of our day sleeping? After all, there are so many other aspects of life that need our attention. Studies have suggested that sleep may function to consolidate memories, help us solve difficult problems, and boost our immune system. However, there’s still no conclusive answer to why sleep is so vital.
This week, one hypothesis is gaining ground. It suggests that sleep is a “state of adaptive inactivity”that conserves energy when activity is either not required or is not particularly advantageous.
In the most recent issue of Science, a group of scientists from the Max Planck Institute for Ornithology tested this theory by looking at a system where near-constant activity, and therefore a lack of sleep, might benefit fitness. In pectoral sandpipers, male fitness is determined by access to females, and at the high Arctic latitudes in which these birds live, extremely long days enable males to engage in near-constant mating displays during periods of high female fertility. If giving up sleep to spend more time wooing potential mates increases the reproductive success of males, sleep in this species might depend more on the value of wakefulness, rather than the benefits of resting.
The researchers recorded electrical activity from the brains and the muscular systems of several male sandpipers via electroencephalogram and electromyogram dataloggers, in order to determine the amount of time the males spent sleeping each day. The sleeping patterns of males varied greatly; some males slept as little as 2.4 hours per day, while others slept more than three times as much. Males that spent the least time sleeping during periods of high female fertility were rewarded; those that slept less interacted with more females, sired young with more females, and sired greater numbers of young overall than males that slept more.
Because male pectoral sandpipers generally return to their breeding grounds yearly, it was possible for the scientists to assess survivorship by using return rates as a proxy; males that didn't return the next year were likely to have died. If sleep deprivation during the breeding season is detrimental to long-term health, males that give up sleep might be less likely to survive until the next year. However, the researchers found that males that were successful in breeding the previous year—those that slept less—were ten percent more likely to return the next year than other males. This suggests that males were not rendered less healthy over the long term by giving up sleep; in fact, they actually returned to breed at greater rates than birds that took more time out of their breeding season to sleep.
The take-home message is surprisingly simple: self-imposed sleep deprivation is positively correlated with both reproductive success and survival in male arctic sandpipers. Furthermore, this study lends some credence to the theory that sleep may not be particularly beneficial when animals have something better to do.
However, the period during which females are fertile is a relatively short three-week window. So males may be able to “catch up” on their sleep after the breeding season when females are not fertile. Additionally, the study did not test any short-term health risks of this strategy, or whether sleep deprivation in these males led to any type of reduced cognitive performance. It is possible that there are ramifications for sleep loss. But, in the grand scheme of biology, reproductive success is what matters, as it determines what traits are passed on to the next generation. And for male pectoral sandpipers, sacrificing sleep for sex appears to be a good strategy.
Male sandpipers do better by choosing sex over sleep
Jerry Oldenettel
ARS' KATE SHAW ON SEX
What we know—and don't know—about the biology of homosexuality
Shifting sexes and sequential hermaphrodites: How sex is determined
Pregnant males and pseudopenises: complex sex in the animal kingdom
A lack of sex drives flies to drink
For fruit flies, the scent of food is sexyView all…
The need to sleep has long plagued scientists. Why do we—and in fact every other animal with a nervous system—spend such large portions of our day sleeping? After all, there are so many other aspects of life that need our attention. Studies have suggested that sleep may function to consolidate memories, help us solve difficult problems, and boost our immune system. However, there’s still no conclusive answer to why sleep is so vital.
This week, one hypothesis is gaining ground. It suggests that sleep is a “state of adaptive inactivity”that conserves energy when activity is either not required or is not particularly advantageous.
In the most recent issue of Science, a group of scientists from the Max Planck Institute for Ornithology tested this theory by looking at a system where near-constant activity, and therefore a lack of sleep, might benefit fitness. In pectoral sandpipers, male fitness is determined by access to females, and at the high Arctic latitudes in which these birds live, extremely long days enable males to engage in near-constant mating displays during periods of high female fertility. If giving up sleep to spend more time wooing potential mates increases the reproductive success of males, sleep in this species might depend more on the value of wakefulness, rather than the benefits of resting.
The researchers recorded electrical activity from the brains and the muscular systems of several male sandpipers via electroencephalogram and electromyogram dataloggers, in order to determine the amount of time the males spent sleeping each day. The sleeping patterns of males varied greatly; some males slept as little as 2.4 hours per day, while others slept more than three times as much. Males that spent the least time sleeping during periods of high female fertility were rewarded; those that slept less interacted with more females, sired young with more females, and sired greater numbers of young overall than males that slept more.
Because male pectoral sandpipers generally return to their breeding grounds yearly, it was possible for the scientists to assess survivorship by using return rates as a proxy; males that didn't return the next year were likely to have died. If sleep deprivation during the breeding season is detrimental to long-term health, males that give up sleep might be less likely to survive until the next year. However, the researchers found that males that were successful in breeding the previous year—those that slept less—were ten percent more likely to return the next year than other males. This suggests that males were not rendered less healthy over the long term by giving up sleep; in fact, they actually returned to breed at greater rates than birds that took more time out of their breeding season to sleep.
The take-home message is surprisingly simple: self-imposed sleep deprivation is positively correlated with both reproductive success and survival in male arctic sandpipers. Furthermore, this study lends some credence to the theory that sleep may not be particularly beneficial when animals have something better to do.
However, the period during which females are fertile is a relatively short three-week window. So males may be able to “catch up” on their sleep after the breeding season when females are not fertile. Additionally, the study did not test any short-term health risks of this strategy, or whether sleep deprivation in these males led to any type of reduced cognitive performance. It is possible that there are ramifications for sleep loss. But, in the grand scheme of biology, reproductive success is what matters, as it determines what traits are passed on to the next generation. And for male pectoral sandpipers, sacrificing sleep for sex appears to be a good strategy.
Male sandpipers do better by choosing sex over sleep
Jerry Oldenettel
ARS' KATE SHAW ON SEX
What we know—and don't know—about the biology of homosexuality
Shifting sexes and sequential hermaphrodites: How sex is determined
Pregnant males and pseudopenises: complex sex in the animal kingdom
A lack of sex drives flies to drink
For fruit flies, the scent of food is sexyView all…
The need to sleep has long plagued scientists. Why do we—and in fact every other animal with a nervous system—spend such large portions of our day sleeping? After all, there are so many other aspects of life that need our attention. Studies have suggested that sleep may function to consolidate memories, help us solve difficult problems, and boost our immune system. However, there’s still no conclusive answer to why sleep is so vital.
This week, one hypothesis is gaining ground. It suggests that sleep is a “state of adaptive inactivity”that conserves energy when activity is either not required or is not particularly advantageous.
In the most recent issue of Science, a group of scientists from the Max Planck Institute for Ornithology tested this theory by looking at a system where near-constant activity, and therefore a lack of sleep, might benefit fitness. In pectoral sandpipers, male fitness is determined by access to females, and at the high Arctic latitudes in which these birds live, extremely long days enable males to engage in near-constant mating displays during periods of high female fertility. If giving up sleep to spend more time wooing potential mates increases the reproductive success of males, sleep in this species might depend more on the value of wakefulness, rather than the benefits of resting.
The researchers recorded electrical activity from the brains and the muscular systems of several male sandpipers via electroencephalogram and electromyogram dataloggers, in order to determine the amount of time the males spent sleeping each day. The sleeping patterns of males varied greatly; some males slept as little as 2.4 hours per day, while others slept more than three times as much. Males that spent the least time sleeping during periods of high female fertility were rewarded; those that slept less interacted with more females, sired young with more females, and sired greater numbers of young overall than males that slept more.
Because male pectoral sandpipers generally return to their breeding grounds yearly, it was possible for the scientists to assess survivorship by using return rates as a proxy; males that didn't return the next year were likely to have died. If sleep deprivation during the breeding season is detrimental to long-term health, males that give up sleep might be less likely to survive until the next year. However, the researchers found that males that were successful in breeding the previous year—those that slept less—were ten percent more likely to return the next year than other males. This suggests that males were not rendered less healthy over the long term by giving up sleep; in fact, they actually returned to breed at greater rates than birds that took more time out of their breeding season to sleep.
The take-home message is surprisingly simple: self-imposed sleep deprivation is positively correlated with both reproductive success and survival in male arctic sandpipers. Furthermore, this study lends some credence to the theory that sleep may not be particularly beneficial when animals have something better to do.
However, the period during which females are fertile is a relatively short three-week window. So males may be able to “catch up” on their sleep after the breeding season when females are not fertile. Additionally, the study did not test any short-term health risks of this strategy, or whether sleep deprivation in these males led to any type of reduced cognitive performance. It is possible that there are ramifications for sleep loss. But, in the grand scheme of biology, reproductive success is what matters, as it determines what traits are passed on to the next generation. And for male pectoral sandpipers, sacrificing sleep for sex appears to be a good strategy.
New study rearranges family tree of birds
The typical narrative about the asteroid-driven mass extinction that occurred 65 million years ago is that it killed off all the dinosaurs and enabled the era of the mammals. That could just be what the dinosaurs want you to think, though. From a different perspective, the aftermath of the extinction saw an explosion of dinosaur diversity, producing the greatest number of living species among any group of tetrapods (vertebrates with four limbs).
We just happen to call those species birds.
The fact that the origins of major groups of birds was so sudden makes it difficult to figure out the evolutionary relationships among them, as the fossil record, when present, shows groups appearing at roughly the same time. A recent attempt to sort out relationships via DNA sequences put some species in close proximity that some in the field found surprising. Now, a new paper is out with a different approach—it rearranges the tree a bit and suggests that many modern birds are descendants of a raptor-like ancestor.
The contrast between the techniques can be considered a difference between depth and breadth. The earlier effort, which we'll call depth, involved obtaining complete genomes from 40 different species of birds. The new one goes broader; it uses only a portion of the genome (a bit under a fifth of a typical bird-sized genome), but analyzes data from nearly 200 species.
The problem breadth is supposed to solve is something called "long branch attraction." It's caused by a basic feature of DNA: when a single base mutates, it only has three possible options that it can change into. As a result, lineages that aren't closely related can, over time, start to look a bit like each other. This is especially problematic when the two branches were separated deep in time (hence, the "long branch" of the name).
The best way to deal with this is simply to add more species. These tend to break up the branches and create clusters of species where there were once individual ones. The clusters more clearly show which groups are most closely related. By analyzing roughly five times as many species, some of the groups of the earlier analysis ended up being broken up and rearranged.
The results are, on some levels, fairly intuitive. All existing water birds—diving, wading, and shore-based—end up in a single group. So do all cranes and the species we'd already thought were their close relatives. When the dates of fossils are used to analyze the time when groups branched off, the results are consistent with a rapid diversification after the mass extinction. In fact, one lineage, which currently contains a single species (the Hoatzin), appears to have branched off from other bird species 64 million years ago.
The results also suggest that the majority of the birds we're familiar with may be the descendants of a raptor-like predator. (We're talking modern raptors, like eagles, rather than the Jurassic Park sort). Hawks are a sister group to land birds. Falcons are a sister group of parrots and their relatives. The fact that all these groups have a raptor as a relative seems to indicate that these groups all had a raptor ancestry.
Obviously, there's still the possibility that looking at more species will shuffle the branches of the evolutionary tree a bit further. And further fossil finds could shift the dates as well. But for now, this seems to be the last word on the origin of the birds, a question the authors call "the greatest unresolved challenge in dinosaur systematics."
New study rearranges family tree of birds
Enlarge / The new data indicates that hoatzins, shown here, are the last survivors of a lineage that branched off shortly after the rest of the dinosaurs went extinct.
Cláudio Dias Timm
The typical narrative about the asteroid-driven mass extinction that occurred 65 million years ago is that it killed off all the dinosaurs and enabled the era of the mammals. That could just be what the dinosaurs want you to think, though. From a different perspective, the aftermath of the extinction saw an explosion of dinosaur diversity, producing the greatest number of living species among any group of tetrapods (vertebrates with four limbs).
We just happen to call those species birds.
The fact that the origins of major groups of birds was so sudden makes it difficult to figure out the evolutionary relationships among them, as the fossil record, when present, shows groups appearing at roughly the same time. A recent attempt to sort out relationships via DNA sequences put some species in close proximity that some in the field found surprising. Now, a new paper is out with a different approach—it rearranges the tree a bit and suggests that many modern birds are descendants of a raptor-like ancestor.
The contrast between the techniques can be considered a difference between depth and breadth. The earlier effort, which we'll call depth, involved obtaining complete genomes from 40 different species of birds. The new one goes broader; it uses only a portion of the genome (a bit under a fifth of a typical bird-sized genome), but analyzes data from nearly 200 species.
The problem breadth is supposed to solve is something called "long branch attraction." It's caused by a basic feature of DNA: when a single base mutates, it only has three possible options that it can change into. As a result, lineages that aren't closely related can, over time, start to look a bit like each other. This is especially problematic when the two branches were separated deep in time (hence, the "long branch" of the name).
The best way to deal with this is simply to add more species. These tend to break up the branches and create clusters of species where there were once individual ones. The clusters more clearly show which groups are most closely related. By analyzing roughly five times as many species, some of the groups of the earlier analysis ended up being broken up and rearranged.
The results are, on some levels, fairly intuitive. All existing water birds—diving, wading, and shore-based—end up in a single group. So do all cranes and the species we'd already thought were their close relatives. When the dates of fossils are used to analyze the time when groups branched off, the results are consistent with a rapid diversification after the mass extinction. In fact, one lineage, which currently contains a single species (the Hoatzin), appears to have branched off from other bird species 64 million years ago.
The results also suggest that the majority of the birds we're familiar with may be the descendants of a raptor-like predator. (We're talking modern raptors, like eagles, rather than the Jurassic Park sort). Hawks are a sister group to land birds. Falcons are a sister group of parrots and their relatives. The fact that all these groups have a raptor as a relative seems to indicate that these groups all had a raptor ancestry.
Obviously, there's still the possibility that looking at more species will shuffle the branches of the evolutionary tree a bit further. And further fossil finds could shift the dates as well. But for now, this seems to be the last word on the origin of the birds, a question the authors call "the greatest unresolved challenge in dinosaur systematics."
New study rearranges family tree of birds
The typical narrative about the asteroid-driven mass extinction that occurred 65 million years ago is that it killed off all the dinosaurs and enabled the era of the mammals. That could just be what the dinosaurs want you to think, though. From a different perspective, the aftermath of the extinction saw an explosion of dinosaur diversity, producing the greatest number of living species among any group of tetrapods (vertebrates with four limbs).
We just happen to call those species birds.
The fact that the origins of major groups of birds was so sudden makes it difficult to figure out the evolutionary relationships among them, as the fossil record, when present, shows groups appearing at roughly the same time. A recent attempt to sort out relationships via DNA sequences put some species in close proximity that some in the field found surprising. Now, a new paper is out with a different approach—it rearranges the tree a bit and suggests that many modern birds are descendants of a raptor-like ancestor.
The contrast between the techniques can be considered a difference between depth and breadth. The earlier effort, which we'll call depth, involved obtaining complete genomes from 40 different species of birds. The new one goes broader; it uses only a portion of the genome (a bit under a fifth of a typical bird-sized genome), but analyzes data from nearly 200 species.
The problem breadth is supposed to solve is something called "long branch attraction." It's caused by a basic feature of DNA: when a single base mutates, it only has three possible options that it can change into. As a result, lineages that aren't closely related can, over time, start to look a bit like each other. This is especially problematic when the two branches were separated deep in time (hence, the "long branch" of the name).
The best way to deal with this is simply to add more species. These tend to break up the branches and create clusters of species where there were once individual ones. The clusters more clearly show which groups are most closely related. By analyzing roughly five times as many species, some of the groups of the earlier analysis ended up being broken up and rearranged.
The results are, on some levels, fairly intuitive. All existing water birds—diving, wading, and shore-based—end up in a single group. So do all cranes and the species we'd already thought were their close relatives. When the dates of fossils are used to analyze the time when groups branched off, the results are consistent with a rapid diversification after the mass extinction. In fact, one lineage, which currently contains a single species (the Hoatzin), appears to have branched off from other bird species 64 million years ago.
The results also suggest that the majority of the birds we're familiar with may be the descendants of a raptor-like predator. (We're talking modern raptors, like eagles, rather than the Jurassic Park sort). Hawks are a sister group to land birds. Falcons are a sister group of parrots and their relatives. The fact that all these groups have a raptor as a relative seems to indicate that these groups all had a raptor ancestry.
Obviously, there's still the possibility that looking at more species will shuffle the branches of the evolutionary tree a bit further. And further fossil finds could shift the dates as well. But for now, this seems to be the last word on the origin of the birds, a question the authors call "the greatest unresolved challenge in dinosaur systematics."
Parrot in captivity manufactures tools, something not seen in the wild
Figaro in action, showing just how awkward it is to manipulate tools with a hooked beak.
Oxford University
Tool use was once thought to be one of the defining features of humans, but examples of it were eventually observed in primates and other mammals. But the biggest surprise came when birds were observed using tools in the wild. After all, birds are the only surviving dinosaurs, and mammals and dinosaurs hadn't shared a common ancestor for hundreds of millions of years. In the wild, tool use has been limited to the corvids (crows and jays), which show a variety of other complex behaviors—they'll remember your face and recognize the passing of their dead.
Parrots, in contrast, have mostly been noted for their linguistic skills, and there has only been very limited evidence that they use anything resembling a tool in the wild (primarily, they seem to use external objects to position nuts while feeding). But a captive cockatoo has now been observed using multiple steps to process a tool, behavior that appears to be completely spontaneous. And it hasnever been seen in this species in the wild.
The bird in question is Figaro, a male Goffin’s cockatoo. The species is native to a group of islands in Indonesia, but Figaro has been living outside of Vienna, where he's watched over by members of the local university's Department of Cognitive Biology. Contrary to what you might expect, Figaro wasn't undergoing any sort of elaborate testing routine when his toolmaking abilities emerged. Instead, he was playing with a stone. And, apparently, Figaro was a bit clumsy with his toy, as he dropped it behind a metal divider.
After failing to retrieve it with his claw, however, the researchers were surprised to see Figaro fly off, retrieve a piece of bamboo, and use that to try to push the stone back where he could access it. The attempt failed, but the researchers were intrigued enough that they gave the cockatoo a bit of added incentive by placing a nut on the other side of the metal screen.
Figaro initially picked up a stick from the enclosure's floor, but this proved to be too short to reach the food. So, he actually splintered off a piece of the enclosure's wooden base, and successfully used that to pull the nut towards the wire until he could use his beak to grab it.
Figaro used a different tool in each subsequent trial, and in most cases made some modifications to it before successfully retrieving a nut. In at least one case, he performed four separate modifications before putting a stick to use in retrieving the nut. He also managed to use the tool in two different ways, often alternating dragging and sweeping motions in his efforts to pull the food within reach.
After observing this, the authors used the same setup to test another male cockatoo, but he showed no indications of tool use. But a female who witnessed Figaro in action (she was in the cage "to avoid the stress of isolation") showed the impressive abilities of birds to absorb social information. Heidi, the bird in question, attempted to insert sticks into the enclosure, as she had seen Figaro do. She did not, however, adjust their sizes or attempt to manipulate them once they were on the same side of the wire mesh as the nut. Perhaps if she had been given more time to observe Figaro at work (he chased her off), she might have had a greater sense of how to use the sticks.
The authors conclude that tool use is within the cognitive capacity of this species, even though they have never been observed using tools in the wild. They're not sure why Figaro had the breakthrough that he did, but it's clear that the behavior, once learned, was sticking around.
The authors note the corvids and parrots are so widely separated within the birds' evolutionary tree that it's unlikely that they had a common, tool-using ancestor. They argue that, although we tend to think of tool use as a distinctive mental capacity, it might be more accurate to consider it as a possible outcome of having some minimum level of what they call "physical intelligence." Goffin’s cockatoos don't normally exercise this capacity but, under the right circumstances, it can be uncovered.
The paper doesn't suggest what their next planned steps are. But I'm intrigued by the possibility that they might allow other members of their flocks to watch Figaro in action. It would provide both an interesting test of birds' ability to engage in social learning. And it could provide a better idea of whether all Goffin’s cockatoos have the same physical intelligence demonstrated by Figaro.
Bird brains are dense—with neurons
What do you think they're using all those neurons for?
Flickr user Teddy Llovet
Birds are smart. They use tools, engage in social learning, plan for the future, and do a variety of other things that were once thought to be exclusively the stuff of primates. But hundreds of millions of years of evolution separate mammals and birds, and structurally, their brains look very distinct. Plus there's the whole size thing. If you look at a bird's head, it's clear that there's not a whole lot of space for mental hardware in it. So how do the birds manage with smaller brains?
While other studies have tackled a lot of the structural differences, a new one released this week in PNAS shows that, to some extent, size doesn't matter. Its authors show that birds pack neurons into their brains at densities well above densities in mammals' brains, putting some relatively compact bird brains into the same realm as those of primates when it comes to total cell counts.
And the funny thing is, we probably should have known this was the case.
If you look at a typical avian brain without knowing much about brains, you'll mostly be impressed by the size (or lack of it). Some of the heaviest brains in birds are found in the macaws, and those weigh in at under 25 grams. The raven, a large bird with a well-deserved reputation for intelligence, has a brain that is typically around 15g. That's in the same neighborhood as a rabbit.
If you know your way around some neuroanatomy, however, other things will stand out. Many of the structures we associate with higher cognition in mammals (and especially in primates) either aren't clearly there or look rather different in birds, which suggests that bird cognition has to be radically different from the cognition in mammals.
But as we have identified the proteins that act as key regulators of mammalian brain development, we have discovered that the same proteins are all there in birds, too. Tracking their expression as the brain develops has allowed us to determine that some of the brain structures that look physically different in birds and mammals actually have the same developmental history and express the same suite of genes when mature. Finally, manipulating the activity of these genes affects bird and mammalian brains in similar ways.
So, all the same basic pieces seem to be there in both birds and mammals, which leaves the issue of raw horsepower. Mammalian brains are simply so much bigger that it seems inevitable that they could get more done.
But size isn't everything. Neural capabilities seem to be based on the number of neurons present, as well as the number of connections they can establish. Could birds simply cram more neurons into the same amount of physical space and thus get more done with a smaller brain?
We should have expected that answer to be yes. It turns out that flying animals tend to reduce the size of their genomes compared to their non-flying kin. This is the case for both bats and birds. One consequence of this smaller genome is that the cells that carry these genomes end up smaller as well. That tendency has been used to argue that the group of dinosaurs that evolved into birds had already been experiencing a shrinking genome for millions of years beforehand.
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SOME DINOSAURS WERE POISED FOR FLIGHT
A new study suggests that the dinosaur lineage that gave rise to birds had a …
But we could just as easily have applied that logic to neurons. If birds' cells are smaller, more cells can be squeezed into the same volume. Under those circumstances, a small brain wouldn't be as much of a liability as it appears. But logic only gets you so far, so a team of researchers set out to try to count all the neurons in the brains of a range of birds, mostly from the songbirds, corvids, and parrots.
Small songbirds, which weigh as little as 4.5g, really do have small brains. Their brains can weigh as little as a third of a gram and only contain about 100 million neurons. But the heavier birds can have brains that weigh more than a dozen grams and pack in more than 2 billion neurons. On average, birds have twice as many neurons per unit mass as mammals do. So a bird called the goldcrest, which Wikipedia introduces as "a very small passerine bird," weighs a bit more than 10 percent of your average mouse but has more than double the neurons.
The largest parrot brains, by contrast, weigh in at 20g, even though parrot body mass is similar to the heaviest songbirds. The parrot brain also has more than 3 billion neurons. In fact, when it comes to the largest corvids and parrots, the authors write that "their total numbers of neurons are comparable to those of small monkeys or much larger ungulates."
Those cells also have an interesting distribution: as more cells are added, they're preferentially added to a region of the brain called the pallium, which in humans handles things like spatial reasoning, language, and memory. As a result, this area has an impressive number of cells. Ravens and keas (a type of parrot that does live in the fjords) have more neurons in the pallium than a Capuchin monkey. A macaw has more than a rhesus monkey.
As with size and weight, there's no simple relationship between the number of neurons in a brain and its capabilities. But the work certainly presents an argument that we shouldn't assume the thought processes of birds have to be limited by their brains' size. And the authors even suggest there might be some advantages; with more neurons packed closer together, signals shouldn't typically have to travel as far before reaching their destination. Thus, birds might perform information processing a bit more quickly than mammals.
Friday 17 June 2016
AFRICAN PENGUIN
Habitat:
Hot sandy areas near the ocean
When you picture penguins, you imagine snow and ice, not sandy beaches, right? That is almost always the case! However, the pint-sized African penguin Spheniscus demersus is one of the few penguin species that is not found in a cold environment. They live in the warm coastal areas of southern Africa and on some surrounding islands. One of the African penguin's most distinctive features is a small pink gland above each eye, which helps them cope with high temperatures in South Africa. The hotter the penguin gets, the more blood is sent to these glands where it is cooled by the surrounding air, and keeps the animal cooler. The glands have a pinker appearance the hotter it gets.
Black and white and cute all over
While the African penguin may not be found in freezing temperatures, they are covered in an array of black, white, and gray dense, waterproof feathers that keep them dry and warm in the cold waters off the African coast. They also have a number of dot-like markings flecked across their white chests. These flecks help to individualize each penguin, as each penguin's feather pattern is as individual as a human's fingerprints. The animal has a distinct sharply pointed beak and black feet. The African penguin is one of the smallest species. Males are generally slightly larger than their female counterparts.
Thursday 16 June 2016
Flora in Kaziranga
Search Results
The flora in Kaziranga National Park chiefly constitute of three major types: alluvial inundated grasslands comprising of tall thickets of elephant grass and short grasses, tropical wet evergreen forests and tropical semi-evergreen forests. But, the main characteristics of flora in Kaziranga are the dense and tall elephant grass intermixed by small swamplands left behind by the receding floodwaters of the river Brahmaputra.
In addition to grasses and forests, the swamps of Kaziranga National Park have an abundant cover of water lilies, water hyacinth and lotus, providing a beautiful look to the surroundings of the park. Rattan Cane, which is a type of climbing palm, also adds to the natural beauty of Kaziranga National Park. According to a Landsat data for 1986, the different vegetation coverage in Kaziranga National Park is as follows: Tall thickets of elephant grasses 41%, short grasses 11%, open jungle 29%, rivers and water bodies 8%, sand 6% and swamps 4%.
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