Wednesday, July 8, 2009

Invasive Species Invade our Inland Waterways

The spiny water flea is an invasive species that has assaulted our inland waterways. It is amazing how such a small creature, one-quarter of an inch (1cm), can be so destructive to native species. It is a predator and a relative of the “fishhook water flea”. In 1982 they were introduced to North America in the ballast waters of European ships entering the Great Lakes. They have spread throughout the Great Lakes and to at least 60 inland lakes in Ontario.
As the name suggests the spiny water flea has a long tail spine with barb-like projections. The head has a large black eye and a pair of swimming antennae. They have a pair of mandibles, or jaws used to pierce and shred their prey. The four pairs of legs are, not for walking, but for catching and holding food while it is being consumed. The two front legs are longer than the others and are used to reach out and catch prey. The other three pairs of legs hold their prey while they eat it.
The spiny water flea preys on small, indigenous organisms called zooplankton, including Daphnia, which are important foods for native fishes. When the populations of this invader reach massive levels, zooplankton consumption can be significant. The invasive species eats about three times as much as our native species and therefore reduces the amount of food available for resident water fleas and juvenile fish.
When water conditions are ideal female spiny water fleas reproduce identical female offspring. Females produce from one to ten eggs that are able to develop into new females every two weeks. When water conditions are poor, low water temperatures or not enough food, females produce only males.
When the females mate they produce “resting eggs” which can remain dormant over long periods of time, ---over winter and even out of water for a period of time. The eggs hatch when conditions improve. The life span of a spiny water flea varies from several days to a few weeks.
The extent of the damage done to fish populations by the spiny water flea has not been clearly determined. Past experience with invasive species indicates that in almost every situation native species have come out second best.
Fish will feed on spiny water fleas but fish smaller than four inches (11cm) long have difficulty swallowing the fleas. The tail spine of the spiny water flea gets caught in the throat of the fish and is literally coughed out. This prevents the fish from getting any nourishment for its efforts.
At the present time the best defence against the spiny water flea is to prevent its transfer to new bodies of water. You should inspect and clean all fishing equipment including lines, nets, lures, boats and trailers before leaving any body of water. Drain the water from your motor, live well, bilge and transom wells. Do not release live bait into any body of water and recheck your fishing gear before every trip on the water.
Your grandchildren will thank you.
Speaking of Nature.
Jim Ferguson, 5313 River Road, R.R.5, Renfrew, Ontario K7V 3Z8 Phone 613-432-2738 email

They are Eating our Lawns Already

There is no frost in the ground to hinder their arrival and the larva of the June bug has begun its destruction of our lawns. We will not see any adults until May but until then the white grubs which are the larva of the June bug will be feeding on the roots of our lawn grasses.
June bug, is a common name for any of several beetles in the scarab family, they are also called June beetles. Actually June bugs are not bugs at all but beetles and there are 100 North American species all of which like the underground parts of any vegetation. There are several imports from other countries as well and they are just as destructive as our native species. Some cause more devastation because they do not have any natural enemies.
The female June bug lays her eggs in the ground where they hatch within a few weeks. The larvae burrow down below the frost line for the winter and return to just below the surface for the summer months and feed on plant roots.
The larvae, known to horticulturalists as white grubs, are white, fat and C-shaped. They burrow in the soil, feed on the roots of plants and damage lawns, pastures and grain crops. The larval stage continues to develop in the ground for two or three years before emerging as an adult. It is these tender morsels that the raccoons and skunks are looking for when they dig up our lawns. I have seen squirrels and chipmunks enjoying them as well.
In summers when there is a large infestation of the grubs the skunks and raccoons will turn over large areas of sod in their search for them. It is difficult to tell which does the most damage, the grubs or the animals searching for them. I am sure we could do without both.
The large brown adult beetles are attracted to lights during May and much of June. They belong to a family of beetles that includes Tumblebugs, Dung Beetles, Rhinoceros Beetles, Hercules Beetles and Elephant Beetles; the family is large in more ways than one.
We are most familiar with the June bug, the brown one we see below our night-lights or climbing up the outside walls of our homes. The adult June bug is about one inch (25mm) in length, brown in colour and has two sets of wings. The front set is hard and used to protect the delicate hind wings, which are used for flying. When the beetle lands it folds the hind wings gently into place and then covers them with the front wings, somewhat like closing the barn doors.
The adult June bugs are just as destructive as the grubs. They feed on flowers and the foliage of various trees and shrubs and are capable of completely defoliating them. The leaves will often return but they are much smaller than the first growth. On rare occasions the leaves do not return until the following spring. Damage to the bark can also take place and other diseases will attack the trees. When these conditions occur the trees will loose lose a year’s growth or they may die.
Speaking of Nature.
Jim Ferguson, 5313 River Road, R.R.5, Renfrew, Ontario K7V 3Z8 Phone 432-2738 Email

One Depends on the Other

Some 65 million years ago, the first bees, wasps, butterflies and moths appeared on earth. They are the insects that depend on flowers as a source of nutrition during their adult life. From that time onward flowers and certain groups of insects became dependent on one another and therefore contributed to the development of each other.
As the plants developed bright coloured flowers and called attention to the nectar and other food supplies insects developed a taste for the sweet nectar and the nutritious pollen. Prior to this the plants had grown structures that folded over one another to protect the reproductive parts of the plant from hungry pollinators. To overcome the added protection new species of wasps and bees evolved that had strong legs and mouth parts capable of opening the flowers to extract the pollen and nectar.
A flower that attracts only a few kinds of insect visitors and attracts them regularly has an advantage over flowers visited by undependable pollinators. It is an advantage for the insect to have a private food supply that is difficult to get to by insects competing for the same food.
Modern flowers have many distinctive features or special adaptations that encourage regular visits by particular pollinators. The various shapes, colours, and odors allow for sensory recognition by specific pollinators.
Flowers such as orchids, snapdragons and irises with their deep, trumpet-like blooms and unusual landing platforms exclude all but a few desired pollinators; the rest must go away hungry.
Bees pollinate flowers while they are foraging. The anthers deposit pollen grains on the bee’s mid section and when the bee moves to another flower the pollen falls off or is scraped off onto the new flower. Beetles push their way into a flower to get to the nectar or pollen and the sticky pollen clings to their head. When they move to a different flower they take the pollen with them and it brushes off as they search for more food.
The long sucking tongue of a butterfly is able to reach into the flowers of daisy to extract the nectar but in the process collect pollen to be deposited when they visit another flower. Moths are active pollinators as they make their rounds. They, like the butterflies, have long tongues and can sip nectar from deep within the flower’s petals. They collect pollen while they are feeding and spread it to other flowers as they move about.
As hummingbirds collect nectar from a lily or any deep-throated species, pollen collects on the bird’s forehead and is then deposited on the next flower the bird visits. Hummers are particularly good at their job because they will visit many flowers of the same species one after another and this makes sure each flower is pollinated.
Lately there has been a drastic reduction in the numbers of pollinators, mainly bees, and some crop growers must buy hives of bees to pollinate their crops. What is causing the decline is not fully understood which prevents a plan from being developed to solve the problem.

Speaking of Nature

Jim Ferguson, 5313 River Road, R.R.5, Renfrew, Ontario k7V 3Z8 Phone 613-432-2738 email

Things Pike Fishermen Should Know

The northern pike spawns in the spring and spawning takes place immediately after the ice is off our lakes and rivers in early April or May. Water temperatures at this time of year range between 40 and 50 degrees Fahrenheit (4.4-11.1 degrees Celsius). The spawning run for a single female lasts about nine days reaching a peak six or seven days after the initial set of eggs. After seven days the run declines rapidly and finally ends on the ninth day. Over the period the water temperatures average about 48 degrees Fahrenheit (nine degrees Celsius).
This species generally spawns during daylight hours on heavily vegetated flood plains of rivers, marshes and bays or our larger lakes and rivers. One spawning run of 6000 mature pike was tabulated in a single creek tributary in a Northern Ontario Lake.
The sexes pair at spawning time and the larger females are usually attended by one large male or two or more smaller ones. They swim through and over the vegetation in the shallow water often not much deeper than seven or eight inches (178-190mm). At intervals the female will deposit eggs on or in the vegetation and the males will cover them with milt. A thrusting of the tail, which scatters the eggs and moves the adult fish to a new spawning area, follows each spawning act.
The spawning act is repeated many times every day over a three to five day period.
There is no nest built and the eggs are scattered at random, usually in groups of from five to sixty eggs at a time. The eggs are about one tenth of an inch (3mm) in diameter, clear, amber in colour and very adhesive. As a result they remain on the vegetation in the spawning area until they hatch.
Egg numbers as high as 595,000 have been reported and they increase with the size of the female. The weight of the eggs has been estimated at 9000 per pound. The number of eggs deposited is high, and the fertility rate is usually over 50% but the number of young that, actually survive is very low.
It has been estimated in one study that of approximately one million eggs laid only 1800 young survived to leave the spawning grounds. This represents a 99.8% mortality rate.
The status of the pike population in local lakes is not clearly known or understood. I have heard from many ardent fishermen that there are not as many fish in our waters as there once were.
There are so many factors involved that it is difficult to put the blame any one offender. Increased amounts of acid rain, ultraviolet light caused by ozone depletion, over fishing, chemical pollution, destruction of natural shorelines and natural spawning habitat all contribute in one way or another to the reduction in fish numbers.
What can we do? First be involved in a catch and release program. Do not fish illegally; the rules are made to help preserve our fish stocks. Be a conscientious conservationist when fishing. Or be like me. Go to fish but do not catch anything.
Speaking of Nature
Jim Ferguson, 5313 River Road, R.R.5, Renfrew, Ontario k7V 3Z8 Phone 613-432-2738 email

Tuesday, April 14, 2009

The record is in the rings

Each growing season in the life of a tree leaves its mark in the ring of a layer of cells formed in the trunk that conduct water and minerals from the roots to other parts of the plant.
The growth rings are visible because of differences in the density of the wood produced early in the growing season and that produced late in the season. The early wood has large cells with thin walls; late wood has smaller cells with thicker walls.
Within a given growth layer, the change from early wood to late wood is gradual but a clear change is visible where the small thick-walled cells meet the larger thin-walled cells of the next growing season.
The thickness of the yearly growth layer will vary from year to year. The amount of light, rainfall, temperature, amount of soil water and the number of frost-free days all play their part in altering the appearance of each layer. The width of the growth layer is a fairly accurate indicator of the amount of rainfall in any particular year. If conditions are good and there is ample water the growth rings are wide if water is scarce the rings are narrow.
In arid regions, such as the tundra where the growing season may be only a week or two long the growth rings are almost too close together to count. Some trees in this area may be two feet high and a hundred years old.
Each growth ring is different and a study of the rings tells the story of the area that could go back several centuries. In a year when fire ravaged a forest the event will be recorded in the charred rings. Which side of the tree received the most heat will show as a dip in the yearly rings.
The closer the rings are together the shorter the growing season. Counting the rings will give a fairly accurate time when the event occurred.
Western White Pines are very large trees, 150 feet (50 m) high and 5 feet (150cm) in diameter and will live up to 400 years. When the growth rings of these trees are studied with modern measuring devices they reveal a great deal about the yearly climate conditions on our west coast.
Information provided by growth rings of both evergreens and deciduous trees is being used to reconstruct past weather conditions and to predict future conditions. With more accurate knowledge of past climate conditions, which may go back hundreds of years, than is provided by human records which go back only a few centuries, it will be possible to determine weather patterns and cycles for rainfall and drought. This knowledge will be used to manage and allocate the resource of the future, fresh water.

Speaking of Nature
Jim Ferguson, 5313 River Road, R.R.5, Renfrew, Ontario K7V 3Z8 Phone 613-432-2738 email

An exported native species

Pearly Everlasting (Anaphalis margaritacea) was exported to Europe a short time after the first settlers arrived in North America. It was easy to grow and did not require a great deal of care and before too many years was common in English gardens.
The name margaritacea is derived from the Greek margarites, “pearl” and referes to the pearly flower heads. The flower heads can be dried and will remain in perfect condition for many years.
Pearly Everlasting is not much more than green foliage for much of the summer but it is valuable in many gardens of Europe and North America for its late summer display of white flowers. The flower heads are pearly white, about half an inch across with papery petal-like bracts around a cluster of yellow or brownish florets. There may be several florets in dense, flat-topped clusters.
The plants form a bushy mound of silvery-grey leaves, bearing upright, with the clusters of florets on top. They make excellent cut flowers either fresh or dried and present a colourful display for several weeks. In the wild they tolerate a variety of soils and can be found in wet or dry, open or often disturbed sites. Once they are established at a site they are tolerant of drought and will return to flowering when conditions permit.
The blooms are attractive to butterflies and are a favourite haunt for late or second hatching fritillaries in August or September. The plants propagate very quickly and are inclined to spread seed over a wide area. In some locals the plants are so thick that they crowd one another out of a place to grow.
In Canada the plants were added to smoking mixtures both as medicine and as a tobacco substitute. As it turned out the substitute was not a good one and smokers became ill from the so-called medicine. Native Canadians used pearly everlasting tea to treat coughs, colds and digestive upsets.
The fuzzy leaves were used as poultices for sores, burns, bruises, swellings and rheumatism. The leaves, stems and flowers were crushed mixed with animal fat and used as a balm to rub on muscles to increase strength and reduced the effects of injuries. It was sometimes chewed for protection from danger.
Pearly everlasting is a member of a plant family that represents one of the three plant communities and their progression from wet to dry, from dense shade to full sun and from north to south. Forests are not only trees. They are a total of hundreds of competing, dependent and cooperative organisms—herbs, grasses, trees, shrubs, vines and fungi each perfectly adapted for survival of its own species in its own part of the forest.
When we walk through the forest or along any trail or road we may pass several different types of habitat and in each of them we find different species. We should be careful not to disturb the habitat or remove any of its members. They grow in that area because that is where their needs are met.

Speaking of Nature
Jim Ferguson, 5313 River Road, R.R.5, Renfrew, Ontario K7V 3Z8 Phone 613-432-2738 email blog address with the Canadian Forestry Association

They are many and ancient

According to fossil records ferns first appeared on earth 400 million years ago. The majority of the 12,000 living species are found in the tropics but many occur in temperate zones.
Ferns are vascular plants (they have vessels that carry liquids to the various parts of the plant) that can usually be distinguished from other plants by their large feathery leaves. Immature ferns develop as a “fiddle head” which looks like the head of a fiddle and which uncoils and spreads as it grows.
The fiddleheads of our most familiar woodlands develop underground for several years. In their final season, they multiply very rapidly, pushing their coiled tops above ground. In a few weeks of growth and uncoiling they become mature fern fronds.
Young fiddleheads, when cooked, look like asparagus and are considered a great delicacy by Maritimers. Fortunately for us they have shared their love of fiddleheads with others across the country.
The stems of ferns are not as complex as the stems of other plants, and are often reduced to a creeping underground root. Although ferns do not display any secondary growth –the type of growth that results in an increase in diameter and the formation of bark and woody parts—some ferns grow very tall. Ostrich ferns which grow along many creeks can reach six or seven feet (1.5-2.0m) tall.
The leaves, known as fronds, are often finally divided into smaller leaves called pinnae; these divided leaves spread widely and therefore collect more sunlight. It is necessary for the ferns to develop this way because they grow on the forest floor where there is dense shade.
Many ferns are almost all leaf, and even in giant tree ferns, the leaf is the main feature, the “stem” being composed of a mass of overlapping leaf bases. The leaf may be bladelike or more often they are finally divided into a regular fringe of smaller leaflets.
The spores of ferns develop on the undersides of the leaves. They are usually clustered; the clusters have a brownish colour and are often mistaken for insect eggs or patches of disease (rust). In a few ferns such as the cinnamon fern only specialized leaves bear the spore sacs, however in most ferns spores develop in all mature leaves.
Some of the spore sacs develop in distinct patterns which help identify the plant. Others are formed around the edges of the leaves. Many ferns including the Christmas fern (gets its name because it stays green all winter) have groups of spore sacs that are covered with a thin scale.
As the spores mature the outside covering dries and shrivels. When the outside ring of the sacs that contain the spores dries out it snaps open sending the powder-like spores into the air. The number of spores produced by a single leaflet may be as high as 52 million. Only a few of these germinate and produce new ferns.

Speaking of Nature
Jim Ferguson, 5313 River Road, R.R.5, Renfrew, Ontario K7V 3Z8 email
Many articles from this column are now on the blog at