Transcript Ch 9 Wildlife Biology Management

Chapter 9
Wildlife Biology and Management
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Study of Life
• Biology is the study of life
– Botany seeks to understand the life of plants
– Zoology is the study of animal life
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Study of Life
• Zoologists study the 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
and habits that help an organism meet
basic needs
– Way in which organism meets basic needs is
often distinctive to it
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Animal Behaviors and Habits
• 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
– Anything organism consumes to get energy
– Amount of food required depends on age, sex,
size, location, season of year
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Life Requires Energy
• Differences exist in ways organisms
obtain nutrients
– different preferred foods
– different digestive systems
• simple stomach, multiple stomachs, gizzard, etc.
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Food Sources
• Organisms differ in types of foods
consumed
– Herbivores: Obtain food directly from plants
– Carnivores: Consume other animals
• also called 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
– Must provide an organism’s basic needs
• Suitable habitat provides adequate shelter
– protection from weather, predators
– places to reproduce
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Shelter
• Shelter can take many forms
– often a form of vegetation or vegetative cover
– can be pile of rocks, hole, cliff overhang, etc.
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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
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Space
• In any habitat, animals must not be
overcrowded
– Overcrowding can result in stress, disease, damaged
habitat
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Arrangement of Basic Needs
• All wildlife requires
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food
water
cover
space
• Habitat containing these basic
requirements will support life
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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
commensalism
competition
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Parasitism
• Relationship between two organisms in
which one feeds on the other without
killing it
– May be plants or animals
– Parasites may be either internal or external
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Parasitism
• Example of a parasitic relationship
– wood tick
• lives on almost any species of warm-blooded animal
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Mutualism
• Two types of animals living together for
their mutual benefit
• Example: tick pickers
– birds remove and eat ticks from many African animals
• Wild animals have parasites removed from them
• Birds receive nourishment from ticks
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Predation
• Situation in which one animal eats another
– predator: does the eating
– prey: gets eaten
• Predators are often critical in controlling
wildlife populations
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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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Commensalism
• Situation in which plant or animal that lives
in, on, or with another but does not help or
harm it
• Example
– vultures waiting to feed on leftovers from a cougar’s
kill
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Competition
• When organisms contend for same food
supply, cover, nesting sites, or breeding sites
– Competition may exist among members of same
species or between or among different species
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Competition
• Competition often results in changes in
population levels
– One species may increase in number whereas the others
decline
– Often the numbers of both species decrease
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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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