Exam 2 Flashcards
What techniques would you use if you want a population estimate
Mark/recapture
Active/passive methods
What techniques do you use when you want a nest success estimate
Nest drag
Radio-telemetry
How can you capture an animal
By hand
Mechanical/physical devices
Use of drugs
The bigger the animal, the more ________ it becomes to capture them
Difficult
Likely more expensive too
Considerations when using capture method
Species
Habitat
Food preferences
Wariness
Population size
Considerations when trapping
Access to animal
Portability of trap
Number of traps
Habitat
Necessary permits needed to put hands on animal
State
Federal
IACUC
Capture methods goals
Safely capture animal
No effect on future behavior or survival
Effective and efficient
Capturing birds by hand methods
Running down and capturing
Day/night, grabbing birds
Capturing birds by mechanical/physics devices
Dip nets
Drop nets
Cage traps
Net guns
Noose poles
Capturing birds by drugs
Alpha-chloralose
Capturing amphibians/reptiles by mechanical/physical devices
Cover boards
Pitfall traps
Capturing mammals by mechanical/physical devices
Leg-hold traps
Culvert traps
Net guns
Noose poles
Cage traps
Induction of chemicals/drugs to capture or restrain animals
Immobilization
Immobilization allows us to handle animal with
Low stress
Low pain
Low risk to animal and researcher
Characteristics of ideal drugs
Safe for animals and humans
Potent
Fast-acting
Good muscle relaxation
Can be reversed
Minimal side effects
Minimum withdrawal time
Low potential for human abuse
Minimal depression on body systems
The reversible loss of sensation that allows clinical procedures to be done with a minimum of pain, discomfort, and side effects to the patient
Anesthesia
The loss of sensitivity to pain
Analgesia
Considerations before using anesthesia/drugs
Species
Age
Weight
Physical condition
Pregnancy
Weather
Drugs used
Equipment
Handling
Approaching animal
Drugs can be administered
Subcutaneously
Intramuscular
Intravenously
Orally
Subcutaneously is the _____ drug
Slowest
Intramuscular is the ____ ______ drug
Most common
Intravenously is the drug that ____ _______
Works fastest
Orally is the drug that’s ____ ________
Not recommended
Two requirement for large animals that cannot be captured first
Adequate muscle mass
adequate circulation
Where can you shot a dart
Shoulder region
Hindquarter
Base of neck
IM injection equipment
Jabsticks
Blowpipes
Dart rifles
When needle goes into tissue, the plastic blocking sleeve slides backwards, allowing drug to escape and pressure to force drug out into tissue
Pressurized delivery system
Depresses the central nervous system filling conscious awarenesss
Stimuli are received but brain normal response is decreased
Sedative
Alleviates the perception of pain
Anesthetics
Fully conscious, but cannot respond
Muscle paralytics
Use in conjunction with other drugs to calm animal
Tranquilizers
Immobilizing drugs CAN produce both
Sedation
Anesthesia
Act on the junction between nerve and muscle
Neuromuscular blocking agents
Act on the brain and spinal cord
Central nervous system agents
Paralyzes, but feel pain
Neuromuscular blocking agents
Produce anesthesia, loss of consciousness
Central nervous system agents
Neuromuscular blocking agents are not
Ethical to use
What are the drugs of choice
Central nervous system agents
Central nervous system agent drugs
Opioids
Cyclohexamines
Neuroleptics
Morphine-like, highly potent in small volumes, loss of consciousness, may be reversed
Ex. Carfentanil
Opioids
Rapid immobilization with altered consciousness, may move tongues and blink
Cannot be reversed
Ex. Ketamine
Cyclohexamines
Tranquilizers
Do not cause loss of consciousness at safe doses
Often used in combination with opioids and Cyclohexamines
Ex. Diazepam, xylazine
Neuroleptics
Immobilizing drug of birds
Gas anesthesia
Ketamine
Immobilizing drugs of amphibians
Gas anesthesia
Immobilizing drugs of reptiles
Ketamine
Gas
Allows us to identify individuals
Wildlife marking
Mark/identify by:
Natural marks
Noninvasive
Invasive
Natural or non-invasive or invasive?
Bands
Neck collars
External color marking
Non-invasive
Natural or non-invasive or invasive?
Radioisotopes
Ear tags
PIT
Tattoos
Ear notching
Invasive
Marker considerations
Minimal pain/stress
No adverse effects
Good retention
Easily recognizable
Fast/easy application
Inexpensive
Hand or distance
Mark-recapture - sampling the ______
Population
Probability of a live animal entering the observed sample in time t
Encounter rate
Probability that an individual is captured during a given time period in an actual trap or net
Capture rate
Probability that a hunter will, during a given time period, shoot a marked animal — shot and recover animals cannot be released to the wild because they are dead
Recovery rate
Probability that an animal marked with colored or numbered tags will be seen by a person and recorded during a given time period
Re-sighting rate
Mark-recapture can provide quick information about ______
Population
Types of populations
Closed
Open
Assume no births, deaths, immigration , or emigration during the study
Normally short time periods
Estimate population size
Closed population
Assume that births, deaths, and movement occur
Usually longer studies
Estimate survival and movement rates
Open population
Number of marked animals released in time period t
Cohort
Capture periods
111
110
101
100
Capture animals in 1st occasion, mark them, capture animals in second occasion
Basic design
Lincoln-Peterson Assumptions
Capture probabilities are equal for all animals at each occasion
Marking does not affect p2
No loss of marks between occasions
All marks at time 2 are reported
Random sample of population each time
Lincoln-Peterson estimation is good for ____ samples
Large
For small samples you use ______ modification
Chapman
> 2 capture occasions
Variation of Lincoln-Peterson
Schnabel estimator
Open = estimating survival
Allows for births and deaths
Assesses survival of individuals not marked
Must have unique marks
At least 3 time periods
Some mortality could occur
CJS
Open Populations (CJS) assumptions
Every animal has same chance of capture, p
Every animal has same probability of surviving to the next sampling period
Marks are not lost/overlooked
Samples are instantaneous (short periods) and animals released immediately
All emigration from the sample area is permanent
Fates of individuals-capture and survival-are independent of other individuals
We assume emigrated animals as
Dead
Quote: It is likely that more money and effort have been wasted on ill-conceived radio-tracking studies than on the use of any other field technique
Sargeant 1980
Quote: it appears that the reason for these ‘ill-conceived’ studies is the general attitude… that be placing transmitters on a handful of animals and ‘tracking’ them, one is guaranteed to obtains good biological data. This fact could not be further from the truth
White and Garrott 1990
Radio telemetry uses
Movements/dispersal
Home range
Habitat use
Survival
Population estimation or other demographic information
Radio transmitter attachment types
Collar/necklace
Backpacks
Harness loops
Modified leg bands
Glue-on transmitters
Subcutaneous anchors
Implants
Mostly for mammals
Too tight causes skin irritation
Too loose goes over neck
Allow for growth, movement
Collar/necklace
Used mostly with birds
Loops around breast and belly
Slowed to large degree
Backpacks
Used mostly with small birds
Loops around legs
Harness loops
Used mostly with birds with relatively long legs
Modified leg bands
Used with birds, bats, mammals, reptiles
Glue-on transmitters
Placed under skin, sutured in place
Used with birds, mammals
Subcutaneous anchors
Surgically implanted into animal
Requires vet
Implants
Transmitters should be less than or equal to ____ to ____ % of body weight
3 to 5
_______ is heaviest thing on transmitter
Battery
_______ __ ________ — bigger battery for longer range
Range of detection
_____ ______ - easier to detect, but burns battery
More beeps
______ _____ - may reduce weight, but sunlight?
Solar powered
_________ _____ - faster signal, burns power
Mortality switch
What reduces drag on flying/swimming animals
Shape of transmitter
VHF stands for
Very high frequency
Signal sent is a pulse of an electromagnetic radio signal
VHF radio-telemetry
Increasing the number of elements _______ directionality of antenna by cancelling noise from other directions
Increases
Allows us to monitor animal without disturbing it
Telemetry
We locate/monitor animal via ______ to not disturb animal
Triangulation
Error in bearings causes
Uncertainty in estimated location
Goal is to have as small an _____ ________ as possible
Error polygon
Sources of error for telemetry
Animal/position behavior - location may attenuate signal
Operator error
Small inaccuracies become larger ones when you are ______ from the animal
Further
What to watch for in telemetry
Reflection (Bounce)
Interference from out-of-phase waves
Absorption/scatter (diffraction)
Height of transmitter or receiver
Radio signals affected by water depth
Noise
Scatter and absorption occur when transmitter is _______ to ground or passing through _____ _________
Close
Dense vegetation
Animal tagged with a GPS-logging system
GPS tags
Platform terminal transmitters
Receive transmission signal from tags
Triangulate on signal
Rental fee
Heavier transmitter
Battery used faster
May need solar to continue power
Satellite PTT telemetry
Predicting behavior of radio-marked animals
Tri-axial accelerometer
Light weight
Record light-levels at the tag’s location
Can infer, broadly, general location on the earth’s surface from the timing of light-dark cycles
Geolocators
Translating location data to answer questions about animal space use and movements
Home range theory
Home range contains essential requirements of
Life
Quote: “… that area traversed by the individual in its normal activities of food gathering, mating, and caring for young”
Burt 1943
Size of home range might be affected by:
Sex
Body size
Foraging strategies
Food availability
Distribution of food resources
Population density
Risk of predation
Quote: “… the extent of area with a defined probability of occurrence of an animal during a specified time period”
Kernohan 2001
The relative intensity or probability of use of areas by an animal, or what is the probability that an animal will use a given point in space in a given period of time?
The utility distribution
Subset of the range excluding occasional outlier excursions. Or, the UD with disproportionately high use compared to the rest of the range
Core area
Defended part of an animals’ home range
Territory
Is home range needed?
How far did my animal move?
No - answered by movements
Is home range needed?
Where on the landscape is my animal found?
Home range may be a good technique, but habitat selection analyses can directly answer
Is home range needed?
What is my animal doing while it moves?
Not useful
Quote: more people use home range analysis than should use home range analysis
Powell opinion
Animal space use decisions
Resource quality and spatial distribution
Costs of movement
Social factors
How is home range data obtained
Telemetry - most common
Multiple recaptures
Marks on animals
_________ ____ is excellent for home range analysis
Radio-telemetry data
Minimum Convex polygon advantages
Simplest
History of use
Flexibility of shape
Ease of calculation
Minimum convex polygon disadvantages
Size increases with number of locations - can’t compare to others
Does not indicate interior use of home range
Normal distribution
Parametric method
Grid cell count advantages
Avoids assumption of underlying distribution
Can determine areas of high use and eliminate outliers
Grid cell count disadvantages
Can miss areas that may be important in home range
Analyses and comparisons are very sensitive to cell size
Same sample size issues as MCP
Value of the UD at a landscape point
The more times an animal is near a given site on the landscape, the probability that the animal uses that site increases
The kernel estimator
No capture histories
Theoretically, we follow animal until it/if dies, study is over, or transmitter fails
Known fate
Keeping track of exposure/observation days
Mayfield survival method
The number of days the animal, or nest, or young exposed to mortality event
Exposure days
Mayfield’s methods assumptions
All nests have constant survival over the nest interval, L
Subjects are not required to enter the study at the same time
Survival is constant for the entire sample; thus, in staggered entry, survival is not different for the newly added individuals
The estimate for variance is based on number of exposure days, so studies with fewer exposure days will have a less precise estimate of survival
Animals that disappear from the study are removed from exposure day count
Assumed to be present until day reported missing
Right-censoring
Now estimate for time period
Daily survival estimate
Kaplan-Meier method assumptions
Animals represent a random sample of the population
Animals are independent
Survival is assumed constant for all animals during specific time periods, but not constant survival throughout the study
Animals not required to enter at the same time
Newly tagged animals are assumed to have the same survival function as previously tagged animals
Working radio-tags are always located, when using radio-telemetry to locate animals
Censoring is a random event, and independent of mortality
The relocation method do not impact survival
Quantity of resource used in a fixed period
Use
Amount of each resource accessible for use
Availability
Disproportionate use, relative to availability
Selection
Indicates some knowledge of animal’s thoughts
Preference
Habitat selection order: first
Location of physical or geographic range of a species
Habitat selection order: second
Location of home range within a study area or geographic range of species
Habitat selection order: third
Habitat components within a home range
Many of our data are
Continuous
Obtain set of used points with habitat measurements
Obtain set of random points with similar measures
Relative selection
Modern approach: discrete choice
