These claws help the lobster defend itself, but also capture and consume its prey. Each claw serves a different purpose: the bigger, blunter one is used for crushing, and the smaller one with sharper edges, for cutting. The Barn Swallow Hirundo rustica is a medium-sized songbird, about the size of a sparrow.
It measures between 15 and 18 centimeters cm in length and 29 to 32 cm in wingspan, and weighs between 15 and 20 grams g. Its back and tail plumage is a distinctive steely, iridescent blue, with light brown or rust belly and a chestnut-coloured throat and forehead.
Their long forked tail and pointed wings also make them easily recognizable. Both sexes may look similar, but females are typically not as brightly coloured and have shorter tails than males. When perched, this swallow looks almost conical because of its flat, short head, very short neck and its long body. Although the average lifespan of a Barn Swallow is about four years, a North American individual older than eight years and a European individual older than 16 years have been observed.
Sights and sounds: Like all swallows, the Barn Swallow is diurnal —it is active during the day, from dusk to dawn. It is an agile flyer that creates very acrobatic patterns in flight. It can fly from very close to the ground or water to more than 30 m heights. When not in flight, the Barn Swallow can be observed perched on fences, wires, TV antennas or dead branches. Both male and female Barn Swallows sing both individually and in groups in a wide variety of twitters, warbles, whirrs and chirps.
They give a loud call when threatened, to which other swallows will react, leaving their nests to defend the area. Freshwater turtles are reptiles, like snakes, crocodilians and lizards.
They also have a scaly skin, enabling them, as opposed to most amphibians, to live outside of water. Also like many reptile species, turtles lay eggs they are oviparous. But what makes them different to other reptiles is that turtles have a shell. This shell, composed of a carapace in the back and a plastron on the belly, is made of bony plates. These bones are covered by horny scutes made of keratin like human fingernails or leathery skin, depending on the species.
All Canadian freshwater turtles can retreat in their shells and hide their entire body except the Common Snapping Turtle Chelydra serpentina. This shell is considered perhaps the most efficient form of armour in the animal kingdom, as adult turtles are very likely to survive from one year to the next. Indeed, turtles have an impressively long life for such small animals.
Most other species can live for more than 20 years. There are about species of turtles throughout the world, inhabiting a great variety of terrestrial, freshwater and marine ecosystems on every continent except Antarctica and its waters. In Canada, eight native species of freshwater turtles and four species of marine turtles can be observed.
Another species, the Pacific Pond Turtle Clemmys marmorata , is now Extirpated, having disappeared from its Canadian range. Also, the Eastern Box Turtle Terrapene carolina has either such a small population that it is nearly Extirpated, or the few individuals found in Canada are actually pets released in the wild. More research is needed to know if these turtles are still native individuals. Finally, the Red-eared Slider Trachemys scripta elegans , has been introduced to Canada as released pets and, thus, is not a native species.
Females tend to be slightly larger than males but are otherwise identical. As its name implies, it is pale tan to reddish or dark brown with a slightly paler belly, and ears and wings that are dark brown to black. Contrary to popular belief, Little Brown Bats, like all other bats, are not blind. Still, since they are nocturnal and must navigate in the darkness, they are one of the few terrestrial mammals that use echolocation to gather information on their surroundings and where prey are situated.
The echolocation calls they make, similar to clicking noises, bounce off objects and this echo is processed by the bat to get the information they need. These noises are at a very high frequency, and so cannot be heard by humans. Narwhals Monodon monoceros are considered medium-sized odontocetes, or toothed whales the largest being the sperm whale, and the smallest, the harbour porpoise , being of a similar size to the beluga, its close relative.
Males can grow up to 6. Females tend to be smaller, with an average size of 4 m and a maximum size of 5. A newborn calf is about 1. Like belugas, they have a small head, a stocky body and short, round flippers. Narwhals lack a dorsal fin on their backs, but they do have a dorsal ridge about 5 cm high that covers about half their backs. This ridge can be used by researchers to differentiate one narwhal from another. It is thought that the absence of dorsal fin actually helps the narwhal navigate among sea ice.
Unlike other cetaceans —the order which comprises all whales—, narwhals have convex tail flukes, or tail fins. These whales have a mottled black and white, grey or brownish back, but the rest of the body mainly its underside is white.
Newborn narwhal calves are pale grey to light brownish, developing the adult darker colouring at about 4 years old. As they grow older, they will progressively become paler again. Some may live up to years, but most probably live to be 60 years of age. Although the second, smaller incisor tooth often remains embedded in the skull, it rarely but on occasion develops into a second tusk.
Tusks typically grow only on males, but a few females have also been observed with short tusks. The function of the tusk remains a mystery, but several hypotheses have been proposed. Many experts believe that it is a secondary sexual character, similar to deer antlers. Thus, the length of the tusk may indicate social rank through dominance hierarchies and assist in competition for access to females.
Indeed, there are indications that the tusks are used by male narwhals for fighting each other or perhaps other species, like the beluga or killer whale. A high quantity of tubules and nerve endings in the pulp —the soft tissue inside teeth — of the tusk have at least one scientist thinking that it could be a highly sensitive sensory organ, able to detect subtle changes in temperature, salinity or pressure.
Narwhals have not been observed using their tusk to break sea ice, despite popular belief. Narwhals do occasionally break the tip of their tusk though which can never be repaired. This is more often seen in old animals and gives more evidence that the tusk might be used for sexual competition. Adult coho salmon have silvery sides and metallic blue backs with irregular black spots. Spawning males have bright red sides, and bright green backs and heads, with darker colouration on their bellies.
The fish have hooked jaws and sharp teeth. Young coho salmon are aggressive, territorial and often vibrantly coloured, with a large orange anal fin edged in black and white. Ptarmigans are hardy members of the grouse family that spend most of their lives on the ground at or above the treeline. Like other grouse, ptarmigans have chunky bodies, short tails and legs, and short, rounded wings.
Willow Ptarmigans weigh from to g, White-tailed Ptarmigans weigh about g, and Rock Ptarmigans are intermediate in size. All ptarmigans have feathered feet, unique among chickenlike birds, which improve their ability to walk in snow. They also have white wings throughout the year. Inflatable red combs above their eyes, which are especially evident in territorial and courting males, are inconspicuous to barely visible in females.
Ptarmigans have three seasonal plumages per year, instead of the two that are usual for most birds. These plumages keep the birds, particularly the female, well camouflaged at all times.
In winter, all ptarmigans of both sexes are basically white. Whereas White-tailed Ptarmigans have permanently white tail feathers, the tails of Willow and Rock Ptarmigans remain black throughout the year. In winter, male—and some female—Rock Ptarmigans sport a black stripe that extends through the eye to the bill as if they had put on charcoal goggles to prevent snow blindness , distinguishing them from male Willow Ptarmigans.
In ptarmigans, the moult, or shedding of old feathers, starts with the head and progresses towards the tail. As soon as the spring snowmelt begins, females moult into a barred breeding plumage of brown, gold, and black. Female ptarmigans are difficult to tell apart in spring, but the overall tones of the White-tailed Ptarmigan females are cooler in comparison to those of the other two species. Breeding males delay their moult. The Roseate Tern Sterna dougallii is a seabird that resembles a small gull, but it has the typically slender body, short legs, and long, pointed wings of all terns.
It is closely related to the Common Tern Sterna hirundo and the Arctic Tern Sterna paradisaea and is frequently found in their company. For these reasons, the Roseate Tern is not easy to identify see drawings. It is a paler grey than Arctic and Common terns, and its tail streamers are considerably longer.
The adult Roseate Tern is 33 to 34 cm in length and has a wingspan of 72 to 80 cm. At a weight of approximately to g, an adult is slightly smaller than a Mourning Dove. It has a black forehead and nape, and its upper wing is a pale grey. Its tail is white with deeply forked outer feathers that give the impression of long streamers when the bird is in flight. The underside of the tern is white, tinged with pink early in the breeding season; however, this pale rosy tint is not a good field mark, or identification characteristic, because it varies from bird to bird, and the colour tends to be bleached out by the sun.
The legs and feet are reddish, and the bill is mostly black, although bills of breeding birds may be red at the base. Male and female birds look alike.
The head of the nonbreeding adult is mottled black and white. The juvenile Roseate Tern has a mottled greyish back and rump and dark bill and legs. Chicks are unevenly covered with down, giving them a spiky appearance; their legs are dark purplish to black.
Signs and sounds All terns have a harsh cry, but the Roseate Tern has a distinctive, two-syllable call — kir-rick. This is often the best way of confirming its presence at a colony. Many naturalists and hunters consider the Wood Duck Aix sponsa to be the most beautiful duck in North America, if not the world.
The male in its multi-coloured breeding plumage, worn from October through June, is unexcelled among ducks. The female is less showy, although still beautiful and more colourful than other female ducks. Wood Ducks are intermediate in size, between the Mallard and Blue-winged Teal; on average, males weigh g and females weigh g.
From a distance, the male Wood Duck on the water appears as a dark-bodied, dark-breasted, light-flanked duck with a striped crested head and a light-coloured throat. At close range, its iridescent plumage, red eyes, and black, red, and white bill are conspicuous. A white eye-ring, light-coloured throat, and fine crest distinguish the female from both the male Wood Duck and females of other species.
Both sexes usually show a downward pointing crest at the back of the head, and their long broad square tails are distinctive features in flight. The wings of Wood Ducks are highly characteristic. The primary wing feathers, which are the 10 outermost flight feathers attached to the wing beyond the wrist, are dark in colour. The outer vanes of these feathers look as if they have been sprayed with aluminum paint. The Wood Duck is the only North American duck so marked.
Shorebirds form one of the most interesting, important, and spectacular groups of birds in Canada. They comprise a diverse group of species, including the plovers, oystercatchers, avocets, stilts, turnstones, sandpipers, yellowlegs, snipes, godwits, curlews, and phalaropes.
To the uninitiated, many species of shorebirds, especially the smaller sandpipers, appear confusingly similar, representing variations on a design involving long legs, a long bill, sharp, dynamic wings, and a streamlined body. These design features all reflect the lifestyle for which the birds are adapted—long legs for wading in water or on mudflats or marshes, the long bill for searching for tiny animal and insect prey by probing into Arctic tundra or a variety of substrates, and long wings and a streamlined body for swift flight over long distances.
Skip to main content. Photo: Marg Werden. At a Glance. Tweet Print. Common Raven vs American Crow Birds Atlantic Cod Atlantic Cod Youth Atlantic Cod 15 seconds Atlantic Cod 30 seconds Atlantic Cod The Atlantic Cod Gadus morhua is a medium to large saltwater fish: generally averaging two to three kilograms in weight and about 65 to centimetres in length, the largest cod on record weighed about kg and was more than cm long!
The Atlantic Cod may live as long as 25 years. Unique characteristics The Right Whale has a bit of an unusual name. Barn Swallow photo by J. Little Brown Bat. Youth Wolf youth. Classic Wolf 30 seconds. Classic Wolf 15 seconds. Classic Wolf long version.
Classic Sugar Maple long version. Environment COP26 nears conclusion with mixed signals and frustration. Environment Planet Possible India bets its energy future on solar—in ways both small and big.
Environment As the EU targets emissions cuts, this country has a coal problem. Paid Content How Hong Kong protects its sea sanctuaries. History Magazine These 3,year-old giants watched over the cemeteries of Sardinia. Science Coronavirus Coverage What families can do now that kids are getting the vaccine. Magazine How one image captures 21 hours of a volcanic eruption.
Science Why it's so hard to treat pain in infants. Science The controversial sale of 'Big John,' the world's largest Triceratops. Science Coronavirus Coverage How antivirals may change the course of the pandemic. Travel A road trip in Burgundy reveals far more than fine wine. Travel My Hometown In L. Subscriber Exclusive Content. Why are people so dang obsessed with Mars? How viruses shape our world. The era of greyhound racing in the U.
See how people have imagined life on Mars through history. See More. United States Change. Indiana has some serious Deer overpopulation issues. As a grouse hunter, I would have very limited success even finding birds, yet we would stumble across deer so plentiful that there is a browse line in most forested areas.
Now the animals are thick as fleas, but the hunting regulations have not kept pace. The firearm season is quite short, the weapons are limited, and the take limits have not changed. All this, and a declining percentage of the population has the time, energy, or desire to hunt makes for a burgeoning deer population.
With the advent of the Chronic Wasting Disease, and the fear of cross species infection from hunting, there is additional pressure against hunting. Despite the need for massive culling, too many people know that high deer populations are destroying orchids, mushrooms, ground nesting birds, and every other animal which competes with the Deer.
I laughed at the part The damage has been insidious — both slow moving and cumulative. I think people get to be too much on this. It think Bloomburg should concentrate more on fixing the problems we create for the forest rather than deer.
By removing predators or refusing to fill their vital role, we subvert the very notion of a balanced ecology. Lmao worst part is some people here probably thought I was serious and thought that idea was great…. Every ecosystem has a carrying capacity threshold that can not be crossed and if so then disease take hold and if you want something really bad look up some of the sicknesses that deer can contract such as CWD or for people who know nothing about the topic chronic wasting disorder which affect the nervous system of the deer and they die and agonizing death.
So next time talk about some thing you know a little about before you make comments like this. I live in Connecticut and I hunt deer — So I know plenty about the negative impacts of too many deer. However, finding people to grant permission to hunt is a huge problem for all of us here, even though there are deer everywhere.
This IS a social issue before anything else. As the article says, even getting people to understand the problem is a huge challenge. The scientific community is in total agreement with the exception of those studies sponsored by anti-hunting organizations But how do you get people to take their blinders off??? To the previous response from Greg Williams. Think about that — because humans have created perfect habitat for deer — Not destroyed it.
We planted crops across the country. We cleared the woods that naturally can not supply enough food for this many deer We removed their predators. What MORE could deer have asked for?
The only Responsible and Ethical thing to do is to control the negative impacts humans have had on nature. Protect the species that have been reduced — and control the species that are in excess. One important thing missing is that whitetail deer are legitimate meat animals and have been hunted with the bow over twenty thousand years.
White tail deer are a native species not an invasive and live a far better healthier life then factory farmed animals with none of the associated pollution. Urban Bow hunting programs that harvest over abundant wild, free running deer are, as nature intended a win — win sustainable situation that has been proved to work in reducing deer herd densities.
There are a number of towns in SW CT whose bow hunting programs have over time steadily reduced their deer populations closer to the number of deer per square mile that all wild life biologists agree on.
The issue of Lyme disease should not be minimzed in the deer debate. And the tick transmits the disease to people and companion animals. The type that writes these articles are environmental extremists and in my view, completely nuts. Unforunately some states, like Pa, has these types in charge of their game management agencies. We need hunter friendlies in top staff positions whether the greenies like it or not.
That is the only way proper management will occur and proper numbers of deer will be the case. And by proper that means more in some areas of Pa than currently is the case. The greenies would whine, but as far as Im concerned they can all go to some other liberal state and push their agenda there. What is the proper number of deer? There were certainly fewer deer when their natural predators like bear, wolves, and cougars were larger in number than they are now.
Hunters would likely prefer a higher number of deer than those who are concerned about other factors. Thanks for sharing this article. Cheers, Ben. Wayne nj population of fifty thousand. Paterson pop. Over I have less than acre of land in Wayne, with several acres behind me. I chase every day and other days several time with air blast horn and broom. I have counted from 6 to 20 deer of the property.
I have been told by the police I am not permitted to even through astone at them. Nj laws stink The deer double every three years. I have lived in Wayne for forty one years. The last 5 to 6 years has been a night mare. Thank you for your interest. I do agree with all of the experts who say deer are in abundance , as a hunter I only harvest enough deer for my family and friends who enjoy eating venison.
I spend many hours in the woods prior to the hunting season preparing for a safe and successful hunting season. I basically Bow Hunt because you have to rely on a maximum of stealth to harvest a deer. In closing I would to say that most ethical hunters truly feel that they are trying to do their part to help a growing problem.
I live in northern Indiana and no matter what the uninformed DNR says, the deer population has dwindled so badly here, there are almost none.
When I moved here 15 years ago, there were generous herds of deer. Now you rarely see one. Contrary to popular belief, hunters do NOT help the situation. Nature thins its herds by the process of eliminating the weak. Hunters attempt to take the biggest and best, thus weakening the process of nature.
Its funny to see people using extreme measures to appeal emotionally to people to push their own political agendas, in this case biodiversity extremism. There is nothing wrong with our forests, at least most of them, nor the deer herd. The days of overpopulation in most areas have been long gone for some time now.
But the forest composition may not be exactly what some want, based solely on their own values. Im sorry, but as a hunter I value whitetail deer in reasonable numbers and Im not going to cry if there is less trillium in the forest. Its still there. You just need to look harder for it.
0コメント