The Shape of a Raindrop

     Despite weather channel depictions and after years of drawing raindrops with a pointed top and rounded bottom, I was surprised to learn that raindrops are not shaped like teardrops.

     Air resistance is not the cause of the typically-drawn shape that appears as raindrops streak across windows or on peoples' face when we dry; that is caused by surface tension of the liquid water on the surface.

     As they fall through the air, raindrops are actually spherical in shape. Smaller raindrops have less air resistance so they are more spherical than larger ones. The larger the raindrop, the more air resistance there is, and greater air resistance actually just flattens the bottom; a pointed tail/trail is actually not formed by air resistance. When a raindrop gets large enough (usually more than 4mm), it will actually split in half and drastically decrease in surface tension, possibly splitting so small that the water just rejoins as moisture the atmosphere.

Sources

Baird, Christopher S.. What Makes Raindrops Tear-Shaped? December 17, 2012 Science Questions with Surprising Answers. http://sciencequestionswithchris.wordpress.com/2012/12/17/what-makes-rain-drops-tear-shaped/

Oblack, Rachelle. The Shape of Raindrops. http://weather.about.com/od/cloudsandprecipitation/a/rainburgers.htm

How do geese keep their feet warm in the winter?

     While watching the migrating geese resting on a lake with a coat and hat and gloves on and still feeling chilly, it's amazing to see the birds swimming atop the icy waters. Sometimes I imagine being a goose, duck, or swan migrating during the winter. Unlike some birds that seek shelter from the elements, they remain on the water. Although they have waterproof feathers atop down feathers to keep their bodies warm, their feet are still exposed to the icy waters yet they are not frozen.

     The key lies in counter-current heat exchange. In the legs of ducks, geese, and other types of birds, the arteries (blood flowing away from the heart) have branches that are very close to branched veins (blood flowing towards the heart), allowing the warmer blood flowing towards the feet to cool, and warming up the blood coming up from the feet. This way, the foot is kept colder; without the branched blood vessels, the blood that reaches the foot is still warm.

     At first it might not seem to answer the question, as it seems to be that they keep their feet warm by making their feet cold? Well, the point is not to keep their feet warm, but it is to make them colder so that the heat needed in other parts of the body is not lost. This works because body heat is lost when the outside environment is colder than the exposed tissue, so the less the different in temperature in a goose's exposed feet with the water, the less body heat will be lost. To reduce the amount of heat lost, they also reduce their surface contact with ice which (according to askanaturalist.com) is the reason why you might see them balancing on one foot at a time. 

     Heat exchange also prevents cold blood from cooling down the parts of the body covered by feathers as the blood flows back towards the heart in the veins.

     This heat exchange is also applied when a bird is in a very hot environment, as it keeps it from overheating, as well as with other animals such as marine mammals, which have a net of branched veins and arteries around their bodies below their skin to protect them from the cold in addition to fat insulation.

Sources

AskANaturalist.com. Why Don't Ducks' Feet Freeze? Ask A Naturalist. Retrieved from http://askanaturalist.com/why-don%E2%80%99t-ducks%E2%80%99-feet-freeze/

Eccentricscheinstist.wordpress.com. Why Don't ducks get Frostbite? Wordpress. Retrieved from  http://eccentricscientist.wordpress.com/2007/01/13/why-dont-ducks-get-frostbite/

About a Bustard -Kori Bustard (Ardotis kori)

Kori Bustard (Ardotis kori)

(photo coming soon)

Conservation Status: Least Concern

Habitat: South and Eastern African grasslands and wooded areas

Physical characteristics: Long neck grey neck and head, long beak,  As a species, the kori bustard is the world's heaviest flying bird, the males weighing up to about 18 kg (39.6 lbs). They display sexual dimorphism, as males may weigh up to twice the weight of females, though they have similar plumage.

Lifespan: The longest recorded lifespan is 26 years in captivity, and there is approximately 86% mortality rate amoungst chicks in the wild.

Notes:

     One of 25 species of bustard, like other bustard species the kori kustard does not typically engage well with humans and will shy away from human contact. Generally they remain silent, however if alarmed they will make a loud barking sound, as well as displaying a "shock display" where the bird bends forward with its tail feathers lifted and spreading out its wings to appear larger than its actual size to predators.

     Their omnivorous diet consists largely of insects, however they also sometimes feed on smaller vertebrates such as lizards, snakes, birds, and small mammals. They also eat fruits including berries (and Tsamma Melons, see "What animals (besides humans) eat watermelons and pumpkins?" post), as well as nuts and Acacia tree gum (hence its alternate name Gompou' which means "gum eating"). They also have the rare habit of sucking up water when drinking. Its predators include eagles, lions, and jackals. Carine bee-eaters (Merops nubicus and Merops nubicodes) will sometimes perch on the back of an active kori bustard and eat the bugs disturbed by the bustard's activity, and may help the bustard detect predators.

     In courtship, the male will inflate his esophagus (up to a peak of four times its regular size), point his crest up and his wing and tail feathers down, and make a low booming noise to attract a female. Males will often perform this together in a group. The rearing of chicks is up to the mother, whose nest is a scrape in the ground with an in-captivity incubation period of 23 days.

Sources

Smithsonian National Zoological Park

     http://nationalzoo.si.edu/SCBI/TropicalEcosystems/KoriBustards/biology.cfm

     http://nationalzoo.si.edu/SCBI/tropicalecosystems/koribustards/default.cfm

Arkive.org.

     http://www.arkive.org/kori-bustard/ardeotis-kori/image-G62000.html

What animals (besides humans) eat watermelons and pumpkins?

     Considering their hard, thick exterior, it takes a level of skill to eat a pumpkin or melon.

(Ice Age, image source: animatedviews.com)

     Tsamma Melons, a relative to watermelons you would find the the grocery store, grow wild in the Kalahari desert is South Africa. Storing large amounts of water and resistant to drought, they are a good water source as well as food source for animals living in the region, including humans and kori bustards.

     If you grow watermelons in a garden in North America you might end up sharing them with some wild neighbours. Raccoons, deer, coyotes, and especially crows are all animals that might eat a watermelon if they found one.

     Despite being at the top of the food chain, coyotes also will eat watermelon. At night a coyote might sneak into a garden where it will break open a watermelon and eat the flesh right down to the rind. 

     The coyote's distinctive destruction to the fruit contrasts with the method which raccoons and deer eat watermelons. They will dig or puncture a hole through the skin to get to the inside.

     Pumpkins, too, are a reason for wildlife visitors in some gardens. Rabbits only eat the leaves (not the fruit itself), nibbling at the tips, similar to it's habitual sampling of leafy greens. 

     Using their digging abilities, mice and moles get to the seeds inside pumpkins by digging a tunnel through the bottom and into the middle. Squirrels, and chipmunks may also dig through a pumpkin in pursuit of the delicious seeds that await inside, sometimes even being found digging through pumpkins left of porches. Unlike the others, woodchucks eat the actual flesh of the fruit.

Sources

Bauer, Mary. What wild Animals eat Watermelons in a Garden? 

http://homeguides.sfgate.com/wild-animals-eat-watermelons-garden-40477.html

Kane, Dan. Tsamma Melons: Watermelon's Wild Cousins.

http://blogs.worldwatch.org/nourishingtheplanet/tsamma-melons-watermelon%E2%80%99s-wild-cousins/

http://www.arkive.org/kori-bustard/ardeotis-kori/image-G62000.html

http://pumpkinnook.com/howto/gardenpests.htm

Sun Pillars

    Sometimes above the sun (or occasionally below), you may see a vertical beam of light stemming from the sun.

Sun Pillar

     This vertical light is an optical phenomenon called a light pillar, sun pillar, or sun dog.

     The most common occurrences of light pillars are avove the sun when it is close to the horizon, although it can also occur with other natural light sources such as planets or various artificial light sources.

     Certain conditions are necessary for a sun pillar to appear because the appearance of a light pillar is created by the reflection of light on horizontal ice crystals in the Earth's atmosphere. When the light reflects off the bottom of the horizontal ice crystals down to the eye or by total internal reflection (the same concept as bike reflectors), it creates the appearance of an upper light pillar (above the sun). This is why it is more common to see a light pillar when the sun is closer to the horizon. When it reflects off the top of a lower ice crystal and up to the eye, you would see a lower light pillar (under the sun).

     The visual result is a towering vertical line of light extending through the sky, of the same colour as the light source.

Sources

http://www.atoptics.co.uk/halo/platpill.htm

http://optics.kulgun.net/SunPillar/

http://earthsky.org/earth/what-is-a-sun-pillar

(originally posted 19/11/2013)

Skywatching: Winter 2013 (Zine article)

    As the seasons change with the Earth’s orbit around the sun, skywatchers around the globe get to marvel at different constellations and sky events throughout the year. Since the sun will be setting earlier, take advantage of longer nights to get a good look up above. Here is a heads up on celestial marvels to keep an eye out for in the northern hemisphere this winter.

Orion

In Greek mythology Orion was a great hunter who was chased into the heavens by Scorpio. In his pursuit of Peleides (or “the 7 sisters” as depicted in the heading), Orion incurred the wrath of their powerful friend Artemis, who saw to it that he was chased into the sky by Scorpio. You can find this constellation by looking for the three stars that make up “Orion’s Belt”.

Cassiopeia

Shaped like a sideways “W”, you can use Cassiopeia to help you locate the North star by going 5 lengths between the middle star and the bottom one.

Week of November 24: Mercury and Saturn

About half an hour before sunrise this week both Mercury and Saturn will pass close to eachother in the low southwestern sky. For the next two days they will remain in the sky together, only with Saturn, the one that will shine brighter, rising, and Mercury descending closer to the sun.

Thursday, December 19: Moon and Jupiter

Passing within 4°55' of eachother, Jupiter and the moon will be at a close conjunction on this night, making it easier to locate in the East earlier, and in the West closer to dawn. Gemini will be marking the place of the conjunction of the Moon and Jupiter, so you will able to easily spot three-in-one.

Bundle Up

It is easiest to see stars and other celestial objects away from the city, where “skyglow”, or light pollution does not block them out. Take friends and family along to share these beautiful sights with them, and even if you don’t plan on being out for too long, make sure you are dressed in layers for the chilly weather of a winter night.

Happy Skywatching!


NOTE: Posted 13 months later as an archive.

Greetings, previous posts, & reusable water bottles.

Dear fellow nature enthusiasts and explorers,

     Hello and welcome! It's just one little corner on the web dedicated to exploring the natural world. I hope you have had a chance to breathe some fresh air today. If you haven't, please forsake the reading of this blog and take a break to go outside.

     Just a note: previous to this post all posts were for specific purposes so the structure of posts and topics will have some more variation. For now, here is a a bit of information about reusable water bottles.

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     It isn't hard to see why reusable water bottles are better for the environment than disposable ones, however when choosing to go reusable, the question is raised on which type is best.

http://www.collegefashion.net/uncategorized/special-earth-day-feature-the-truth-about-bottled-water/

(The source of the above image is a great article about bottled water).

     Back in middle school in Green Club we hosted a reusable water bottle sale and sold hundreds of reusable aluminum water bottles. They were durable, they didn't make water taste funny, and a selection of funky decals made it more appealing to a wide audience. A handful of people already had reusable plastic ones, and although it seemed like everyone loved the aluminum ones, reusable plastic bottles have their own benefits.

     One of the greatest benefits of the aluminum ones is that they are durable and will most likely last a very long time, however the metallic taste alone in some is reason enough to pass. I got a deal for an aluminum water bottle that doesn't taste metallic and still in good condition after a number of years, but at regular price they are typically significantly more expensive. Another one that I got for free is in better condition probably because I avoid using it due to the metallic taste of the water, and it may be more of a waste of resources and pollution caused from production.

     If you are planning to go with the metal ones, choose wisely; if it's really cheap, it probably tastes like metal.

     The plastic ones have proven to be especially convenient for trips as they don't weigh as much as the aluminum ones, but they are definitely more breakable and likely to leak. Noe reusable plastic ones are BPA (Bisphenol-A) free, but avoid leaving it in warm environments so that other chemicals in the plastic don't contaminate the water.

     Each has its own benefits and drawbacks. Personally, I prefer a metal one for school because it is more durable and will be used every day (and as long as I make sure I put the cap back on properly I am confident enough that it won't spill all over my books), and the reusable plastic one for day trips and long walks.

     For reusable plastic bottles that have a little crack at the spout, I find tying a cloth around the neck with a rubber band is effective enough in keeping leakage at bay.

     Both have their advantages and weaknesses, and really it depends on what's more important to you. Below is a table listing the pros and cons of each. Feel free to mention points that I have missed in the comments. 

Table 1: Comparing types of reusable water bottles.

	Pros	Cons
Metal (Aluminum /Stainless steel)	- durable* - good for juices - usually a wider selection of designs/styles - may keep contents cooler longer	- sometimes makes the water taste metallic (especially Aluminum) - over time inner coating might start to flake off (especially around the spout)
Reusable Plastic	- lightweight - you can see how much water is left - usually cheaper - wider selection of shapes/forms > some have built-in filters	- it may retain the taste of drinks such as juice - should not be left in warm environments - more breakable - cannot be washed in a dishwasher

*Note: Both may break if put in a freezer with water inside.

What kind of water bottle do you prefer?

Soil Salinization

By Ashley Gervais-LeClaire, Kijana Henry, and Melody Tadeo

This was a group project for an environmental science class about the causes, effects, and potential solutions of soil salinization. This is the handout, and you can follow this link to see Ashley's Prezi.

Soil Salinization

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The buildup of salt in soil occurs when there is insufficient irrigation, and salts from the water remain in the soil increasing the salt concentration, degrading the soil. Soil salinization affects approximately 33% of the world’s irrigated land, and can cause damage to biodiversity, agriculture, and water sources.

Natural Causes:

- Water movement causes salt to accumulate in soil increasing salt concentration when water evaporates and leaves salts behind. Risk increases with arid soil and when there is more meltwater than plants need, and decreases with more rainfall.

- Overwashing and seepage of saline waters and salt spray from crashing waves in saltwater bodies.

- Rising of the water table.

Anthropogenic Causes:

- Road salts washing onto land.

- Overuse of fertilizers.

- Improper water management

- Over-exploitation of groundwater leading to intrusion of saline water in the water table.

- Fallowing and overgrazing in dryland areas.

Soil Salinization in Canada:

-  Occurs in the Southern areas of the prairies. Saskatchewan and Alberta are at greater risk because they are more arid than Manitoba.

-  The decrease in Summer Flow farming had decreased the salt content of the prairie soil. (Summer Flow is a farming practice that leaves farmland out during growing season so the nutrients in the soil are retained for future crops.)

-  Along with the nutrients the salt in the soil is also retained making the soil for salt.

Effects:

- Many plants are intolerant of high levels of salt, because the salts decrease water uptake from the roots, excepting halophytes (salt-tolerant plants).

eg. red buckeye, white ash, honeylocust, saltbush, St. John’s wort, and bayberry.

Mosses are often very tolerant to to sodium salts (such as the most common in salinization, NaCl), but are susceptible to potassium salts.

- Kills plants, lowering biodiversity of plants and reduces food sources for other species.

- Potential desertification of arid lands.

- Many crops are harder to cultivate in agriculture, decreasing human food sources, reducing sales for farmers, and having a negative impact on the economy.

- Water sources can be tainted by salinization in surrounding soil, decreasing water quality and affecting aquatic ecosystems and other species relying on the water source.

Solutions and Preventative Measures:

- Minimize the use of fertilizers, and ensure that fertilizer use is in safe doses.

- Planting trees in agricultural areas (“agroforestry”) reduces risk of soil salinization.

- Using organic matter to improve soil structure, drainage and moisture holding capacity.

- The planting of salt-sensitive plants uphill or away from salted roads, and planting salt-tolerant plants where there is high risk of salinization.

- Mulching to prevent evaporation and buildup of salts.

- Leaching through sufficient irrigation and monitoring the quality of irrigated water, ensuring that it has safe amounts of salt (< 0.5 g/L is best).

Bibliography

Appleton, B. e. (2009, May 1). Trees and Shrubs that Tolerate Saline Soils and Salt Spray Drift - Home -

Virginia Cooperative Extension . Publications and Educational Resources - Home - Virginia Cooperative Extension . Retrieved February 19, 2013, from http://pubs.ext.vt.edu/430/430-031/430-031.html

Dregne, H. E. (n.d.). Desertification of Arid Lands. Center for International Earth Science

Information Network. Retrieved March 8, 2013, from http://www.ciesin.columbia.edu/docs/002-193/002-193.htm

Eblin, J. (n.d.). Use of Salt to Kill Moss | eHow.com. eHow | How to Videos, Articles & More -

Discover the expert in you. | eHow.com. Retrieved February 19, 2013, from http://www.ehow.com/facts_7201481_use-salt-kill-moss.html

Food and Agriculture Organization of the United Nations. (n.d.). Forests, Trees and Food. FAO:

Food and Agriculture Organization of the United Nations, for a world without hunger. Retrieved February 19, 2013, from http://www.fao.org/docrep/006/U5620E/U5620E05.htm

Food and Agriculture Organization if the United Nations. (n.d.). Water quality for agriculture. FAO: Food

and Agriculture Organization of the United Nations, for a world without hunger. Retrieved March 5, 2013, from http://www.fao.org/docrep/003/T0234E/T0234E02.htm

Gergely, T. (n.d.). Soil Salinisation. EUSOILS - European Soil Portal Home Page. Retrieved February

19, 2013, from http://eusoils.jrc.ec.europa.eu/library/themes/salinization/

Department of Primary Industries. (n.d.). Chapter B7. Managing saline soils. NSW Department of

Primary Industries. Retrieved May 3, 2013, from www.dpi.nsw.gov.au/__data/assets/pdf_file/0008/127259/Managing-saline-soils.pdf

Stocking Salmon in Lake Ontario (cons project)

(Updates June 1, 2015)

This was an oral presentation for a biology research project and presentation for stocking Salmon in Lake Ontario. I was assigned to present to cons of stocking Lake Ontario with Salmon, though there are many other benefits that are just not covered in this half of the assignment.

The Cons

The cons of stocking salmon generally looks towards the ecosystem in a more holistic view, then kind of zooming on specific side-effects.

• They are non-native species, competition for native species

• Over-Predation on Alewives
• These are bad for the ecosystem as a whole and fishing industry
• Heavy reliance on human maintenance

Competition for Native Species

Despite the need for more salmon, there a study conducted in 2009 shows that there is a reproducing native salmon population in Lake Ontario. The study found that the 2.3 million Chinook salmon stocked in Lake Ontario annually produce less than half of the Chinook in Lake Ontario. Most of them were born wild in streams like the Salmon River in New York, so by releasing non-native and invasive strains we are creating more competition for prey for natural strains. These non-native species reduces biodiversity of other native fish too, such as Lake and Brook Trout and American Eel, all of which are in decline in Lake Ontario.

More recent research also suggests concerns over the long-term predator-prey balance, and with other factors such as weather, other invasive species, natural reproduction and others make take unpredicted effect in changing the ecosystem’s balance. An example of dangers weather poses to populations was in 1976–1977 when alewife populations were depressed because of unusually cold temperatures.

A Threat the Alewife Population

A rising issue is that Chinook salmon in Lake Ontario are going beyond controlling the population of alewives, but are beginning to overwhelm it. Although they were an invasive species and had to be controlled after they established themselves, they have become a food supply for different predators and statistics are showing that there may not be enough anymore.

We can look to Lake Huron’s ecosystem where alewife populations collapsed in 2004, which also brought down the fishing industry with it. The collapse in Lake Huron has been attributed to the salmon stocking, which is the same thing that is being done in Lake Ontario. Mark Ebner, fish assessment biologist with the Chippewa Ottawa Resource Authority, likens trying to balance alewife populations to walking on a tightrope where “you can fall off on either side” meaning that although we don’t want too many alewives, not enough to support the ecosystem is also bad.

Past evidence of such a threat to Lake Ontario is demonstrated by past need to constantly modify the number of salmon released so as not to overwhelm the alewives; a very delicate changing balance. In the early 90s their populations were of a concern so salmonoid stocking levels were reduced to 4.5 million, and now must be maintained between 4 and

5.5 million per year.

From 1974-1977 as alewife populations went down because of predators such as non-native salmon, their prey, zooplankton, had a growing population. The balance of zooplankton population is also an important part of the lake’s ecosystem, such as being prey to algae and energy storage. These changes also cause other changes in the water-quality of the lake, including eutrophication and also contamination of other fish species. Cultural (human-induced) eutrophication led to nuisance algal blooms and water quality deterioration in Lake Ontario in the past, specifically 1940s-70s.Today there are similar issues in Lakes Huron and Ontario because of phosphorus levels and algae population, and the contamination of some fish is also a concern for human health because of bioaccumulation when fish are eaten by people.

Growing Dependence on Human Maintenance

Because of all these changes to the ecosystem management of the lake has become very complex, heavily relying on human maintenance. In 2010 the Committee on the Status of Endangered Wildlife In Canada declared the Atlantic Salmon to be extinct in Lake Ontario, as all the different strains that have been introduced to attempt to replace the extinct species from the 1800s unfortunately have failed to give any evidence of self-sustaining populations, so therefore the ecosystem relies a lot on human activity and monitoring.

Being able to maintain balance within an entire ecosystem is a heavy responsibility which has built up over time because we have to be able to maintain not only direct connection with the salmon, but also with all the other species they effect. The more human attempt to control the ecosystem, the more control it requires to be sustained so if we choose to continue to release non-native salmon into Lake Ontario, it is vital that we are prepared to handle the responsibility to reduce negative impacts on the other species living in it.

Icy Northern Winds

     It had been exceptionally windy in the neighbourhood for the little while, as cold fronts came in and icy winds from the north come dancing alone  bring winter. Sometimes the wind makes it difficult to get clear pictures of plants, but this time the cold north wind it made it very easy because the constant freezing winds froze the leaves stiff in their place, pointing south, like a sign of crossroads for migrating birds.

Wind-frozen Leaves

     It was like time froze and for a few short days, the wind remained even as it was still.