jryoung
Well-known member
I was browsing through the Elk Management Plan in Idaho and the section on OHVs really caught my eye....a 5,800% increase since wolf introduction.
Figure 8. OHV registration in Idaho from 1973-2011.
Harvest Vulnerability. — There are several key management considerations regarding access and travel management. Roads open to motorized travel increase hunter access and subsequently increase elk vulnerability to harvest (Leptich and Zager 1991, Unsworth and Kuck 1991). Leptich and Zager (1991) documented higher bull mortality rates (62% mortality) in highly roaded areas compared to areas with few roads (31% mortality) in Idaho. In the highly roaded area, no bull lived past 5 years, whereas the area with few roads had bulls living in excess of 10 years. In highly roaded areas, there were fewer than 10 bulls per 100 cows. Closing roads
boosted sex ratios to nearly 20 bulls per 100 cows and unroaded areas had almost 35 bulls per 100 cows. Unsworth and Kuck (1991) concluded bull elk in roaded habitats were more than twice as likely to be killed during hunting seasons as those in areas with few roads.
Adequate numbers of older age-class bulls are required for elk populations to function properly. Squibb et al. (1986) documented that heavy hunting pressure interfered with normal breeding by delaying conception dates of elk. Additionally, the breeding age of bulls also effects elk productivity in a similar fashion. When older bulls are present in a population, conception dates in cow elk are earlier and more synchronous, resulting in calves being born earlier and over a shorter time period each spring (Noyes et al. 1996). A synchronous birth pulse results in fewer calves taken by predators in the spring. Calves born later in the year will subsequently be smaller entering winter and more susceptible to predation and starvation. Access management is a tool that wildlife managers can use to maintain robust elk populations and maintain public hunting opportunities without restricting seasons(e.g. controlled hunts, weapon restrictions, shorter seasons, or seasons during less desirable time of year).
Seasonal Issues. — Road and trail closures during critical times of the year, such as during winter or calving seasons, can be beneficial to elk populations. However, there are issues to consider from recreational use of motorized vehicles by non-hunters or during times of the year outside of hunting seasons. In areas with high road densities, elk exhibit higher levels of stress and increased movement rates (Rowland et al. 2005, Naylor et al. 2009). Naylor et al. (2009) exposed elk to different types of recreational activity. Exposure to all-terrain vehicles (ATV) caused the largest reduction in elk feeding and resting time and increases in elk movement, followed by mountain biking, hiking, and horseback riding. Limiting human disturbance can eliminate unnecessary energy expenditures of elk during winter when forage quality and quantity is reduced (Parker et al. 1984). To ensure the healthy development of an elk fetus, cow elk must minimize energy costs that exceed those required for maintenance (Geist 1978). Calving season closures have been recommended when reduced productivity of elk during calving season was documented after being disturbed by humans (Shively et al. 2005). The energetic cost of moving away from disturbance associated with roads and trails may be substantial (Cole et al. 1997) and could limit population productivity or reduce an elk’s ability to withstand winter by depleting fat reserves (Cook et al. 2004).
Habitat Use. — The displacement of elk away from roads and trails may cause substantial reductions in habitat utilization and habitat effectiveness. Human disturbance associated with roads and trails negatively influence elk behavior because elk vacate otherwise suitable habitat to avoid human activity (Lyon 1979, 1983, Naylor et al. 2009). Displacement of elk into poorer habitat might be equally or more detrimental than increased energetic costs caused by movements (Hobbs 1989). When elk are displaced into poor quality habitats, they may be
forced to use poorer quality forage and expend more energy on thermoregulation (Cassirer et al. 1992). Water and riparian areas are important to lactating elk (McCorquodale et al. 1989), but in Idaho many roads and trails follow drainages, thus making these important habitats less available to elk. Research has shown that quality of summer and fall ranges largely determines the condition of an elk heading into winter, and largely determines whether that elk can survive
winter (Cook et al. 2004). A relatively small difference in forage quality consumed by elk in summer and autumn can have very strong effects on fat accretion, timing of conception, pregnancy rates of lactating cows, calf growth, yearling growth, yearling pregnancy rates, and winter survival rates.
Another issue related to motorized access to roads and trails is displacement of elk onto adjacent private land where hunting is restricted (Wertz et al. 2004, Proffitt et al. 2010). Damage to crops, haystacks, and fences often result, at significant cost. Additionally, agricultural damage and reduction of rangeland forage meant for domestic livestock reduce landowner tolerance toward elk. Such intolerance generally leads to more liberal elk harvest as IDFG reduces the local elk population to address agricultural depredations. By simply limiting motorized access in these areas, elk may remain on public land longer and public hunting opportunities can be maintained or increased (Rowland et al. 2005).
Figure 8. OHV registration in Idaho from 1973-2011.
Harvest Vulnerability. — There are several key management considerations regarding access and travel management. Roads open to motorized travel increase hunter access and subsequently increase elk vulnerability to harvest (Leptich and Zager 1991, Unsworth and Kuck 1991). Leptich and Zager (1991) documented higher bull mortality rates (62% mortality) in highly roaded areas compared to areas with few roads (31% mortality) in Idaho. In the highly roaded area, no bull lived past 5 years, whereas the area with few roads had bulls living in excess of 10 years. In highly roaded areas, there were fewer than 10 bulls per 100 cows. Closing roads
boosted sex ratios to nearly 20 bulls per 100 cows and unroaded areas had almost 35 bulls per 100 cows. Unsworth and Kuck (1991) concluded bull elk in roaded habitats were more than twice as likely to be killed during hunting seasons as those in areas with few roads.
Adequate numbers of older age-class bulls are required for elk populations to function properly. Squibb et al. (1986) documented that heavy hunting pressure interfered with normal breeding by delaying conception dates of elk. Additionally, the breeding age of bulls also effects elk productivity in a similar fashion. When older bulls are present in a population, conception dates in cow elk are earlier and more synchronous, resulting in calves being born earlier and over a shorter time period each spring (Noyes et al. 1996). A synchronous birth pulse results in fewer calves taken by predators in the spring. Calves born later in the year will subsequently be smaller entering winter and more susceptible to predation and starvation. Access management is a tool that wildlife managers can use to maintain robust elk populations and maintain public hunting opportunities without restricting seasons(e.g. controlled hunts, weapon restrictions, shorter seasons, or seasons during less desirable time of year).
Seasonal Issues. — Road and trail closures during critical times of the year, such as during winter or calving seasons, can be beneficial to elk populations. However, there are issues to consider from recreational use of motorized vehicles by non-hunters or during times of the year outside of hunting seasons. In areas with high road densities, elk exhibit higher levels of stress and increased movement rates (Rowland et al. 2005, Naylor et al. 2009). Naylor et al. (2009) exposed elk to different types of recreational activity. Exposure to all-terrain vehicles (ATV) caused the largest reduction in elk feeding and resting time and increases in elk movement, followed by mountain biking, hiking, and horseback riding. Limiting human disturbance can eliminate unnecessary energy expenditures of elk during winter when forage quality and quantity is reduced (Parker et al. 1984). To ensure the healthy development of an elk fetus, cow elk must minimize energy costs that exceed those required for maintenance (Geist 1978). Calving season closures have been recommended when reduced productivity of elk during calving season was documented after being disturbed by humans (Shively et al. 2005). The energetic cost of moving away from disturbance associated with roads and trails may be substantial (Cole et al. 1997) and could limit population productivity or reduce an elk’s ability to withstand winter by depleting fat reserves (Cook et al. 2004).
Habitat Use. — The displacement of elk away from roads and trails may cause substantial reductions in habitat utilization and habitat effectiveness. Human disturbance associated with roads and trails negatively influence elk behavior because elk vacate otherwise suitable habitat to avoid human activity (Lyon 1979, 1983, Naylor et al. 2009). Displacement of elk into poorer habitat might be equally or more detrimental than increased energetic costs caused by movements (Hobbs 1989). When elk are displaced into poor quality habitats, they may be
forced to use poorer quality forage and expend more energy on thermoregulation (Cassirer et al. 1992). Water and riparian areas are important to lactating elk (McCorquodale et al. 1989), but in Idaho many roads and trails follow drainages, thus making these important habitats less available to elk. Research has shown that quality of summer and fall ranges largely determines the condition of an elk heading into winter, and largely determines whether that elk can survive
winter (Cook et al. 2004). A relatively small difference in forage quality consumed by elk in summer and autumn can have very strong effects on fat accretion, timing of conception, pregnancy rates of lactating cows, calf growth, yearling growth, yearling pregnancy rates, and winter survival rates.
Another issue related to motorized access to roads and trails is displacement of elk onto adjacent private land where hunting is restricted (Wertz et al. 2004, Proffitt et al. 2010). Damage to crops, haystacks, and fences often result, at significant cost. Additionally, agricultural damage and reduction of rangeland forage meant for domestic livestock reduce landowner tolerance toward elk. Such intolerance generally leads to more liberal elk harvest as IDFG reduces the local elk population to address agricultural depredations. By simply limiting motorized access in these areas, elk may remain on public land longer and public hunting opportunities can be maintained or increased (Rowland et al. 2005).
