Texas Mountain Lions - Current Status Currently, Mountain Lions in the state of Texas
are classified as unprotected, nongame animals.
Under this classification, the numbers of Mountain
Lions being killed is unregulated which means
that Mountain Lions can be killed year round
regardless of age or sex. In addition, mountain
lions in Texas have no bag limit and can be killed
in any number.
The population is mainly restricted to the western
part of Texas (Trans-Pecos region and the western
part of the Edward's plateau) and to southern Texas. Most Mountain Lion mortalities in Texas are due to
predator control activities (traps, snares, or poison)
or due to opportunistic hunting. The true effect of unregulated killing on the Texas
Mountain Lion population is unknown. The few
studies that have been done indicate the following
(see tables below for more detailed data): - Mountain lions are experiencing low
- survivorship mainly due to predator
- control and hunting practices (Tables 1- 4).
- A high percentage of female mountain lions
- is being killed, a fact indicating that the
- population is being harvested at an unsustainable
- level (more lions are being killed than survive)
- (Table 6).
- Due to killing practices, mountain lions exhibit
- a skewed age group (population mainly composed
- of younger individuals), an unhealthy situation for
- a wild (or any) animal population (Table 5).
It is unclear how many Mountain Lions currently
live in the state of Texas. More research is needed
in order to determine the health and viability of the
state's Mountain Lion population. Mountain Lion Mortality Rates (Tables 1 - 4) Important Notes: - Individuals with fate unknown were excluded
- from the analysis.
- Individuals not part of the sampled, collared
- group were excluded from the analysis.
- The effect of trapping, sedating and collaring
- Mountain Lions on mortality rate is unknown.
- It is possible that the act of collaring the lions
- increases mortality by an unknown factor.
**Adams, 2003 – South Texas (1999 – 2001)
By 1999, only four Mountain Lions originally collared by
Harveson in 1994 were still alive. Number originally
collared, 21; number considered for this analysis, 18;
overall mortality, 77.8%. Studies show that annual mortality rates exceeding
25% result in Mountain Lion population decline
(Cougar Management Guidelines, chapter 4). Texas Mountain Lions - Age Structure A population composed of younger individuals
indicates that the Mountain Lions, who live in the
wild 12 to 13 years, do not survive long and are
being killed at an average age of 2.86 years (Table 5).
This age distribution is characteristic of an
exploited Mountain Lion population
(Smith 1990, Harveson et al. 1996)
Age-Sex Composition Analysis Studies show there is a correlation between
the age and sex of killed Mountain Lions
within a harvested population and the leve
of exploitation (killing) of that population*. The study provides the following information
regarding Mountain Lions' vulnerability
(susceptibility) to being killed (see also
explanation below): The list is from the MOST vulnerable to
LEAST vunerable: - Subadult males due to their great
- dispersal distances
- Resident males due to their large
- territories
- Subadult females (during their
- dispersal periods)
- Resident females without young
- (larger territories)**
- Females with older (>6 months)
- kittens (medium size territories)
- Females with young (<6 months)
- kittens (smallest territories)
Studies show that in a highly hunted
/exploited population, as the level of
exploitation increased and the population
declined, the proportion of adult females
in the harvest increased, the proportion
of sub-adults in the harvest decreased and
the mean age of harvested adult females
decreased (Cougar Management Guidelines, 2005).
Table 6 indicates the high percentage of females
comprising the reported harvested Mountain Lions
in Texas. Despite the small sample size, more than
half the Mountain Lions killed are females,
an indicator that the less vulnerable part of
the population is being killed, which may
mean overexploitation of the population***.
* Barnhurst 1986; Stoner 2004; Anderson and
Lindzey 2005; Choate et al. 2006; Mountai
Lion Management Plan, Wyoming Game and
Fish Department 2006.
** Females are known to decrease their territory
size when they have dependent young and begin
increasing it as their young gain more independence.
*** The relationship between overexploitation of a Mountain
Lion population and the sex-age of the animals killed is as follows:
- Subadult males are the most vulnerable individuals
- within a Mountain Lion population in terms of being
- killed. They are the ones that will disperse farthest
- from their mother's territory seeking an empty territory
- or attempting to take over another male's territory
- Therefore, those young male mountain lions are the
- ones we mostly expect to see in a healthy, but
- harvested population.
- Adult Males are the second most vulnerable
- Mountain Lions within a healthy Mountain
- Lion population since they occupy large
- territories and may seek females throughout
- that area and beyond.
- should not be found in high proportion in a
- healthy, harvested Mountain Lion population.
- If they are, it is an indication that the
- population is overexploited when it comes to
- the number of Mountain Lions being killed.
|
No comments:
Post a Comment