Florida Panther Puma concolor coryi

Family: Felidae, Cats view all from this family

Description The Florida panther is a subspecies of Puma (or mountain lion, cougar). A large, unspotted cat, it has a relatively small head and a long, black-tipped tail that reaches nearly 2/3 of its body length. The Florida panther is generally smaller and darker than other Puma subspecies. Typically, a Florida panther has a tawny upperside and pale gray underside. Dark spots occur at base of whiskers, and ears are short and rounded, with dark backs. Florida panthers have long, heavy legs and large feet. Juveniles are buff with black spots. Adult measurements are as follows: L 6–7' (1.5–2.13 m); Ht 24-28" (59-69 cm); Wt 65 up to, and exceeding, 161 lb (29-73 kg). Females are smaller than males.

Endangered Status Following years of persecution and habitat loss, the Florida panther population had been reduced to such a small size that in 1967 it was listed by the federal government as endangered throughout its historic range. Once found throughout the southeast, initial surveys confirmed the presence of only 30 individuals remaining in south Florida. Studies revealed low genetic variation and physical abnormalities associated with inbreeding depression. In 1995, wildlife managers embarked on a genetic restoration program, releasing female Texas puma into south Florida. Preliminary analyses suggest the program was successful; genetically-based defects have decreased and survival and reproduction have increased. Today there are about 80 Florida panthers remaining in 5% of their historic range. Though the population has grown in recent years, its isolation and small size, diminishing habitat, and human activities jeopardize its continued existence. Hopefully, with current conservation and scientific efforts underway, the Florida panther will continue to survive and someday recover.

Breeding Female panthers reach sexual maturity at about 1 ½ to 2 ½ years of age, and males at about 3 years of age. Florida panthers are polygamous, meaning that they mate with more than one partner. A female signifies her sexual availability through urine scent and vocalizations. Gestation (or pregnancy) lasts 90 to 98 days, and litters consist of 1 to 4 kittens. Females usually will not become reproductive again until her kittens are 1 ½ to 2 years old. Births occur throughout the year but are most common during the spring. Females give birth and rear their kittens in a den. Dens are located in dense, close-to-the-ground vegetation, such as saw palmetto. Kittens weigh slightly less than 1 pound at birth and are born with spotted grayish-brown fur and closed ears and eyes. By 4 months of age, the kittens’ eyes begin to turn brown. The spots on the kittens’ coats are well-faded by 6 months of age, but do not fully disappear until after 1 year of age.

Dispersal Dispersal is the movement of an individual from its place of birth to the area where it reproduces (i.e., to its home range). For Florida panthers, dispersal begins when juveniles become independent of their mothers, around 14 months of age. In general, males disperse further than females, and females tend to settle near their mother’s home range. The greatest dispersal distance reported for a juvenile Florida panther was made by a young male that dispersed 139 miles, followed by a second dispersal of 145 miles.

Home Ranges Home ranges are areas where an animal conducts its basic activities of resting, hunting, mating, and caring for young and where habitat requirements for prey are met. As top carnivores, Florida panthers are wide-ranging and require large home ranges to acquire sufficient prey and meet all their other needs. Male panthers typically have larger home ranges than females. The average home range size of a female Florida panther and male Florida panther is 179 km2 (or 69 miles2) and 362 km2 (or 140 miles2), respectively. Home ranges exceeding 1300 km2 (approx. 500 miles2) have been reported.

Mortality Most wild panthers do not live more than 12 years, although in 2001, biologists documented the death of a 19-20 year old female panther. The two major sources of panther mortality are vehicular collisions and intraspecific (between panther) aggression. Other sources include viruses, bacterial infections, parasites, congenital heart defects, and environmental contaminants such as mercury. To reduce the risk of disease and parasites, agency biologists administer vaccines to all captured kitten and adult panthers as a part of the panther management program.

Habitat As habitat generalists, Florida panthers use a mosaic of habitats that includes cypress swamps, agricultural areas, freshwater marshes, hardwood hammocks, and pine flatwoods. These habitats serve a variety of panther needs –ranging from cover for resting, denning, and stalking prey to open areas for prey habitat and panther dispersal. Human-induced habitat loss, degradation, and fragmentation continue to reduce habitat connectivity and availability while posing deadly obstacles such as highways, a leading source of panther mortality. As habitat becomes scarcer, intraspecific (between panther) aggression may increase, further reducing the imperiled population.

Diet Florida panthers primarily eat white-tailed deer and feral hogs, though they will eat other animals such as raccoons, armadillos, rabbits, rats, birds, and alligators.

Hunting Florida panthers hunt at dawn and dusk. They rush short distances and spring at their prey. They kill by a bite to the neck or skull. An adult male typically consumes larger-sized prey (e.g., deer) every 8 to 11 days, while an adult female with kittens may consume more. After eating, panthers "cache" their prey by putting debris over the carcass. Panthers may return to feed on the same carcass over several days.

Range Historically, the Florida panther ranged throughout the southeastern United States. Today, however, Florida panthers occur with regularity only in south Florida, about 5% of their historic range. Reproduction is known to occur in 5 counties of south Florida: Collier, Hendry, Lee, Miami-Dade, and Monroe.

Hurricanes and Birds

Hurricane Erin, Gulf Coast of Florida, 1995
© Terry Livingstone

Northern Gannet
© E. R. Degginger/Color-Pic, Inc.

With all the recent attention on Hurricanes Fay and Gustav, many people are wondering about the effects of hurricanes and tropical storms on birds. While numbers are hard to come by, it is clear that a lot of birds are killed outright by hurricanes. This is especially true of seabirds, which have nowhere in which to seek shelter from these storms. Beaches may be littered with seabird carcasses following major storm events. Most Atlantic hurricanes occur in late summer and early fall. Fall storms coincide with bird migration and may disrupt migration patterns severely. Many birds get caught up in storm systems and blown far off course, often landing in inhospitable places or simply arriving too battered and weakened to survive. Others, while not killed or displaced by storms, may starve to death because they are unable to forage while the weather is poor. The number of birds that die as a result of a major hurricane event may run into the hundreds of thousands.

Healthy bird populations are able to withstand such losses and have done so for eons. However, hurricanes can have severe impacts on endangered species, many of which occur on tropical islands, often among the places hardest hit by hurricanes. For example, Hurricane Hugo in 1989 killed half of the wild Puerto Rican Parrots existing at that time. The Cozumel Thrasher, found only on Mexico's Isla Cozumel, was pushed to the edge of extinction by Hurricane Gilbert in 1988. Hurricane Iniki may have wiped out the last survivors of as many as three bird species when it hit Hawaii in 1992.

Apart from the direct, physical effects hurricanes may have on birds, they also can have detrimental effects on bird habitats. Cavity-nesting species can be especially hard hit because the trees in which they nest often are blown down or snapped off at the cavity. Hurricane Hugo, which hit the Carolinas in 1989, destroyed most of the area's nest trees of the endangered Red-cockaded Woodpecker; one forest lost 87 percent of its nest trees and 67 percent of its woodpeckers. Only through the installation of artificial nest boxes have these populations been restored to pre-storm levels.

Although birds blown out of their normal haunts by storms often don't survive, bird-watchers by the hundreds may flock to see them. Usually, such sightings involve seabirds blown inland and appearing on lakes and reservoirs. First state records of many species have been obtained in this way. Some birders even head into hurricanes to see lost birds.* Others raptly study weather maps to try to predict where hurricane-swept birds will wind up. Recently, during Isabel, birders were staked out in an organized fashion around New York's Cayuga Lake to see what showed up. Land birds blown out to sea typically perish unnoticed.

It's important to remember that the long-term effects of hurricanes on birds aren't necessarily negative. Every disturbance event is bad for some species but good for others. For instance, hurricanes create gaps in forests, creating habitat for species that require a brushy understory. Birds blown off course occasionally establish entirely new populations; such events may be responsible for much, if not most, colonization of remote islands by birds. Furthermore, hurricanes have been around for a long time and are part of the system in which birds evolved. It is only when they have impacts on species already pushed to the brink by humans, or if hurricane activity is increased by global climate change, that there is cause for concern.

Rise and fall of the dinosaurs

	Rise and fall of the dinosaurs contents T. rex would not have recognised the world that the first dinosaurs lived in. In this series of articles, Dr Jo Wright explores how the dinosaurs evolved as the world around them changed. New blood When dinosaurs first appeared the world was very different. There were no mammals, no birds and no lizards. But there were some lizard-like reptiles. Time of the titans In the Early Jurassic, dinosaurs started getting larger. Diplodocus was over 30 metres long - but even he wasn't safe from predators. A cruel sea While dinosaurs dominated the land, huge marine reptiles ruled the water. Ichthyosaurs looked very like dolphins - but they weren't the top predators of the Jurassic seas. Giant of the skies The largest animals ever to fly were pterosaurs. But during their reign, birds as we know them were also beginning to appear. Spirits of the ice forest There's considerable evidence that dinosaurs once lived at polar latitudes. How did they survive the cold? Land of the giants Argentinosaurus was the largest dinosaur ever - 35 metres long, and up to a hundred tonnes in weight. The giant claw 75 million years ago the Mongolian desert was home to dinosaurs of all shapes and sizes - including one with the largest claw of all time. Death of a dynasty Why the dinosaurs died out is one of the most frequently asked questions of dinosaur experts. Will we ever know the answer?

The Queen of Trees Introduction

• The Queen of Trees ~ Video: Mutual Dependence
• The Queen of Trees ~ Video: Giving Food and Shelter
• The Queen of Trees ~ Photo Essay: An Extraordinary Ecosystem
• The Queen of Trees ~ Fig Trees: From the Sacred to the Strangler
• Video Segments: The Secret World of Sharks and Rays
• Lesson Overview
• The Vanishing Lions ~ Introduction
• Animal Guide: Honeybee
• Silence of the Bees ~ Video: Full Episode
• Silence of the Bees ~ Introduction

NATURE reveals the importance of an unlikely partnership between a regal tree and a tiny wasp in The Queen of Trees.

It may be one of nature’s oddest couples: a tiny wasp that can barely be seen, and a giant fig tree, the sycomore, which shelters a remarkable menagerie of wildlife among its limbs. The wasp and the fig depend on each other for survival. Without the wasp, the tree could not pollinate its flowers and produce seeds. Without the fig, the wasp would have nowhere to lay its eggs.

The Queen of Trees shows this delicate dance of survival in exquisite detail, including spectacular close-ups of the wasp’s remarkable life inside a ripening fig. To capture such incredible images, filmmakers Victoria Stone and Mark Deeble spent two years camped out near a giant sycomore fig in Kenya’s outback, documenting the tree’s pivotal role as a source of food and shelter for everything from gray hornbills, Africa’s largest bird, to swarms of invading insects searching for food. In a surprising turn, some insects come to the tree’s aid — sparking a battle you won’t want to miss.

Video: An Exciting New Season of NATURE

• Raptor Force ~ Introduction
• Updates from the Field: Swimming with Lava
• Raptor Force ~ Photo Essay: Nature’s Top Gun
• Raptor Force ~ Download Raptor Wallpaper
• Dogs That Changed The World ~ Introduction
• Dogs That Changed The World ~ Photo Essay: From Wolf to Dog
• Raptor Force ~ Video: Falcon Cam
• Raptor Force ~ Raptor Vision Game
• Violent Hawaii ~ Video: Full Episode
• The Cloud Blog ~ BLM Postpones Removal of Pryor Wild Horses

NATURE’s 27th season premieres October 26 and promises to be one of the series’ most exciting, featuring such locations as the Arctic wilderness, the Drakensberg mountain range in southern Africa, and the wondrous Victoria Falls on the border of Zambia and Zimbabwe. NATURE will also feature what’s in our own “backyard” with an in-depth look at the American bald eagle, as well as a new chapter in the chronicle of the Rockies’ most famous stallion: Cloud. To tantalize your appetite, here’s a sneak peak at three upcoming shows.

Beautifully photographed, White Falcon, White Wolf takes place on the Canadian Arctic’s otherworldly Ellesmere Island, and features an intimate view of the struggles of two families — a pack of white wolves and a family of rare gyrfalcons.

In The Wolf That Changed America, NATURE takes a decidedly different approach by using historical recreations to tell the story of one of America’s earliest conservationists, Ernest Thompson Seton, and his obsession with Lobo — the wolf that changed his life.

Finally, sizzling up the screen is Kilauea: Playing With Fire. Emmy Award-winning cameraman Paul Atkins boldly goes where few would dare — into waters as toasty as 100 degrees Fahrenheit to film lava flows and explosions from Hawaii’s Kilauea volcano. Caution — this footage is hot!

Dogs That Changed the World

Selective Breeding Problems

• Dogs That Changed The World ~ Photo Essay: Hard-Wired Behaviors
• Dogs That Changed the World ~ Video: Hard-Wired?
• Dogs That Changed The World ~ Introduction
• Dogs That Changed The World ~ Interactive Map: Discover Ancient Breeds
• Dogs That Changed the World ~ Video: Speedy Saluki
• Dogs That Changed The World ~ Medical Dogs
• Underdogs ~ Photo Gallery: Working Dog Breeds
• Dogs That Changed the World ~ Video: Behind the Scenes
• Dogs That Changed The World ~ Photo Essay: From Wolf to Dog
• Lesson Overview

In the same way that inbreeding among human populations can increase the frequency of normally rare genes that cause diseases, the selective breeding that created the hundreds of modern dog breeds has put purebred dogs at risk for a large number of health problems, affecting both body and behavior.

Some conditions are directly related to the features breeders have sought to perpetuate among their dogs. As they deliberately manipulated the appearance of dogs to create or accentuate physical characteristics that were considered aesthetically pleasing, like the flat face of a bulldog or low-slung eyelids of a Bloodhound, breeders also created physical disabilities. The excessively wrinkled skin of the Chinese Shar-Pei causes frequent skin infection; Bulldogs and other flat-faced (or brachycephalic) breeds such as the Pekingese have breathing problems because of their set-back noses and shortened air passages; Bloodhounds suffer chronic eye irritation and infection.

The unnaturally large and small sizes of other breeds encourage different problems. For example, toy and miniature breeds often suffer from dislocating kneecaps and heart problems are more common among small dogs. Giant dogs such as Mastiffs, Saint Bernards, and Great Danes are nearly too big for their own good. Researchers have found a striking correlation between a dog’s large size and a frequency of orthopedic problems like hip dysplasia. Large dogs are often prone to heat prostration because they can’t cool down their bodies (tiny dogs, by contrast, have a hard time staying warm), and because of the massive weight they must support, these breeds are prone to malignant bone tumors in their legs. Meanwhile, the huge head and narrow hips of the Bulldog can necessitate that their pups must be born by Caesarean section.

Other health problems among purebreds are the product of both inbreeding and bad genetic luck. The genes responsible for many genetic diseases are “recessive,” which means that two copies of a damaged gene, one from the mother and one from the father, must be present in an individual for the disease to occur. Individuals that carry only one copy of the disease gene don’t have the condition, and are carriers of the disease. Normally, because disease genes are relatively rare, it is unlikely that both the mother and the father will be carriers, and even less likely that they’ll both give the disease gene to their offspring. But that’s not the case for purebred dog breeds, where genetically similar individuals are intentionally mated, increasing the concentration of disease genes. It’s like stacking a deck of cards with ten extra aces and ten extra face cards; the loaded deck increases your chance of hitting blackjack in a game of 21-but what you “win” might be allergies or a predisposition to cancer.

Bloodhounds suffer chronic eye irritation and infection.

Skin problems

A skin allergy, atopic dermatitis, inflicts itchy, inflamed skin on as many as 15 percent of all dogs, but certain breeds are particularly susceptible. Dog breeds prone to atopic dermatitis include Dalmatians, Vizslas, and several terriers, such as the Boston Terrier, Bull Terrier, and the West Highland White Terrier. The numerous skin folds of a Chinese Shar-Pei, so valued by some breeders, can become breeding grounds for staphylococcus and other bacteria, which cause frequent skin infections. Also, excess wrinkles of skin on the face can rub on the eye, causing lesions and, potentially, blindness.

Immune system disease

In autoimmune disorders, an individual’s immune system, which normally works to fight off foreign invaders, launches a misguided attack against its own tissues and cells. A number of inherited diseases compromising the immune system have been noted in dogs, including primary severe combined immunodeficiency (a dog version of the “bubble boy” disease) among Basset hounds, Cardigan Welsh Corgis, and Dachshunds. Addison’s disease, an autoimmune disease that affects the hormone-producing adrenal glands, occurs more frequently among several particular breeds, including the Bearded Collie, Portuguese Water Dog, and Standard Poodles. Diabetes mellitus, an autoimmune disorder affecting the body’s response to sugars, shows up more frequently among Samoyeds and Australian Terrier dogs.

Blood disorders

Bassett Hounds are prone to an inherited abnormality the effects the ability of the platelets in the blood to clump together after an injury. The blood doesn’t clot properly, leading to hemorrhage and bruising. Clotting problems also plague dogs with von Willebrand’s disease, a genetic condition frequent in Doberman Pinschers.

Neurological, behavioral, and sensory

Neurological and behavioral problems afflict many pure breeds. Bull Terriers, for example, often compulsively chase their tails. Pugs are be predisposed to Pug Dog encephalitis, a fatal brain disease. Scottish Terriers are affected by Scottie Cramp, a disorder that causes the dogs to lose muscle control when they get excited. German Shepherds may inherit degenerative myelopathy, a crippling spinal cord disease that causes weakness and eventually paralysis.

Hearing and vision

Hereditary hearing loss is common in Dalmatians, Australian Cattle Dogs, and English Setters. Alaskan Malamutes, Siberian Huskies, Samoyeds, Bichon Frise, and more than 60 other purebred dogs suffer from inherited forms of cataracts, while progressive retinal atrophy, a common cause of blindness in purebreds, is particularly a problem in Old English Sheepdogs and Papillons.

Heart disease

Sudden death from cardiac disease is recurrent in several dog breeds, including Doberman Pinschers, Great Danes, Irish Wolfhounds, and German Shepherds. Boxers can be genetically predisposed to an irregular heartbeat. High blood pressure afflicts many small breeds including Poodles, Cocker Spaniels, Staffordshire terriers, among others.

Other organs and systems

Low thyroid function crops up most frequently in Alaskan Malamutes, English Setters, Golden Retrievers, Keeshonds, Samoyeds, and Siberian Huskies. Gastric torsion, or bloat, a potentially life-threatening inability to expel gas from the digestive system, is common among deep-chested breeds such as the Great Dane, Doberman, and German Shepherd. An inherited form of kidney disease affects English Cocker Spaniels, while Dalmatians are prone to kidney stones and Basenjis suffer from Fanconi Syndrome, a potentially fatal inherited disease in which the kidneys fail to reabsorb nutrients. Liver damage and cirrhosis are common in Bedlington Terriers because of an inherited condition called copper toxicosis, in which high levels of copper accumulate in the liver.

Cancer

Cancers are strongly influenced by genetics, and so it is not surprising to find various types of cancer among different dog breeds. For example, bone cancer, or osteosarcoma, is considerably more frequent among large and giant breeds of dogs, such as the Irish Wolfhound, Great Dane, Rottweiler, Labrador and Golden Retriever, Greyhound, and Saint Bernard, because their bones are stressed by carrying so much weight. High rates of malignant blood vessel tumors are seen among Golden Retrievers, which are also prone to leukemia and brain tumors. German Shepherd Dogs and Chow Chows are predisposed to gastric cancer, while Scottish Terriers are 18 times more likely to develop bladder cancer than are other breeds.

Orthopedic

Hip dysplasia, in which looseness in the hip joint causes excessive wear that eventually leads to arthritis, is most common among large dogs, especially those like the German Shepherd Dog and the Saint Bernard which have heavy, broad hips. The long neck and large head of breeds such as the Great Dane and the Doberman can cause the compression of the spinal cord in neck vertebrae, leading to wobbling and falling (”wobbler syndrome”). Selective breeding of the disproportionately short legs of breeds such as the Basset Hound and the Dachshund has led to bowed legs and chronic problems with elbow dislocation; the short legs and long back of Dachshunds causes them to suffer more often from ruptured vertebral disks. Because of their small bones, toy and miniature breeds are more likely to experience patellar luxation, the slipping or dislocation of the kneecaps.

Silicon highlights remaining questions over anthrax investigation

Did Bruce Ivins weaponize deadly spores?

Amber Dance

The deadly anthrax bacterium.MedicalRF.com / Alamy

Nearly two months after the suicide of scientist Bruce Ivins — whom the US Federal Bureau of Investigation (FBI) claims was solely responsible for mailing a series of letters laced with anthrax in 2001 — questions still remain over whether he was actually able to produce those anthrax spores.

Scientists initially believed that the spores had been weaponized – modified to make them disperse more easily and penetrate tissue more deeply.

But one of the scientists who first drew that conclusion has now changed his mind. Nature finds out why he thinks he got it wrong; why it matters for those trying to tie up the Ivins case; and what it means for the chances of a similar attack happening in the future.

What was the initial evidence that the 2001 spores were weaponized?

The powder was described as being 'weightless' and 'smoke-like'. One of the first scientists to work on it was Peter Jahrling, then a virologist at the US Army Medical Research Institute of Infectious Diseases in Frederick, Maryland. He recalls that he couldn't even weigh out a fraction of it: "It literally jumped off the spatula and was repelled by the weighing paper; it was like nothing I had ever seen before." Under an electron microscope, Jahrling and a colleague observed black dots that they speculated might be particles of silicon dioxide, or silica. Materials analysis by the Armed Forces Institute of Pathology in Washington DC confirmed that the sample contained both silicon and oxygen, and many assumed that the elements were combined as silica.

Why would a silicon compound increase the spores' virulence?

Spores are sticky, and tend to clump together. One method of weaponizing the spores is to coat them with something that interrupts the weak van der Waals interactions between each particle. Tiny particles of silica would do the trick, allowing the spores to float individually through the air. Silicon and oxygen can also form polymers called siloxanes, and such compounds are used to make inhaled medicines more dispersible.

Why have Jahrling and others changed their minds?

In 2002, as part of the FBI investigation, scientists at Sandia National Laboratories in Albuquerque, New Mexico, used electron microscopy to analyse the composition of the spores. The results were finally made public last month. They found silicon and oxygen in the spore coat, but not on the most external layer, the exosporium. The location of the silicon, the FBI says, suggests that it was incorporated naturally into the structures during growth, not added as a final coating to weaponize them.

But other experts disagree with the conclusion. "I don't think the guys at Sandia understand that the exosporium is not some kind of brick wall," says Stuart Jacobsen, a research chemist based in Dallas, Texas, who is an expert on the preparation and properties of fine-grained powders and has followed the case closely. "It's more like a chain-link fence." Decades ago, a study found that the exosporium is porous to various small molecules¹.

How might silicon get into the spores naturally?

The FBI points to experiments from 1990, in which scientists found some silicon in naturally grown spores². Another hypothesis, suggested by Serguei Popov, an anthrax researcher at George Mason University, Manassas, Virginia, is that the bacteria picked up a bit of silicon from anti-foaming agents while they were being grown. To produce the large number of spores in the contaminated envelope analysed - one trillion spores per gram — Popov infers that the perpetrator must have had to grow a large-scale bacterial culture in a fermenter, where silicon-containing anti-foaming agents are commonly used.

But this would add a relatively low concentration of silicon to the spores. Deliberate weaponization would probably leave much higher amounts. At a House of Representatives Judiciary Committee hearing on 16 September, Representative Jerrold Nadler (Dem.) quizzed FBI director Robert Mueller about the quantity of silicon present in the spores. Mueller did not answer the question.

Why does this matter to the investigation?

Many scientists involved in the investigation still wonder: could Bruce Ivins, in a few late-night lab sessions and in secret, have engineered the powder in the letters? An answer to this would help to determine whether Ivins was guilty, and if so, whether he needed assistance from other parties. It would also help defence experts to assess how easy it would be for others to mount a similar attack in the future.

"I don't think it would be horrendously difficult to make stuff that was moderate quality," Peter Setlow, a microbiologist at the University of Connecticut Health Center in Farmington, told Nature in August. But Jacobsen and others say the fact that the FBI has apparently failed to produce a powder to match the attack material suggests it must be very difficult to make. That might put it beyond Ivins's reach.

If the spores could not be made by a single scientist in a few evenings, that would suggest the spores came from elsewhere – possibly from a state-organized programme.

What happens next?

"The truth will come out when all the data are revealed," Jahrling says. But there is no indication from the FBI that more data are forthcoming anytime soon. Until they are provided, there will continue to be suspicions and speculations about the silicon in the spores.

• References

  1. Gerhardt, P. & Black, S. H.. J. Bact. 82, 750–759 (1961).
  2. Stewart, M. et al. J. Bact. 143, 481–491 (1990).