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The class Amphibia consists of animals that are dependent upon water for reproduction but are otherwise quasi-terrestrial and live part of their lives on land. They descended from fishes about 350 million years ago and today are represented by about 9800 species such as the familiar frogs, toads, and salamanders. To see newts (salamanders) and tree frogs in their annual "Rite of Spring" seeking water for breeding, visit Stebbins' Cold Canyon Reserve, one of the field trip sites, in late February or March.


Here are several chapters (in  format) from the ’s .

Figure 9.1 Northern spotted owl.

Prohunting argument. Experts have reported that decreasing mountain lion populations result in decreased depredation. Reported livestock depredation incidents have increased since the hunting moratorium started in 1971, and mountain lions are the major cause of depredation losses. Sport hunting decreases mountain lion populations and thus would decrease depredation, and the revenues received from the sale of hunting permits could supply funds to compensate for depredation losses. This would also decrease the likelihood of attacks on humans.

9.2.2 Life History and Ecology of the Spotted Owl

Anti-hunting argument. Studies have shown that mountain lion populations are not capable of depressing deer populations. The North Kings area (see above) suffered from extensive loss of habitat during the years of the hunting moratorium, and loss of habitat is recognized as a major cause of declining deer populations. Also California deer populations decreased most during the years that there were bounties on mountain lions, which suggests that something else besides the mountain lion is affecting deer numbers.

Farmers' fields and gardens are also importance repositories of biological resources.
In this context, it has been acknowledged that forests are rich in biological resources.

However, these forests are declining as a result of deforestation.

Increasingly, we are realizing that species can be as dynamic as the landscapes in which they live. They can change through time and one species can give rise to hundreds of distinct local forms, each evolving in a few generations. For example, the threespine stickleback (), a small fish, has been called by evolutionary biologist Michael Bell "a superspecies made up of semispecies!" What we know as the species (the superspecies) is found in coastal regions throughout Eurasia and North America. Throughout its wide distribution it is easily recognizable to us as a threespine stickleback. The stickleback is a very widely distributed form because it can live in both salt and fresh water. The saltwater form can invade isolated coastal streams and lakes, where it settles down and becomes non-migratory ( a genetic characteristic, indicating natural selection at work). In each of the lakes and streams the new form can develop distinctive characteristics and will not interbreed with any marine sticklebacks it might encounter. In a few hundred years (or less), in essence, a new species has evolved (the semispecies). If a natural disaster occurs (e.g. , the eruption of Mt. St. Helens), the local species may go extinct in a wink of a lava flow, and the process starts again. A conventional taxonomist could spend a lifetime decribing each of the hundreds of isolated stickleback populations as a species, but there seems little point in doing so. More important is understanding and appreciating the beauty of the evolutionary process -

Such management practices are in consonance with Principle 8(e) of the Forest Principles.

from The Big Woods by Ellis Lucia

If the effort to save endangered species is a war, then the effort to save the northern spotted owl (Strix occidentalis) is a major battle (Figure 14.1). On one side there is the powerful forest products industry whose goals seemingly are mutually exclusive with the spotted owl's survival. Aligned with the forest products industry is the United States Department of Agriculture's Forest Service which seems reluctant to protect the owl. The opposition is an alliance of conservation groups and scientists including the National Wildlife Federation, the National Audubon Society, the Sierra Club, and conservation biologists. The acrimony between the two camps is apparent in official statements, advertisements, and actions made by both sides on this issue. The forest products industry refers to conservationists and environmentalists as CAVEs - citizens against virtually everything - while extreme environmentalists drive steel spikes into trees, ostensibly to prevent logging but also endangering loggers. Despite the animosity in this conflict, there is reason for optimism; the spotted owl can be saved and this case can be used as a blueprint to resolve future conflicts in efforts to save endangered species.

In this context, the world's forests have been under threat and are declining.

Water Pollution Middle School nmctoastmasters

Predation hypothesis. Great horned owls and goshawks prey on juvenile spotted owls. The multilayered canopy of old-growth forests provides refuge for young spotted owls from these large predatory birds.