A Walk by the River

...nature-trail along Thames river

A cold breeze swept across the street and hushed the rustling leaves in the corners. Fall neared its end, and the breeze cleared the way for winter. It was a fine day, as the sun warmed the earth’s surface and the bright blue color spilled across a cloudless sky. What a day to explore, thought I.

It had been months since I went on a proper nature-walk, so I did not want to miss the opportunity and the fantastic weather. I went to the Thames River watershed, a beautiful place to explore some fauna. Although the season was not right, I did come across some hardy species that could withstand the near zero temperatures. My wish was to capture everything I could, and learn more about the North American flora and fauna, but the White-tailed Deer, although common, topped my wish list!

The landscape was dry for most part and I walked on a thick blanket of golden brown leaves, covering every part of the forest floor. I hunted for mushrooms in the litter, but bad luck, everything was bone dry! The crumbling noise of dead leaves, the sweet music of the river, the song of chickadees and quacking geese was welcoming indeed. I was home.

I went to the river first, following the quacking Canadian Geese as they swam by merrily, and watched me curiously. That was quite a sight, and I heard them all along the trail. Canadian goose is very common at the river, and a cluster of them is often seen flying during dusk. This goose is native to N. America, and breeds in Canada and northern US.

“By the early 20th century, over-hunting and loss of habitat in the late 1800s and early 1900s had resulted in a serious decline in the numbers of this bird in its native range.” Wikipedia

Ironically, today, the Canadian Geese population is considered as pests in some parts, for reasons such as their droppings and the bacteria in their droppings, noise and ‘confrontational’ behavior.

Canadian Geese Call can be heard HERE

Northern Cardinal, male - image was taken in October'09

I walked upstream, and had a glimpse of a male Northern Cardinal, a beautiful brightly colored bird that is hard to go unnoticed. But like any other bird, one glance at this fellow and he is gone!

“The Northern Cardinal is a territorial song bird. The male sings in a loud, clear
whistle from the top of a tree or another high location to defend his territory.
He will chase off other males entering his territory. The Northern Cardinal
learns its songs, and as a result the songs vary regionally. It is able to
easily distinguish the sex of another singing Northern Cardinal by its song
alone.” Wikipedia

It has a fantastic call that can be heard HERE

As I strolled further, I spotted few Black Capped Chickadees on the canopy, flittering around from branch to branch and picking insects on the barks and in thickets. These birds are so quick that I haven’t had the opportunity to click any yet. It is a bird of the Tit family, and is a curious one. One of these did come down to see what I’m doing over there! This behavior is reported in rural or forested areas according to Wikipedia.

“During the fall migration and winter, chickadees often flock together. Many other species of birds, including titmice, nuthatches, and warblers can often be found foraging in these flocks. Mixed flocks stay together because the chickadees call out whenever they find a good source of food. This calling out forms cohesion for the group, allowing the other birds to find food more efficiently. When flocking, Black-capped Chickadees soon establish a rigid social hierarchy.” Wikipedia

To listen to its call go HERE

With all the birds busying themselves, keeping their distance from me, I was amazed to see a moth out of nowhere! It fluttered happily around the dried grass blades, and settled in a bush. What a sight, I told myself, how long had it been since I saw a butterfly, or even a moth for that matter? Three months to be exact. Three months is a long time, if you come from a tropical country and see no butterfly!

So I took some pictures, and passed it onto the Marvellous in Nature and Dave - helped me identify it.

The moth is Alsophila pometaria - the Fall Cankerworm Moth, a moth that goes on wing during fall until December. I saw several individuals fluttering in the warm sunlight, but only one offered a photograph.

“The fall (and spring) cankerworms defoliate a variety of hardwood species in the spring. Hosts include the red and white oak groups, maples, elms, hickories, ash, and cherry. Heavy defoliation usually occurs in May and June, and can cause growth loss, mast reduction, and, if coupled with other stresses, may result in mortality. Its greatest impact is often felt in high public use areas where defoliation reduces the aesthetic value, and larvae and their droppings create a nuisance.” Source - http://www.fs.fed.us/r8/foresthealth/idotis/insects/fallcank.html

I thanked the moth and treaded on looking up and down, trying to find mushrooms and other creatures of the woods. And just so I glanced upon a scurrying Eastern Gray Squirrel, I’m sure she noticed me first, and went into hiding! I got a few shots from the thicket, and let her go on her way up the tree.

She went up, her eyes constantly spying on me, and lay flat on the bark, as if invisible – well camouflaged from me! Thence I saw many Eastern Gray Squirrels, including the melanistic form and enjoyed their constant chuckle.

This herb caught my eye, and I am still in the process of identifying it....and this flower, belonging to Asteraceae, yet unidentified.

The grass and some shrubs were green by the lake, so I explored a few, and as I sat down to get some shots, suddenly a White-tailed Deer came from the woods and stood by the water, staring right at me. I was seen, again. I slowly mounted a tele-converter lens, and got into the position to shoot. Behind her came two more young deer – as alert as her. The doe sensed danger and stomped her feet to the ground – a behavior observed in most deer to set the alarm for danger.

“White-tailed deer are generalists and can adapt to a wide variety of habitats. The largest deer occur in the temperate regions of Canada and United States. Commercial exploitation, unregulated hunting and poor land-use practices, including deforestation severely depressed deer populations in much of their range. Conservation practices have proved so successful that, in parts of their range, the white-tailed deer populations currently far exceed their carrying capacity and the animal may be considered a nuisance.” Wikipedia

They then passed into the tall grass, along the banks of the river. At last, I saw the deer! I then decided to walk along the river edge, perhaps sight a buck this time but, I met them again, them eyeing me as I walked through the thickets.

I bid them farewell, and wandered into the woods again, and heard something scurrying on the forest floor, another squirrel, I thought. So I watched curiously and saw a pair of Mourning Doves, well camouflaged on the ground. It is one of the most widespread birds in N. America.

"It is the leading gamebird, with up to 70 million birds shot annually in the U.S., both for sport and for meat.” Wikipedia

It's Call can be heard HERE

I continued walking and until now, I had not come across any significant human impact on this ecosystem that stood on the brink of human encroachment. But I was wrong. A nigh fifty meters I walked, and came across a sight that is not uncommon. A pipeline draining all the wastes into the river!

The water was fluorescent green in color, a color that symbolizes radiation! But the fishes in that water were abundant and no dead fishes floated above. Just a dye, perhaps but who in the world would discard dyed water into a beautiful river? The fact is that this is one of the many, many waste outlets going to one of the many, many rivers around the world. It is not shocking, it is plain stupid. So why crib about it?

Well, let’s take a look at the river:

“The Thames River is one of the largest and most biologically diverse rivers in Ontario. The river is arguably the City of London’s most significant natural feature and an environmental asset. It flows through the centre of the city and is used by thousands of residents and tourists alike.”

Source - http://www.clear.london.ca/Thames_River.html

The river has seen its ups and downs with respect to Phosphorous levels, and so on. It has been clean for most of its life, and many programs have been implemented in conserving this river ecosystem. So when you see waste being discarded off into the river, one will naturally doubts its survival in long term.

The trail was pleasant and rewarding in many ways. Who said only greenery hides the real beauty? It’s everywhere, even in a dense dried, dusty thicket or a dried, cold riverbank!

References:

1. Birdjam - Know the Birds you hear

2. Forest Health Protection - Fall Cankerworm and Spring Cankerworm

3. The Clear Network - Community of London Environmental Awareness Reporting Network

4. Wikipedia - Thames River, Canada Goose, Black Capped Chickadee, Mourning Dove

Eyestory

A brief look at the eyes

Eyes of Bamboo Pit Viper staring straight at me

Ever had the feeling of being watched – that uncomfortable sense which presses you hard against a wall, eating your mind inside out, and leaving you vulnerable and at god’s mercy? Often so, it is a game played by our mind. But there comes a moment when you see those eyes, staring right at you. And that’s when you feel it – the fear of being hunted.

Eyes are meant for seeing. Yet there is more than meets the eye. Eyes speak, eyes express, and eyes display sheer joy or utter sadness. Eyes are an identity of a person, a community or of an entirely different species.

A cautious White Breasted Kingfisher keeps its eye on me as I duck through a thicket to take it's picture

Eyes are what I am going to talk about today. With a myriad of hues, from green to blue and brown to black, humans have one of the most beautiful eyes on this planet. But there are some that are beyond imagination, far better from our vision and beyond our understanding. These eyes belong to those primitive arthropods, the magnificent birds and reptiles, amphibians and mammals, and other creatures of the seas.

The evolution of eyes is one subject that deserves a book. So instead, let’s see the sort of eyes we commonly come across on forest paths, at night, or as a sheer surprise. Such eyes are highly evolved, sometimes most serene or just stunningly haunting.

Ocelii of a Jumping Spider (Family Salticidae). Every Spider family has distinct eye-pattern which aides in its identification upto Family level.

The simple eye, or Ocelli, is the primitive one and persists today only in arthropods. It literally means a “small” eye! They are best seen in Spiders, in arrangements of either six or eight.

The Arrows point to the three Ocelii on a Copera sp. damselfly

In insects, they are generally placed high on head and function as light-sensitive-organs in the sense they do not form a clear image what-so-ever.

The compound eyes of a Robber Fly. Those tiny dots are actual individual ommatidia

The compound eye, Ommatidium, is a hundred or a million tiny lenses – photoreceptor cells, cemented together by pigment cells, and each tiny lens acts as an individual eye – capturing the picture and passing the message over to brain. These eyes are best seen in insects, where they form a major portion of the head.

The large eyes that of a Dragonfly (Blue tailed Yellow Skimmer) that makes Odonates supereme predators

For instance, in dragonflies – the ommatidium are so large that they cover two third of the head! These give the insects not only a “light sensing” organ, but a picture of what’s around. However, much of the vision is in the UV spectrum of the light. Hence, most insects don’t see the colors as we see.

A Syrphid Fly with its large eyes covering its face

The eyes of the insect world are much complex and large in proportion to their body size. This, along with sensitive hair, alert antennae and a sense of smell – has made them one of the successful animals living today – far successful than where humans stand in the line of evolution.

Common Indian Tree Frog - Frogs have a good eye sight and aide them in hunting at night

As we come to higher organisms, we see the eyes much similar to that of humans. These can rightly be called complex eyes, for they can detect colors extremely well, can see in the distance, and are capable of following fast actions. Such eyes further evolved and made some animals to see in pitch dark. By adjusting the amount of light entering the retina, the pupil can be positioned with respect to the intensity of the light.

Thus, we have eyes with a round pupil as in humans, a vertical pupil as in cats and reptiles and other nocturnal creatures, a horizontal pupil in some and large, bulging eyes that are hard to forget like that of an owl. These nocturnal creatures, bounce the light back if flashed by a light source such as headlights, torch or a camera flash. This is an adaptation where the reflected light is again reflected back onto the retina – thus giving the animal a supreme night vision as compared to that of humans.

Vertical eyeslit of a Bamboo Pit Viper gives it a sinister look!

The most striking eyes I have ever seen are that of a Bamboo Pit Viper, those large, green eyes with a vertical pupil, giving a sinister look to the snake. These eyes are that of a nocturnal animal and that’s what the Pit Viper is.

A Baby Vine Snake showing eyes with a horizontal slit

And horizontal pupils that of the Vine Snake, which gives them such an elegant look, so beautiful and seemingly fragile.

Geckos have cryptic eyes and one of the most beautiful in my opinion.

All these eyes speak for their owner. And one look from them is enough to either scare you or put you in a trance. So, keeping this in mind, some animals evolved further to recreate eyes, but only this time, those eyes could not see. Such are the false eyes, which are a part of mimicry – the game of life and death.

Owlet Moth - Spirama Retorta - showing large "owl" like false eyes on its wings

These eyes can be seen on insects in common, such as in Lepidoptera. Some moths display big, bright eyes on their wings – such as the Owl Moth – and are a treat to watch really, but are so original that they do keep predators at bay. It is a common occurrence in butterflies, some mantids, and even higher animals such as fishes and snakes. This is a clear instance where eyes speak louder than words!

On a last note, let us not forget the vivid colors of nature that please our eyes, the sight of birds and butterflies, or a tiny flower on a wasteland. If there was no organ such as eyes, there would be no beauty around, and if there was no beauty in nature, we wouldn’t have eyes. Eyes are more than just to look out for danger, or look for food. Our eyes have come a long way, from being the simplest light-detecting-device to designing a false eye. Some evolved excellent eyesight, while some gave up eyes completely. It is the vision that comes first if we want to understand something in its full form and structure, and is a nature’s gift we all must be grateful for. If you want the blind to see, to share the world of colors, do plan to donate them once your days are done.

FAQs about Eye Donation http://eyebank.med.utoronto.ca/DONATION.HTM

Gift your Sight http://www.freewebs.com/giftyoursight/

Eye Donation http://www.eyedonation.org/

Bharat Eye Bank - facts http://www.bharateyebank.org/factsabout.php

Asian Lady Beetle - An Invasion!

Harmonia axyridis

"There are around 18 species of ladybird beetles in Ontario, all of which feed on aphids and mealy bugs. However, Harmonia axyridis was considered very effective in eradicating the pest problems associated with crops such as soya. Hence it was introduced into USA and thus entered Canada. Here is an account entailing general information and observations on this beetle. "

Asian Lady Beetle showing the "W" mark on it's pronotum

Asian Lady Beetle is a beautiful ladybird native to eastern Asia. It is easily identified by the “M” or “W” mark – whichever way you see it, on the pronotum (just behind the head). It lives for one to three years, depending on the availability of food and surviving winter several times. When disturbed – or handled – it produces an odor to deter predators, the smell is however insignificant and can be easily washed away. They are gentle and do not bite to humans, but some people are allergic to this beetle.

It was first introduced in USA in the year 1916 to control the pest population of aphids, and after consecutive efforts, it became acclimatized to the area. Thence it ever spread farther, and reached Canada. It is now abundant than the native Ladybird beetles seen around. In Europe as well, the species spread quickly and almost replaced native ladybirds of Britain.

- Photographed at Lake Huron during Summer

This is one of the rather skeptical cases of introducing an exotic species to control the pest population in a certain country. There are failed instance which includes introduction of Cane Toad in Australia, to control the beetle grubs that damaged sugarcane. However, the toad developed taste for the native beetles, and soon became an invasive species. This resulted in a decline in the native insect biodiversity along with receding reptile population due to competition for food.

There are several successful cases of biological control of pest population by exotic species. One of the cases is, in which the cottony cushion scale insect – a pest on citrus trees, was the reason for major loss of the Californian citrus industry. A vedalia beetle and a parasitoid fly were then introduced from Australia to control the pest population. After a few years, the pest was completely controlled by these exotic predators. And the availability of food, in this case, the scale insect, determined the population density of the exotic predator, thus controlling its invasiveness.

Aphids are hemiptera bugs, feeding on plant sap. They reproduce extremely rapidly and thus expand and exploit the food sources available, including crops. Photographed in India.

However, not all such cases are like these. In case of Harmonia axyridis, the beetle was successful in eliminating aphids – a farmer and a gardener’s nightmare. So long as the beetle consumed the aphids, all was okay. But it spread rapidly all over the place, and replaced the native populations of ladybirds – through competition for food. This resulted in a loss of native biodiversity, and that is not good! Also, it is known to damage crops such as grapes.

“Adults feed on grapes in the late fall for sugars to survive during hibernation. However, they get harvested along with the grapes. When crushed with the grapes they impart a musty odor to juice or wine. The odor is because of a compound called methoxypyrazine, which is a stable compound and resistant to heat, fermentation and filtering. ” Timothy E. Martinson et al, The Buzz on Asian Lady Beetles

Albeit these facts, this beetle is still considered a blessing by a farmer – thanks to its gregarious appetite for aphids.

All Ladybird beetles hibernate during winter season. And so, the best time to see them – in their thousands – is during autumn. This is the time when, all of a sudden, they come and land on trees and buildings. They make it into your homes, and are a menace. But they don’t mean to. They are actually seeking shelter from the coming of cold. Therefore, they seek the corners and warm places so as to survive the winter.

“Houses – particularly light colored ones – look like rock faced cliffs to lady beetles in the fall. This has been a minor problem in Central NY since the mid 90s.” Timothy E. Martinson et al, The Buzz on Asian Lady Beetles

Five different morphs as seen during the invasion

Now, you may come across a myriad of colors from orange to red and melanistic forms, and patterns (such as no spots, less spots, dark spots, so on) on these lady beetles marked with an "M" on the pronotum, and thus around fifteen morphs - or more, exist today, out of which, I recorded only five in London ON. These morphs are a result of genetic variation.

In nature the lady beetles shelter in tree crevices, under rocks and in leaf litter. But unfortunately, they land up on big structures like high rise buildings – mistaking them to be trees, and seek shelter in apartments. But worry not, it’s a pleasurable company!

Two, dormant lady beetles inside home

According to my observations, many of these beetles that made into my house died after two weeks. And the ones that were all over the place outside, vanished. I think the death was because of being active throughout the time – thanks to the constant warmth provided by my heater but, no food source. The rest of those who vanished must have sought a protective shelter and slept calmly.

So, after a long winter sleep, the ladybirds rise up and go on a search for mates. This happens during spring time. That’s the time when they congregate again and invade homes – actually, to seek shelter for mating. Thus be the life of these beautiful, yet invasive Ladybirds – Harmonia axyridis.

Thank you for reading!

References:

1. Timothy E Martinson, The Buzz on Asian Lady Beetles, Finger Lakes Vineyard Notes #8, August 12, 2002
http://www.grapesandwine.cals.cornell.edu/extension/edocs/Asian%20Lady%20Beetles%201.pdf

2. Kevin W Ker, Questions and Answers about H. axyridis (Pallas), April Harmonia axyridis Seminar, 2002
http://www.brocku.ca/ccovi/news/Q&A.html

3. Kevin W Ker, Multicolored Asian Lady Beetle – New Insect or just Overlooked in Ontario
http://www.brocku.ca/ccovi/news/Asian_Lady_Beetle_-Harmonia_axy.pdf

4. Catherine R Weeden et al, Biological Control: A Guide to Natural Enemies in North America
http://www.nysaes.cornell.edu/ent/biocontrol/info/biocont.html

5. Caltagirone, L. E., Doutt, R. L. The History of the Vedalia Beetle Importation to California and its Impact on the Development of Biological Control
http://arjournals.annualreviews.org/doi/pdf/10.1146/annurev.en.34.010189.000245

Other websites:
http://en.wikipedia.org/wiki/Harmonia_axyridis
http://en.wikipedia.org/wiki/Biological_pest_control

Eastern Gray Squirrel

Sciurus carolinensis

A common mammal of the neighborhood in Canada, it is seen scurrying on parapets and on top of houses, on pine trees and maples. I spent a pleasant time photographing and video-shooting these squirrels.

Here is one of her stance where she curiously and slyly gave me a glance. It is a squirrel native to Eastern and Midwestern USA and southerly Canada. It was introduced in UK and has largely displaced the native Red Squirrel (S. vulgaris). The Gray Squirrel shares its distribution with Fox Squirrel, which is often confused to be a Gray Squirrel. - Wikipedia

From my observations, I found these squirrels fairly common in Mississauga – a suburb of Toronto, and came across several but rather uncommon melanistic forms. The melanistic forms were more conspicuous compared to the common, ordinary squirrels. I also found them to be timid as compared to the latter.

On a contrary, in London ON, I saw a healthy population of the melanistic Eastern Gray Squirrels, about three individuals per one ordinary squirrel. I cannot ascertain why such a difference, but surprisingly, the melanistic squirrels here are not as shy as in Mississauga, and will be often seen sniffing right beside the path. I have seen only two ordinary coated squirrels here.

The melanistic form, which is almost entirely black, is predominant in certain populations and in certain geographic areas, such as in large parts of southeastern Canada. - Wikipedia
It is a typical pose of a squirrel that defines its binomial name. According to Wikipedia, “The genus, Sciurus, is derived from two Greek words, skia, meaning shadow, and oura, meaning tail. This name alludes to the squirrel sitting in the shadow of its tail.”

Given HERE is the video that show’s one of the Squirrel behaviors. The Squirrel sat all cuddled up in the pose in the above picture.

After sensing my presence, this Squirrel started making squeaking and chucking sounds. It started wagging its tail and seemed to tell me “I have seen you!” It is a warning signal that Squirrels all over the world use, in territorial disputes, or in presence of a predator such as a raptor or a snake. This squirrel did not start displaying warning signs until I was pretty close to her (at about 15 feet). I presumed a low profile, laying flat on the ground and making no sudden movements. After a while I stood to my feet and the squirrel – in a fraction of a second – vanished in the trees. This is because she probably thought my stance to be threatening and big. It is obvious and easy to observe this behavior – whether you are in the field or, just gardening in your backyard!

All these squirrels observed were not tamed in anyway and I did not see people feeding them, which is a good thing. They do however visit backyards and eat up the pears and apples! These squirrels are the wild-neighbors who now share their natural habitat with a human habitat. Rest of the wild-neighbor list includes Raccoons, Skunks and Rabbits, and in areas close to woods – White Tailed Deer.

I am glad to have sighted these until now, but never had an opportunity to photograph them. The squirrels, on the other hand, are always present and give you a nice company if you’re alone! I find it amusing to see them chuckle and play around trees and lawns as I walk huddled in a hoodie to the lectureroom.

For more on Eastern Gray Squirrel - HERE (Wikipedia)

For more on Fox Squirrel - HERE (Wikipedia)

And another very interesting documentation on Eastern Gray Squirrel -HERE (Hiker's Notebook)

This is my first post away from India. I squeezed out time to do some natural observations around my base in Canada, and this is the creature that struck me first. Keep watching for more!