Angela Campher Biodiversity & Conservation Biology University of the Western Cape Bellville 7535 Contemporary Amphibians: Are we changing their environment ?

 “Amphibians occurs within three groups namely salamanders and newts: toads and frogs: and caecilians”-Mader (2004)  organ level of organization - body cavity containing organs  tube-in-tube body plan and have a coelom General Characteristics of Amphibians

 Have some outstanding feature that was not seen within other groups of organisms before - presence of limbs  - tongue * use to catch prey  - eyelids * functions to keep eyes moist  - ears * able to hear or pick-up sound waves  - voice * which is produced in the larynx  Within their life cycle they have both an aquatic and terrestrial life stage. General Characteristics of Amphibians

 They undergo metamorphosis - which is the process by which an organism undergoes a change in body form.  Amphibians have smooth, non-scaly, moist skin which is porous and which contains a mucus layer  The mucus layer is secreted by mucus glands within the skin, the skin has various functions namely  - water balance, respiration, temperature regulation General Characteristics of Amphibians

 Amphibians are ectotherms, this means that they are dependant upon the environment to regulate their temperature (body) - Mader (2004) General Characteristics of Amphibians

 Group 1 - Salamanders and Newts, represent earliest fossil, they have two pairs of legs-90º angle to each other  - dorsi-ventrally flattened body, elongated  - movement via sinusoidal motion  - are carnivorous, feeding on invertebrates e.g. snails Characteristics of three groups

 Group 2 - Frogs and Toads, have a fused head and trunk with the absence of a tail  They have muscle padded hind legs which are long and powerful for jumping, frogs vary from toads in that it’s skin is smooth and that they have long legs.  Toads on the other hand have warty skin and snout body's, also preferring a dark and moist habitat away from water, where as frogs live by or in fresh water streams or masses. Characteristics of three groups

 Group 3 - Caecilians, seems to resemble amelids owing to their long worm-like body forms.  They reach lengths of 1 metre and have folds on their skin-thus resembling segments (but it is not). Characteristics of three groups

 Their dependence on environmental conditions for body temperature regulation allow for them to occur within certain places in the world.  They are found within various Biogeographical realms e.g.  - Australia  - Afro and Neotropical  - Oceanic or Nearctic  - Palearotic and or Indomalayan Realms Geographical Distribution

 More specifically they are abundant in North and South America, Africa, Asia, Europe, Middle East, Australia and Oceania.  Amphibians do not occur in Greenland or Antarctica owing to extremely cold condition.  Their diversities are higher in the tropics. Geographical Distribution

 Amphibians are highly successful seen that they have made it possible to occupy various areas or countries world wide.  They are directly dependant upon the habitats these countries provide thus also being able to occupy various biomes.  Forests, Savannas, Shrublands, Grasslands, Aquatic habitats and Deserts are biomes which they can persist and survive in.  Within these habitats you will find them readily under rocks, stones, logs and close to fast flowing streams. Supportive Habitats

 The largest amount of amphibians are found within wetlands or rain forests  These biomes are being readily changed and the habitats for frogs are thus being threatened and this affects the abundance and diversity of amphibians directly Supportive Habitats

 Amphibians existed on earth 300 million years ago  They first appeared on the earth during the Devonian Period million years ago  This was because the Devonian Period which was known as the Age of fishes, allowed for the amphibian to evolve, owing to the fact that Labe- finned fishes are believed to be ancestral to the amphibians  The Carboniferous swamp forest was the suitable habitat for primitive amphibians owing to its high water, food and trees supply The Carboniferous Period - Age of Amphibians

 Those favourable resources today have been threatened over the past few decades and have thus affected our current Amphibian populations world wide  There are 6000sp of known amphibians and their abundance's are being decreased rapidly over the past 50 years The Carboniferous Period - Age of Amphibians

 Past climates provided conditions for maximum vascular plant growth, insect population flunishment and amphibian expansion in both diversity and number  When looking at climatic conditions today, we have to realize that our climate has undergone changes over the past few decades  Proxy data and instrumental measurements of climatic variables have provided us with information about climatic conditions over millions of years ago Climate Change

 There are various factors responsible for this change and these changes are affecting amphibian population abundances world wide Climate Change

 There is a link between climate change and amphibian number decline owing to temperature precipitation fluctuations  Climate change is not directly responsible for this decline but it does affect the organisms variability to diseases and this will lead to a decrease in population number or death of species  Various factors plays a part in amphibian species decline, it has to be noted that some factors are more influential than others Factors Affecting Amphibian Decline

 Destruction and alteration of their natural habitats  introduction of predators into their habitats  consumption of amphibians by humans e.g. red legged frog  pollution of the water and atmosphere  climate change observed or change in climatic conditions  increased level of radiation and  transformation of landscaped  draining of wetlands Amphibian Decline is owing to the:

 spreading of wildlife diseases e.g. Chytridiomycosis and Ranaviral  deformation and malformation of species owing to environmental conditions Amphibian Decline is owing to the:

 When looking at the list of factors causing a decrease in amphibians species numbers then it is evident that most of those factors are due to human activity  Therefore yes, we are changing their environment, we are changing the natural habitats of amphibians through planting crops-agriculture and deforestation  We are either introducing other species into amphibians habitats which out compete current amphibians and or feed on them (predation) Are we changing contemporary amphibians environment?

 Because of the increase burning of fossil fuels we are raising the amount of green house gases in the atmosphere thus causing global warming  This allows for an increase in local climates, owing to the pollution of the atmosphere and the population levels in the water has now become more concentrated  Ozone also allows for increased levels of the UV-B radiation to penetrate the earth’s surface and this is harmful towards amphibians Are we changing contemporary amphibians environment?

 Swing to urbanization landscapes have been transformed and this caused a change within the amphibian environment thus affecting their development directly - wetlands were also drained for human advantage e.g. stream channelization  There is therefore a link between climate change and declines5 Are we changing contemporary amphibians environment?

 There are 6000 known species of amphibian and 1/3 threatened, this is 32% of the species consisting of 1856 sp in total  43% of amphibians 2469 species are decreasing in population number  Decreases with in amphibian diversity and number is seen in cities, country sides, rainforests and wetlands  Most species declines are surprisingly seen within protected parks The Effects on Biodiversity

 Some species has gone extinct in Australia and Coasta Rica namely the Gastric breading frog (1980) and monteverde golden toad as well  Because of Amphibians dependence on their environment, owing to juvenile stage being aquatic and adult stage being terrestrial, their life as a whole is sustained by the maintenance of their habitats. The Effects on Biodiversity

 The rapid decrease in amphibians sp number has been identified and has been listed as one of the most severe issue as to date by conservationist.  Many conservationist have found methods in which to conserve the amphibian species which we do still have living today  One method used is to educate communities (human) about amphibians and how we are affecting these populations directly, thus then also allowing humans to have a direct part in the conservation of amphibians What can we do?

 This is done through monitoring of certain areas and forming artificial natural habitats for amphibians  There are numerous Amphibian Conservation groups globally  examples are the :  PARC - Partners in Amphibians and Reptile Conservation  ACA - Amphibian Conservation Alliance  CARCWET - Canadian Amphibian and Reptile Conservation Network What can we do?

 There are conservation groups world wide but yet there is still a decline in amphibians occurring  This shows us the serenity of this issue What can we do?

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