New study measures fence collision mortality, informs conservation

Do barbed-wire fences pose a threat to lesser prairie-chickens? A recent study of more than 1,700 miles of livestock fences in Kansas and Colorado found little evidence of fence collision mortality. The study helps create a more detailed picture of threats to the lesser prairie-chicken populations across their range.

For resource managers working to conserve lesser prair0069amyerickson-copyie-chickens, it’s critical to accurately
identify threats and develop effective practices to address them. Scientific studies help provide the data that can help focus effort and funding on those practices that have a clear and significant positive effect.

Until recently, scientific data related to lesser prairie-chicken conservation has been limited. In recent years, however, as the range-wide population of this once-abundant prairie grouse dropped to historic lows, an unprecedented research effort has been underway to better understand the ecology, threats, and effective conservation of this species.

One of the overarching revelations of the emerging research is that threats and conservation strategies can vary across the prairie-chicken’s range. Effective management needs to accommodate and respond to these variations. Mortality due to fence collisions appears to be one such varying threat, perhaps corresponding with variations in fence density.

Like its cousin, the greater sage-grouse, the lesser prairie-chicken is a relatively low-flying bird, particularly when flushed. Many, though not all, research studies have shown that, for sage grouse, fences pose a significant threat and that fence-marking with vinyl tabs can reduce that mortality by more than 80%.

For lesser prairie-chickens, research has yielded less conclusive results. Several studies sampling various parts of the lesser prairie-chicken’s range in Kansas, Texas, Oklahoma, and New Mexico showed little or no fence-related morality. One study in Oklahoma showed high mortality related to fence collision. No studies have yet assessed the effectiveness of markers in reducing prairie-chicken mortality.

The new fence collision study, led by biologist Samantha Robinson of Kansas State University, came down conclusively on the side of minimal mortality from fences. Both by surveying fence lines and by tracking radio-marked birds, the research team found little fence-collision risk.

0268davidhaukosSpecifically, the research team documented only 1 fence-collision mortality in more than 12,700 recorded fence crosses by radio-tagged birds. During fence surveys, they found 3 carcasses that bore evidence of predator-related death. They also found 12 sites of potential collisions (dropped feathers), but could not conclusively document mortality of any lesser prairie-chicken due to a fence collision.

So how does this study help inform lesser prairie-chicken conservation practices? Current management recommendations for the species focus on the studies that indicated a significant threat from fence collision. Because of that, federal agencies like the Natural Resources Conservation Service, which leads the Lesser Prairie-Chicken Initiative, have required and provided financial assistance to mark and/or remove fences as part of conservation management planning.

Read the fence collision research report.

The report from Robinson’s team suggests that, given the low incidence of fence collisions for prairie-chickens in low-density fence areas (< 2 km of fence per km2), marking fences in such areas uses resources that could be more effectively applied to improving the quality and quantity of prairie habitat.

“Hopefully given the results of this study, the time and money invested in marking fences can be refocused to grassland management and protection and restoration of farms and ranches,” said Robinson.

The team additionally recommended that land managers aim to maintain low fence densities to avoid increasing risk to lesser prairie-chickens, such as what is found in Oklahoma.