Mineral Lick Visitation by Mountain Goats, Oreamnos americanus

Abstract

Many species, including Mountain Goats (Oreamnos americanus), are known to visit mineral licks, but the extent and duration of use are poorly understood because most studies consist of observations at licks. I studied the movements to, from, and near mineral licks of 11 mountain goats in Washington wearing Global Positioning System (GPS) collars for a total of 169 goat-months of tracking and evaluated chemical composition of six mineral licks compared with reference soil samples. I recorded 101 mineral lick visits to 13 mineral licks. Each GPS fix was classified as moving toward a mineral lick, in the vicinity of a lick, on an excursion from a lick, moving away from a lick, or not associated with lick use. Depending on annual movement patterns associated with lick use, each Mountain Goat was classified as a Migrant (single lick visit of long duration, n = 3 Mountain Goats), Sojourner (few visits of short duration, n = 2), Commuter (many visits of short duration, n = 5), or Resident (lick within normal range of movements, n = 1). Most mineral lick visits took place 01 June-15 August with peak visitation about 14 June-29 July. Migrants typically stayed in the vicinity of licks about a month (but as long as 51 days) whereas other mountain goats visited licks for 0.1-8 days (median = 1 day). Migrants also tended to take longer and move farther than other Mountain Goats when on movements to and from licks. Most Mountain Goats moved toward mineral licks faster (km/hr) than they moved away from licks. All licks had higher concentrations of sodium than reference samples (1.5-27 times as high), although concentrations of calcium, potassium, and sulphate tended to be higher as well, whereas magnesium was not. Mineral lick visitation has costs (energetics of travel, reduced forage, and predation risk). Depending on the importance of these costs, mountain goats evidently use various strategies for exploiting mineral licks as exemplified by the movement types (migrant, sojourner, commuter, or resident). Notably, most of the Mountain Goats in this study crossed national forest, county and Washington Department of Fish and Wildlife region boundaries to another to visit mineral licks. Thus, coordination among administrative units is needed in management of Mountain Goats and mineral licks they use.