0

0

1503 days ago,
553 views

PowerPoint PPT Presentation
The Problem. Awesome Dismal Swamp National Wildlife Refuge is home to an expected 300 dark bearsThe Virginia Department of Game and Inland Fisheries opened the GDSNWR to a constrained bear chase December first and second of 20 bears totalSeveral every living creature's common sense entitlement and ecological gatherings dissented the VDGIF choice, saying the chase would harm the delicate bear populationThe VDGIF reacted by saying the chase

Demonstrating the Effects of Opening the Great Dismal Swamp to Black Bear Hunting Tristan Tronic

The Problem Great Dismal Swamp National Wildlife Refuge is home to an expected 300 mountain bears The Virginia Department of Game and Inland Fisheries opened the GDSNWR to a constrained bear chase December 1 st and 2 nd of 20 bears add up to Several every living creature's common sense entitlement and natural gatherings challenged the VDGIF choice, saying the chase would harm the delicate bear populace The VDGIF reacted by saying the chase would have an insignificant effect

Modeling the Effects of a Limited Hunt: What's Known Bear populace elements have been appeared to depend just on the female populace Bears can be partitioned into four subgroups, each isolated by around one year of improvement: Cubs, Nonreproductive subadults, Subadults, and Adults

Bear Population Model C n+1 = α S n + α An A N n+1 = β C n S n+1 = β n A n+1 = β S n + β An A n α = generation rate β = survival rate

0 .28 .58 .8 0 .71 0 .76 .91 1 30 120 Linear Model for Open Season Based on survivability and multiplication saw in chased bears in western Virginia Initial circulation of subpopulations not notable, with the exception of that half of the populace will be female, and there will be around four circumstances the same number of grown-ups as subadults.

Results of Linear Model Population appears to develop regardless of chasing But the direct model for an open season expect a chasing weight that is unreasonably low for Southeastern Virginia Female Bears Years

Non-Linear Model for Fixed Quota Hunt C n+1 = α S Sn + α An A N n+1 = β C n S n+1 = β n A n+1 = β S Sn + β An A n Natural bear survival up to 25 – 30 years is high, thought to be 1 for this test It is seen in Virginia that seekers kill female bears 40% of the time, and of those 60% are nonreproductive subadults, 10% are subadults, and 30% are grown-ups H = Number of bears permitted to be killed every year β N = 1 – H*.4*.6/n β S = 1 – H*.4*.1/S n β A = 1 – H*.4*.3/A n - 1/25

1 30 120 Non-Linear Model for Fixed Quota Hunt 0 .28 .58 1 0 (1 – H*.24/n ) 0 (1 – H*.04/S n ) (1 – H*.12/A n - .04)

Matlab Program clear all h=20; y=zeros(4,20); y(:,1)=[1;1;30;120;] t=zeros(4,20); t(1,1)=sum(y(:,1)); for n=1:19 A=[0 0 .28 .58; 1 0; 0 1-(h*.4*.6)/y(2,n) 0; 0 1-(h*.1*.4/y(3,n)) 1-1/25-(h*.3*.4)/y(4,n);] y(:,n+1)=A*y(:,n); t(1,n+1)=sum(y(:,n+1)); end plot([1:20],y(1,:),'*r',[1:20],y(2,:),'xb',[1:20],y(3,:),'og',[1:20],y(4,:),'xr',[1:20],t(1,:),'or'); legend('cubs','nonreproductive subadults','reproductive subadults', 'grown-ups', 'add up to');

Results: Proposed 20 bears/year

Results: 100 bears/year

Results: 110 bears/year

Results: 20 bears/year, 25% of ordinary proliferation rate for grown-ups and subadults

Problems with the Model Assumes that all bears conceived in asylum remain in shelter, and no new bears relocate in Assumes consummate nonhunting survivability, not sensible for high human thickness zone Initial bear populace dubious Assumes chasing examples and bear multiplication will be the same as in western Virginia, which is topographically unmistakable

Conclusions A constrained chase of 20 bears for each year doesn't appear to adversely influence the bear populace Given the vulnerability in the genuine size and conceptive capacity of the bear populace, extending the chase further may bring about eradication

Sources "Bears on the Move." Virginia Dept. of Game and Inland Fisheries. 2004. http://www.dgif.virginia.gov/chasing/va_game_wildlife/bears_on_the_move.html "Awesome Dismal Swamp National Wildlife Refuge and Nansemond National Wildlife Refuge Final Comprehensive Conservation Plan July 2006" http://www.chesapeake.va.us/administrations/citizen_info/pdf/GDSNWRfinalCCP8-2-06.pdf Klenzendorf, Sybille. "Populace Dynamics of Virginia's chased mountain bear population." Dissertation. Virginia Polytechnic Institute, 2002. http://scholar.lib.vt.edu/propositions/accessible/etd-02122002-160752/unhindered/Klenzendorf.pdf "Lottery will pick seekers for asylum's first bear chase." Applegate, Aaron. Virginian-Pilot, October 7, 2006. http://content.hamptonroads.com/story.cfm?story=112263&ran=39762

SPONSORS

No comments found.

SPONSORS

SPONSORS