South Dakota's GFP decapitating ecosystem recovery

From the blog of the Cougar Rewilding Foundation:

Black Hills cougar population is extremely important to the recovery of cougar populations in the Midwest. It’s likely that a high percentage of the scattered subadult male dispersers now showing up in states such as Minnesota, Iowa, Wisconsin and Illinois originated in the Black Hills. If the Black Hills population is drastically reduced, it may mean no more dispersers in the Midwest and no recovery of breeding populations there.

Just one of the many holes in SDGFP’s 2010-2015 Mountain Lion Management Plan you could drive a bus through By Amy Rodrigues

The South Dakota Department of Game, Fish & Parks (SDGFP) has submitted its 2010-2015 Mountain Lion Management Plan for public review. The new plan calls for reducing the state’s mountain lion population by about 80 to 100 cats in order to bring their estimated population total down from an approximated 251 lions to only 150 to 170 mountain lions. The current 251 estimate includes kittens. Since mountain lion kittens may not legally be hunted, and South Dakota fails to recognize that killing a mother lion often results in her orphaned kittens starving to death, their mountain lion management plan ultimately calls for the removal of 80 to 100 adult lions. Read more.
Dr. John W. Laundre' :

First, I would like to complement the South Dakota Game, Fish, and Parks for their holistic guiding philosophy (Page 15) regarding the return of mountain lions to the state of South Dakota, specifically, the Black Hills region. As an ecologist and specifically a predator ecologist, I find the views expressed there to be refreshing and enlightened regarding the role of mountain lions (and all predators ) in ecosystems. I, like you, have come to see that predators such as mountain lions are needed elements in maintaining the biodiversity of an ecosystem.

I applaud your goal of trying to manage mountain lions in accordance with sound biological information. What you have expressed here indeed should be the guiding principles for your Department and the State. However, upon reading the accompanying document and based on my experience of working with mountain lions for over 20 years, I do find that there may be some concern regarding management goals established. I would like to address these concerns in the spirit of your guiding philosophy to manage mountain lions with the best possible biological principles.

Before I get into specifics, I would like to state that I am not opposed to a hunting season on mountain lions but am opposed to the possible overuse of this resource, which would then endanger the population, and your guiding philosophy. Mountain lions, as a hunting resource should be treated as a trophy species, one who’s taking should rank up with that of bighorn sheep, African lions, and other noted wildlife species. They should not be hunted as vermin nor the privilege to hunt them sold cheaply. Having said that, here are my concerns.
The biggest concern I have is in regards to the accuracy of your estimates of the number of mountain lions there are in the Black Hills. This concerns me because, as you know, if one overestimates the population size, the projected number of animals to be removed can have a very destabilizing impact on the population and could lead to a loss of ecological functionality of the mountain lions in the Black Hills. With regards to the estimates that have been made of the current population level (251 animals), first I think it needs to be made clear and maintained throughout the document what you really mean is 160 adult animals, being reduced to 138 per year, plus the 113 kittens of various ages. To use the 251 number obviously inflates the perception of the population size and the total density of the area, e.g. Black Hills is 8,400 km sq and at 251 lions, it is a density of 3 lions/100 km sq but at 160 lions it is only a density of 1.9 ADULT lions/100 km sq and is normally how the density is expressed. If, as you point out, you feel the population is currently stable, that means that excess animals, mostly young dispersers, will be leaving the Black Hills and the stable resident population is the lower number. To use the higher number makes it seem to the general public that there are more lions there then biologically there really are. IF you want to maintain this stable number around 160, then you can talk about what will happen to these excess animals produced each year, many will disperse, as they should be allowed to, many will die from other causes (we still do not have an idea of what mortality rates of dispersing animals are), some will fill the slots vacated by resident animals, some can be removed by the hunt. How many depends on the mortality and dispersal levels.

Based on your estimate of 160 adult lions, I am not sure what that would all equate to as a final number of animals that could be removed by hunters. I would need to sit down and go through the calculations. I am just saying that it is a more biologically correct way of presenting the data on the number of lions there actually are. Regarding that number, however, I do have some concerns as to how the 160 (and the 113 kittens) was derived. The first concern I have is that it does not provide any possible range of error. You do use a standard deviation on page 5 but I am not sure where that came from. What I do see is that only one set of values (e.g. one MAXIMUM growth rate, one percent of females with kittens, etc., most from just one area, the desert of New Mexico, hardly like the Black Hills) when we know biologically these values can change yearly in one area and do change geographically. What this does is present just one scenario and thus one estimate of the number of lions. And more specifically, without any knowledge of whether or not these values apply to your population in the Black Hills. As examples, why would we use only the maximum growth rate from a desert population of mountain lions for a population in a totally different habitat? It could be lower than that and if it is, the resulting population estimate would not have any bearing in reality. Even if it did, the repeated use of single values likely makes any final estimate to be far from reality. For example, you used 50% as the number of females with kittens at any one time. Other studies have shown that it could be as low as 20%. If that is the case for the Black Hills, the number of kittens produced and surviving each year drops from 113 to 45, quite a difference.

As for the estimate of the number of adult females based on the “capture/recapture” estimate of females killed by hunters, this also relies on just one estimate and unfortunately because of the small sample size (5/35) and possible bias of hunters to not shoot collared animals, could lead to an overestimate of the number of females. If a hunter passed up just one collared female, the total number of collared females that would have been killed would be 6/35 and would result in an estimate of only 93 females in the population rather than 112. Running this number of females through all the numbers, we get only 93 kittens, etc. etc. And if 2 collared females were passed over, it goes even lower. So because of all these unknowns, we really don’t know if the ADULT lion population in the Black Hills is 160, 100, ???.

I know it is difficult to get these numbers and that should not stop us from attempting to come up with an estimate but to use just single values, especially those which seem to exaggerate the population size, which seems to be the case here, is not biologically honest. What needs to be done, and has been done in a lot of instances, is to present a range of estimates (worse case/best case scenarios) so that the public has an idea as to in what range the lion population size likely falls. What I suggest is that all the population estimate figures need to be reworked using a wider range of data than just one study so that reasonably low and high estimates can be presented and then use these for the basis of your management decisions. This would be more biologically correct and more politically transparent. As the guiding philosophy states, you need to provide accurate information to the public regarding the mountain lions. Your current population estimates are by far not accurate nor justifiable. California lost its ability to hunt mountain lions because they could not justify their population estimates and I feel that, as presented, nor can South Dakota. Until we have a reasonable RANGE of possible population estimates, it appears that the Department is attempting to justify higher killing of mountain lions by inflating the population numbers. I would hope that that is not the case.

One last concern I have is regarding the orphaning of kittens (birth to independence). Though one can reduce the number of less than 3 month old kittens orphaned by changing the season dates and trying to find those that are, there still will be small spotted kittens left out in the woods to starve to death. The public needs to know this. Also, by the calculations presented, 40 % of the females killed will have kittens between 3 months and 1 year old. Though there is a 71% survival rate (again one value from one study), this still means that out of the 20 females with these age kittens, 17 died of starvation and over 40 survived uneducated! These become the trouble makers, the ones who will go to human inhabited areas and eat pets or domestic stock, or attack people. Are we not exacerbating the dilemma of problem cougars (which some then use as an excuse to kill more)? I think that there can be an acceptable level of orphaning but the current management plan does not achieve it. Lastly, I would like to observe that many of the management strategies proposed here, if applied to ungulates, would be considered biologically unacceptable. For example, would the Department propose that out of a bighorn sheep population of 160 adult (huntable animals), hunters could kill 40 of them, including females?? Would the Department allow the killing of does with spotted fawns? For that matter, would current game laws permit hunters to shoot deer, take their head and hide and leave the meat in the forest? I think these issues need to be addressed and the public be made aware of them if the all the public is to make sound decisions on the management of mountain lions. I end by again applauding the Department’s guiding philosophy but urge it to use this philosophy and a wider range of sound mountain lion science to produce a more scientifically sound management plan. In my professional opinion it seems that this document was develop based on selective use of existing science, mainly to produce inflated estimates of mountain lion numbers. Some could interpret this as a way to justify the higher kill levels that appear to be predetermined based mainly on political factors. For the sake of transparency, and producing a more legally sound management document, I hope that you consider my observations and concerns.

Kevin Woster is hosting comment at Take It Outside. The Black Hills hydrologic region is at risk to state-sanctioned butchers. Contact them to stop the slaughter.