REGULATIONS AND THE MULE DEER HARVESTPOLITICAL AND BIOLOGICAL MANAGEMENT
R i c h a r d N. Denney
Big Game S u p e r v i s o r
Colorado D i v i s i o n of W i l d l i f e
Denver, Colorado
Abstract
The mule d e e r p o p u l a t i o n i n Colorado, and i n t h e
west g e n e r a l l y , began i n c r e a s i n g d u r i n g t h e 1 9 2 0 ' s from
a low a t t h e b e g i n n i n g of t h e c e n t u r y t o an a c c e l e r a t e d
high i n t h e l a t e f o r t i e s t o t h e e a r l y s i x t i e s , then
began a r a p i d d e c l i n e t o t h e p r e s e n t . H a r v e s t s followed
t h i s same p a t t e r n . The a p p l i c a b l e s e a s o n r e g u l a t i o n s
r e s u l t i n g i n t h e s e h a r v e s t s stem from b i o l o g i c a l cons i d e r a t i o n s ( v a r i o u s p o p u l a t i o n and f o r a g e p a r a m e t e r s )
and p o l i t i c a l i n f l u e n c e s ( t r u e p o l i t i c s , a s w e l l a s s o c i o l o g i c and economic f a c t o r s ) . The a p p l i c a t i o n of comp u t e r i z e d systems a n a l y s i s i n t h e form of h e r d s i m u l a t i o n
models i s advanced a s a means of measuring t h e impact of
v a r i a b l e m a n - c o n t r o l l e d management p r a c t i c e s . T h i s c a n
n o t o n l y i d e n t i f y a r e a s of c o n c e r n , b u t a l s o p o i n t o u t
t y p e s , amounts and q u a l i t i e s of d a t a needed, w i t h o u t
impacting t h e a c t u a l r e s o u r c e w i t h t r i a l and e r r o r methods.
INTRODUCTION
During t h e mid-1850's t h e p i o n e e r s a r r i v i n g i n
t h e t e r r i t o r y of what i s now Colorado found v a s t
numbers of d e e r , e l k , b i g h o r n sheep and b e a r i n t h e
mountains west of Denver. Though most of t h e s e
p i o n e e r s were i n i t i a l l y i n s e a r c h of g o l d , many comm u n i t i e s were e s t a b l i s h e d , and, because t r a d e and
s t o r e goods were l i m i t e d and d i f f i c u l t t o o b t a i n ,
w i l d game was t h e primary s o u r c e of meat f o r t h e s e
p e o p l e . As t h e communities became more permanent
t h e i r meat needs were s u p p l i e d i n c r e a s i n g l y by prof e s s i o n a l e x p l o i t e r s of t h e abundant w i l d l i f e .
Market h u n t e r s began t o make such i n r o a d s on v a r i o u s
b i g game p o p u l a t i o n s t h a t t h e c i t i z e n s became
alarmed. Hunter (1959) e s t i m a t e d t h a t 100,000 b i g
game a n i m a l s p e r y e a r must have been k i l l e d t o supp l y C o l o r a d o ' s p o p u l a t i o n a t t h a t time. I n 1867
t h e f i r s t game laws were e n a c t e d , which p r o h i b i t e d
t h e t a k i n g of w i l d l i f e d u r i n g t h e b r e e d i n g s e a s o n .
S t i l l , no s p e c i f i c s e a s o n s o r l i c e n s e s were i n e f f e c t , b u t game laws became i n c r e a s i n g l y r e s t r i c t i v e .
By 1903 t h e f i r s t d e e r l i c e n s e was a u t h o r i z e d a t
$1.00, b u t e l k , a n t e l o p e and b i g h o r n sheep s e a s o n s
were s t i l l c l o s e d , and b i s o n had d i s a p p e a r e d by t h e
t u r n o f t h e c e n t u r y . The e a r l y 1 9 0 0 ' s r e p r e s e n t e d
t h e low p o i n t i n Colorado's b i g game p o p u l a t i o n s ,
b u t through sound w i l d l i f e management t h e game h e r d s
were b u i l t up t o t h e p o i n t t h a t by 1960 t h e y were
some o f t h e most i m p o r t a n t i n t h e n a t i o n .
w e s t e r n s t a t e s was a f f e c t e d through many d i f f e r e n t
t y p e s of r e g u l a t i o n s and a d m i n i s t r a t i v e p h i l o s o p h i e s . R e g a r d l e s s of t h e management approach,
whether i t was u l t r a - c o n s e r v a t i v e o r s u p e r e x p l o i t i v e , t h e mule d e e r t r e n d has followed e s s e n t i a l l y t h e same p a t t e r n throughout t h e west: a
g r a d u a l b u i l d - u p of h e r d s b e g i n n i n g i n t h e 1 9 2 0 1 s ,
w i t h a peaking somewhere i n t h e l a t e f o r t i e s o r
e a r l y f i f t i e s t o t h e e a r l y s i x t i e s , and t h e n a
g e n e r a l d e c l i n e d u r i n g t h e s i x t i e s , and c o n t i n u i n g
t o the present.
There i s a n i n c r e a s i n g number of a d v o c a t e s of
t h e concept t h a t w i l d l i f e c o n s t i t u t e s an e a r l y
In the
warning system of ecosystem d e t e r i o r a t i o n .
f a c e of c u r r e n t knowledge t h i s c a n h a r d l y b e r e f u t e d . There a r e many p e o p l e , p a r t i c u l a r l y t h e
g e n e r a l p u b l i c , who a r e q u i c k t o l a y t h e mule d e e r
d e c l i n e on o v e r s h o o t i n g allowed by l i b e r a l regul a t i o n s . The f a l l a c y of t h e a n t l e r e d o n l y management concept i s i l l u s t r a t e d by t h e f a c t t h a t s t a t e s
(Arizona, C a l i f o r n i a and Oregon) w i t h p r i m a r i l y
buck o n l y h u n t s have c r i t i c a l l y low buck t o doe
r a t i o s , w h i l e s t a t e s h a r v e s t i n g b o t h s e x e s (Colorado,
Idaho, Nevada and Utah) have e x p e r i e n c e d o n l y h a l f
t h e h a r v e s t d e c l i n e of t h e former (Salwasser 1975).
Inasmuch a s t h e mule d e e r d e c l i n e i s g e n e r a l
throughout t h e w e s t , i t i s obvious t h a t t h e c a u s e
must be a composite of many f a c t o r s , some of which
we probably have n o t i d e n t i f i e d t o d a t e . I n view
of t h e r e t u r n t o p o p u l a t i o n f l u c t u a t i o n s of t h e
T h i s i s s i m i l a r t o t h e h i s t o r y o f b i g game i n
most of t h e w e s t e r n s t a t e s . During t h e 1 9 5 0 1 s , howe v e r , t h e management of mule d e e r i n t h e v a r i o u s
87
Requlutations and the Mule Deer harvest
p a s t , i s i t p o s s i b l e t h a t c e r t a i n c y c l i c phenomena
a r e b e i n g e x h i b i t e d i n a s p e c i e s t h a t we n e v e r p r e v i o u s l y c o n s i d e r e d t o be c y c l i c ? I doubt t h i s , b u t
i n t h e l i g h t of t h e h a b i t a t d e c r e a s e and d e g r a d a t i o n
e x p e r i e n c e d i n t h e west i n t h e p a s t 20 y e a r s , we w i l l
never again s e e the i n c r e d i b l e h a r v e s t s o f a c e n t u r y
a g o , o r t h e documented k i l l s of t h e r e c e n t p a s t .
This paper w i l l attempt t o e v a l u a t e the various
r e g u l a t i o n s p e r t a i n i n g t o mule d e e r h a r v e s t i n Color a d o ( p r o b a b l y a p p l i c a b l e t o t h e e n t i r e w e s t ) , how
t h e y were e f f e c t e d by b i o l o g i c a l and p o l i t i c a l cons i d e r a t i o n s and how such c o n s i d e r a t i o n s may a f f e c t
r e g u l a t i o n s i n f u t u r e mule d e e r management.
Biologically-Based Regulations
Colorado h a s a t t e m p t e d t o manage i t s b i g game
p o p u l a t i o n s on t h e b a s i s o f h e r d u n i t s . The o n - t h e ground b i o l o g i c a l d a t a o b t a i n e d by D i v i s i o n p e r s o n ne 1 i n c l u d e d :
1.
P o p u l a t i o n t r e n d c o u n t s o b t a i n e d on w i n t e r
c o n c e n t r a t i o n a r e a s by a e r i a l and ground
observations.
2.
P r e - and p o s t - s e a s o n s e x and a g e r a t i o s
o b t a i n e d by a e r i a l and ground o b s e r v a t i o n s
on s e l e c t e d s e a s o n a l r a n g e s .
3.
Wounding l o s s a s s e s s m e n t based on f i e l d
observations.
4.
W i n t e r m o r t a l i t y based on f i e l d work i n
winter concentration areas.
5.
Browse p r o d u c t i o n and u t i l i z a t i o n d a t a
d e r i v e d from measured i n t e n s i v e t r a n s e c t s
and e s t i m a t e d e x t e n s i v e t r a n s e c t s on w i n t e r
ranges.
6.
Deer-days u s e p e r a c r e d e r i v e d from p e l l e t
group c o u n t s i n a s s o c i a t i o n w i t h game range
analysis transects.
7.
R e s e a r c h d a t a from s p e c i f i c p r o j e c t s on
d e e r r a n g e and p o p u l a t i o n dynamics.
COLORADO MULE DEER HARVEST
During t h e p e r i o d 1940 t h r o u g h 1975, Colorado
has y i e l d e d a mule d e e r h a r v e s t of 2 . 7 m i l l i o n a n i mals t o o v e r 4.7 m i l l i o n h u n t e r s f o r a n a v e r a g e
s u c c e s s r a t i o of 57 p e r c e n t . T h i s 3 6 - y e a r p e r i o d
c o v e r s an e r a of r e l a t i v e l y g r a d u a l mule d e e r popul a t i o n i n c r e a s e u n t i l a peak was reached i n t h e l a t e
f i f t i e s and e a r l y s i x t i e s , a t which time a n a c c e l e r a t e d d e c l i n e t o t h e p r e s e n t was e x p e r i e n c e d .
The a n t l e r e d and t o t a l h a r v e s t s , h u n t e r p r e s s u r e and
s u c c e s s r a t i o s a r e i n d i c a t e d i n F i g u r e 1.
A d d i t i o n a l b i o l o g i c a l d a t a which have b e e n cons i d e r e d i n formulating season r e g u l a t i o n s , but
d e r i v e d a f t e r - t h e - f a c t , a r e t h e buck, d o e and fawn
s t a t i s t i c s o f t h e a n n u a l h a r v e s t s , and t h e p e r c e n t a g e of y e a r l i n g s a s d e t e r m i n e d from d e n t i t i o n
d e t e r m i n a t i o n s a t check s t a t i o n s , cementum a n n u l i
from i n c i s o r s o b t a i n e d a t check s t a t i o n s o r m a i l e d
i n by h u n t e r s , and a n t l e r c o n f i g u r a t i o n i n s p e c t e d
a t check s t a t i o n s o r o b t a i n e d from s u r v e y s .
A b r i e f comment on e a c h of t h e b i o l o g i c a l
f a c t o r s and t h e i r e f f e c t i n s e t t i n g s e a s o n r e g u lations follows:
F i g u r e 1.
L i c e n s e s a l e s and d e e r h a r v e s t , 1940p r e s e n t , Colorado.
During t h i s 3 6 - y e a r p e r i o d a t o t a l of 1 , 5 3 3 , 1 2 1
bucks, r e p r e s e n t i n g a n a n n u a l a v e r a g e of 42,587, was
harvested.
Broken down i n t o t h e t h r e e most r e c e n t
five-year periods, the annual antlered harvest averaged 6 0 , 9 5 1 d u r i n g 1961-65, 43,853 d u r i n g 1966-70,
and 44,788 d u r i n g 1971-75.
During t h e 36-year p e r i o d ,
1971 was t h e o n l y y e a r i n which t h e h a r v e s t was
l i m i t e d t o bucks o n l y .
H u n t e r s u c c e s s d u r i n g t h i s p e r i o d h a s ranged
from a low of 26 p e r c e n t i n 1975 t o a h i g h o f 8 8 . 6
p e r c e n t i n 1957, b u t does n o t r e p r e s e n t a f u n c t i o n
o f t h e d e e r p o p u l a t i o n a l o n e . The h a r v e s t regul a t i o n s a f f e c t i n g t h e s e h a r v e s t s were two d e e r of
e i t h e r s e x i n 1957, and a n t l e r e d o n l y w i t h some
l i m i t e d e i t h e r s e x p e r m i t s i n 1975. What were t h e
c o n s i d e r a t i o n s involved i n t h e s e types of divergent
seasons?
R e g u l a t i o n s a d t h e Mule Deer H a r v e s t
1. P o p u l a t i o n Trend Counts. A e r i a l and ground
c o u n t s o f d e e r a r e made on e s t a b l i s h e d a r e a s o r
r o u t e s , u s u a l l y on w i n t e r r a n g e s , and under a s
n e a r l y comparable c o n d i t i o n s of time of y e a r , snowc o v e r and s y s t e m a t i c s a s p o s s i b l e . I n c o n s i s t e n c i e s
i n w e a t h e r , a f f e c t i n g snow d e p t h and c o v e r a g e ,
ambient t e m p e r a t u r e s and winds, d e t r a c t from t h e
r e l i a b i l i t y of such c o u n t s by i n t r o d u c i n g v a r i a b l e s
i n f l i g h t o r c o u n t c o n d i t i o n s , v i s i b i l i t y and d e e r
behavior. Population determinations a r e not possib l e from such c o u n t s , a n d , a t b e s t , t h e y c a n o n l y
s e r v e a s an index t o t h e g e n e r a l population trend
o v e r a r e l a t i v e l y long p e r i o d of time.
Another t y p e of t r e n d c o u n t h a s b e e n employed on t h e P i c e a n c e d e e r h e r d s i n c e 1947, and
t h a t i s a c o u n t d u r i n g o n e o r two days i n A p r i l of
comparable p h e n o l o g i c a l c o n d i t i o n e a c h y e a r o f t h e
d e e r c o n c e n t r a t i n g on t h e n a t i v e hay meadows of
P i c e a n c e Creek and i t s t r i b u t a r i e s . A t r a c k c o u n t
was made of a p o r t i o n o f t h i s m i g r a t i n g h e r d ,
u s u a l l y d u r i n g t h e month of May, f o r a number o f
y e a r s u n t i l a b o u t 1957 when road c o n d i t i o n s on
F l a g Creek f o r c e d i t s t e r m i n a t i o n . However, d u r i n g
i t s l i f e , t h e t r a c k c o u n t s were up t o two o r t h r e e
t i m e s h i g h e r t h a n t h e meadow c o u n t s on comparable
y e a r s . A l l t h a t c a n be s a i d of such c o u n t s i s t h a t
t h e y may r e p r e s e n t a minimum number p r e s e n t , b u t
what p e r c e n t of t h e t o t a l h e r d p o p u l a t i o n i n t h a t
a r e a i s unknown.
Trend c o u n t s on mule d e e r have had l i t t l e
d i r e c t i n p u t i n t h e f o r m u l a t i o n of s e a s o n regulations.
2.
Sex and Age R a t i o s . While we t a l k a b o u t
p r e - and p o s t - s e a s o n s e x and a g e r a t i o s , t h e emphasis
h a s been on p o s t - s e a s o n c l a s s i f i c a t i o n s , and t h e s e
a r e p r i m a r i l y a e r i a l , a l t h o u g h some ground c o u n t s
a r e conducted i n s e l e c t e d a r e a s . These d a t a have
a greater potential i n influencing the establishment
of r e g u l a t i o n s t h a n h a s been r e a l i z e d i n p r a c t i c e .
To t h e b e s t of o u r knowledge, o u r buck t o doe r a t i o s
have n e v e r been low enough t o i n f l u e n c e fawn prod u c t i o n . The number of fawns y i e l d s a n i n d e x t o
h u n t i n g s e a s o n s u r v i v a l , and, b a r r i n g unusual w i n t e r
m o r t a l i t y , an i n d i c a t i o n of h e r d r e c r u i t m e n t i n t h e
y e a r l i n g a g e c l a s s t h e upcoming s p r i n g .
S i m i l a r l y , we have long used t h e p e r c e n t a g e
of y e a r l i n g s i n t h e h a r v e s t a s an i n d i c a t o r of h e r d
h e a l t h . The u t i l i z a t i o n of s e x and a g e d a t a i n herd
management r e g u l a t i o n s w i l l be d i s c u s s e d i n more
d e t a i l i n a n o t h e r s e c t i o n of t h i s paper.
3.
Wounding Loss. Other t h a n s u p e r f i c i a l
s u r v e y s , we have no documentation of t h e impact of
wounding l o s s . We have used a rule-of-thumb f i g u r e
of 5-and-10, t h a t i s , a wounding l o s s of f i v e p e r
c e n t of t h e h a r v e s t i n buck o n l y a r e a s , and t e n p e r
c e n t of t h e h a r v e s t i n e i t h e r s e x a r e a s . I f e e l
t h a t t h i s i s t o o c o n s e r v a t i v e . Wounding l o s s r e c e i v e s l i t t l e c o n s i d e r a t i o n i n e s t a b l i s h i n g regul a t i o n s , b u t may r e c e i v e a t t e n t i o n when more r e f i n e d
management i s implemented.
4.
Winter M o r t a l i t y .
Evaluations of winter
m o r t a l i t y a r e . b a s e d on f i e l d checks a f t e r t h e c r i t i c a l w i n t e r p e r i o d , and u s u a l l y i n a r e a s of w i n t e r
c o n c e n t r a t i o n s . The p e r c e n t a g e of such l o s s i n a
s p e c i f i c h e r d a r e a i s e s t i m a t e d on t h e b a s i s of
dead d e e r c o u n t s , and r e l a t i v e t o p a s t d a t a . These
l o s s e s a r e p r i m a r i l y c o n s i d e r e d t o be a f u n c t i o n of
m a l n u t r i t i o n and a s s o c i a t e d overcrowding and overu t i l i z a t i o n of l i m i t e d w i n t e r r a n g e s , though t h e
amount and c h a r a c t e r o f snow, minimum s u s t a i n e d
t e m p e r a t u r e s , p r o t e c t i v e c o v e r and wind a r e known
f a c t o r s . Such d a t a impact on r e g u l a t i o n s p e r t a i n i n g t o a n t l e r e d o n l y o r e i t h e r s e x s e a s o n s , and
f o r m e r l y on bag l i m i t s when we h e l d two and t h r e e d e e r seasons.
5.
Range A n a l y s i s .
P r o d u c t i o n and u t i l i z a t i o n
e s t i m a t e s on key browse s p e c i e s on i m p o r t a n t w i n t e r
r a n g e a r e a s a t one time formed t h e primary b a s i s
f o r Colorado mule d e e r management. U n f o r t u n a t e l y ,
t h i s i s no l o n g e r t r u e , and w i l l b e d i s c u s s e d under
p o l i t i c a l considerations.
During most of t h e
f i f t i e s and s i x t i e s , however, r a n g e t r a n s e c t d a t a
provided s i g n i f i c a n t i n p u t i n r e g u l a t i o n d e t e r m i n a t i o n s , and could s t i l l do so.
Two d e e r s e a s o n s were i n i t i a t e d i n 1950
p r i m a r i l y on t h e b a s i s o f range c o n d i t i o n s i n an
e f f o r t t o b r i n g t h e h e r d s i n t o what was f e l t t o
be t h e c a r r y i n g c a p a c i t y of t h e w i n t e r r a n g e , and
two, and even t h r e e - d e e r , s e a s o n s were h e l d i n
l a r g e a r e a s of t h e s t a t e u n t i l 1969. These s e a s o n s
were e s t a b l i s h e d i n t h e b e g i n n i n g b e c a u s e h u n t e r
p r e s s u r e was l i m i t e d and we had t o u t i l i z e t h e
sportsman r e s o u r c e we had a v a i l a b l e . As h u n t e r
r e c e p t i v e n e s s and p r e s s u r e i n c r e a s e d , c e r t a i n
p o l i t i c a l c o n s i d e r a t i o n s were brought t o b e a r , a s
discussed later.
6. P e l l e t Group Counts. P e l l e t group c o u n t s
were conducted i n c o n j u n c t i o n w i t h r a n g e t r a n s e c t s ,
and c o n v e r t e d t o d e e r days p e r a c r e on t h e b a s i s of
13 p e l l e t groups p e r d e e r p e r day a s determined by
research i n v e s t i g a t i o n s a t t h e L i t t l e H i l l s Experiment S t a t i o n on P i c e a n c e Creek. Because of t h e
many v a r i a b l e s and c o n t r o v e r s y we d i d n o t c o n v e r t
t h e s e d a t a t o p o p u l a t i o n s , b u t r a t h e r used them a s
a deer winter range pressure index r e l a t i v e t o p a s t
y e a r s and o t h e r a r e a s , and c o r r e l a t e d w i t h browse
u t i l i z a t i o n . The o t h e r comments under Range Analys i s a l s o apply here.
7 . Research. Deer i n v e s t i g a t i o n s i n i m p o r t a n t
a r e a s have y i e l d e d d a t a which have i n f l u e n c e d
s e a s o n r e g u l a t i o n s t o some e x t e n t i n t h o s e a r e a s
s p e c i f i c a l l y . I t was a n e a r l y F e d e r a l Aid p r o j e c t
t h a t s t i m u l a t e d t h e two-deer s e a s o n c o n c e p t i n t h e
Uncompahgre P l a t e a u , which e v e n t u a l l y was a p p l i e d
a l m o s t w e s t e r n - s l o p e wide. C e r t a i n t y p e s of s e a s o n s
and mandatory check s t a t i o n s were p a r t of and r e s u l t e d from t h e Middle Park d e e r s t u d y . The r e s u l t s
of c u r r e n t d e e r s t u d i e s and t a s k f o r c e s w i l l und o u b t e d l y be a p p l i e d t o f u t u r e r e g u l a t i o n s .
P o l i t i c a l Considerations
P o l i t i c a l , i n t h e s e n s e used h e r e , i s a r e a l
P a n d o r a ' s box.
It not only includes p o l i t i c s i n
t h e commonly a c c e p t e d d e f i n i t i o n , b u t a l s o i n t h e
c o n t e x t of economics and s o c i o l o g y .
The c o n s t r a i n t s imposed by s t a t e s t a t u t e s o r
p o l i t i c a l bodies can d i r e c t l y a f f e c t t h e l a t i t u d e
t h a t a c o n s e r v a t i o n agency can e x e r c i s e i n w i l d l i f e management. Colorado i s f o r t u n a t e i n t h a t i t s
s t a t u t e s a u t h o r i z e t h e W i l d l i f e Commission t o
e s t a b l i s h p o l i c i e s and s e t r e g u l a t i o n s f o r w i l d l i f e
management. Even w i t h t h i s t y p e of a u t h o r i t y , s t a t e
w i l d l i f e a g e n c i e s can b e s u b j e c t e d t o c o n s i d e r a b l e
p r e s s u r e through i m p l i e d t h r e a t s of a l t e r n a t i v e
laws, o r even m a n i p u l a t i o n s of budget r e q u e s t s .
For
example, a w e s t e r n s t a t e ' s commission e s t a b l i s h e d a
r e g u l a t i o n intended f o r a three-year longevity, but
a f t e r two y e a r s i t was found t o be i n e f f e c t i v e , and,
i n f a c t , d e t r i m e n t a l t o t h a t agency's o b j e c t i v e s
and s u p p o r t i v e d a t a j u s t i f i e d t h e r e p e a l o r r e v i s i o n
of t h e r e g u l a t i o n . However, word was r e c e i v e d from
t h e s t a t e l e g i s l a t u r e t h a t t h e y would s e t t h e
s e a s o n s i f t h e a g e n c y ' s r e g u l a t i o n s were n o t cons i s t e n t . I n t h e p o l i t i c a l world, i t seems t h a t
c o n s i s t e n c y i s of h i g h e r m e r i t t h a n b e i n g f l e x i b l e
enough t o admit a m i s t a k e and c o r r e c t i t ! I n ano t h e r c a s e a l e g i s l a t i v e committee h a n d l i n g a cons e r v a t i o n a g e n c y ' s budget r e q u e s t s u b t l y s u g g e s t e d
a r e g u l a t i o n p e r t a i n i n g t o t h e i d e n t i f i c a t i o n of s e x
on a b i g game c a r c a s s be l e s s r e s t r i c t i v e , and i t
was changed.
A major p o l i t i c a l impact on s t a t e w i l d l i f e
,?eguZations and the Mule Deer Harvest
f o r two-deer s e a s o n s i n t h e e a r l y f i f t i e s were
q u i t e e f f e c t i v e , and l i c e n s e s a l e s i n c r e a s e d a s a
r e s u l t . A new p h i l o s o p h y , e c o n o m i c a l l y - o r i e n t e d ,
a r o s e . Why g i v e t h a t second d e e r away, when w i t h
i n c r e a s e d h u n t e r p r e s s u r e we c o u l d s e l l a second
l i c e n s e a t a reduced f e e and g e n e r a t e some more
income? The m u l t i p l e l i c e n s e was b o r n i n 1957,
and was u t i l i z e d u n t i l 1970.
a g e n c i e s c o u l d be i n t h e o f f i n g , pending t h e f i n d i n g s
of c o u r t s and t h e r e s u l t s o f a p p e a l s i n New Mexico
and Montana on n o n r e s i d e n t l i c e n s e f e e s . I f nonr e s i d e n t s become e n t i t l e d t o h u n t on t h e same
l i c e n s e s t r u c t u r e t h a t r e s i d e n t s d o , s e a s o n regul a t i o n s w i l l have t o be t a i l o r e d t o meet a n i n c r e a s e d h u n t e r demand through r e s t r i c t i o n s on s e x '!
and numbers of h a r v e s t and s h o r t e n e d s e a s o n s , t o
l e s s e n t h e b i o l o g i c a l impacts on t h e b i g game.
The i n f l u e n c e of p u b l i c a t t i t u d e s , a s o c i o p o l i t i c a l c o n s i d e r a t i o n , i s e x e m p l i f i e d by t h e
a c t i o n s o f landowners i n t r a d i t i o n a l l y bucks o n l y
a r e a s i n t h e l a t e f o r t i e s when e x t e n s i v e e i t h e r
s e x s e a s o n r e g u l a t i o n s were implemented. Many of
t h e s e p u r i s t s posted t h e i r lands a g a i n s t doe
h u n t e r s , and undoubtedly caused some r e s t r a i n t on
t h e p a r t of t h e Colorado Game and F i s h Department
i n designating additional e i t h e r sex hunting areas,
u n t i l some of t h e s e same r a n c h e r s began t o e x p e r i e n c e h a y s t a c k damages from t h e b u r g e o n i n g d e e r
populations.
Many p o l i t i c a l impacts on r e g u l a t i o n s a r e s o
i n t e r t w i n e d t h a t t h e y i n v o l v e economics, s o c i o l o g y
and b i o l o g y . An example i s i n t r a - a g e n c y p o l i t i c s
where f o r p u b l i c r e l a t i o n s and economic r e a s o n s i t
was d e c i d e d t o s e t t h e g e n e r a l s e a s o n r e g u l a t i o n s
i n March t o f a c i l i t a t e g e t t i n g t h e i n f o r m a t i o n on
opening d a t e s and a r e a s o u t t o t h e p u b l i c .
This
e a r l y s e t t i n g o f s e a s o n s was t o meet p r i n t i n g deadl i n e s and a l l o w t h e sportsmen t o a r r a n g e n e c e s s a r y
v a c a t i o n time f o r h u n t i n g . The impact o f t h i s
reached t o the f i e l d l e v e l , because w i n t e r m o r t a l i t y
c o u n t s and range t r a n s e c t s could n o t be completed
b e f o r e May due t o c o n t i n u i n g w i n t e r r a n g e use and
l a c k of a c c e s s , a l t h o u g h t h e numbers of l i m i t e d
e i t h e r s e x p e r m i t s would be s e t i n May. T h i s t i m e
s c h e d u l e h a s p r o b a b l y been one of t h e g r e a t e s t contributing factors t o the decline i n obtaining the
i n d i c a t e d b i o l o g i c a l d a t a . Furthermore, i n regard
t o l e g a l p o l i t i c s , t h e a t t o r n e y g e n e r a l has d e c r e e d
t h a t t h e agency must have i t s recommendations f o r
season r e g u l a t i o n s a v a i l a b l e f o r p u b l i c i n s p e c t i o n
20 days p r i o r t o commission a c t i o n . T h i s means, i n
r e a l i t y , t h a t t h e r e g u l a t i o n s must be w r i t t e n f o r
b i g game s e a s o n opening d a t e s and a r e a s i n F e b r u a r y .
The i n c r e a s e s i n Colorado l i c e n s e f e e s e f f e c t i v e
i n 1976 w i l l r e s u l t i n socio-economic i n f l u e n c e s on
season r e g u l a t i o n s . Resident d e e r l i c e n s e f e e s
h a v e gone from $10.00 t o $13.00, w h i l e n o n r e s i d e n t
f e e s have gone from $50.00 t o $90.00.
We w i l l
have t o e x p e r i e n c e a t l e a s t one s e a s o n under t h i s
new s t r u c t u r e t o e v a l u a t e t h e e f f e c t o f p r o b a b l e
d e c r e a s e d h u n t e r p r e s s u r e on h e r d management obj e c t i v e s , t h e n c o n s i d e r what r e g u l a t i o n o p t i o n s
w i l l best a t t a i n the desired harvest.
HERD SIMULATION MODEL
P u b l i c s a f e t y and w e l f a r e a r e a form o f p o l i t i c a l c o n s i d e r a t i o n i n s e t t i n g s e a s o n s . F o r example,
i n Colorado, t o s p r e a d t h e f i r s t day of s e a s o n
p r e s s u r e and r e d u c e t h e p o s s i b i l i t i e s of h u n t e r
f a t a l i t i e s and a c c i d e n t s , t h e d e e r s e a s o n and e l k
s e a s o n were s e p a r a t e d i n 1971 from t h e i r p r e v i o u s l y
c o n c u r r e n t t i m i n g . Though a h i g h p e r c e n t a g e of e l k
h u n t e r s were a l s o d e e r h u n t e r s , t h e y t h e n had t o
hunt t h e s e r e s p e c t i v e s p e c i e s a t d i f f e r e n t times,
t h u s r e d u c i n g t h e t o t a l number of h u n t e r s i n t h e
f i e l d d u r i n g one s e a s o n . T r u e , t h e r e was some
economic impact i n reduced t o t a l l i c e n s e s a l e s ,
b e c a u s e many h u n t e r s , p a r t i c u l a r l y n o n r e s i d e n t s ,
who p r e v i o u s l y hunted b o t h s p e c i e s c o u l d n o t a f f o r d
two s e p a r a t e h u n t i n g t r i p s , and t h e r e f o r e o n l y h u n t e d
one s p e c i e s .
For a l m o s t 20 y e a r s C o l o r a d o ' s d e e r management
e f f o r t s were d i r e c t e d toward r e d u c i n g overpopul a t i o n ~t o t h e c a r r y i n g c a p a c i t y of t h e most
critical factor
t h e w i n t e r range.
I t was always
s t a t e d and g e n e r a l l y a c c e p t e d t h a t t h e d e e r c o u l d
come back f a s t e r t h a n t h e browse. The r e g u l a t i o n s
i n s t i t u t e d t o a f f e c t t h i s r e d u c t i o n began w i t h
e i t h e r s e x s e a s o n s , t h e n two d e e r s e a s o n s , and
f i n a l l y m u l t i p l e l i c e n s e s e a s o n s ( v a r y i n g from
u n l i m i t e d a d d i t i o n a l l i c e n s e s t o one a d d i t i o n a l
l i c e n s e , w i t h one d e e r p e r l i c e n s e t o two d e e r
a l l o w e d on t h e second l i c e n s e , and, i n some c a s e s ,
two d e e r on b o t h t h e o r i g i n a l and t h e m u l t i p l e
license).
I n a d d i t i o n t o m u l t i p l e bag l i m i t s , t h e
t i m e s and l e n g t h s of s e a s o n s were v a r i e d t o o b t a i n
increased harvests.
P o s t s e a s o n s were u t i l i z e d i n
r e l a t i v e l y s m a l l a r e a s when d e e r were on l a t e f a l l
t r a n s i t i o n a l o r w i n t e r r a n g e s . S i n c e 1963 management o b j e c t i v e s g e n e r a l l y have been e i t h e r t o
s t a b i l i z e t h e d e e r h e r d s , o r t o i n c r e a s e them
numerically.
-
When a r c h e r y d e e r h u n t i n g was s t a r t e d i n Color a d o i n 1948, t h e bow h u n t e r s c o u l d h u n t on a r e g u l a r
d e e r l i c e n s e which was v a l i d a t e d f o r t h a t p u r p o s e ,
and i f u n s u c c e s s f u l i n bowhunting, t h e y c o u l d u s e
t h a t l i c e n s e i n t h e r e g u l a r d e e r s e a s o n . I n 1961
a n a r c h e r y d e e r l i c e n s e was e s t a b l i s h e d by t h e l e g i s l a t u r e , and i f a n a r c h e r was u n s u c c e s s f u l d u r i n g
bowhunting s e a s o n , he c o u l d t h e n p u r c h a s e a r e g u l a r
d e e r l i c e n s e and hunt w i t h a r i f l e . Again, i n d e s i r i n g t o d i v e r t h u n t e r p r e s s u r e from t h e r e g u l a r
s e a s o n , a one-and-only h u n t c o n c e p t was e s t a b l i s h e d
i n 1974 through r e g u l a t i o n , wherein no one c o u l d
p u r c h a s e more t h a n one l i c e n s e f o r a g i v e n s p e c i e s
d u r i n g t h e y e a r . The e f f e c t t h a t t h i s had was t o
weed t h e m a r g i n a l bowhunters o u t of t h e a r c h e r y r a n k s
and put them r i g h t back i n t o t h e more s u r e - f i r e r i f l e
season.
The b i o l o g i c a l l y - b a s e d
ReguLations cmd t h e
MdZe
C u r r e n t h a r v e s t d a t a a l o n e do n o t a l l o w a n
a c c u r a t e d e t e r m i n a t i o n of mule d e e r p o p u l a t i o n s ,
p a r t i c u l a r l y on a s t a t e w i d e b a s i s , due t o more
v a r i a b l e and r e s t r i c t i v e s e a s o n s a p p l i e d under
p r e s e n t management p r a c t i c e s . T h e r e f o r e , game
management u n i t s have been combined t o form d a t a
a n a l y s i s u n i t s , which a r e c o n s i d e r e d t o be more
r e a l i s t i c t o t a l h e r d year-round h a b i t a t . Herd
d a t a c a n now be a n a l y z e d by a computer s i m u l a t i o n
o f h e r d s t r u c t u r e , a s w e l l a s t h e e f f e c t of v a r i o u s
i m p a c t s , b o t h r e a l and s i m u l a t e d , on t h a t h e r d ,
o t h e r f a c t o r s remaining e q u a l . T h i s t y p e o f s y s tems a n a l y s i s i s guided by Dr. Jack Gross, U. S.
regulations providing
Deer Hurvest
90
F i s h and W i l d l i f e S e r v i c e , and conducted by Tom
P o j a r , Colorado Division of W i l d l i f e . Systems anal y s i s has t h e p o t e n t i a l f o r i n d i c a t i n g t h e impacts
of r e g u l a t i o n s on a given herd, whether they be
b i o l o g i c a l l y o r p o l i t i c a l l y generated. By plugging
i n known d a t a f o r t h e p a s t s e v e r a l y e a r s , c e r t a i n
c a u s a t i v e f a c t o r s may be i n d i c a t e d a s r e s p o n s i b l e
f o r given herd r e a c t i o n s .
m o r t a l i t y r a t e of 22 p e r c e n t was used from 1963
through 1971, 40 p e r c e n t f o r 1972, 50 p e r c e n t i n
1973, then 22 p e r c e n t from 1974 onward. Using t h e
y e a r l i n g h a r v e s t a s a n index t o fawn s u r v i v a l from
t h e previous w i n t e r , t h e y e a r l i n g h a r v e s t s i n 1973
and 1974 support t h e i n d i c a t e d increased w i n t e r l o s s
of fawns r e p o r t e d f o r 1972 and 1973. This add i t i o n a l fawn m o r t a l i t y r e s u l t e d i n a downward popul a t i o n t r e n d i n t h e s i m u l a t i o n , which i s a c t u a l l y
what happened i n t h e f i e l d . The alignment of t h e s e
d a t a with t h e s i m u l a t i o n i s probably one of t h e
s t r o n g e s t p o i n t s of t h i s a n a l y s i s .
The Uncompahgre P l a t e a u i n southwestern Colorado r e p r e s e n t s a d e e r herd on which our most comp l e t e d a t a a r e a v a i l a b l e . This herd u n i t i s composed
of two game management u n i t s , 61 and 62, comprising
d e e r d a t a a n a l y s i s u n i t D-19. The systems model
begins i n 1963 and i s p r o j e c t e d through 1980. Actual
h a r v e s t d a t a a r e displayed i n Figure 2 r e l a t i v e t o
t o t a l and buck ( a n t l e r e d ) h a r v e s t , h u n t e r p r e s s u r e
and success r a t i o s from 1950 t o 1975. Inasmuch a s
t h e complete s i m u l a t i o n p r i n t o u t i s e x t e n s i v e , only
c e r t a i n d e t a i l s of t h e a n a l y s i s w i l l be h i g h l i g h t e d
here.
Table 1 l i s t s a comparison of simulated and
r e p o r t e d values f o r pre- and post-season bucks and
fawns p e r 100 females. The pre-season buck t o doe
r a t i o s a r e simulated above t h e r e p o r t e d v a l u e s , a s
t h e r e g i o n a l b i o l o g i s t , Hal Burdick, f e e l s t h a t
many bucks a r e missed during t h e s e counts.
The alignment of t h e s e d a t a lend support t o
t h e c l o s e n e s s of t h e s i m u l a t i o n model t o t h e a c t u a l
herd s t r u c t u r e . and even though
- s .v e c i f i c v a l u e s a r e
not always i n agreement numerically, t h e g e n e r a l
t r e n d s follow t h e same curves.
The model i n d i c a t e s a population of t h i s herd
r i g h t now of approximately 35,000 d e e r , w i t h a
post-season population p r o j e c t i o n by 1980 of j u s t
over 50,000 animals, IF t h e 1975 h a r v e s t of 2,500
i s maintained, and IF t h e system remains s t a b l e .
CONCLUSIONS
..: .
I
"W
a
I / I C m - / o J -
a-sa
As important and necessary a s b i o l o g i c a l
management of mule d e e r i s , t h e v a r i o u s f a c e t s of
p o l i t i c a l management may p r e s e n t s i g n i f i c a n t o b s t a c l e s t o sound w i l d l i f e management, and t h e cons t r a i n t s imposed by p o l i t i c a l l y - o r i e n t e d r e g u l a t i o n s
may have on mule d e e r herds can now be i n d i c a t e d
experimentally through systems a n a l y s i s w i t h simul a t i o n models, t h u s s p a r i n g t h e r e s o u r c e from t h e
consequences of i l l a d v i s e d o r poorly timed impacts
w i t h i n human c o n t r o l .
r
Figure 2.
5
to,
rr
I
8,
,a,
7-
I
I
8.L
,to
10
108
8,
v
I
6
6,
I,
I
5
5
I
6,
I,
1
r,
Uncompahgre P l a t e a u (GMU 61 6 6 2 ) , 19501975, d e e r data.
.
Three s e t s of fawn m o r t a l i t y r a t e s were used
i n t h e model, based on f i e l d d a t a . A fawn w i n t e r
.
The a p p l i c a t i o n of systems a n a l y s i s t o simul a t i o n modeling of w i l d l i f e populations i s
Table 1. Comparison of simulated and r e p o r t e d values f o r pre- and post-season
buck and fawn t o doe r a t i o s on t h e Uncompahgre P l a t e a u , 1967-75.
Bucks p e r 100 Females
Fawns per 100 Females
Pre-season
Post-season
Pre-season
Post-season
Simulated Reported Simulated Reported Simulated Reported Simulated Reported
Year
--
91
R e g u Z a t i m and the Mule Deer Harvest
r e l a t i v e l y new. S e v e r a l s t a t e s a r e b e g i n n i n g t o
e x p l o r e t h e p o s s i b i l i t i e s o f t h i s system, i n c l u d i n g
t h e I n t e r s t a t e Deer Herd Study o f C a l i f o r n i a and
Oregon ( S a l w a s s e r 1975a, S a l w a s s e r and R u t h e r f o r d
9 7 5 ) , and t h e Nevada F i s h and Game Department
(Glenn C h r i s t e n s e n , p e r s . c o r n . ) .
Computer a n a l y s i s i s n o t a panacea, and i s only
a s r e l i a b l e a s t h e d a t a programmed.
Simulation
modeling w i l l n o t of i t s e l f s o l v e t h e enigma o f t h e
mule d e e r d e c l i n e i n t h e w e s t , b u t i t c a n h e l p
i d e n t i f y a r e a s of c o n c e r n where a d d i t i o n a l o r more
r e l i a b l e d a t a a r e needed.
LITERATURE CITED
Hunter, G i l b e r t N.
1959. A hundred y e a r s of Color a d o h u n t i n g . Colo. Dept. of Game & F i s h , Denver.
1959 Colo. Big Game I n f o . , p. 2-3.
S a l w a s s e r , Hal.
1975. The i n t e r s t a t e w i l d l i f e s t u d y a fresh perspective.
Mzuri Drumbeat, 2 ( 1 6 ) : 6 - 7 ,
18-22, 24.
.
1975a. I n t e r s t a t e w i l d l i f e s t u d y :
S p r i n g 1975 c o l l e c t i o n . Univ. C a l i f . , B e r k e l e y .
I n t e r i m R e p t . , 47 p.
and Kenneth E. R u t h e r f o r d .
1975. I n t e r s t a t e w i l d l i f e s t u d y . Data Package #1. Univ.
C a l i f . , B e r k e l e y , and Oregon W i l d l . Comm. 22p.
~ e y u b a t i o n sand the Mule Deer Harvest