Tag Archives: Habitat loss

Endangered Spring Migration It’s All About Timing

Endangered Spring Migration It’s All About Timing

Monday March 14 2011

Red-Breasted Merganser

 

Just as scientists are beginning to answer basic questions about migration, many migratory birds and other animals are in trouble

Are you starting to see some of your favorite birds come back from their wintering grounds? As the seasons change, many bird species come and go in the natural phenomenon of migration. Today, scientists are just beginning to answer some of the most basic questions about migration. But a shadow hangs over their research: Many migratory birds—and other migratory animals–are in trouble.

MIGRATION BASICS

Waterfowl in danger

Spring Migration begins

Migration all year

What is migration? Many creatures wander, but only some are true migrants. Most biologists define migration as repeated seasonal movement between breeding and non-breeding grounds by the same individuals.

How far do birds migrate? Thanks to tracking devices, we now know the astounding distances that some migrating species travel. For sheer distance, nothing beats migrating birds. Sooty shearwaters astonished scientists by flying more than 40,000 miles in a loop from New Zealand to Chile, Japan, Alaska and California before a trans-Pacific trip back to New Zealand. The birds averaged more than 200 miles per day for 200 days.

Longest Known Non-stop Bird Flight: The real migration champ was a bar-tailed godwit that flew 6,340 miles nonstop between New Zealand and North Korea, where it rested briefly before continuing nearly a thousand additional miles to its breeding grounds in Alaska.

HOW DO BIRDS FIND THEIR WAY?

Migratory Birds

There are a range of techniques migrating birds use to navigate:

* Earth’s magnetic field: This was discovered by a series of experiments in the mid-1970s which reversed magnetic fields around songbirds, triggering them to fly the wrong direction. It is now known that some 50 species including birds follow magnetic pathways.
*Circadian clocks: innate temporal rhythms in the biochemical, physiological or behavioral processes of all living things, from plants to birds
*Internal compasses: Using the sun or stars as a compass to determine direction
*Smells: Some birds, including pigeons, use olfactory clues to find their way.
*Geographical features such as mountain ranges and coastlines. Most migrants seem to rely on a combination of these techniques depending on conditions.

Migratory bird
Some stay all year
First signs in north america

WHY SCIENTISTS NEED TO UNDERSTAND MIGRATION
“The nonbreeding season drives a lot of what happens during rest of the annual cycle,” says Peter Marra, a research scientist at the Smithsonian Migratory Bird Center at the National Zoo. That cycle’s middle stages—the actual travel—remain terra incognita to scientists. The sheer number of habitats used at different points during migration presents a formidable challenge to conserving migratory birds.

NEW TECHNOLOGIES TO STUDY MIGRATION
The recently announced ICARUS Initiative will launch a satellite devoted to migratory animals and develop tiny, powerful transmitters that will allow researchers to follow creatures as small as insects across broad stretches of time and space.

WHAT ARE THE THREATS TO MIGRATORY BIRDS?

The sights and sounds

*Habitat loss and degradation. The habitats of migratory species nearly everywhere are under pressure from deforestation, farming and expanding human populations. Human-made obstacles also hinder travel. In many cities, skyscrapers, for example, kill migratory songbirds.
* Global warming. Researchers are reporting new behaviors among migratory animals worldwide that may stem from changing climate—shifts in breeding ranges, mistiming of cues and departures, for example. “Since the wintering habitats are changing at different rates than more northerly habitats, things can get really of out sync,” says the Smithsonian’s Marra.

Out of whack: In the Netherlands, some populations of pied flycatcher have crashed because the birds are arriving from African wintering grounds too late to feast on a once predictable bounty of caterpillars. Higher springtime temperatures in Europe are causing the insects to hatch earlier than they once did.

CAN MIGRANTS ADAPT?

Trumpeter and Tundra swan native species
Mute Swans adapt well

No one knows. Recently, some birds have shown flexibility by changing routes or timing or breeding sites in response to new environmental conditions. In the Midwest, for instance, ducks are arriving later in the fall and resting longer before continuing south, perhaps in response to higher temperatures.

Along the east coast of Massachusetts, where temperatures are rising and the insects on which birds feed on hatching sooner, 8 of 32 migratory songbirds looked at have begun arriving earlier from their wintering grounds—primarily species that winter in the southern United States as opposed to farther away in the Tropics.

“But I think it would be dangerous to assume that all species can adapt,” says Princeton University ecologist David Wilcove. As Wilcove writes in his book No Way Home: The Decline of the World’s Great Animal Migrations, “The irony is that just as the phenomenon of migration is slipping away, we are entering a golden age for studying it.”

Spring Migration: It’s All About Timing

Timing and luck

From January to June, each migratory species has its own special time to return to summer breeding grounds
Somewhere in North America, there is probably some kind of migratory movement of birds every day. But spring migration—the mass movement of birds toward their breeding grounds—happens with predictable timing each year. The precise local timing varies, of course, with latitude and elevation. “Early spring” might mean early February in the southernmost states, late March or early April in the north, or even May in the far north and high mountains.

Mass Migrations

Among the first groups of birds to move north are waterfowl: ducks, geese, and swans may begin migrating as soon as frozen lakes and marshes start to thaw. Even in the northern Provinces, flocks of waterfowl may arrive in late February. Also on the move this early are some species that migrate mostly within North America, spending the winter as far north as they can. They include killdeer and red-winged blackbirds.

Some birds of prey also start to migrate in early spring. Bald eagles, rough-legged hawks and red-shouldered hawks are actively moving north even while wintry conditions still prevail.

Other surprisingly early migrants include purple martins, returning from South America and reaching Florida and Texas by late January and making it to northern states by the end of March.

Blue heron nesting zone

Many native sparrows tend to be early migrants, with large numbers moving in southern states in March and in northern states by early April. Kinglets and sapsuckers are in this moderately early wave as well. And most blackbirds move north during the first half of the spring.

 

Shorebirds (sandpipers, plovers and their relatives) have a protracted migration, with some species represented among the earliest and latest migrants. Pectoral sandpipers and American golden-plovers, wintering in South America, come back to southern provinces by the end of February and reach northern provinces by March. Many other species migrate later, with peak passage in most areas during April and May. Long-distance migrants that winter in southern South America, white-rumped sandpipers peak in  central Canada and  United States in late May or early June.

Southern Ontario

 

The great northward flood of songbirds that have wintered in the tropics—including warblers, tanagers, buntings, grosbeaks, orioles, vireos and thrushes—occurs primarily during April and May, filling North American woodlands with color, song and activity. For many birders, warblers are particular favorites; there are several places in the country where you can see more than 30 species of these tiny, colorful gems during the course of the season.

Deer Migration Huge

By early June, aside from a few shorebirds and straggling songbirds, spring migration is over across most of North America. This is when birders turn their attention to local nesting species—and get ready to watch for the first of the fall migrants, which in some areas start showing up by early July.

New Born signet
Mute swan
Refections of spring

Sources: National Wildlife Foundation, Wikipedia

 

Doug Worrall Photography

Plants Are Vanishing Faster Than Animals

Vanishing Act

Saturday February 12 2011

 


Did you see the TV mystery “Vanishing Act” ? Did you read Jodi Picoult’s book entitled “Vanishing Act” about the nature and power of memory ? Similarily, plants are vanishing (disappearing) faster than other life forms ! Louisiana State University botanist James Wandersee calls it PLANT BLINDNESS. The fact remains – plants are vanishing faster than animals ! In 2,009, the International Union for the Conservation of Nature calls the current plant and animal loss of biodiversity a crisis. Animals that have vanished include: (1) Sturdee’s Pipistrelle, (2) Red Bellied Gracile Opossum, (3) Schaumburg’s Deer, (4) Caspian Tiger, and (5) the Western Black Rhinoceros. The American Institute of Biological Science’s Louis Harris poll indicated “nearly all biologists attributed the loss to human activity especially the destruction of plant and animal habitats.” In the garden of vanishing plants is the native ground hugging vine Beach Clusterine ( Jacquemonia Reclinata ) grows in areas most desirable to prime real estate in the U.S.A. The loss of what appears to be a few weeds to some can be of vital importance to human life ! For example, the National Geographic News stated “The Madagascar Rose Periwinkle is an ordinary plant with extraordinary capabilities.” This nondescript low-growing plant has small white flowers with pink centres and glossy green leaves. More importantly, two drugs Vincristine and Vinblastine derived from the Rosy Periwinkle are used to treat Childhood Leukemia and cases of Hodgkin’s disease. Many of the estimates of species loss are extrapolations based on global destruction of rain forests and other rich habitat, such as, the Amazon rain forest tiny Wild Camu Berries – world’s richest source of natural Vitamin C.

Canadian-Periwinkles
Canadian-Periwinkles

As urban sprawl development becomes increasingly diffuse and dispersed the distinction between “suburb” and “forest” become less clear. One cause of extinction is plant and animal Habitat Destruction. But Habitat Fragmentation is also causing extinction. That is, natural vegetation ( Forests ) being cleared for agriculture, logging or urban development dividing habitats that were continuous not separate fragments. Small patches of habitat support small populations of animals and small populations are more vulnerable to extinction ! The Canadian Tall Grass Prairie is vanishing faster than ever. The Tall Grass Prairie are unique to the eco-system comprised of tree and shrub growth and dominated by species of grass ( i.e., Bluestem ), which can grow to shoulder height. In Northern Ontario, cottage areas are being replaced by city-type mansion dwellings. These lands are being landscaped and manicured and the native weeds and plants are hacked down by local township equipment along country roads and laneways. Extinction is a natural event. The average duration of a species is 2 – 10 million years, where scientists estimate one to two species became extinct per year. Present day human activity accelerated this rate of extinction to one to two species per hour ! A President of the Center for Plant Conservation predicts “The present threat of extinction is 30% of our plants, by 2,070.”

Cormorant haven
RBG Fishway cootes

The “VALUE OF PLANTS” is unseen by some people. Vanishing strains of the Wild Native Sunflowers to make cultivated varieties cost $384 million a year just for the Genetic contributions. Germplasm is genetic endowment and usually the genetic constitution related to wild plants. Germplasm are preserved as seeds in gene banks. Therefore, in light of vanishing wild areas and plants “Germplasm Resources” are extremely important. Seeds of Diversity Canada have seeds from 1,200 varieties of plants and vegetables. These include Pruden’s Purple Tomatoes (pink), and, B.C. Blue Potatoes (Violet when baked). The Canadian Journal of Plant Science concluded that Genetic Mapping can be useful for improvements in Sorghum Bicolor – a grass species cultivate for its edible grain. This study tested ten agronomic characteristics including plant height, leaf width, spike length, ratio of stem and leaf weight, fresh plant weight and dried plant weight. Another study published in 2,011 investigated leaf starch and leaf mass. Leaf starch contents is an indictor of plant carbon status that shows potential for CO 2 enrichment ; and, leaf starch was also affected by leaf position and light. . A study of molecular analysis shows molecular markers have been introduced to leaf tissue culture research that can potentially be used in various facets of pertinent studies with berry crops. The value of plants is punctuated by the fact that 25% of all prescription drugs contain ingredients derived from plant compounds, according to the Fish and Wildlife Service. The most popular seeded legume for forage production in northern Ontario and Quebec is Red Clover (Triflian Pratonre L. ) but because of the poorly drained soils that prevail and high precipitation in the fall they are disappearing. To rectify this a study shows Tall Fescue and Orchard Grass could be a good alternative to plant with Red Clover.

vanishing Bull rushes
Loss of vegitation

Habitat destruction, habitat fragmentation, urban sprawl, over-harvesting, invasion of Non-Native species, environmental degrading (pollution/pesticides) and climate change are detrimental to native plant life. Steps you can take to prevent plants from vanishing are(1) : to become involved in environmental and conservation activities; (2) to develop workplace knowledge skill sets (data entry, workshops on how to grow and protect plants and planting them;(3) in your environment plant more diversity by finding out what plants grew there prior to human invasion and plant some available species; (4) and most importantly, when you see rare plants, leave them alone to grow and re-seed by taking photographs, not specimens. To rectify the plant vanishing act we should remember to reduce environmental degradation by maintaining sufficient forest cover and native plants.

Heron in flight
mirror mirror in the water
Hop and skip

Sources: The Canadian Journal of Plant Science; National Geographic News, the Center for Plant Conservation, The International Union of Conservation of Nature,

By Jacqueline

Doug Worrall Photographer