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Monthly Archives: May 2011

Diamondback Terrapin

Diamondback Terrapin

Named for the diamond-shaped growth rings on its top shell, the diamondback terrapin (Malaclemys terrapin) a turtle native to the eastern and southern United States.

Fast Facts

Length: 7.5 inches (females); 5 inches (males).
Weight: 1.5 lbs (females); 0.5 lbs (males).
Lifespan: 25-40 years.
The diamondback terrapin is light brown, gray or black on top with a bottom shell that ranges from yellow to olive in color.

Diet

Diamondback terrpains consume fish, snails, worms, clams, crabs and marsh plants.

Range

The diamondback terrapin is found along the Atlantic Coast of the eastern United States from Cape Cod to the Florida Keys and west along the Gulf Coast to Texas

Behavior

The diamondback terrapin is believed to be the only turtle in the world that lives exclusively in brackish water (containing some salt, but not as much as ocean water), habitats like tidal marshes, estuaries and lagoons. Most terrapins hibernate during the winter by burrowing into the mud of marshes. Although diamondback terrapins live in tidal marshes, estuaries and lagoons, their preferred nesting sites are sandy beaches.

Reproduction
Mating Season: May through July.
Gestation: Around 60 days.
Clutch size: 8-12 eggs.

The gender of diamondback terrapin offspring is determined by temperature – a higher nest temperature produces more females while a lower nest temperature produces more males.

The hatchlings emerge from August to October and are completely on their own. Only 1 to 3% of the eggs laid produce a hatchling, and the number of hatchlings that survive to adulthood is believed to be similarly low.

After hatching, some young remain in the nest during the winter although most emerge and enter the nearest body of water.

Climate Change and Other Threats

The diamondback terrapin is threatened by habitat destruction, road construction (terrapins are common roadkill) and drowning in crab traps.

Climate change is also poised to bring major changes to the terrapin’s habitats and life cycle. By the end of this century, sea level is projected to rise between 2.25 feet under a low emissions scenario and up to 3.25 feet under the highest emissions scenario.

Due to land subsidence in the Northeast, the effect of the rise will seem about 10 to 20% higher than the actual. Salt water incursion into brackish tidal marshes will alter their character and potentially make large areas saltier than the terrapin can tolerate. Storm surges and beach erosion threaten their preferred nesting habitats. And higher temperatures on nesting beaches could skew the sex ratios of offspring.

Legal Status/Protection

  • Endangered Species Act (ESA): Diamondback terrapins are a species of concern.
  • IUCN Red List: Near threatened.
  • The diamondback terrapin is officially protected by several individual states.
 
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Posted by on May 30, 2011 in Animal in North America

 

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Desert Tortoise

Desert Tortoise

The desert tortoise (Gopherus agassizii) is a large herbivore and the official reptile in the states of California and Nevada. No other tortoise in North America shares the extreme conditions of habitats occupied by the desert tortoise.

Fast Facts

Height: 4-6 inches.
Length: 9-15 inches (shell length).
Weight: 8-15 lbs.
Lifespan: 50-80 years.
The desert tortoise has a high domed shell, or carapace, that is greenish to dark brown in color. Its front limbs have heavy, claw-like scales and their flat shapes are well-designed for digging.

Diet

Varies throughout the desert tortoise’s range. A desert tortoise’s diet may include herbs, grasses, some shrubs and the new growth of cacti and their flowers.

Population

The number of desert tortoises has decreased by 90% since the 1950’s. Recent estimates indicate that there are about 100,000 individual desert tortoises existing in the Mojave and Sonoran deserts.As late as the 1950’s the desert tortoise population averaged at least 200 adults per square mile. More recent studies show the level is now between 5-60 adults per square mile.

Range

The desert tortoise can be found in the Mojave and Sonoran Deserts of southern California, Nevada and Utah. They inhabit semi-arid grasslands, desert washes and sandy canyon bottoms below 3,500 ft

Behavior

The desert tortoise is able to live where ground temperatures may exceed 140 degrees F because of its ability to dig underground burrows to escape the heat. It is one of the most elusive inhabitants of the desert, spending up to 95% of its time under ground to escape the heat of the summer and the cold of winter. They live in burrows which they dig. These can be 3-6 feet deep. They will spend November through February in a torpid or dormant state in their underground burrows.

Their most active time is in the spring when they will forage for food. During the hottest, driest periods of the year the tortoise conserves water already stored in its body. This is especially important in the hot, dry Mojave Desert summers. Winter hibernation aids in minimizing water loss.

Much of the tortoise’s water intake comes from moisture in the grasses and wildflowers they consume in the spring. To maximize the utilization of infrequent rainfall, tortoises dig catchment basins in the soil, remember where these are, and may be found waiting by them when rain appears imminent. Water that reaches the bladder is not lost to the system but can be drawn upon as needed. Adult tortoises may survive a year or more without access to water.

Reproduction
Mating Season: Late summer to early fall.
Gestation: 10-12 months.
Clutch size: 4-6 eggs.
Females do not breed until they are 15 to 20 years old. Survival of juveniles is low: only 2-3 per 100 hatched may live to become adults.

Climate Change and Other Threats

The desert tortoise is very sensitive to human disturbances, and this has led to the decimation of many of its populations throughout the desert southwest. Increased urban development in the deserts of California and other states have fragmented and reduced suitable habitat. Certain fatal diseases appear to be spreading among tortoise populations. Poaching, the use of off-highway vehicles within tortoise habitat and crushing by automobiles have also continued to threaten tortoise populations.

Ravens cause significant levels of juvenile tortoise predation in some areas of the Mojave Desert with more prevalence of human disturbances.

Climate change projections suggest that difficult times may be ahead for the desert tortoise as heat and droughts expand over the region. Like all reptiles, tortoises have minimal ability to self-regulate their internal temperature, and thus must retreat to the shade of vegetation or their burrows once the air temperature reaches above 91 degrees Fahrenheit, in order to keep their body temperatures out of the danger zone. Droughts also force the tortoises to spend more time in their underground burrows to minimize water loss; thus both heat and drought decreasing the amount of time they are able to spend feeding. Droughts limit the availability of nutritious forage for the tortoises.

Females also lay fewer eggs during drought years. Furthermore, the sex of the young turtles is determined by the soil temperature during incubation. Temperatures above 88.7 degrees Fahrenheit produce female tortoises, so prolonged high temperatures could skew the sex distribution of future generations. Extremely high soil temperatures (above 95 degrees) are lethal to the developing young.

Defenders at Work

Defenders was influential in listing the Mojave population in 1989, and in the early 1990s helped secure key acquisition lands. The Mojave population of the desert tortoise is still declining drastically due to staff constraints, funding shortfalls, and lack of public support for necessary recovery actions. The Desert Tortoise was listed under the Endangered Species Act in 1989 and a team of experts developed a recovery plan to guide its recovery in 1994. Currently there is a mandated review of the recovery plan which Defenders is involved in.

Legal Status/Protection

  • Endangered Species Act (ESA): The desert tortoise is listed as threatened.
  • IUCN Red List: Vulnerable. Desert tortoises are listed as vulnerable.
  • CITES: Desert tortoises are listed in Appendix II.
 
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Posted by on May 30, 2011 in Animal in North America

 

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American Crocodile

American Crocodile

American crocodiles (Crocodylus acutus) are well-armored with tough, scaly skin. They are gray-green or olive-green with long, slender snouts, which distinguish them from their cousin, the alligator. Also unlike the alligator, the fourth tooth on the bottom jaw of the American crocodile is visible when its mouth is closed. South Florida is the only place where you can find both crocodiles and alligators.

Fast Facts

Length: 7-15 feet.
Weight: 150-450 lbs.
Lifespan 60-70 years.

Diet

An American crocodile’s diet consists mainly of small fish, invertebrates, reptiles, birds and mammals.

Population

There are more than 1,000 American crocodiles, not including hatchlings, in Florida.

Range

American crocodiles are found in southern Florida, the Caribbean, southern Mexico and along the Central American coast south to Venezuela.

Behavior

American crocodiles inhabit brackish and saltwater habitats and are typically found in coastal mangrove wetlands, ponds, coves, creeks and canals. Decidedly less aggressive than the infamous Nile and Australian crocodiles, American crocodiles are shy, reclusive and rarely seen by people.

Reproduction
Mating Season: January and February.
Gestation: 2-3 month egg incubation.
Clutch size: 35-50 eggs.
In April or May, the female crocodile will build a nest of loose dirt in a mound by the water’s edge and lay her eggs. She buries the eggs and fiercely guards her nest. When the eggs hatch in July or early August, the female helps carry her young to the water. But, unlike the alligator, she will not continue to care for her young.

Climate Change and Other Threats

Once hunted intensively for their hides, today, loss of habitat to human development, illegal killing and roadkill are the greatest threats faced by American crocodiles. As sea level rises due to climate change, a significant portion of crocodiles’ coastal wetland habitat may face saltwater incursion or inundation.

Legal Status/Protection

  • Endangered Species Act (ESA): American crocodiles are listed as endangered under the ESA, except in Florida, where they are listed as threatened. The Florida Endangered and Threatened Species Act lists the Florida population as endangered.
  • IUCN Red List: Vulnerable.
  • CITES: American crocodiles are listed in Appendix I.
 
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Posted by on May 30, 2011 in Animal in North America

 

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Colorado River Basin Fish

Colorado River Basin Fish

The Colorado River Basin is home to at least 14 native species of fish. Four of these fish are endangered—the Bonytail (Gila elegans), Razorback Sucker (Xyrauchen texanus), Colorado pikeminnow (Ptychocheilus lucius), and Humpback chub (Gila cypha). These fish evolved over millions of years in the Colorado River Basin, and are unique to the ecosystem.

Bonytails

Bonytails are dark gray, silver and white with small heads, large fins and streamlined bodies

Length: 16-18 inches, though some have been known to grow to 2 feet.

Diet: Insects and plant matter.

Lifespan: Bonytails can live as long as 50 years.

Reproduction: Bonytail spawn in spring and early summer at age of 5 to 7 years.

Population: Bonytails are the rarest of the four endangered fish in the Colorado River basin. There are no known reproducing populations in the wild.

Threats: streamflow regulation, habitat modification, competition with and predation by nonnative fish species, hybridization, and degraded water quality.

Razorback suckers

Razorback suckers are brownish-green, white and yellow with a sharp edged hump on their backs. They have fleshy lips that they use to suck up their food. Their hump gives them stability when swimming in strong currents.

Length: Usually 16-18 inches long, though some have been known to grow up to 3 feet.

Diet: Insects, plankton, and plant matter.

Lifespan: Razorback suckers have have been known to live to 40 years or more.

Reproduction: Spawn in the spring at as early as 3 to 4 years old.

Population: The existing population is mainly adult fish, due to high death rates of young fish.

Threats: Streamflow regulation, habitat modification, competition with and predation by nonnative fish species, and degraded water quality.

Colorado pikeminnows

Pikeminnows are olive-green and gold with torpedo shaped bodies. These fish are the largest species of minnow native to North America, they can grow to 6 feet long and 80 pounds or more!

Length: Usually 18 to 22 inches, though some pikeminnows have been known to grow to 6 feet in length.

Diet: Pikeminnow young feed on insects, adults feed on other fish.

Lifespan: Pikeminnows have been known to live to 40 years or more.

Reproduction: Spawn in late spring to early summer at around 5 to 6 years of age.

Population: There are populations in the Green and Colorado Rivers that are stable and reproducing. A small population can be found in the San Juan River Basin.

Threats: Streamflow regulation, habitat modification, competition with and predation by nonnative fish species, and degraded water quality.

Humpback chubs

Humpback chubs are gray or olive with silver sides and white bellies and sport large humps on their backs. Spawning adults have reddish gills.

Length: 14-16 inches.

Diet: Insects, plankton, and plant matter.

Lifespan: Humpback chubs have been known to live to nearly 30 years.

Reproduction: Spawn in spring and early summer at as early as 2 to 3 years of age.

Population: There are 6 known populations that are small but stable.

Threats: Streamflow regulation, habitat modification, predation by nonnative fish species, parasitism, hybridization with other native fish, pesticides and pollutants.

Climate Change and Other Threats

While western settlers valued the Colorado pikeminnow as food, calling them “white salmon” or “Colorado salmon,” they considered bonytails to be undesirable and began poisoning them in order to introduce other, nonnative species into the Colorado River. Since then the two main threats to the four species of endangered fish have been:

  • Introduction of Invasives: More than 40 non-native fish species have been introduced to the upper Colorado River basin, and prey on native fish and compete with the native fish for resources
  • Water Development: Before the construction of dams and reservoirs, these fish were adapted to short periods of torrential flooding or very low flows and to longer periods of variable but less extreme flow conditions. The river was made of cooler water from snowmelt in the spring and early summer and warmed over the summer months. It also carried a large sediment load throughout the year. Man-made dams and barriers have disrupted river flows and degraded habitats and water quality.

Other threats include  pesticides, and climate change. The most important feature of observed and projected climate changes in the Southwest is the impact on precipitation and water availability. Much of the area is already experiencing a severe drought, and climate change projections indicate that the region will be substantially drier in the future. These changes will have obvious consequences on stream flow in the Colorado River Basin.

Climate changes will also impact the snow pack on which river flows depend. In a region that is already experiencing water conflicts between agriculture, urban water use and ecosystem health needs, climate change will likely necessitate changes in how water is allocated and substantial investments in conservation.

Legal Status/Protection

Endangered Species Act (ESA): All four species of fish are considered endangered.

  • 1973: Humpback chub and Colorado pikeminnow are listed (both initially determined to be endangered in 1967).
  • 1980: Bonytail is listed.
  • 1991: Razorback sucker is listed.

IUCN Red List: The bonytail and razorback sucker are both listed as endangered. The pikeminnow and humpback chub are both listed as vulnerable.

 
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Posted by on May 30, 2011 in Animal in North America

 

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Clouded Leopard

Clouded Leopard

Named for the large cloud-like spots on its body, the clouded leopard is a medium-sized cat that sports a grayish or yellowish coat. The spots, which are generally dark brown with a black outline, provide excellent camouflage in the leopard’s forest habitat. Clouded leopards have long, strong tails and powerful, stout legs. They are also known to be one of the best climbers in the cat family.

Fast Facts

Height: 10-16 inches at shoulders.
Length: 2-3 feet (tail also measure at 2-3 feet).
Weight: 35-50 lbs (males); females significantly smaller.
Lifespan: While little is known about their lifespan in the wild, clouded leopards have been known to live up to 17 years in captivity.

Diet

Clouded leopards eat varied prey, from birds to monkeys to wild pigs.

Population

The clouded leopard’s reclusive nature has made it hard to determine population size. However, there is evidence of declining populations and one of the four subspecies is thought to be extinct.

Range

Historically clouded leopards were found in much of Southeast Asia from Nepal to southern China. Today, four subspecies are found in the following regions: Nepal to Burma; southern China to eastern Burma; Sumatra, Borneo and Java; Taiwan (thought to be extinct in the wild). The Bornean clouded leopard has been identified as a new cat species

Behavior

Clouded leopards live in forests at elevations of up to 8,000 feet and spend much of their lives in trees. Their bodies are well adapted to this arboreal lifestyle. While their strong tails help them to balance while perched on tree branches, their specially adapted ankle bones and large paws allow them to both climb while hanging upside down under branches and climb down trees head first! When a clouded leopard spots its prey on the forest floor, it leaps down on it from above.

The social behavior of clouded leopards is virtually unknown. They are, however, thought to be solitary animals. And though they are mostly nocturnal, evidence has shown them to be active during some periods of the day.

Reproduction
Mating Season: Can occur during any month but in captivity between December and March.
Gestation: 85-93 days.
Litter size: 1-5 cubs
At birth, kittens weigh five to six ounces, and do not open their eyes until they are 12 days old. Clouded leopard kittens nurse until they are five months old and do not develop adult coloration until they are six months old.

Threats

Rapid habitat loss due to deforestation, illegal hunting for traditional Chinese medicines and demand for its beautiful pelt may be driving the decline of clouded leopard populations.

Reasons For Hope

Defenders of Wildlife is working to pass legislation that would help conserve 15 species of great cats and rare canines that exist outside the U.S. In April 2009, the U.S. House of Representatives approved the Great Cats and Rare Canids Act (HR 411) aimed at conserving 15 of the world’s rarest wild cats and canids, including lions. The bill now needs approval by the Senate before being made law.

Legal Status/Protection

  • Endangered Species Act (ESA): The clouded leopard is listed as endangered.
  • IUCN Red List: Vulnerable.
  • CITES: Appendix I.
 
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Posted by on May 30, 2011 in Animal in North America

 

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Chimpanzee

Chimpanzee

Closely linked by DNA, chimpanzees (Pan troglodytes) are one of the four species of great apes that are the closest living relatives of humans – the other two being gorillas and orangutans. Great apes are different from monkeys for a variety of reasons: they are larger, walk upright for a longer period of time, don’t have tails and have much larger, more developed brains.

Fast Facts

Size: Chimpanzees stand approximately 4 feet high.
Weight: Chimpanzee males weigh between 90 and 120 pounds, while females weigh between 60 and 110 pounds.
Lifespan: Chimpanzees rarely live past the age of 50 in the wild, but have been known to reach the age of 60 in captivity.

Diet

Chimpanzees are omnivores, meaning they eat a wide variety of foods that includes fruits, nuts, seeds, and insects. Chimps occasionally hunt and eat meat.

Population

An estimated 100,000 to 200,000 chimpanzees remain in the wild.

Range

Chimpanzees can be found in 21 African countries. Chimps prefer dense tropical rainforests but can also be found in secondary-growth forests, woodlands, bamboo forests, swamps, and even open savannah.

Behavior

Chimps live in communities. These communities are composed of family groups of three to six individuals, totaling about 50 animals. Hierarchies are formed by the adult males of the community, which is led by one alpha (the highest) male. Adolescent females may move freely between communities, although territory is strictly patrolled and conflicts can occur between neighbors.

On the ground, chimpanzees usually walk on all fours using their knuckles for support with their hands clenched, a form of locomotion called knuckle-walking.

Reproduction
Most mothers give birth to one young an average of every five to six years in the wild. Young chimps stay with their mothers for up to 10 years.

Threats

Habitat destruction is the greatest threat of the chimpanzee. Large population decreases are also blamed on hunting and commercial exportation.

Legal Status/Protection

  • Endangered Species Act (ESA): Chimps are listed as endangered under the Endangered Species Act.
  • IUCN Red List: Both species of chimpanzee, the common chimpanzee and the bonobo, are listed as endangered.
  • CITES: Chimpanzees are listed in Appendix I.
 
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Posted by on May 30, 2011 in Animal in North America

 

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Cheetah

Cheetah

The fastest land animal in the world, the cheetah is a marvel of evolution. The cheetah’s slender, long-legged body is built for speed. Cheetahs are tan in color with black spots all over their bodies. They can also be distinguished from other big cats by their smaller size, spotted coats, small heads and ears and distinctive “tear stripes” that stretch from the corner of the eye to the side of the nose.

Fast Facts

Height: 2 ½ -3 feet (.8-.9m) at the shoulder.
Weight: 110-140 lbs (50-64kg).
Top Speed: 70mph (113 km/hr).
Lifespan: 10-12 years.

Diet

Cheetahs eat mainly gazelles, wildebeest calves, impalas and smaller hoofed animals.

Population

In 1900, there were over 100,000 cheetahs across their historic range. Today, an estimated 9,000 to 12,000 cheetahs remain in the wild in Africa. In Iran, there are around 200 cheetahs living in small isolated populations.

Range

Historically cheetahs were found throughout Africa and Asia from South Africa to India. They are now confined to parts of eastern, central and southwestern Africa and a small portion of Iran.

Behavior

Found mostly in open and partially open savannah, cheetahs rely on tall grasses for camouflage when hunting. They are diurnal (more active in the day) animals and hunt mostly during the late morning or early evening. Only half of the chases, which last from 20-60 seconds, are successful.

Cheetahs knock their prey to the ground and kill with a suffocating bite to the neck. They must eat quickly before they lose the kills to other bigger or more aggressive carnivores.

Cheetahs are also typically solitary animals. While males sometimes live with a small group of brothers from the same litter, females generally raise cubs by themselves for about a year.

Reproduction
Mating Season: Throughout the year.
Gestation: Around 3 months.
Litter size: 2-4 cubs
Cubs are smoky in color with long, woolly hair – called a mantle – running down their backs. This mantle is thought to camouflage cubs in grass, concealing them from predators. Mothers move cubs to new hiding places every few days. At 5-6 weeks, cubs follow the mother and begin eating from their kills.

Threats

The cheetah’s future is uncertain due to a variety of threats. The biggest is habitat loss due to human encroachment. In addition, they often deal with declines in prey and conflicts with humans. There is also high cub mortality due to predation by carnivores like lions and hyenas that are in competition with the cheetah, as well as genetic inbreeding which leads to abnormalities.

Reasons For Hope

The cheetah’s future may look dim, but conservationists have been working to lessen the decline in some areas. Similar to Defenders of Wildlife’s work with farmers in the Northern Rockies, in the early 1990′s conservationists began educating livestock farmers around Namibia about how to reduce cheetah/livestock interactions and teaching farmers how to avoid conflict through breeding schedules and the use of guard dogs to protect livestock as alternatives to resorting to the rifle.

These efforts, along with stronger enforcement of endangered species and anti-poaching laws and habitat restoration for the cheetah, have resulted in stabilized populations in that country.

Legal Status/Protection

  • Endangered Species Act (ESA): Cheetahs are listed as endangered under the ESA.
  • IUCN Red List: Vulnerable. A cheetah population decline of at least 30% is suspected over the past 18 years (3 generations).
  • CITES: Cheetahs are listed in Appendix I.
 
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Posted by on May 30, 2011 in Animal in North America

 

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