Reptile and amphibian endangerment
Páginas: 17 (4072 palabras)
Publicado: 26 de septiembre de 2010
Slide #2
[pic]
Amphibians and reptiles are vertebrates, along with fish, birds, and mammals.
Worldwide, there are approximately 6,300 known amphibian species and 6,000 known reptile species
Amphibians and reptiles are collectively called herpetofauna, or "herps" for short. The body temperatures of nearly all amphibians and reptiles are primarily determined by external sources of heat,such as the sun, water, or ground. This limits their distribution and activity time, but allows them to live on about one-tenth of the energy that similar-sized mammals and birds require. They control their body temperatures by moving to cooler or warmer areas as necessary.
Reptiles such as snakes, turtles, and lizards:
•Have dry skin and scales, shields, or plates to help keep their skinfrom losing moisture.
•Most reptiles with feet have claws on their toes.
•Reptiles lay shelled eggs or bear live young.
•Young reptiles have the same body forms as their parents, though they may differ in color or pattern.
Amphibians such as frogs, toads, and salamanders:
•They spend at least part of their lives in water habitats such as flowing streams, seasonal pools, or other wetlandtypes.
•Have moist skin that lacks scales, feathers, or hair.
•Most adult amphibians have lungs, but respiration also occurs through the skin—a process that can only occur if the skin is moist.
•Unlike reptiles, amphibians’ toes are usually clawless, and their eggs lack shells and are laid in water or a moist environment to protect them from drying out.
•In general, amphibian eggs hatch intoaquatic larvae (or tad- poles) that eventually metamorphose into the adult form that is more terrestrial.
Slide #3
[pic]
Much like certain fish species, amphibians and reptiles are often the first to show signs of a weakened or changing ecosystem.
Stream salamanders in particular are extremely sensitive to changes in their environment because they spend their entire lives (from egg tolarva, to lung less adult) in or near streams and adults breathe exclusively through their skin.
They play important roles in the ecosystem, as both predators and prey, on land and in water.
Reptiles and amphibians are also indicators of direct human threats to a habitat.
Reptiles and amphibians are an important part of the food web.
They play important roles in the ecosystem, as bothpredators and prey, on land and in water.
Reptiles provide an ecological service to humans by controlling pests such as mice, rats, slugs, crickets, termites, and other insects.
Amphibians also assist in controlling insects viewed as pests—mosquitoes (larvae and adults), moths, fruit flies, house files, crickets, and slugs (among others).
Amphibians are important in medical research.Compounds derived from them provide biomedicines.
Amphibians and reptiles also have played an important role in human culture.
Seed dispersal!
Many reptile and amphibians play an important role in the ecosystem that they are present in. Often you will find that Reptiles and Amphibians are found to be keystone species to their environment. Thus, if they are removed from their ecosystem notonly will they parish but their whole ecosystem may fall.
Slide #4
[pic]
Vertebrate animal taxa are disappearing at disproportionately high rates.
Amphibians and reptiles have the highest threat status of all terrestrial vertebrates, with significantly more species at risk than either birds or mammals (IUCN, 2006).
Both Reptiles and amphibians are going in a global decline for severalreasons.
These are: …
Slide #5
[pic]
Habitat change is unanimously accepted amongst conservation biologists, as being the primary cause of biodiversity loss worldwide and the situation for amphibians and reptiles is no exception.
Many habitats are disappearing due to human population growth and development.
Of those habitats that do remain, many are not large enough to support...
[pic]
Amphibians and reptiles are vertebrates, along with fish, birds, and mammals.
Worldwide, there are approximately 6,300 known amphibian species and 6,000 known reptile species
Amphibians and reptiles are collectively called herpetofauna, or "herps" for short. The body temperatures of nearly all amphibians and reptiles are primarily determined by external sources of heat,such as the sun, water, or ground. This limits their distribution and activity time, but allows them to live on about one-tenth of the energy that similar-sized mammals and birds require. They control their body temperatures by moving to cooler or warmer areas as necessary.
Reptiles such as snakes, turtles, and lizards:
•Have dry skin and scales, shields, or plates to help keep their skinfrom losing moisture.
•Most reptiles with feet have claws on their toes.
•Reptiles lay shelled eggs or bear live young.
•Young reptiles have the same body forms as their parents, though they may differ in color or pattern.
Amphibians such as frogs, toads, and salamanders:
•They spend at least part of their lives in water habitats such as flowing streams, seasonal pools, or other wetlandtypes.
•Have moist skin that lacks scales, feathers, or hair.
•Most adult amphibians have lungs, but respiration also occurs through the skin—a process that can only occur if the skin is moist.
•Unlike reptiles, amphibians’ toes are usually clawless, and their eggs lack shells and are laid in water or a moist environment to protect them from drying out.
•In general, amphibian eggs hatch intoaquatic larvae (or tad- poles) that eventually metamorphose into the adult form that is more terrestrial.
Slide #3
[pic]
Much like certain fish species, amphibians and reptiles are often the first to show signs of a weakened or changing ecosystem.
Stream salamanders in particular are extremely sensitive to changes in their environment because they spend their entire lives (from egg tolarva, to lung less adult) in or near streams and adults breathe exclusively through their skin.
They play important roles in the ecosystem, as both predators and prey, on land and in water.
Reptiles and amphibians are also indicators of direct human threats to a habitat.
Reptiles and amphibians are an important part of the food web.
They play important roles in the ecosystem, as bothpredators and prey, on land and in water.
Reptiles provide an ecological service to humans by controlling pests such as mice, rats, slugs, crickets, termites, and other insects.
Amphibians also assist in controlling insects viewed as pests—mosquitoes (larvae and adults), moths, fruit flies, house files, crickets, and slugs (among others).
Amphibians are important in medical research.Compounds derived from them provide biomedicines.
Amphibians and reptiles also have played an important role in human culture.
Seed dispersal!
Many reptile and amphibians play an important role in the ecosystem that they are present in. Often you will find that Reptiles and Amphibians are found to be keystone species to their environment. Thus, if they are removed from their ecosystem notonly will they parish but their whole ecosystem may fall.
Slide #4
[pic]
Vertebrate animal taxa are disappearing at disproportionately high rates.
Amphibians and reptiles have the highest threat status of all terrestrial vertebrates, with significantly more species at risk than either birds or mammals (IUCN, 2006).
Both Reptiles and amphibians are going in a global decline for severalreasons.
These are: …
Slide #5
[pic]
Habitat change is unanimously accepted amongst conservation biologists, as being the primary cause of biodiversity loss worldwide and the situation for amphibians and reptiles is no exception.
Many habitats are disappearing due to human population growth and development.
Of those habitats that do remain, many are not large enough to support...
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