Chapter 9: Population Assessment

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Chapter 9 Population Assessment

• March 20, 2007

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9.9 Purposes of marking, tagging, banding

• Mark-and-(1) studies are a major reason
• Some assumptions
• Mark/tag/band will not affect behavior,
  mortality, or likelihood of recapture of the
  animal
• May be able to derive (2) information limitation
  to this is that only the minimum distance moved
  is known

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Marking methods

• Toe clips, fin clips, ear notches, tattoos, heat
  brands, freeze brands, and even radioactive
  shake-and-bake methods
• These methods often involve some form of (3) of
  the animal again, must make sure that they do
  not affect the behavior of the animal

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Toe clipping
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Ear notches
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Tattoos
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Tagging banding methods

• These involve the (4) of an artificial structure
  to the organism
• Such as
• Neck collars
• Leg bands
• Ear tags
• Internal tags

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Neck collars
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Leg bands (aluminum and/or colored plastic)
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Ear tags
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Telemetry

• This involves electronic devices that are placed
  on or in an animal that relay info to biologists
• Some are mortality-sensing
• Some can deliver anesthetics
• Allow for monitoring animals at a distance
• Are set at a specific radio frequency
• GPS units can be programmed to emit signals at
  set intervals to preserve battery life

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Telemetry

• Consists of two main parts
• The transmitter, which is attached to the animal
  (some are solar-powered)
• Usually runs on a radio frequency, but GPS units
  have become more popular
• The receiver, which is used by the biologist
• This can be handheld, attached to a vehicle or
  aircraft, or can even be tied into a satellite

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Telemetry on mammals

• Usually attached via a (5), but bats can have
  their transmitters glued on or worn as a backpack
  or harness

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Telemetry on birds

• Like with bats, usually glued on or worn as a
  harness/backpack

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Data
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Flight in Birds
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Skeletal adaptations

• Number of fusions and reinforcements in the
  skeleton combine delicacy (i.e., lightweight)
  power
• Most of the larger bones are, to a degree, (6),
  though many are reinforced with internal struts
• Bill (beak) is lightweight and toothless

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Bones
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Sternum

• Sternum has a large (7) that anchors the large
  flight muscles, all of which are found on the
  chest (none on the back!)

(Sword-billed Hummingbird skeleton)
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Other skeletal adaptations

• Thorax (chest) is rigid and reinforced for
  strength
• Extensions of bone connect one rib to the next
  (for rigidity) these are called (8)
• Hand, finger, wrist bones are all (9) to
  further add rigidity and strength

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Skeleton
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Flight muscles

• Two flight muscles are found in birds the
  pectoralis and the supracoracoideus both are
  located on the pectoral girdle (i.e., chest)
• Pec muscle is the largest and accounts for 15 of
  the weight of the bird (is responsible for a
  birds downstroke (aka the power stroke)
• The two flight muscles operate back and forth
  during flight via a pulley system

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How the flight muscles work
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Basic aerodynamics of flight

• A cross-section of a birds wing reveals it to be
  an (10), which is an asymmetrically curved
  structure that tapers in the rear
• The asymmetrical layout allows for lift modern
  airplanes operate on this exact process
• Lets see how it works

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Airfoil
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Flight

• Birds must flap their wings to generate forward
  thrust (jet engines use their engines for this)
• Birds can also alter the angle of their wings to
  go up, down, or slow altogether (much like the
  moving parts on the rear of an airplane wing)

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Hummingbirds

• Because they have much more range of motion in
  their (11), hummingbirds can fly like a
  helicopter rather than a fixed-wing aircraft
  this enables them to hover, fly forward and
  backward
• When hovering, their wings move in a figure-eight
  pattern (like us treading water)
• Their tails are very useful in steering

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Flightless birds

• Flight muscles are expensive to produce if you
  dont need them, lose them (along with the keeled
  sternum)
• Diving birds have smaller wings because they trap
  less air and are less buoyant
• Bones may be less hollow (again, less air
  trapped), so divers can move underwater more
  easily