Tag Archives: Doug Worrall

Information on Dragonflies,Oiling of eggs Hamilton

Information on Dragonflies Hamilton

Thursday July 12 2012

Dragon Flies so colourful

Wildlife This year at Harbour-front Trail, Cootes Paradise and the great lakes are few and far between.The lack of snow-pack , Spring rains has left the water level three feet less than last year, therefore less wildlife and fewer Images. Last year there was over 12 Signets born in Hamilton Harbour, this year due to the City of Hamilton Oiling Swan eggs and Canadian geese eggs there was only one signet born, all because they say the swans are causing e-Coli Bacteria and making it dangerous for people to swim in the water. I am against the oiling of eggs because the swans sit on the eggs for three Months without any offspring. People complain to the city that there is too much Canadian geese  droppings where they walk. The wildlife was here before us, please leave Mother Nature alone, Humans think they can control everything they come in contact with. Now look at the world we live in, nothing for children too be amazed and nothing to learn, It is like a Silent Spring-Shame- Shame

eight eggs and only one signet-city oils eggs Hamilton

Readers at pics4twitts send me images quite often, Lois McNaught also walks the Harbour-front trail  Daily and has the same observations as most regulars, “where have all the wildlife gone?”

Morning Hamilton Harbour

Doug Worrall

Information on dragonflies. Did you know that they eat mosquitoes, have over 20,000 eyes, have been the subject of an old wives tale, and have even been mistaken for fairies? Find out many more interesting fact…

Dragonflies

Usually living near water, the dragonfly is one of earth’s creatures that are not only very useful, but also beautiful. They belong to thee insect group Odonata. Dragonflies come in varied colors; their bodies often blue, green, purple, and even bronze. Their wings seem to shimmer as if made of silver, especially when under the moonlight.

Dragon Fly

Starting out life as small nymphs underwater, they grow to be approximately three inches long, with a wingspan averaging two to five inches in width. While this may seem large for an insect, keep in mind that as they have evolved from pre-historic times, they have gotten considerably smaller. Evidence shows that at one point in time they may have had a wingspan of over two “˜feet’! One very interesting fact of the dragonfly is his six legs. Each of the legs is covered in short bristles. Using their bristle-covered legs to form an oval shaped basket allows them to scoop insects, such as mosquitoes, right out of the air. Dragonflies not only eat mosquitoes; they also keep the fly population and other flying insects under control.

Eastern-Tiger-swallowtail
Eastern-Tiger-swallowtail

Surprisingly, dragonflies will spend only a very short part of their life span as actual dragonflies. They will live as nymphs for up to four years, shedding their skin up to fifteen times, yet when they finally mature into adults, the dragonfly stage, they will survive only a few months.

Gray catbird

Dragonflies have fascinated modern man for years. They have become the basis of both legends and old wives tales. One such old wives tale refers to a dragonfly as a “˜darning needle’. An old legend tells of people who would wake up after falling asleep outside to find their ears and eyes sewn shut by these crafty insects. If dragonflies were seen swarming over a doorway, it was said to foretell of heavy rains on the way.

Mangrove Tree Nymph

For as long as man and dragonflies have coexisted, people have mistaken dragonflies for fairies. “˜Fairy tales’ have been told of little people fluttering about worldwide. Upon closer inspection, the fairies are found to be groups of dragonflies.

Painted Lady Butterfly on Coneflower
Painted butterfly.

Facts about Dragonflies

Question Mark Butterfly

 

How fast can dragonflies fly? In excess of sixty miles and hour!

How many eyes does a dragonfly have? They have two main eyes, but each of these eyes are made up of approximately 20,000 to 25,000 tinier eyes, allowing them to zero in on the flying insects that are their daily meals.

Post and image Doug Worrall

Doug Worrall

Photos by Lois McNaught

Water Force and Motion in Lake Ontario

Water Force and Motion in Lake Ontario

Friday August 13th 2010

Force and Motion.  Water has mass,  moving water has velocity, and currents therefore create  momentum.  The circulation of water in the Great Lakes involves surface and subsurface currents, with a seasonal cycle of vertical circulation superimposed.
Lake Ontario is one of the best characterized in the Great Lakes, from a physical limnological point of view.  The water basin is almost like the idealized basis drawn in textbooks.  This results in rapid response of currents and water temperature to wind.  In fact, westerly winds of Summer produce a thick Epilmnion (range of temperature for the top 20 feet of water) in the south-eastern end of the lake and an exceedingly thin non-existent Epilmnion in the west-end (Hamilton Harbour).
The Great Lakes have been defined as a “softwater” nature, their seasonal cycles of turnover,  lake levels,  precipitation, and their short period  seiches (a wave that has repetitive variation in lakes for a few minutes to a few hours).  To indicate breakdown in the Water Budget components statistical data emphasizes Lake Ontario’s precipitation falling directly into the lake is approximately equal to evaporation from the lake surface. The Weather Ships Observation Logs of the Canadian Dept. of Transport have also analyzed lake and land winds for Lake Ontario.

Weather Ships
Water circulation of the Great Lakes involves horizontal surface water. currents, and vertical water movements. The three types of movement are related temporarily and spatially, and they have various degrees of co-existence.  The Horizontal Surface Currents Circulation in the Spring and Summer period of stratification are controlled by (1) the winds, (2) the flow through of drainage from the watershed.  Lake Ontario usually is the first of the Great Lakes to reach maximum elevation and minimum elevation due to climate and its position in the drainage system.  Other factors include, (3) the rotation of the earth (Coriolis force) and the rotation of the earth is constant.  The final factor (4) is local topographic and/or hydrodynamic influences.
Water current patterns in deep basins apparently involve  energy increments from winds of the preceding 10 – 12 days, with the increments decreasing exponentially with increasing time prior to the observation day.  Lake Ontario is a relatively smooth trough but it is asymmetrical with the axis of its deepest position lying south of the mid-line.  It is also an  open-lake system.  The Institute of Science and Technology, Great Lakes Division at the University of Michigan examined open-lake water surface currents.  These surface currents many have (1) geostrophic relationship to the density field, or (2) a secondary relationship in which boundaries or wind set-up play a part. In an open-lake situation surface currents exhibit the following characteristics:
  • Primary relationship to the causative winds is characterized by redistribution of the field of  density in such manner that less dense water lies on the right side of the current (Northern Hemisphere), and, the current moves in a direction of 30 to 45 degrees to the right of the wind movement.
  • Secondary relationship involves a physical or hydrodynamic barrier against which initial currents moving to the right of the wind can pile up and produce a slope upon which secondary currents move, with the less dense water of the slope on their right, in a direction which the barrier imposes on the long axis of the slope.  Shores are common physical barriers; windless areas or other  currents are  common hydrodynamic barriers.
The Great Lakes exhibit a modified seasonal turnover cycle; wind mixing establishes turnover at the end of the Autumn cooling period and maintains it throughout the Winter until the Spring warming period is established.  This wind mixing was indicated in a 2,000 study by the Aquatic Ecosystems Science section of the Ontario Ministry of Natural Resources. Their emphasis was water temperature.  They stated ” Temperature is one of the most important factors driving the reproduction growth and development of aquatic organisms.  Therefore,  the ability to predict thermal patterns is essential for modelling aquatic habitats.”

Evaporation

In Lake Ontario there is a TENSE highly competitive pressures claiming more water for various uses : domestic, industry, power, agriculture, navigation, recreation, and Fish and Wildlife. At the same time far too much water is made useless by POLLUTION !

Pollution
Need for clean water

By Jacqueline Hope you enjoy the information and the Pictures “Happy Friday The 13th”