Harvest Management

4 Sources of uncertainty in Adaptive Management

• Structural uncertainty

  • additive or compensatory

• Environmental uncertainty

  • each year is different

• Partial observability

  • can we trust collected data?

• Partial controllability

  • how good of shots are our hunters

  • harvest rate modelled versus discrepancies

4 model Framework accounts for

Additive or compensatory

density dependence (strong or weak)

Additive

Natural deaths and death from hunting mortalities different

Compensatory

Ducks that die from hunting would’ve died anyways

order of most reliable model to least

?SaRw
SaRs
ScRw
ScRs

How is Climate Change affecting the Non Breeding season

Deep south getting warmer

sea level rise

cold winters, intense weather and freezing

degradation of inland rice fields

drought, less flooded wetlands, loss of habitat

salinity changes

What affects geese migration

landscapes, availability of rice

What will happen to migrating waterfowl

Less migration, shorter distances, or more resident species due to conditions

Webless game birds

Cranes, rails,

Sandhill cranes

low harvest, illegal in many states

Rails and gallinules

some states permitted,
harvest overall lower, no one really shoots them

Coots

More coots shot, but little information on populations, likely doesn’t matter

Woodcock

Forest specialist, hard to hunt
hunted more than snipe, less than coot

Snipe

less than woodcock and coots
shoot with little information

Mourning dove

most hunted game bird in NA

Hotspot

females found

Hotshot

one dominant male

Female preferences

large gathering of males for female choice

Turkey

2nd big game animal in US next to white deer
social birds, allowing success of stocked turkey after early translocation

Examples of R3 programs

Recruitment, retention, and reactivation

• college hunt

• first hunt

• women hunt

  • generally worse for youth, lack of retention, but better for adults

  • (mathematical modelling)

Botulism

90% of disease in waterfowl

by millions

bacteria in maggots

Why are waterfowl susceptible to disease

gregarious in high numbers

migratory

farm duck interactions

inherent susceptibility (ex. cholera)

Pathology of botulism in aves

periperal nerous system, death by downing

What cultures botulism in water qualityt

heat, high pH, stagnant water

Managing botulism

frost, cold, draining, flushing

Avian Cholera

Kills fast,
studied in eiders

Eider are prone to

Avian Cholera
- susceptible, also more susceptible with handling
- more susceptible with larger clutch

Avian influenza

Protein binding, receptors that bind disease

restricted window for transmission, helps to inform decisions on risk

Lead poisoning

ingestion for grit

which ducks are prone to lead poisoning

resident ducksdep

exposed to winter birds why?

hens, depuration, shunting toxins to eggs
lead in soil affecting all