Download Chapter-9-Wildlife-Biology-and-Management

Chapter 9
Wildlife Biology and Management
© 2009 Delmar, Cengage Learning
Study of Life
• Basic needs of animals
– Food, water, shelter, and space
• These basic needs are of equal importance
• Suitable wildlife habitat requires a balance of these
requirements
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Animal Behaviors and Habits
• Life is the product of distinct behaviors
• Behavior is both learned and
instinctive
– instinctive: evident at birth
– learned: behavior picked up through life
experiences
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Life Requires Energy
• Food
– Amount of food required depends on age, sex,
size, location, season of year
– Differences exist in ways organisms obtain
nutrients
• Herbivores: Obtain food directly from plants
• Carnivores: Consume other animals (predators)
• Omnivores: Consume both plants and other animals
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Water
• Organisms differ in their relationship to a
necessary resource: water
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Some require standing water
Some drink water
Others get water from food they eat
Still others absorb water from the environment
Aquatic organisms actually live in water
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Shelter
• All organisms have basic habitat needs
– Habitat: Home where organism eats, rests, and
reproduces
• Suitable habitat provides adequate shelter
• Shelter can take many forms
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Space
• All organisms have a home range
– Area within which they live and obtain resources
– Size of home range varies
– Tolerance of others’ presence varies
• In any habitat, animals must not be
overcrowded
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Arrangement of Basic Needs
• Optimal populations achieved when
basic needs are appropriately arranged
– What if primary food supply is across a fourlane highway?
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Wildlife Relationships
• Many organisms participate in many types
of relationships
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parasitism
mutualism
Predation (important in controlling population)
commensalism
competition
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Predation
• Populations of predators and prey tend to
fluctuate widely
– When predators are in abundance, prey becomes scarce
because of overfeeding
– When prey becomes scarce, predators may starve or
move to other areas
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Preserving Wildlife
• Various efforts have been made to protect
wildlife
• U.S. Endangered Species Act
– passed to protect at-risk animal species and their
habitats
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Preserving Wildlife
• U.S. Endangered Species Act
– identifies two classes of at-risk species
• endangered: immediate danger of extinction
• threatened: at risk of becoming endangered
– Strategies include transplanting organisms, hatcheries,
breeding programs
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Human Impacts on Wildlife
• Humans impact wildlife in many ways
– Habitat destruction is the single greatest threat facing
wildlife
• Habitat destruction occurs as a result of
many human activities
– Construction, farming, mining, timber harvesting, and
pollution
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Stewardship
• Wildlife and other natural resources should
be managed with a long-term view and
commitment to the resources
– Will require knowledge of proven management
practices and ecology and habitat requirements
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Stewardship
• Wise stewardship occurs when managers of
natural resources make management
decisions based on dependable information
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Extinction
• Extinction of species is serious concern
• Several factors contribute to extinction
– introduction of alien species that outcompete native
species
– overhunting by humans
– lack of adaptability in a species
– slow rate of reproduction
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Extinction
• Destruction or modification of habitat
– single greatest cause of extinction
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Managing At-Risk Species
• Managing populations of endangered or
threatened species is difficult
– Effective management of endangered species must be
based on reliable research
• Managing at-risk species will involve
providing acceptable shelter and food
sources
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Managing At-Risk Species
• Management decisions must be applied in a
variety of habitats
– farms, forests, wetlands, streams, lakes, and ponds
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Managing Farmlands
• Management of farm wildlife often involves
providing suitable habitat
– usually by-product of farming or ranching practices
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Managing Farmlands
• Farmland management techniques include
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leaving corners of fields unharvested
leaving shrubs and brush piles
leaving crop residue standing through winter
planting crops attractive to wildlife
harvesting farm and ranch wildlife by hunting
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Managing Forests
• Managing forests often focuses on
increasing populations of a certain species
– If species is present, the goal is to maintain its
population
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Managing Forests
• Management of forests often involves
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developing a forest-management plan
making clearings to provide new growth
selective harvesting to produce a variety of habitats
leaving piles of brush for cover
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Managing Forests
• Developing a forest-management plan
– taking an inventory of species
– goal setting for habitat and species within it
– deciding how to support desired species
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Managing Wetlands
• Most important habitat to wildlife
– provide food, nesting sites, and cover for many species
of wildlife
• Wetland management techniques include
– impounding or holding water
– cutting trees to open up wetland area
– leaving hollow trees for nesting
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Managing Wetlands
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establishing open, grassy areas around wetlands
planting vegetation for food and cover
protecting from pollution
providing artificial nesting areas
breeding and release programs
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Managing Streams
• Protecting existing is critical because we
cannot build new streams
• Stream management plans usually focus on
fish
• Management of streams often involves
– preventing overgrazing of stream banks
– limiting access to stream by livestock
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Managing Streams
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maintaining streamside vegetation
sustaining desirable species of wildlife
balancing populations with food supply
using hatchery and stocking programs
regulating sport fishing
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Managing Lakes and Ponds
• Management techniques similar to streams
• Several management practices unique to
standing water
– controlling pollution
– sustaining desired mixtures of species
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Managing Lakes and Ponds
– maintaining appropriate dissolved oxygen levels
– eliminating unwanted species
– stocking desired species
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