1. Market Hunting - See text

2. Midcontinent Light Geese Example
Includes Greater and Lesser Snow Geese (blue and white color phases)
and Ross geese

3. Greater and Lesser Snow geese on Atlantic and Mississippi Flyways Use Hudson’s Bay
as breeding ground and stopover areas (“Midcontinental light geese”)

4. Reduced Hunter Harvest Climate shift on BG Result:
1965 present:
Greater Snow 30, ,000
Lesser Snow million
Ross , ,000
Population sizes from
Why the Increase?
Agriculture
Sanctuaries
Reduced Hunter Harvest
Climate shift on BG
Result:
Higher adult survival/condition
Higher repro

5. Goose “grubbing” for rhizomes
& tubers results in major
shifts in vegetation

7. Hudson Bay Study Site
1984
Is it really geese?
1997

8. Is it really geese? – The exclosure experiment
At Hudson Bay 35% of habitat destroyed, 30 % damaged, 35% overgrazed

10. Recall the ways hunting can be used to alter outcome:
Season
Method of Take
Bag Limit
# of Hunters
Which animals

11. Management Response
Conservation Order Light Goose Hunts ordered by USFWS
Extend Hunting Season into Spring
Methods
Electronic calls
No limit on number shells shotgun contains
Bag limit
No daily bag limit imposed, set by states

13. USFWS
Final Environmental Impact Statement:
Light Goose Management June 2007
The management goal for light geese in the mid-continent region is to reduce the population by 50% from the level observed in the late
1990s. The management goal for greater snow geese is to reduce the population to 500,000 birds.

14. Lethal Trapping - More controversial than hunting
See Table 10-3 for pro-con views
Leghold trap
Snare

15. 1994 AZ Ban on trapping on federal/state lands
Effect on harvest – lab exercise
Current Regulations:
1) Only on private lands or special designations
2) License, written exam, course required
3) All traps labeled, padded jaws, offset
4) Checked daily, kill target or release non-target
5) Written annual report to AZGFD
Exemptions:
Livestock losses
Federal, state, county, local health departments
Rodent control

16. Examples of use of trapping:
Mesocarnivores on refuges/breeding grounds
Garretson and Rohwer JWM 65:
41km2 sites, ½ trapped other not trapped
Trappers paid $18,000 for 5 mos
2404 coons, skunks and foxes
Response: Doubled duck nesting success 23% vs 43% and return rate
(so what was management goal in this case?)
Recommendations:
1) Treat large areas, with high repro potential
2) May not be necessary where coyotes prey on
coons, skunks and foxes
3) Need public acceptance – rural area so
acceptance was… high or low?

17. 2) Introduced Exotic Species
Nutria (Coypu) Native of South America
5-8 young/litter 2-3 litters per year
Introduced for fur in 1930’s

18. Intro in La in 1930 – 20 million by 1950
1970 – 10,000 trappers in La
,700

19. Convert marsh to open water Cost: millions of $
Effects:
Destroy levees
Consume crops
Convert marsh to open water
Cost: millions of $
Chesapeake Bay of Maryland
CONTROL Options???

20. Lethal Trapping – worked in Great Britain where coypu eradicated
Alternatives to lethal trapping?
1) Live trapping and removal
Cost
Remove to where?
2) Contraception
Availability
3) Poison
Non-target effects
Reduced suffering?
Limiting access
Reintroduce predators
Feasibility
Acceptance

21. Arizona’s Coypu?