What Are Species Ranges?

A region where a certain species may be found during the course of its existence is known as a species range. Areas where individuals or groups may migrate or hibernate are included in a species' range. The region where a certain species may be found during the course of its life is known as its range. 

 

Every species of life on Earth has a distinct geographic distribution. For instance, rattlesnakes are found exclusively in North and South America in the Western Hemisphere. Arizona in the United States is home to 13 different species of rattlesnakes, making it the state with the broadest range of these reptiles. Only four rattlesnake species may be found east of the Mississippi River.

 

While some species have a large range, others only inhabit a small region. In Africa, the Middle East, and Asia, for instance, the leopard's (Panthera pardus) range spans more than 20 million square kilometers (7.7 million square miles). The Iriomote cat (Prionailurus iriomotensis), a rare species of wild cat, is found exclusively on Japan's Iriomote Island. Only roughly 292 square kilometers make up its range (113 square miles).

 

Species are considered to have a cosmopolitan distribution if their ranges span the majority of the planet. Balaenoptera musculus, the scientific name for blue whales, are widespread across the world's oceans. Humans (Homo sapiens) live on every continent bar Antarctica, exhibiting a global distribution.

 

On the other hand, the Antarctic midge (Belgica antarctica) is unique to Antarctica and can only be found there. Endemism describes the distribution of species with a small geographic range, such as the Antarctic midge or the Iriomote cat.

 

Disjunct distributions are seen in species having two or more ranges that do not overlap. Sometimes the ranges of these animals are divided by mountain ranges, deserts, or even seas. The pueraria lobata plant, which grows in the southern islands of Japan, the Southeast Asian continent, as well as the United States, has a patchy distribution. The range of the Eurasian pygmy shrew (Sorex minutus) across Europe and the island of Ireland is fragmented.

 

Various factors affect a species' distribution. Climate is one of the key elements. For instance, since polar bears (Ursus maritimus) walk on sea ice, the quantity of sea ice that accumulates throughout the winter determines the extent of their range. Cacti and other succulent plant species can survive in very hot and dry environments. In environments with a lot of rain or extreme cold, they cannot live.

 

Also affecting species range are food supplies. Only areas with access to food allow for the survival of living beings. Several varieties of bamboo, particularly dragon's head bamboo, provide practically all of the nutrients needed for the giant panda (Ailuropoda melanoleuca) (Fargesia dracocephala). The giant panda's natural habitat is confined to the dragon's head bamboo's native region, namely the western Chinese highlands of the Qinling and Minshan.

 

Species that depend on one food source must locate another one, expand their range, or risk extinction when it vanishes or changes its range. The icy, northern latitudes are the Arctic fox's (Alopex lagopus) habitat range. Lemmings and other tiny rodents make up the bulk of its diet. Due to its specialized adaptation to the Arctic, the Arctic fox cannot expand its range if lemmings are more challenging to hunt. (Lemmings are neither endangered nor scarce. They only get more challenging to hunt when the Arctic fox must contend with other species, like the red fox, for the prey.) In their habitat, Arctic foxes may also find seals, fish, and even carrion, or dead animals.

 

Water is essential to a species' range, much like food. Some animals are found in riparian environments, which are found along rivers and streams. River otters and other creatures rely on the ecology of the river to survive. The animals downstream often cannot survive when humans dam rivers to create reservoirs or generate energy. They have lost all of their range. In actuality, habitat loss is the main concern facing endangered species today.

 

For animals without a habitat that contains freshwater, access to water may also define an animal's species range. During the dry season, several African elephant species travel more than 60 kilometers (100 miles) in search of streams and drinking holes. The boundaries of their distribution are determined by the hunt for fresh water.

 

Species range may also be determined by landscape factors. Because it inhabits hilly locations, the mountain goat (Oreamnos americanus) earned its name. The Rocky Mountains, Cascade Mountains, and Chugach Mountains make up its extensive range in western North America.

 

The distribution of a species might alter throughout time. The summer and winter ranges of many species vary. Winter migration for Canada geese (Branta canadensis) takes them to northern Mexico and the southern United States, where they spend the summer.

 

Additionally, the breeding regions of certain species vary. There are several Pacific salmon species that may be found in both freshwater and saltwater. In freshwater rivers and streams, they are born and spend their early years. When they are adults, they go to the ocean. Some salmon remain close to their native stream, staying within a few hundred kilometers, while others, like the Chinook salmon (Oncorhynchus tshawytscha), and may migrate up to 4,023 kilometers (2,500 miles). Salmon return to their home range in freshwater when it's time to breed. The cycle starts again when the eggs hatch in new water.

 

By moving them, humans have altered the geographic distribution of several species. "Introduced species" are these. A living organism may introduce itself accidently by "hitch-hiking" with careless human tourists. This has been going on for a very long time. For example, importation is likely to blame for the Eurasian pygmy shrew's disjunct range. According to scientific studies, the emergence of the Eurasian pygmy shrew population in Ireland coincided roughly with the arrival of European settlers.

 

Even now, species are being unintentionally spread to new habitats. The zebra mussel (Dreissena polymorpha) is native to lakes and the Black and Caspian seas in central Asia. These creatures unintentionally travelled outside of Asia in the 20th century when they hooked up with huge cargo ships. They finally made it to North America's Great Lakes, where they created a new range.

 

Like many other introduced species, zebra mussels pose a serious danger to the region's natural species. For instance, the brown tree snake (Boiga irregularis), which is endemic to Australia and the adjacent islands, was unintentionally sent or flown as cargo to Guam. Many native birds and reptiles on the island became extinct as a result of the brown tree snake since few indigenous species could defend themselves against this new predator. The number of native plant species also decreased since some of the animals it killed were pollinators.

 

Also on purpose, people move animals into new habitats. People move plants and animals for use as pets, food, ornaments, and pest management. The Burmese python (Python molurus bivittatus), which lives in the Florida Everglades, is one of the most well-known instances of an imported animal. The snakes were kept as pets and originated in the Southeast Asian rainforests. Burmese pythons need a lot of care and food, and some pet owners who couldn't provide for them just released the snakes into the Everglades' marshes. The Everglades, which have a hot, muggy environment akin to the rainforests of Southeast Asia, are a haven for pythons. For food and resources, pythons compete with local animals like the American alligator.

 

Additionally, plants might be introduced to new habitats and endanger indigenous species. With its lovely lavender-colored blossoms, the purple loosestrife (Lythrum salicaria) barely appears dangerous. But the marshes of North America have suffered significant harm from this plant. In the 1800s, people imported the flower from Europe for ornamental and therapeutic uses. Along riverbanks and other freshwater marshes, the plant grows quickly. Numerous insect species pollinate it, and it produces a large number of seeds. It may thus swiftly spread, lessen water flow, and obstruct the growth of natural plants like cattails.

 

More than half of the native plant species have been replaced by purple loosestrife in portions of the marshes of the Chesapeake Bay in the U.S. state of Maryland. For local species, it offers inadequate food, shelter, and nesting locations. Its tangled, deep root structure is capable of clogging irrigation and drainage canals.

 

The range of animals is impacted by climate change. Climate changes may cause ranges to shift, expand, or contract. Climate change may sometimes even lead to the extinction of certain species. For instance, due to today's milder temperature, many species that were suited to Ice Age conditions—like mastodons, mammoths, and saber-toothed cats—no longer exist.

 

Over the course of our planet's history, the climate on Earth has seen several changes. Natural occurrences and cycles cause these shifts. Today's climate change is a result of human activity. The ranges of many different creatures are impacted by this global warming.

 

For instance, the colorful European bee-eaters (Merops apiaster) are indigenous to northern Africa and the Mediterranean coast of Europe. Bee eaters first appeared in central Europe in the 20th century. These warm-weather birds now have nesting locations in Germany and the Czech Republic, which were before too chilly for them.

 

Climate change promotes warm-water organisms in aquatic habitats. Brown shrimp (Farfantepenaeus aztecus), grouper, and southern flounder are extending their ranges throughout the U.S. Atlantic coast from the Carolinas to the Chesapeake Bay. Unfortunately, rising temperatures and greater competition for resources pose a danger to animals that have historically resided in the bay, such as rockfish, sturgeon, and clams.

 

When their ranges grow, species that are regarded as pests or that transmit illnesses may have a devastating effect on nearby populations. For instance, numerous species of the spruce budworm in western North America are harmful to evergreen trees. The insect's traditional habitat includes the woods of the Canadian province of British Columbia as well as the state of Washington in the United States. For the first time ever, warming temperatures are enabling this caterpillar to munch its way all the way to Alaska in the United States. The American and Canadian wood sectors are under danger due to the spruce budworm's increased range.

 

As the environment warms, several mosquito species are extending their range. Malaria, encephalitis, West Nile virus, and yellow fever are just a few of the illnesses carried by mosquitoes that may be fatal to humans. The extended range of mosquitoes has left many communities and healthcare institutions unprepared for the rise in cases that it will bring.

 

In the 1960s, people introduced the Pacific oyster as a commercial bivalve to the North Sea of Europe. To reproduce, this oyster needs water that has a very precise temperature and is warm. People assumed that the species was securely contained in aquaculture farms since the chilly North Sea was not the appropriate temperature. Unfortunately, as a result of global warming, water temperatures have shifted. The Pacific oyster began successfully reproducing in the North Sea in the 1990s, and it has since started replacing some of the local oyster species.