How to get more from readings

SECTION 1
Chapter 1

Chapter 2

Chapter 3
Chapter 22
Chapter 4
Chapter 5

SECTION 2
Chapter 6
Chapter 7

Chapter 8
Chapter 9
Chapter 10

Chapter 20

SECTION 3
Chapter 11
Chapter 12
Chapter 13
Chapter 14
Chapter 15
Chapter 16
Chapter 17

SECTION 4
Chapter 18
Chapter 19
Chapter 21

Chapter 23

The term Conservation has been associated with managing a rather limited range of natural resources; those materials regarded as either useful or of necessity to humans. In the 1970s, an increasing number of conservationists expressed interest in the welfare of other species-organisms that have no obvious impact on human welfare and therefore not ordinarily regarded as "resources". In addition, attention was directed toward the conservation biotic communities and ecosystems. Wildlife management expanded and as time passed more game species gained protection. Aldo Leopold championed the application of the sciences of biology and ecology to management in his seminal work Game Management. The Wildlife Society formed and devoted itself to the development of management practices based on sound biological principles and high professional standards. The focus of wildlife management spreads from game animals to the more inclusive categories of birds and mammals with emphasis on the management of populations and their habitats.

1. The broadening scope of managing wildlife and their habitats encompasses the subject of biodiversity.
2. To include the management of endangered species and maintenance of ecosystems
   1. Biologists felt that the distinction between these broader approaches and the traditional focus of wildlife management warranted a new discipline known as Conservation Biology.
3. The Society for Conservation Biology was organized in 1986 a year later the publication of the society's journal Conservation Biology was released.
   1. The new society was described as crisis oriented, more theoretical, and more global than The Wildlife Society.
      1. The central goal of wildlife management was identified as the manipulation of animal populations-primarily vertebrates. wildlife management leans toward selected species of birds and mammals
      2. whereas conservation biology stresses the maintenance of biological diversity. Conservation Biology addresses the full range of plant and animal taxa.
   2. Differences in background in training represented another area where wildlife biologists may be distinguished from conservation biologists.
      1. Wildlife biologists graduate from colleges and universities where applied sciences such forestry and agriculture are curriculum standards.
      2. Conservation Biology is a synthetic discipline with highly diversified memberships including genetics, physiology, geography, and oceanography. Etc.
   3. Regardless, wildlife management and conservation biology are viewed as complementary disciplines whose existence broadens understanding of environment. To be sure, there is no shortage of concern whether for deer or ducks, butterflies or orchids, prairie or rain forest.
4. Preserving Biodiversity means the halting the loss of genes, species, and ecosystems. This is a primary goal of conservation biology.
   1. North America represents of the prime locations for conserving biodiversity. Why?
      1. relatively low human pop.
      2. Relatively short period of significant environmental alteration since settlement
      3. Affluent population (we got money)
      4. Presence of well-trained biologists and resource managers.
      5. Agencies and academic institutions attuned to management and biology
      6. Environmental laws are present and enforced
      7. State and federal ownership of wildlife refuges, Parks, forests, and other large areas of land
   2. Large areas of land are especially important for the protection of biodiversity.
      1. One third of the area of the United States is held in federal ownership and managed by biologists.
   3. However, the existing reserves by themselves are not sufficient to protect biodiversity in a large part of the United States
      1. which means biodiversity must become a management goal on other types of public land (i.e. National parks, National Forests etc.).
      2. In addition, few large reserves are being added to the current holdings of public lands.
   4. Land managers are accepting the importance of biodiversity and are applying the tenets of conservation biology to resources in their care.
   5. Success of conservation biology goals depends on interagency cooperation
   6. Privately owned land as sites for biodiversity management programs are also being considered.
5. The focus of conservation biology is directed toward three levels of diversity within the broad realm of biology:
   1. the loss of genetic diversity,
   2. the loss of species diversity,
   3. loss of ecosystem diversity.
   1. Genetic variation, the variation of genes in one pop. to the next, occurring within some species has long been of interest to wildlife managers.
      1. i.e. Canadian geese genotypes produce various sizes and behavior.
      2. To that end, it helps with identification.
   2. Conservation biologist possess a more specific interests in genetic variation (or the loss of genetic diversity).
      1. Genetic bottleneck occurs when only a few individuals provide the total pool of genes for a population. The example of a few lions surviving a disease leaving only a limited genotypes for future generations.
      2. Genetic bottlenecking lessens gene heterozygosity (the amount of variation of genotypes) in a population potentially causing low reproductive success and sperm abnormalities.
      3. Founder effect is used to characterize circumstances in large populations when a small gene pool occurs resulting from survival of genes specific to the descendants of just a few "founders" occurs. It also occurs on islands when they are colonized by only a few individuals.
      4. Fragmentation of populations by human activities has also increased gene variation. The example of wild turkeys' reintroduction caused the highest recorded gene variation for birds of any species.
   3. Species diversity or the number of species naturally occurring within a community, may have implications for the traditional species-specific focus of wildlife management.
      1. Predator-prey relationships are dependent on pop. size and diversity
      2. Food webs are complex and dynamic containing several predators and numerous prey species.
6. Conservation biology takes a broader view, than traditional wildlife management, of the composition of a natural community and species diversity. Efforts are directed toward relatively inconspicuous species of animals, many of which play crucial roles in pollination, herbivory, seed dispersal, and nutrient cycling.
   1. The component species in some communities maybe very complex and in high numbers.
      1. 8.15 million species of beetles live in the canopies of 50,000 species of tropical trees.
      2. Extrapolated from that 30 million species of arthropods could live in the entire strata of these trees. This is just one segment of one of the world's ecosystem and each species plays a role in the working of that environment
      3. Conservation biologists including entomologist, statisticians, etc would be concerned about these communities
7. Ecosystem diversity has come to the attention of biologists as well.
   1. All ecosystems have been disturbed in some way: off-road vehicles, overgrazing, logging, erosion, and of course wetlands are especially impacted from agricultural development.
   2. Wildlife Managers and conservation biologists have similar goals for the protection of ecosystems but are aimed at different levels in ecosystem structure.
      1. Wildlife managers again tend to be species specific.
         1. To their credit, wildlife managers assumed most of the leadership in the development of techniques with habitat intervention.
      2. Conservation biologists give attention to natural communities and their diversity. Giving attention to genetics, species, and ecosystems as a whole.
   3. Differences in the two discipline lies primarily in the academic training and outlook of each group. Wildlife management includes regulated harvest of selected species and devotes attention to manipulating numbers and their habitats, whereas conservation biologists devotes efforts toward a broader range of organisms and their habitats.
8. Population genetics are a concern for the conservation biologists for they have tried to determine why small populations fail to grow in an otherwise apparently suitable environment.
   1. Field studies suggest high genetic variation favors survival and low genetics variation does not.
   2. Plant or animals lacking genetic diversity are susceptible to adverse factors that may prove so disastrous as to rapidly eliminate the entire population.
   3. Inbreeding depression a main cause for low genetic diversity occurring when siblings mate, resulting in extreme homozygosity (many similar genes).
   4. Conversely, a population with considerable genetic variability is more likely to include some members resistance to certain diseases.
   5. When subspecies (races) interbreed the offspring can experience diminished fitness. That is to say the offspring are heterzygosity (many dissimilar genes) and have difficulty with adaptations to local conditions.
   6. Reduced fitness occurs with matings among individuals with diverse genetic backgrounds. The resulting condition is called outbreeding depression.
   7. The point to be made is that there exists a genetic diversity window that species of plant and animals must fall to ensure the best chances for healthy propagation. That is to say a healthy balance of similar and dissimilar genes.
      1. The book uses the example of cheetahs and the extreme of homozygosity (inbreeding depression) which produced reduced sperm count high infant mortality and asymmetry of their skulls.
      2. This again would fall under the studies of conservation biologists but the importance of genetic information to wildlife management is apparent.
   8. Wildlife managers should seek other explanations for poor reproductive performance other than external factor such as food supply, disease, and other environmental factors.
   9. This prevents any overlooking of real causes and time wasted investigating non-issues.
   10. Genetics is one example of the clear connection between the conservation biologist and wildlife managers.
9. The Wolves of Isle Royale
   1. Isle Royle, an island park in Lake Superior, is home to a community of 11 wolves that have exhibited slow growth in the abundance of food supply and other factors.
      1. Investigation of one hypothesis lead to researching the genetic variability between the island wolves and those populations on the mainland.
      2. The results indicated that the island wolves had low genetic variation, poor fitness and juvenile survival, poor reproductive success, low resistance to canine diseases
   2. It is probable that they were the descendants of a single female who had immigrated across an ice bridge. (Founder Effect)
   3. This study illustrates the contributions and interdisciplinary studies that each conservation biologists and wildlife managers share for problem solving.
10. Northern Spotted Owl
    1. No subject in the past decade has been as controversial as this bird and its habitat the old growth forests of the northwest. It's relevance here is the combined efforts of wildlife managers and conservation biologists.
    2. The problem being the economic importance of the clear cutting harvest of old growth forests and the ecological importance of spotted owls.
    3. The solution lies in the concepts of conservation biology and wildlife management.
    4. Increasing spotted owl distribution will help prevent their extinction.
       1. Large blocks of habitat with many individuals are required
       2. Blocks (patches ) should be near each other
       3. Sites between protected habitats help dispersal when they is reasonably suitable habitat for the species.
11. Island Bbiogeography (MacArthur and Wilson 1967) set in motion ideas concerning the number of species that might exist on sites of various sizes. The concept has at it's core the species /area relationship which proposes simply that larger sites contain more species than smaller locations.
    1. Larger locations have higher colonization and are less likely to experience extinction.
       1. One example is the reptilian and amphibian fauna occurring on series of islands.
          1. Initial colonizations were high, as time passed the rate diminishes as more of the immigrants belong to species already present.
          2. In addition, species disappeared (local extinction) because species are at risk as the pool of species increases.
       2. Predators are often lacking in vertebrate communities on many islands; their populations occur at lower densities as their prey making them less successful on island ecosystems.
    2. Geographical factors play a major role in the nature of an island biota. i.e. distance from the mainland.
       1. Mainlands provide a source of colonists so it follows that the number of species reaching an island decreases as the distance form the mainland to island increases.
       2. The dynamics of colonization and island extinction create a state of equilibrium in the island biota.
    3. Other species characteristics are considered such as pioneering ability, ability to reach an island, and capacity for successful colonies.
       1. Species with wind borne propagation are generally most successful
       2. Species that can survive long periods in water.
12. Criticisms of the Theory of Island Biogeography as a model
    1. It is an equilibrium theory model.
       1. colonization and island extinction are assumed to lead to an equilibrium.
       2. all species are treated equally in the model.
    2. Assumes that the environments on an island remain constant throughout colonization and extinction.
    3. It discounts the possibilities that succession and other types ecological or physical change will influence the presence or absence of species.
    4. No allowance is made for increases in the number of species by evolution.
13. Where can Island Biogeography concepts be applied ?
    1. True islands… like Gilligan's
    2. Islands of habitat
       1. remaining patches of tall grass prairies
       2. Mountain tops and caves
       3. Artificial settings like woodlots, cemeteries and parks.
    3. It can be used establish the minimum area required for nature reserves.
    4. Wetlands and their wildlife management
    5. Determines size, and isolation factors important for the variation of avifauna.
    6. Bigger not always better;
       1. smaller marshes increase habitat heterogeneity and fulfills various needs of breeding ducks and other wildlife.
14. Increased distances between habitats impair the stability of metapopulations
    1. which are nearby but separated groups of the same species between which individuals move.
    2. Despite their lack of size small wetlands may provide important sources of stock for reestablishing temporarily extirpated metapopulations.
15. Corridors are connections between separate areas of similar habits.
    1. The interest for wildlife managers is with suitable corridors; plants and animals may travel between islands.
       1. This prevents inbreeding depression by maintaining gene flow between segments of large populations.
       2. Enhancement of species richness, removing the negative effects of fragmentation of habitats.
    2. Ideally, corridors should be planned before vegetation is altered but usually is an after thought to development.
    1. Corridors and wildlife management
       1. Corridors have been proposed for connecting fragmented areas of habitat for mountain lions in southern California.
          1. Currently a population of 15 - 20 mountain lions requires an area of 2,200 Km² if a corridor permitted movement between smaller patches the same individuals could perhaps live on a total of 600 to 1600 Km² thus allowing for more development.
          2. The book refers to this as rescue effect.
    2. Conservation biology and corridors
       1. There is less than full agreement on corridors as a tool of conservation biologist.
          1. Introduction of pathogens, predators, or exotic species are among the dangers.
       2. It is felt that the benefits corridors provide do not justify the establishing of reserves that are too small for their intended purpose.
       3. Corridors also create edge, which can be detrimental to selected species.
       4. Increased mortality near edges can create population sinks, where animals move into the area but do not survive there, this is more harmful than beneficial.
    3. Corridors are not cheap: money, money, money is required.
       1. But corridors increase biodiversity: a goal of conservation biology.
       2. An alternative to corridors is translocation
          1. Managers could periodically move animals from isolated population to another.
          2. This promotes genetic heterogeneity of small populations.
       3. Establishment of satellite populations reducing risks of catastrophes.
       4. Hastens recovery of species following habitat restoration.
       5. Lessens the effects of fragmentation for species whose abilities to disperse are limited.
16. The Fragmented Forest
    1. Harris (1984) illustrated the effects of fragmentation of the old growths forests in the Cascades.
       1. Wood warblers populations were in decline because forest patch sizes were too small.
          1. The inner core forest, where the wood warbler communities thrived, became fragmented, too small an area, for sustaining the population.
          2. Nest parasitism by brown-headed cowbirds, an edge species, took advantage of the fragmentation and the lack of inner forest protection formally possessed by the wood warbler. The newly opened woodlands thereby offer cowbirds additional habitats in areas once covered by unbroken forests. Thus providing cowbirds access to many more host species.
          3. The result was an increase in cowbird populations and a significant decrease in wood warblers as well as Kirtland's warbler and white headed sparrows and other more desirable songbirds.
17. Minimum Viable Populations
    1. The term minimum viable populations gained currency with the enactment of the National forest Management Act of 1976.
       1. This act required the US Forest Service to maintain "viable populations" for all species of vertebrates living in the national forests.
       2. The concept of MVP implied a magic number that will ensure the continued presence of wildlife populations.
       3. A problem existed which is that the threshold varies with species and other factors such as location affects the number.
    2. A MVP must not only maintain itself but also be large enough to survive several types of random events.
       1. The development of a time defined MVP standard was created similar to the one for flood events.
          1. 50 yr. flood, a flood whose magnitude only occurs once every 50 years
       2. A MVP for any given species in any given habitat is the smallest isolated population having a 99 percent chance of remaining extant for 1,000 years despite the unforeseeable effects of demographic, environmental, and genetic stochastically, and natural catastrophes.
          1. But any variation of this definition should include explicit set of performance criteria. (i.e. 90 percent chance of persistence for 500 years)
       3. Fragmented populations of bighorn sheep illustrates MVP usage
          1. No populations of sheep fewer than 50 persisted for more than 50 years.
          2. Populations of 100 sheep persisted for 70 years.
          3. The results suggest a threshold of 50 sheep, below which populations of sheep cannot survive and a MVP of 100 is necessary for long term persistence.
18. The area required for the conservation of vertebrates increases proportionally with increases in the size of MVP and the length of the period of persistence.
    1. Shaffer defined the random and chance events effecting populations calling them Stochastic events.
       1. Demographic stochasticity, occurrence of an unfavorable death rate or other feature of population ecology. (i.e. heavily skewed sex ratio)
       2. Genetic stochasticity, results from the chance occurrence of unfavorable genetic circumstances. (i.e. bottleneck)
       3. Environmental stochasticity, occurrence of unusual levels of predation, parasitism, disease, or other decimation factors. (i.e. cowbirds)
       4. Natural catastrophes, floods, fires, droughts, heat/ colds.
    2. The extinction of the Heath hen provides the example:
       1. The range of the health hens steadily declined in the last century until only 100 remained on Martha's Vineyard.
       2. A fire, (natural catastrophe), destroyed a large part of that habitat.
       3. The following winter heavy predation, (environmental stochasticity), reduced the population again.
       4. A rebound occurred but a disease struck (environmental stochasticity), the population fell to less than 100.
       5. Thereafter increasing sterility, (genetic stochasticity), and an imbalance in sex ratio, (demographic stochasticity), further diminished the remaining population.
       6. By 1932, the heath hen was gone forever.
19. Human Population - Difficulties in managing wildlife runs into the face of the increasing human population
    1. The human population is probably the most severe problem faced in human history and is the one most likely to result in breakdown of both normal ecosystems function and social structure. The fall of biodiversity ensues.