Members of the Congressional Animal Protection Caucus sent a letter to the House Committee on Natural Resources requesting an oversight hearing of the Bureau of Land Management’s (BLM) Wild Horse and Burro Program.
The letter comes in response to the recent disease outbreaks at two off-range facilities in Caсon City, CO, and Wheatland, WY, resulting in the deaths of over 150 horses due to equine flu and strangles.
“After reviewing assessments of the off-range facilities evaluated this year, we are concerned about documented trends of inadequate biosecurity controls, understaffing, lack of recordkeeping, limited access to hay and water, and issues related to pen maintenance,” the letter said.
The letter questioned BLM’s plans to round up 22,000 wild horses and burros “under the guise of” reaching appropriate management levels “that are determined through unclear means” and add to the already estimated 60,000 horses currently being held at off-range facilities.
“We believe an oversight hearing of the Wild Horse and Burro Program is merited to protect the well-being of captured horses and to ensure that the BLM is focusing its efforts on humane on-range management,” the letter concludes.
The letter was signed by Reps. Dina Titus (D-NV-01), Steve Cohen (D-TN-9), Eleanor Holmes Norton (D-DC), Ted Lieu (D-CA-33), Albio Sires (D-NJ-8), Peter DeFazio (D-OR-4) and Salud Carbajal (D-CA-24).
The letter comes amid a study released in the journal Applied Animal Behaviour Science on the effects of gelding wild horses on behavior and population control.
The study was conducted by the U.S. Geological Survey (USGS) and Colorado State University (CSU) between 2017 and 2020 on two herd management areas (HMAs) in western Utah, the Conger and Frisco HMAs.
“The populations have increased dramatically over the past 10 to 20 years. More recently, it’s just been an exponential increase, so the (BLM) is looking for different ways of managing the horses to control population growth,” Sarah King, a research scientist in the Natural Resource Ecology Laboratory at CSU, said.
The study conducted demographic observations year-round at both HMAs to record survival and foaling rates, using the Frisco HMA as a control group. In December 2017, 27 adult males from the Conger HMA (42 percent of adult males in the population) were gelded and returned to the range with their social groups.
The study’s findings concluded gelding is a safe tool for wild horses.
“Gelded horses neither suffered a loss of body condition following gelding, nor gained noticeable weight. Instead their body condition fluctuated similarly to other males on the range across seasons and years,” the study said.
Despite hypothesizing geldings would lose interest in mares due to the loss of testosterone, the study found gelded horses retain the full suite of equine behaviors, including reproductive behaviors. Gelded harem stallions stayed and defended their mares, but by the end of the four-year study, almost all of the harems had disbanded.
“It was actually really interesting to find that gelding had minimal effects on male behavior,” King said. “It seemed a really positive thing that although the males were castrated, they were continuing to maintain their associations with mares.”
The biggest difference between geldings and intact males was among bachelors. The study found that gelded bachelors tended to stay bachelors, which “suggests that social or sexual experience may play a role in the drive to attain or maintain a harem, which could additionally be affected by lower testosterone levels in bachelors.”
Evaluating gelding as a population growth management tool, the study found the herd’s birthrate declined after the first year. However, it bounced back after a few years.
“Statistical modeling of a horse population predicted that more than 90 percent of the male population would need to be sterilized in order to achieve meaningful population growth suppression,” the study noted.
The study also suggested that gelding may be effective in conjunction with other control measures.
CSU and King will use the results to explore female behavior, social networks, group changes and resource selection concerning the movement of wild horse herds. — Charles Wallace, WLJ editor
