Comments on the Pryor Mountain Wild Horse Range Fertility Control Preliminary Environmental Assessment

The Mustang Center submitted comments to the BLM regarding the Pryor Mountain Wild Horse Range Fertility Control Preliminary Environmental Assessment. The Mustang Center has maintained a consistent viewpoint regarding the use of PZP on the Pryor horses. The proposed alternative caused us to look closely at our records to determine impact of the various thresholds. We believe firmly that care must be taken to keep the gene pool as varied as possible. Read our comments and know that we have taken time to analyze the proposal and make comments that could best ensure the long term success of the Pryor horses. We will keep you informed of the decisions once the BLM releases them.

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February 16, 2015

Mr. James M. Sparks
Field Manager
BLM – Billings Field Office
5001 Southgate Drive
Billings, MT 59101
Dear Jim,

We are writing in regard to the Pryor Mountain Wild Horse Range Fertility Control Preliminary Environmental Assessment (DOI-BLM-MT-0010-2015-0006-EA).

As we come off of the current fertility control plan, we feel that the program has thus far been successful. When this all begin, we underestimated the difficulty in being able to actually treat the mares in the spring time. Between snowy roads, windy days, and those old wary mares, everyone who worked on this project really had their work cut out for them. However, lessons were learned, and we appreciate the team that kept up with it and gotten the job done. Based on these lessons and other observations during these past years, we offer the following comments.

We agree that mares over the age of 21 should no longer be treated. It is unlikely that these mares are fertile due to having received so many treatments. Further, these mares are smart and wary of darting. As such, treating them would be a waste of effort and could also make it more difficult to successfully treat younger mares who are with them. Additionally, we recommend that each mare scheduled for treatment be given a treatment priority based on her harem’s composition: Younger mares with higher potential fertility should be treated before older mares who have had multiple treatments and have lower potential fertility.

The proposed plan states that mares could be treated at any time of the year. We recommend that this be reconsidered. It may be fine to treat an older mare who has received many treatments at any time of the year. However, we do feel that there is increased risk for undesirable results to occur with younger mares who are treated outside of the spring months. We feel that it is possible to treat the majority of the younger mares in the spring, especially if strategic planning, as discussed above, were implemented.

The proposed plan significantly takes kinship into consideration with the new Thresholds. This is important to us for two reasons. First, this is consistent with our goal of seeing proper management of the bloodlines currently on the Range. Second, it is consistent with the current Herd Management Area Plan, which places emphasis on the importance of maintain proper kinship within this herd. We do have some questions and concerns with the Thresholds.

The first and second Thresholds could easily be combined into one. Both have the same intent and combining them would bring clarity of this intent. These Thresholds state that all mares in the 5-9 year old cohort should be allowed to have at least two offspring that are at least 1 year old. They also state that the mare will restart treatments if she has at least one offspring remaining on the Range after her other offspring have been removed, died, or both. This implies that a mare will not resume treatments after turning 10 if she does not meet these criteria. This must be explicitly stated in the proposed plan as it is important; these two Thresholds should supersede the simple age requirements. For example, Gaelic Princess (200623) has had one foal. This foal was removed from the Range. As such, based on the Thresholds, she should not be treated: She has not had two foals that are at least 1 year old, and she currently has no offspring on the range. However, Gaelic Princess turns 10 in 2016. If she does not have a foal in 2015 that survives to be at least 1 year old, it is not appropriate for her to automatically resume treatments just because she moved into the 10-19 year old cohort. There are currently other mares in the 5-10 year old cohort at risk of being in a similar situation. Again, the proposed plan must state that a mare that moves into the 10-19 year old cohort still must meet these two Thresholds before being able to be treated.

There are currently 5 mares on the Range that are in the 10-19 year old cohort yet have no offspring on the Range. Under the current and proposed plans, these mares will never be allowed to have any descendants on the Range simply because they turned 10. One of these mares, Polaris (199732), has had many offspring with low survival rates; and so this is not necessarily bad that she is in this category. However, the four remaining mares (Adona (200028), Aurora (200036), Beulah (200108), and Baileys (200140)) would not have met the Thresholds; and this situation should not be allowed to happen again under the proposed plan.

To simplify the proposed plan and address these concerns, we recommend that the proposed plan’s simple treatment requirements for mares in the 10-19 year old cohort be removed. Instead, we recommend that mares over that are at least 5 years of age resume treatments after meeting the criteria of the first two Thresholds. Once these criteria have been met, than the mare can resume treatments until she turns 20. This would be a true equal opportunity plan: Every mare that is at least 5 years old should be allowed to have at least 2 foals that survive to be as least 1 year old; and she should be treated if at least one of these offspring is still on the Range. If a mare only has one offspring on the Range and is currently being treated, that offspring must never be allowed to be removed, though it is possible that the offspring could die before it reproduces.

We do not fully understand the need for the third Threshold, which states “Any mare that was missed as a young mare would be primed and given a booster regardless of age”. If a mare somehow did not receive her primer and any subsequent boosters at ages 2, 3, and 4, she would resume treatments once she met the first and second Thresholds anyway. Please consider if this Threshold is necessary.

We recommend that the fourth Threshold be reconsidered.

  • First, we recommend that the proposed plan state that mares 21 and over that are not being treated still count as treated mares for this Threshold.
  • Second, we recommend that the goal of this Threshold be that a range of up to 80-90% of mares be treated instead of having the goal be only 90%. If this range was used as the goal, we do not believe that this Threshold is even necessary: Under the proposed plan, we estimate that up to 68% of the herd’s mares would be treated in 2015 if every 2-4 and 10 and older mares were treated. If mares meeting the criteria of the first and second Thresholds were treated, the number would move to 80%.
  • Third, clearly define how kinship would determine how the remaining 5-9 year olds would be treated under this Threshold.

Ideally, the first and second Thresholds would be used here. However, if these Thresholds no longer applied to the fourth Threshold, then a definition of over- and underrepresented bloodlines would need to be developed so that members of underrepresented bloodlines within the 5-9 year old cohort would not be treated though members of overrepresented bloodlines that may not meet the first and second Thresholds may be treated. We do not have a specific recommendation on these definitions, though we would be happy to go over our current kinship chart with you so that these definitions can be developed.

We feel that it may be appropriate to also extend the definitions of over- and underrepresented bloodlines to the first and second Thresholds. The goal of these Thresholds is to ensure that each mare has 1 offspring on the Range that is at least 1 year old prior to resuming treatments. However, there may be cases where a mare should have at least 2 offspring before resuming treatments. Echo (199110) was the only known descendant of mare 70-023; most of 70-023’s offspring were removed. Echo was a relatively successful mare, having 8 offspring. However, 5 of these offspring were removed; and her only offspring on the Range is currently Bristol (199705). Due to a significant injury, Bristol has a reduced chance to successfully reproduce and have the opportunity to increase this bloodline’s size. 2 out of 3 of Bristol’s estimated offspring were removed. This bloodline is in danger of being lost, and more management decisions significantly factor into this. This situation could have been prevented; it should not be allowed to happen again. Again, we would be happy to work with you to develop definitions that would objectively allow for conservative decisions to be made for members of underrepresented bloodlines.

We feel that the fifth Threshold would be effective in allowing the herd’s numbers to increase to appropriate levels if the population were to fall below 100 individuals. All efforts should be made to prevent the population from getting so low as a result of management decisions. However, there are many unpredictable and uncontrollable environmental risks in the Pryors that this Threshold could help to mitigate. It is important to acknowledge these risks, especially when comparing the management of this herd to that of the Assateague herd.

Fully understanding how each of the Thresholds applies to any given mare at any given time was admittedly difficult for us. We created a flow chart to better understand the Thresholds, and we recommend that this type of chart be created and included in the proposed plan to eliminate any questions that may arise from the many different scenarios that can and will occur on the Range. We have attached a copy of our flow chart for your reference. In addition, we attached a second flow chart which could simplify and clarify using the modifications to the plan that we have recommended.

The proposed plan would start this spring and last indefinitely. Though we feel that the new Thresholds provide good protection, we also feel that the proposed plan should include more specifics on adaptive management should unforeseen events occur that need quickly addressed. The goal of a fertility control plan is to reduce or eliminate the need for gathers. This is beneficial from social, genetic, and economic perspectives. Still, even a fertility control program needs to be designed to properly allow for the herd and the Range to be managed for long-term survival instead of simply looking to achieve a certain population size. While a certain population size may be beneficial for the long-term survival of the Range, the composition of that population may not be beneficial for its long-term survival. We feel that the proposed plan makes good progress in ensuring herd health. However, it still may be prudent to make this a 5 year plan so that lessons learned from it can be used as necessary to further refine the next plan.

Thank you for all of the hard work and thought that went into the proposed plan. We also thank you for taking the time to read and consider our thoughts on the proposed plan. Please do not hesitate to contact us if we can provide any additional information to assist you.

John T. Nickle
President, Pryor Mountain Wild Mustang Center

Published in: on February 23, 2015 at 8:56 pm  Comments (10)