This panel specifies features related to alternatives that involve gathers, if they are selected.
Gather cost ($ per horse) is calculated during each gather as a consequence of the number of horses gathered using data from the Bureau of Land Management.
This panel specifies features related to alternatives that involve removals, if they are selected.
This panel specifies features related to alternatives that involve GonaCon treatment during a gather, if they are selected.
This panel specifies features related to alternatives that involve PZP-22 treatment during a gather, if they are selected.
This panel specifies features related to alternatives that involve ZonaStat treatment during a gather, if they are selected.
The application assumes that ZonaStat treatment will always involve treating with a booster shot after the first treatment.
This panel specifies features related to alternatives that involve IUD treatment, if they are selected.
This panel specifies features related to alternatives that involve mare sterilization, if they are selected.
This panel specifies features related to vaccine darting alternatives, if they are selected.
The 'ZonaStat (darting)' alternative assumes that all horses are re-treated in the first year after an individual is treated, even during darting.
Use this panel to customize features related to graphing of results (e.g., legend position).
Reasonable starting values are provided, but can be adjusted manually or using arrows in the input boxes. Values must be provided for each the above boxes, except Population name. The user then must specify two details about the simulation:
The user can then select from among seven management alternatives to be simulated and compared:
Gather Options: the user can specify the short-term cost of holding horses that have been gathered (e.g., $7.60 per horse per day). The per-horse cost of gathers cannot be specified by users; rather, this value is estimated during each gather year using the best available information describing how gather size influences per-head gather cost provided by the Bureau of Land Management.
Removal Options: The 'Removal years' input box allows the user to specify a fixed removal schedule; removals will be performed before any year entered in the box if the population size exceeds maximum AML before that year. The second box ('Reactive removals') allows the user to specify an alternative form of removals, where removals are performed before any year when the population exceeds maximum AML if sufficient time has passed since the previous gather ('Minimum gather interval'). If the 'Reactive removals' box is not selected, the 'Minimum gather interval' value will be ignored; alternatively, if the 'Reactive removals' box is selected, the 'Removal years' values will be ignored. For the 'Removal years' input, the order of values does not matter and values will only be used that are less than or equal to the user-defined 'Projection interval'.
The 'Selective removals' box will specify whether removals will involve adjusting the sex ratio of any animals being returned to the range in ways that would decrease future population growth. Sex-ratio adjustment requires gathering sufficient horses so that (1) a removal can be performed to reduce the population size to the target population size, and (2) the sex-ratio of horses to be returned to the range can be adjusted to be male-biased. Releasing more males than females can decrease population-wide reproduction in the short term relative to releasing individuals at random. The sex-ratio adjustment of horses being returned to the range can be adjusted with the 'Male proportion of population returned after a removal' input. The 'Selective removals' box must be ticked for the sex-ratios of removed and released horses to be manipulated with the 'Male proportion of population returned after a removal' input. If the 'Selective removals' box is not ticked, removals are not selective and horses are removed independent of sex (i.e., 'gate-cut' removal).
Additional inputs related to removals include: the maximum number of individuals that can be removed from a population in a single year ('Maximum number removed per year'), the number of years that removed animals will be projected in 'off-range' holding facilities ('Number of years to project holding population'), the long-term holding cost of each horse ($2.02 per day) ('Long-term holding cost'), the proportion of horses in holding that are adopted out to private citizens each year ('Proportion of horses adopted each year'; e.g., 0.69; see above), the cost of federal agencies to adopt out a horse (e.g., $1700) ('Net adoption cost to agency'), and the percent reduction of females that give birth in captivity the first year after removal (when compared to the proportion of females give birth that year in the wild; e.g., 25%) ('Foaling reduction [%] of removed females in captivity the first year after removal').
GonaCon Options: the user can specify the years that females are treated with GonaCon ('Treatment years'), the ages of females that are treated (ranging from 0 [foals] to 20 [all individuals 20 years old and up]) ('Treatment ages'), the percentage of age-eligible females that will be treated with GonaCon (0, 0.25, 0.5, 0.75, or 1) ('Treatment percentage'), the cost of each GonaCon treatment (e.g., $50 per shot) ('Treatment cost per shot'), whether females are kept in short-term holding to receive a booster treatment ('Hold to give booster'), and the number of days to keep females in holding before giving a booster treatment (e.g., 30 days) ('Days in holding until booster'). Primer and booster shots of GonaCon are identical and have the same cost. As with 'Removal years', the order of input values for 'Treatment years' and 'Treatment ages' does not matter and values will only be used that are less than or equal to the user-defined 'Projection interval'.
PZP-22 Options: the user can specify similar input parameters as with GonaCon, but PZP-22 treatment involves different treatments for primer and booster doses. The initial primer treatment of PZP-22 involves one dose of PZP pellets (e.g., $400 per shot) and one dose of ZonaStat-H (e.g., $30), but subsequent booster treatments in later years only involves one dose of ZonaStat-H. The user can adjust costs for primer and booster treatments as necessary. The ‘Days in holding’ option represents the number of days a mare is held for sorting and treatment before being released back to the range.
ZonaStat-H Options: the user can specify the same input parameters as with GonaCon. Howeer, all ZonaStat treatments are assumed to be identical in cost (e.g., $30).
Intrauterine Device (IUD) Options: the user can specify the years ('Treatment years') and ages of females ('Treatment ages') for IUD-treatment. Only non-pregnant females can be given an IUD; a veterinary exam (e.g., ultrasound) is required for all gathered, age-eligible females to determine which females can receive an IUD. Because relatively few females will not be pregnant during gathers, the models assume that all non-pregnant females are treated. The user can specify cost of ultrasound (e.g., $30 per female) ('Ultrasound cost'), the number of days mares are held to treat and observe all age-eligible, non-pregnant females (e.g., 14 days) ('Total holding days for screening, treatment, and observation'), cost of each IUD (e.g., $60) ('Materials cost'), cost of veterinary work to place each IUD (e.g., $50) ('Treatment cost'), and the proportion of IUDs that are retained among treated females each year ('Retention rate (per year)'; e.g., 0.87; i.e., 87% of IUDs are retained each year).
Mare Sterilization Options: similar to vaccine-treatment options, the user can specify the percentage of mares to be treated, the years and ages of females for mare sterilization treatment, cost (e.g., $500), and number of days for post-treatment observation before mares are released (e.g., 14 days).
Darting Options: the user can specify the years ('Treatment years') and ages ('Treatment ages') for females that will be treated with vaccine by darting, the proportion of the female population that can reasonably be treated by dart in a year ('Proportion of female population (%) that can be darted'), the percentage of age-eligible females that are available for darting and will be darted ('Treatment percentage'), whether darting scenarios will attempt to boost GonaCon-treated individuals during the individual's first treatment year ('Are individuals re-treated with GonaCon by dart…'), and the per-animal cost to deliver vaccine by dart (e.g., $250 per treatment). There is no booster option for the 'ZonaStat (darting)' alternative, because that function assumes that all horses are re-treated in their first treatment year, regardless of treatment by hand or dart. Note: if the booster option is clicked for GonaCon, this assumes that all individuals darted for the first time will be darted again that year as a booster; it may be difficult to retreat the same individuals in a year. For compound alternatives with 'Removal (year 1) and fertility control', the alternative will ignore (1) inputs from 'Removal years' beneath Removal Options drop-down and (2) inputs specifying 'Treatment years' beneath the GonaCon or ZonaStat-H drop-downs; instead, a removal will be performed in the first year and age-eligible females will be treated with vaccine according to the 'Treatment years' beneath the Darting Options drop-down.
Graphing Options: the user can specify whether the minimum and maximum Appropriate Management Levels and persistence threshold are included on graphs, and whether the first figure's legend is in the top left or bottom left of the graph.