Characteristics of Ungulate Behavior and Mortality Associated with Wire Fences

Abstract

We studied the characteristics of pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus), and elk (Cervus elaphus) mortalities associated with wire fences along roads in Colorado and Utah, USA, from June 2004 to June 2005. We estimated an average annual mortality occurrence of 0.25 mortalities/km for the wire fences studied (0.08 mule deer mortalities/km, 0.11 pronghorn mortalities/km, and 0.06 elk mortalities/km) or 0.5 mortalities/km of road. The highest wire fence-mortality rates in our study area occurred during August, which coincided with weaning of fawns. Mule deer and pronghorn jumped fences in .81% of observed crossings. Mortalities were largely caused by animals getting caught between the top 2 wires. Mule deer experienced higher fence-mortality rates than elk or pronghorn because they crossed fences more frequently (P , 0.001) and spent more time in road right-of-ways (P , 0.001) than the other species. Juveniles were 8 times more likely to die in fences than adults. Woven-wire fences topped with a single strand of barbed wire were more lethal to ungulates than woven wire with 2 strands of barbed wire above it or 4-strand barbed-wire fences (P , 0.01). There was a direct relationship between the frequency of fence mortalities and ungulate abundance (r 2 ¼ 0.83). Traffic volumes were inversely related to fence-mortality frequencies (r 2 ¼ 0.50) and ungulate densities along the right-of-way (r 2 ¼ 0.50). (WILDLIFE SOCIETY BULLETIN 34(5):1295-1305 2006)

Mortality in a Predator-free Insular Environment: the Dwarf Deer of Crete

“…Causes of juvenile mortality in the wild today are many, but the ones most frequently mentioned in relevant studies include accidents, starvation and malnutrition, diseases including congenital defects, extreme weather conditions, low neonatal body weight, inadequate maternal protection, high population density, and predation (Sarno et al, 1999). With regard to accidents, a study of mortality associated with wire fences in the western United States (Harrington and Conover, 2006) showed that juveniles of pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus), and elk (Cervus elaphus) were eight times more likely to die from fence-related accidents than adults. Interestingly, the highest mortality associated with wire fencing was observed during August, coinciding with the wean- ing of fawns.…”

Fences Impede Long-distance Mongolian Gazelle (Procapra gutturosa) Movements in Drought-stricken Landscapes

“…In May 2008, Russian border guards temporarily dismantled fences in a good-will gesture that allowed passage for some gazelles. However, for a long-term solution, relatively minor changes to existing wire fences, such as the removal of the bottom strand of wire, lay down fences, or buck and pole fencing may be suf¿ cient to allow Mongolian gazelles to cross and avoid entanglement or prevent access to important forage (Harrington & Connover, 2006;Yoakum, 2004;Scott, 1992;Kindschey et al, 1982); however this solution Figure 3. Mongolian gazelles attempting to cross and one already successfully crossed a portion of the Trans Mongolian railway fence in Govi Sumber Aimag, Mongolia.…”

“…The impact of fencing on the ability of wildlife to access crucial habitat can have devastating affects and have the potential to severely reduce their numbers, prevent population recovery, and cause economic damage (Bies, 2007;Cohn, 2007;Harrington & Connover, 2006;Ringrose et al, 1997;Williamson & Mbano, 1983). Animal species whose life histories entail longdistance movements may be especially sensitive to habitat fragmentation and associated humangenerated barriers to movement (Berger, 2004).…”

Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change

“…The final set of environmental variables comprised elevation, distance to wetlands and rivers, vegetation communities, distance to protected areas, distance to urban settlements, and slope. the survival probability of ungulates crossing highways, even in low traffic conditions (Harrington & Conover, 2006). We therefore allocated the maximum resistance value of 100 in fenced sections of the highway.…”