Posts Tagged ‘endangered species’


Last spring, I added a native species to my garden, an Eastern Prickly Pear Cactus (Opuntia humifusa). A cactus that is native to Ontario? Yes, it’s true! Opuntia humifusa, one of about 200 opuntia species, is native to the southernmost reaches of the province. Native populations can still be found in Point Pelee National Park and in Fish Point Provincial Nature Reserve on Pelee Island. Opuntia humifusa is listed as hardy to Canadian Zone 5 (USDA 4).

I was very pleased that my cactus over-wintered well and looked bright and healthy this spring. It is growing with an unidentified sedum, which bloomed earlier this spring, and donkey-tail spurge (Euphorbia myrsinites) to its right. This weekend, I was very excited to see its first two flowers. They were lovely, soft yellow blooms, a couple of inches across. Several additional flowers are still developing.

Parks Canada describes Eastern Prickly Pear thus:

The Eastern Prickly Pear Cactus (Opuntia humifusa) is a perennial, low-spreading, succulent cactus with jointed, rounded, but flattened, green stems measuring 5 to 12 cm in length. Stem segments are fleshy or firm, and sparsely covered with clusters of barbed bristles and spines. It occurs in small patches or large, scattered colonies of thousands of stems.

Like many other plants and animals, Opuntia humifusa has been under siege from human activities and has joined an ever-increasing list of endangered species in Ontario. As such, an official “recovery plan” has been developed for Opuntia humifusa and you can read it for yourself at the Ministry of Natural Resources website, linked here.

Unfortunately, as the need for better protection of our biological heritage increases, our government agencies are failing to respond. On the contrary, the federal Conservatives have acted belligerently to undo the limited environmental protection that did exist in a blinkered vision of Canada as a haven for unfettered resource development. To add insult to injury, the provincial Liberals are currently moving to “streamline” environmental legislation. We are failing to protect the interests of future generations of all living things, including humans.


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When this summer’s drought left the riverbed dry, it afforded the opportunity to look for freshwater mussels. Members of the Phylum Mollusca, mussels are related to snails, slugs, clams and oysters, and even octopuses. Mussels are sometimes called living filters. They play an important role in aquatic ecosystems by cleaning the water. They also provide food for assorted fish and wildlife such as raccoons.

There are 41 native species of mussels in Ontario. Of these, 28 species are in decline or threatened with extinction. Mussels are among the most endangered organisms in North America, threatened by many human activities from pollution to habitat destruction.

Perhaps the most severe threat to the native mussel population has been the introduction of the zebra mussel, an invasive species. Zebra mussels attach themselves to the shells of native mussels by the hundreds or even thousands, causing them to die from lack of oxygen or food. Native mussels have been nearly eliminated from much of the Great Lakes system and St. Lawrence river, as well as watersheds where zebra mussels have been introduced.


Eastern Floater (Pyganodon cataracta)

Freshwater mussels are the largest and longest-living freshwater invertebrates in North America. Their life spans can reach many decades. They occupy a wide variety of habitats, from small streams to lakes, but have their greatest diversity in large rivers, which supply a constant supply of oxygen and food and a variety of habitat types.

Mussels spend their lives buried in the substrate of their aquatic home. They feed by drawing water in through a siphon and passing it across gills to filter out small particles of algae and bacteria. The reproductive cycle of freshwater mussels is amazingly complex.

During spawning, males release sperm into the water and females living downstream take in the sperm through their siphons. Eggs are fertilized in a specialized portion of the female’s gills called marsupia. Embryos remain in the gills until they have reached a larval stage called glochidium.


Giant Floater (Pyganodon grandis)

When conditions are right, depending on temperature, photoperiod and time of year, the female mussel releases her glochidia into the water where they must quickly attach themselves to the gills or fins of an appropriate fish host. The glochidia then become encysted in the tissues of the host fish and get nourishment from its body fluids for a time ranging from a week to over 6 months.

They transform into juvenile mussels during this parasitic phase. Once metamorphosis is complete, the juvenile ruptures the cyst and falls to the river bottom, where it burrows into the mud and remains for the next few years. Most mussel species have only a few specific host species and the chances of a glochidiium surviving are low. Mussels produce millions of glochidia to improve the odds of some reaching adulthood.


Eastern Lampmussel (Lampsillis radiata)

I found evidence of 3 species in our local riverbed. Some of the Eastern Floater shells were quite large and sturdy, while the single Eastern Lampmussel I found was small and more fragile, a real beauty with striking green rays.

Mussels are an example of the astounding lives lived by so many creatures to which most of us are oblivious. Perhaps if Canadians had a greater awareness of the wonderful richness and diversity of life that surrounds us, and how little we know and understand it, they might be less apathetic regarding cuts to scientific research and the protection of waterways.


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Ring-tailed Lemurs

At Saunders Country Critters, two species of lemurs are on display. Pictured above are two Ring-tailed Lemurs (Lemur catta). As their name suggests, they have distinctive tails, about 60 cm (23 inches) long, ringed in black and white. When walking on all fours on the ground, they hold their tails aloft like flags. Ring-tails are the species of lemur most commonly kept in captivity. In their native Madagascar, they are found in the dry south and south-western regions, inhabiting deciduous forest with grassy undergrowth and dense scrubland. Lemurs are diurnal, active during the day. On sunny mornings, especially after a cool night, lemurs may “sunbathe”, sitting upright in the treetops with their arms outstretched or crooked on their knees, exposing their bellies to the warm rays. In lemur society, females are dominant over males.

Also represented are Black and White Ruffed Lemurs (Varecia variegata). The white ruff that gives them their name runs under the chin and around the cheeks, ending as tufts on the ears. Ruffed Lemurs are noted for their loud, raucous calls, and the lemur pictured below was pleased to demonstrate this feature. Black and White Ruffed Lemurs live in the primary and secondary rainforest in the lowlands and mid-altitude regions of Madagascar.

Lemurs are primates, found only on Madagascar, the 4th largest island in the world. Madagascar separated from Africa more than 100 million years ago. About 80% of the plants and animals found there are endemic, found nowhere else on Earth. Madagascar is so unique it is sometimes termed “The Eighth Continent”. People reached Madagascar only about 1500 years ago, but since then about a third of lemur species, (mostly the largest, most slow-moving ones) have become extinct, and about 80% of those remaining are threatened with extinction. Black and White Ruffed Lemurs are classed as Critically Endangered, meaning that they face a very high risk of extinction in the near future. Ring-tailed Lemurs are classed as Vulnerable, meaning they face a high risk of extinction in the medium-term future. The main threat to lemurs is the overpopulation of the island by impoverished humans. Lemurs suffer from the uncontrolled destruction of their forest habitat, overgrazing and wildfires, and wood collection for charcoal production. They are also subject to poaching for food and collection as pets.

Unfortunately, far from improving, the outlook for lemurs has recently taken a turn for the worst, as political turmoil has broken out on Madagascar, threatening the $400 million eco-industry, a vital source of income, and turning loose pillaging gangs in the forests.

Black and White Ruffed Lemur

Black and White Ruffed Lemur

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