Yellow-legged gull chicks in their nest (image credit: Contando Estrelas)
Birds and animals emanating alarm calls to warn
their offspring about possible predator presence is a common occurrence in the animal
world. However, a new study published in nature Ecology and Evolution journal shows that Yellow-legged gull eggs which are exposed to such alarm calls can imbibe
that information and pass it on to other nest mates through vibrations,
inducing developmental changes at embryonic stage and also influencing anti-predator
behavior in later life.
As part of the study, the researchers collected 90 eggs from a large
colony of Yellow-legged gulls from Salvora Island in Spain and conducted an
experiment to investigate whether alarm calls about predators ‘heard’ by the
eggs induce anti-predator traits in the chicks when they hatch. They
have created an experimental group – clutches of 3 eggs each, (totaling 45)
which were exposed to alarm calls – and a control group –clutches of 3 eggs (totaling
45) which were not exposed to alarm calls.
Vernal Hanging Parrot (Loriculus vernalis), also known as Indian Hanging Parrot or the Green Hanging Parrot is the smallest of the resident parrots in India. Distributed across North East India, East India, Western Ghats and Bangladesh in the Indian sub continent, Vernal Hanging Parrot is usually found in broad leaved evergreen and moist deciduous forests fringes. Sri Lanka has a close cousin, but a separate resident species known as the Sri Lankan Hanging Parrot (Loriculus beryllinus).
We have recently spotted two himalayan bulbul chicks right out of their nest trying to fly for the first time. Apparently, their nest was inside a bathroom near a house. So when the mother bulbul spotted humans near the chicks who are trying to fly for the first time, it started showing a peculiar behavior.
Watch the Himalayan Bulbul trying to distract the intruders.
The bird, with its wings and tail spread to the maximum view, was literally running all over the place in the opposite direction of where the chicks were siting. It was making a peculiar sound. Obviously, it was pretending as if it can not fly. this could be a way to distract a potentail enemy from the chicks. The intruder by following the prominent and bigger bird than the silent and static chicks will move away from them.
Yellow Coster (Acraea issoria) is a beautiful leathery winged butterfly with a weak but persistent flight, found in countries in the oriental region, like India, Thailand, China, Vietnam, Myanmar and Sumatra. In India, it is seen in the Himalayan foot hills of Uttarakhand, Himachal Pradesh, Arunachal Pradesh, Assam, Mizoram, Nagaland, West Bengal and Sikkim, usually in valleys which are situated at an altitude between 500 to 1500 meters from sea level.
Commander is one of the most beautiful butterflies in India. You may spot this vividly coloured butterfly right from Southern Western Ghats to North Eastern regions. The brilliant reddish brown on its upper side will attract your attention easily.
Usually seen along forest roads, water courses, open places and even close to villages, especially if its larval host plant Mussaenda is available around. If you are planning to take a close look at a Commander, its usual posture of wings pressed flat helps you get a good look. However, if you go close, it will take short flights and keep the distance.
Watch a cute, small Cinereous tit (Parus cinereus) desperately trying to drink from a water tap. Cinereous tit (Parus cinereus) is an interesting small bird which belongs to Paridae and is found in parts of South East Asia, including India. Earlier they used to be considered as a sub species of great tit. this video was recorded from Himachal Prdesh, India
Elephant herds in Silent Valley National Park in Western Ghats of Kerala
(Photo Courtesy: N P Jayan)
Wild tuskers in Southern Western Ghats are
just like birds. Not that they can fly, but like their winged friends,
they play a crucial role in the seed dispersal of some plant species
found in this rare biodiversity hotspot, says researchers who
studied the seed dispersal role of elephants here.According to their study, Asian elephants (Elephas maximus) are important seed
dispersing agents of some fruit bearing plants in the semi-deciduous, thorny
forests of the Nilgiri Biosphere Reserve, the oldest biosphere reserve in India which lies in the Western Ghats.
By examining the fruit seeds and remnants in
elephant dung piles in the study areas, the researchers found that this biggest
terrestrial animal plays a key role in the seed dispersal of at least eight
different plant species found in the area like Acacia intsia (Twisted Acacia),
Artocarpus heterophyllus (Jack Fruit),
Bauhinia racemosa (Bidi Leaf Tree),
Grewia hirsuta (Kukurbicha), Grewia
tiliifolia (Dhaman), Mangifera indica
(Mango), Tamarindus indica (Tamarind)and Ziziphus
mauritiana (Indian jujube). Among these eight, Wild Tamarind and Twisted
Acacia are the favorite fruit of the tuskers, since their presence was significantly more in the dung piles than the other six species, says the study which is published in the Journal of Threatened Taxa.
Earlier research in Asian and African forests have shown that elephants are a very effective seed dispersing agents. They devour huge amount of fruits and carry the seeds to long distances from the parent tree with their behavior of moving to wide-ranging areas. Moreover, seeds are defecated intact. It is also observed that the dung piles often provide a nutritious medium for seed germination.
Fruit
Diet of the Pachyderms in the Nilgiris
The study has also revealed some
interesting insights into the food habits of the wild elephants in Nilgiris.
According to the researchers, elephants in the area consume more fruits during
dry season when compared to the wet monsoon season. “Seeds and other fruit
parts appeared in the dung piles significantly more frequently during the dry
season than in the wet seasons”, says the study.
Moreover, tuskers prefer a fruity diet more
in the thorny forests, than in a moist deciduous area, shows the results of the
study. The study also confirms the sometimes notorious truth of the tuskers’ irresistible
temptation for mango and jack fruits when they are in moist deciduous areas in
NBR. Remnants of both of these fruits were frequently found in the dung piles
from moist deciduous areas. Often, fruiting jack fruit trees are blamed for
wild elephants raiding villages in the forest fringes of NBR.
However, pachyderms have dislikes for certain
items in their fruits menu, says the study. Fruits of Z. mauritiana are less preferred by these animals, as indicated by
the lower presence of these fruit remnants in the dung piles, despite the wide presence of the plant in the forests of NBR.
But don’t misunderstand that the wild elephants
in Western Ghats consider fruits as their favorite item like their African and
Malayan counter parts, reminds the researchers. Grass species like bamboo are
the first preference for tuskers in these areas. Fruits are second or third in
the list. “Elephants consume a lesser number of fruit species in the tropical
dry forests of Nilgiri Biosphere Reserve than in the rainforest habitats of
Asia and Africa”, points out the study.
Asian
Elephant Population in the Nilgiris
The study was carried out in Mudumalai
Wildlife Sanctuary which is presently a Tiger Reserve, Nilgiri North,
Sathiyamangalam and Coimbatore forest divisions, Bandipur Tiger Reserve and
Wayanad Wildlife Sanctuary which all come under Nilgiri Biosphere Reserve.
According to the figures of the last
elephant census, the area holds the one of the largest population of Asian
elephants in the world, with approximately 4,500–5,800 individuals.
During the study period, the research team
extensively followed elephant herds and bulls in these areas. According to the
researchers, they have collected fresh dung piles whenever defecation was
observed. On a total, they have examined 455 elephant dung piles during the
whole study period.
Nagarajan Baskaran and Ajay A. Desai of Bombay Natural History Society have co-authored the study.
Games are an integral part of primate life. It is the same reason which makes sports pages a must in the better primate's newspapers. Studies have shown that animals that lead a social life, including primates use games as a way to teach the young survival tactics and other lessons needed in the life.
Below is a photo series of two young bonnet macaques (Macaca radiata diluta) indulging in wrestling games. Taken from the Agroha temple compound , Hissar in the Indian state of Haryana.
1. Wont let you go just like that !
2. Lets play Undertaker and Triple H
3. Here we go
4 This is a Scissor lock
5. You are done !
6. Want another chance !
As you can see, I was not very good in captioning the pictures. If you have suggestions on better captions, please mention it in the comments. Thank you.
Aralam(Kannur): Marking the beginning of yet another season
of butterfly migration, Aralam Wildlife Sanctuary in Kannur District of Kerala
witnessed a large congregation of Dark blue tiger, Common crow and Double banded crow butterflies of Daniane family at Pothanplavu area of the sanctuary
during the second week of January.
According to sources in the Malabar Natural History Society,
a Calicut based nature organization which conducts a routine butterfly survey
at the sanctuary with the support of Kerala Forests and Wild Life Department to
observe and document migration, there could be more than 3 lakh butterflies
roosting at Pothanplavu area only. During the survey, at least two similar roosts
were reported at different places in the sanctuary. According to sources, the
roosting flies could be a part of large flocks of butterflies which were
reported migrating from Nadukani plains of the Nilambur forest during last week.
Dark Blue Tiger (Tirumala septentrionis) butterflies roosting at Aralam WLS
A roost or congregation is a group of butterflies which perch
on trees or plants, often with limited physical activities and with almost no
feeding. Usually butterflies do not shift their roosting sites every year, so roosts
were earlier observed in Aralam almost in the same places during migration
season.
“During a roost, migrating butterflies live through weeks with limited
or no activity like feeding.” says Dr. Jafer Palot who has conducted studies
about the butterfly migration in the Kerala part of Western Ghats. “However, we
have observed mating behavior among roosting butterflies”, he said during a lecture
to the team members who took part in the survey.
Butterfly roost at Aralam WLS: Video Clip
Common Albatross migration at Aralam Wild life Sanctuary
The survey teams have also reported that the migration rates
of Albatross butterflies from the sanctuary was more this year during the
survey days, unlike last year. According to a press release issued by MNHS, a
peak point of Common Albatross Migration was observed this year with a maximum count
of more than 500 butterflies in 5 minutes time, all along the Cheenganni River
of the Park. Last year, the rate was very minimal, mainly owing to the shrinking
of mud puddling sites, according to sources.
According to researchers and volunteers who took part in the
survey, groups of migrating common albatross butterflies were often followed by
Bluebottle, Great Orange Tip and Painted Saw-tooth butterflies.
The butterfly migration here is usually observed during the end of the winter season and before the starting of summer.The phenomenon has been
routinely observed by the annual butterfly survey for the last twelve years. The survey is the only one to be conducted in any protected areas in India for such a long period to record the changing butterfly diversity
and migration patterns.
Butterfly migration
in South India: Changing notions
Despite 12 years of documentation, the mystery of butterfly
migration in the Kerala part of Western Ghats in general and that to and from
Aralam WLS remains an unsolved mystery for many reasons. Though the migratory behavior
among butterflies were thoroughly studied in many countries (the monarch
migration from US to Canada, for instance), the scholars in the country are yet
to crack the nut of complete secrets of these winged travelers.
Butterflies in mud puddling during migration
“In the early years we thought that the migration flocks
going through the sanctuary were actually coming from Wayanda and were going to
Kodagu in Karnataka through Kottiyoor. However, with the information network
getting wider and people from different parts of the state alert us on any sight
of butterfly swarms moving in particular direction for prolonged period of
time, we now know that the phenomenon is not restricted to a single route or region”,
says Dr. Palot. During their later studies, they have found that the phenomenon
can be mainly connected with altitude, since the general pattern of Common Albatross
migration shows that the flies are moving from high altitude to low altitude
and vice versa during specific seasons.
Though the phenomenon is more correctly understood as altitude
migration now, many questions are still left unanswered. During surveys in 2008,
more than 5000 butterflies were recorded moving down the stream every five
minutes, making a rough figure of 4 lakh butterflies during the season. “We
don’t know how this much butterflies come up together at a time during the
season”, says a researcher. “Neither do
we know where they flies disappear”, adds he.
“There should be sorts
of factory run by nature which produces this much lakhs of butterflies upstream
to trigger large scale migrations,” said Dr Palot while interacting with the
survey teams. It needs thorough investigations, he said.
Dark Blue Tiger (Tirumala septentrionis) and Crow butterflies roosting at Aralam WLS
However, researchers got a clue this time, since one survey
team spotted female Albatross butterflies laying eggs on a lesser known larval
host plants on the migration routes. According to their assumption, the wide
presence of the plant could be the factory which produces tens of thousands of Common
Albatross butterflies during a migration season.
Pale Four- Line Blue
reported from Aralam WLS
According to MNHS sources, the survey has also added a new species
to the butterfly diversity of the sanctuary, with one team spotting and
photographing ‘Pale Four-Line Blue’ from the sanctuary for the first time in
the past 12 years of the survey. With the new report, the sanctuary has 244
different butterfly species, which makes it one among the top protected areas
in the country for its butterfly diversity.
The survey has also recorded more than 140 species of
butterflies from the sanctuary, with rare sightings like Red Spot Duke, Common Onyx,
and the Western Ghats endemic Malabar Tree Nymph. As many as 84 butterfly
watchers from Kerala and Karnataka took part in the camp.
Sharks are one of the most dreaded organisms under water. The
killer label has made them a nightmare for divers all along the globe. However,
a recent study reveals crucial information about the vision of sharks which can
help avert fatal encounters with sharks under water.
Ornate Wobbegong (Orectolobusornatus) Image Courtesy: Peter Halasz
In the study which was published in the Biology Letters, a
team of researchers explains the peculiar vision system in sharks. Existing knowledge
about sharks’ way of looking at things reveals that they are most likely to be color
bind. However, the new study confirms this understanding and exposes the reason
behind.
The single con cell
aka looking at a grey world
The study has analyzed the cone monochromy in two species of
carpet sharks (the spotted wobbegong Orectolobus maculatus and the
ornate wobbegong O. ornatus) at molecular level. Cones are special
type of light sensitive cells inside the retina of the eye of the organism. The
cone cells are used for distinguishing fine details and different colors. They
often work well under brighter light conditions. However, the cone cells in the
eye of sharks can detect light rays from a single spectrum which makes them color
blind.
The researchers have isolated the visual opsin genes of the
two genuses of carpet sharks to search for an answer for the monochromy at
molecular level. During the analysis, the researchers have found that only two
opsin genes were present in the carpet sharks – RH1 and LWS. Among these, RH1
is related to rod cells while LWS is related to cone cells. This analysis
confirms the fact that sharks has only a single cone cell type on their retina,
which in turn explains why sharks may be looking at a grey world.
Rudimentary color
vision
Since their color vision is not functional, researchers consider
a possibility of sharks comparing the signals from the rods and con cells in
their retina at intermediate light levels. Whales actually
have similar vision mechanism. If the sharks also do so, they will
have a rudimental color vision. But researchers were unable to detect any behavioral
evidence to support this theory.
The study is a crucial one about the evolution of color
vision among vertebrates. There are very less studies on color vision in
organisms like sharks, skates and rays. It also points to the trend of convergent evolution - a phenomenon in which unrelated groups of organisms develop similar traits (here color blindness among sharks and whales).
Better understanding,
less conflicts
The study may help develop invisible fishing nets in the future
which will reduce the rate of shark death due to accidental by-catch. This is
presently is the major threat to the shark population in the world. It will
also help make less attractive wetsuits for divers which will reduce fatal
encounters with sharks.
Mating with a virgin female may be a preference among some
human males, possibly decided by their cultural or social training background.
But it is the most preferred option among the fruit fly (Drosophila melanogaster) males, and they make the choice based on a
learning process, says recent research.
It was earlier noticed that male fruit flies which try to
court with already mated females are often rejected by them. However, a
rejected male, more successfully spots virgin females later. It was a mystery that
how the males were able to distinguish mated females from virgins. Now, the mystery
has been unraveled.
cis-Vaccenyl Acetate
(cVA) a.k.a the pheromone key to the mystery
As per the study, a pheromone (particular chemicals produced
by insects to communicate between the members of the community) named cis-Vaccenyl
Acetate (cVA) helps male fruit flies to identify mated females. cVA is usually
deposited on female fruit flies while mating, thus making them different from other
virgin females.
To confirm this, the researchers have disabled the ability in
certain fruit fly males to sense the presence of the pheromone. Later they
found that such males selected already mated females as partners. Similarly,
when they engineered the gens of a group of female fruit flies in such a way
that they will produce cVA without engaging in mating, all other males in the experiment
avoided them mistaking them for already mated.
While trying to unravel the mystery behind how the fruit flies
successfully understood the pheromone signal, the researchers found that the dopamine
levels in their brain have a direct connection to the phenomenon.
Dopamine lessons for the fruit
flies
The research has found that the dopamine level in the brain
in a fruit fly male fluctuate when they come closer to a female for mating. According
to the researchers, the dopamine fluctuation in the presence of cVA on a mated
female and the subsequent rejection by her, function as a learning process in
males. Thus an unsuccessful courtship increases the male fruit fly’s
sensitivity towards the presence of the pheromone, decreasing the chances of it
selecting an already mated female for courtship later.
“The learning
experience can be mimicked by artificial activation of dopaminergic neurons,
and we identify a specific class of dopaminergic neuron that is critical for
courtship learning. These neurons provide input to the mushroom body (MB) γ
lobe, and the DopR1 dopamine receptor is required in MBγ neurons for both
natural and artificial courtship learning”, says the paper.
Thus the study has revealed that
learning triggered by dopaminergic neurons has a major role in deciding the
mating strategies of the fruit flies, and possibly in other insects and
organisms.
If you think only birds and humans sing, you are wrong. A group of scientists has discovered that
elephants also sing just like humans. They
have also found that you may not beat them in singling low-pitch, since elephant
songs are often infrasonic, at 20 Hertz or below frequency. The infrasonic
rumble, according to the scientists, is hardly audible for human beings.
Despite being
low-frequency, the song is audible to a distance of six miles to other elephants,
which is why they use it to communicate and keep in touch with herd members.
Elephant song is no cat’s purr
illustration showing the singing mechanism in elephants
Image courtesy:sciencemag
The discovery sets
aside a wide ranging speculation that the sounds produced by muscle twitching by
neural stimuli as in the case of cat’s purring. The scientists, according to
the paper, have found that the sound was made by the vibration of the vocal
folds when air from the passes through the larynx in a self-sustained manner. It is exactly what happens when humans sing
too.
To find out the secret,
the researchers used the larynx of a dead elephant at a Berlin zoo by setting
it up in the laboratory to record the high speed video clips of the flow-induced
vocal fold movements. Since the larynx was excised, it was clear that there is
no neural stimulus involved.
Young elephants perform like heavy metal singers, when
excited
According to the statement
by a member of the research team, they have also observed some similarities between
young elephants and heavy metal singers. Both of them scream in such a way to
create irregular pattern of vocal fold vibration, often to make it audible like
a scream. The difference is that heavy metal singers do so while performing,
young elephants, when they are highly excited.
The researchers also
claim that the principles they have developed with the help of the observations
can be applied to different mammals.
Christian T. Herbst,
W. Tecumseh Fitch and Angela S. Stoeger of University of Vienna, Roland Frey of
Leibniz Institute for Zoo and Wildlife Research, Jörg Lohscheller of University of Applied
Sciences, Ingo R. Titze of University of Utah and Michaela Gumpenberger of
University of Veterinary Medicine Vienna co-authored the paper.
Lining up ants are a usual sight that has amazed everybody
during their childhood days. While changing environmental conditions and
increased competition trigger nest relocation among ants, how they carry out the
logistics of relocating hundreds of members and resources to the new nest is
very interesting.
It is widely known that the ants keep the line with the help
of trails marked by chemicals from their body called pheromones to reach the
destination. However, a new research has revealed another method, called tandem running
found among Diacamma indicum ants
-a species found in Sri Lanka and India - being used in colony
relocation.
Tandem run is a reason why you find ants doing something like
shaking hands with each other. To initiate
a tandem run, a leader ant, often an adult, will repeatedly make antenna
contact with a potential follower. Then turning around by 180 degrees, the
tandem leader will provide her abdomen to the follower. The follower will then touch
the abdomen of the leader with the antennae signaling that she is ready for the
move. Thus the pair moves to the nest all the while keeping continuous physical
contact.
You believe it or not,
ant colonies were found taking almost same time to relocate to new nests in
this way, no matter what distance they cover. The study found one ant colony which
moved to a shorter distance destination taking as much time as another which traveled
to a distance six times farther. To adjust this, during long distance
relocations, more worker ants took the role of leaders initiating tandem run
which in effect made the relocation faster for the whole colony.
It was also
observed that D. indicum ants allow only the broods and males to be followers,
and they never swap leaders and followers during a tandem run.
Interestingly, D.
indicum ants don’t have an egg-laying queen, unlike many other ant species.
The egg-laying role is taken by a worker ant called gamer-gate. During relocation,
the gamer-gate was either tandem run or self explored to the new nest without
company of retinue, unlike the queen ants in other species.
Honey Bees consider animal urine mixed water as their 'Complan', says a recent research
Honey bees are known to feed on nectar and pollen from flowers. But
ever heard of them sucking waste water, that too from animal dung? A recent
observation on honey bees (Apis dorsata)has revealed that they tend to
flock on water from animal waste found in the sewage tracts of animal sheds mainly to meet
their nutritional needs.
Apis dorsata feeding on waste water from animal sheds
Experiments have revealed that bees often show
some attraction towards water with animal waste content . An average of 33.33
percent bees were attracted towards water with
animal waste content in the experiment while only 20 percent of them were attracted to pure
water. Similarly, stingless bees which belong to subfamily Meliponinae are also known to feed on feces and decaying
flesh, which is less expected from such 'sweet' insects.
The answer to the unexpected phenomenon lies in the
influence certain amino acids have, in the normal growth of a bee. Bees need at least ten different amino acids for their normal growth. Apart from
that, they need water and salts to meet their natural growth requirements.
Thus the usual nature of animal urine gives a complete
planned food option to bees as it contains sodium (Na+), potassium (K), chloride, magnesium
(Mg2+), Calcium (Ca2+) ions, organic molecules like urea, creatinine and uric
acid. Other substances like carbohydrates, enzymes, fatty acids, hormones,
pigments and mucins are also present in small amounts.
So, in short, honey bees consider animal urine mixed water as a health drink - their 'Complan' luring them to to flock on animal waste just as they flock on to flowers for honey.
Did you ever notice such bizarre insect behavior? Let us know in the comments.
.jpg "Drosophila melanogaster")
