Durability and Longevity of Tympanuchus pallidicinctus (Lesser Prairie-Chicken) Fence Tags in Kansas and Colorado

Grouse species worldwide are declining due to habitat loss and degradation, climate change, and anthropogenic disturbance (Storch 2007). Anthropogenic development, such as roads, energy infrastructure (e.g., powerlines, oil wells, wind turbines), and fences have well documented negative effects on grouse population behaviors and demographics (Braun 1998, Pruett et al. 2009, Gillan et al. 2013, Hovick et al. 2014, Plumb et al. 2019, Patten et al. 2021). Fence lines remain a concern due to their high frequency on the landscape and vicinity to important demographic sites. These demographic sites include leks, which are focal areas for mating, nesting, and brood rearing. In Europe, fences have been identified as a significant source of mortality for several grouse species (Catt et al. 1994, Baines and Andrew 2003). In North America however, there is mixed evidence that fence collisions are a substantial source of mortality for several grouse populations. While fence collisions have been considered as a possible mortality risk for Centrocercus urophasianus (greater sage-grouse) populations (Stevens et al. 2012, U.S. Fish and Wildlife Service [USFWS] 2013, Van Lanen et al. 2017), other studies have shown that fence collisions are not a major mortality source for the species (Connelly et al. 2000, Blomberg et al. 2013).

To reduce mortality risk for grouse, removing fences would be ideal; however, with current grazing practices, it is unrealistic and costly. Marking fences with high visibility markers, such as fence tags or netting, is a recommended practice to reduce direct collisions due in part to its low cost (Natural Resources Conservation Service [NRCS] 2010, Sage Grouse Initiative 2014, Trout and Kortland 2012). These fence markings consist of tags or netting hung or strung between fence wires. Marking fences has reduced collisions for several grouse species in Europe and for C. urophasianus in North America (Baines and Andrew 2003, Christiansen 2009, Stevens et al. 2012, Van Lanen et al. 2017). However, several other species of grouse exist in North America, and little is known about the potential effects of fence collisions or the use of fence markings on their populations.

Understanding effects of fence collisions is especially important for a declining prairie grouse found on the Southern Great Plains, Tympanuchus pallidicinctus (lesser prairie-chicken). T. pallidicinctus populations have declined since the 1980s, largely due to habitat loss as native grasslands have been converted for row-crop agriculture and energy development (Van Pelt et al. 2013, Haukos and Boal 2016, Hagen et al. 2017). This has caused the U.S. Fish and Wildlife Service to propose listing population segments of the species as threatened and endangered under the Endangered Species Act (USFWS 2021). Cattle production is the dominant land use for remaining grasslands in the T. pallidicinctus range, resulting in varying densities of fences throughout the bird's distribution. Despite this, studies have found fence collisions to pose little risk to T. pallidicinctus in the northern part of their range in Kansas and Colorado (Rodgers 2016, Robinson et al. 2016), where the majority of the population resides (Nasman et al. 2021). In the southern part of their range however, one study reported high mortality rates from fence collisions in Oklahoma (39.8%) and New Mexico (26.5%; Wolfe et al. 2007). To mitigate collision risk for T. pallidicinctus, Wolfe et al. (2009) suggested increasing fence visibility by attaching fence tags.

Application of fence tags may be a cost-effective solution to avoid fence collisions by T. pallidicinctus, but little is known about tag longevity. Most applied tags are made of undersill vinyl designed to last at least 20 years. Wolfe et al. (2009) found no visible wear or deterioration after approximately three years following deployment in the field. However, field conditions can be harsh, including wear by weather, cattle, and wildfires; therefore, longevity

Figure 1.

Study sites in the U.S. Forest Service Comanche (A) and Cimarron (B) National Grasslands in Kansas and Colorado, USA, where applied fence tags were counted on marked fence lines...