Effects of large‐scale gold mining on migratory behavior of a large herbivore

Abstract

Abstract. Loss of migratory corridors has been identified as an important ecological issue among species that exhibit long-distance migration worldwide. Increased mineral exploration and development has raised the level of concern over the protection of terrestrial migration routes for ungulates. Mineral exploration and other types of development may adversely affect migratory corridors for large herbivores, but little is known about functional effects on migratory behavior and resource selection. To address these important questions we examined movement patterns and resource selection to understand the effects of an operating gold mine on migratory pathways of mule deer (Odocoileus hemionus). We captured and applied radio collars to female mule deer (n ¼ 43) on the migratory pathway and in the proximity of an active mine in the Ruby Mountains of eastern Nevada. We used Brownian Bridge Movement Models to delineate stopover sites for each individual during both the autumn and spring migrations. We calculated linear efficiency of movement along the migration path and movement rate between stopover locations outside and within the mining area to determine the effects of the mine on movement patterns. We also used resource selection functions to determine if mule deer avoided areas with extensive excavation and disturbance of the land surface when navigating through the mine complex. Our results indicated greater linear efficiency of movement along the migration path and movement rates between stopover locations outside the mine when compared with movement through the mine complex. Additionally, mule deer that migrated through the mine complex avoided the highest disturbance levels by spending the majority of their time in undisturbed habitat patches. These results suggest an increase in energy expenditure of mule deer navigating through highly disturbed areas, which may have fitness consequences for migratory animals. Such increases in energy expenditure during migration may decrease survival or productivity of migratory populations of large, terrestrial mammals.

Functional attributes of ungulate migration: landscape features facilitate movement and access to forage

“…, Blum et al. ). We expected selection of stopovers to be more sensitive to disturbance than migratory corridors, because forward movement ceases within stopovers and deer generally spend more time in stopovers than they do in movement corridors (Sawyer and Kauffman ).…”

“…, Blum et al. , Skarin et al. ), which may underscore their importance in sustaining long‐distance migrations.…”

“…, Sawyer and Kauffman , Blum et al. ). Previous research has revealed that mule deer synchronize their initiation (Monteith et al.…”

“…For example, some route segments are used primarily for movement (i.e., movement corridors), whereas in other route segments, forward movement slows to remain in sync with vegetation phenology as those areas (i.e., stopover sites) are used for extending foraging bouts (Sawyer and Kauffman 2011). Other functional attributes such as parturition areas or security habitat exist for some migrations, but movement corridors and stopovers are common among ungulates that migrate long distances (>50 km; White et al 2010, Monteith et al 2011, Sawyer and Kauffman 2011, Blum et al 2015. Previous research has revealed that mule deer synchronize their initiation (Monteith et al 2011, Lendrum et al 2013) and movement Kauffman 2011, Aikens et al 2017) during migration to correspond with plant phenology, which allows individuals to exploit young, protein-rich plants that are highly digestible (Albon and Langvatn 1992, Lendrum et al 2014, Merkle et al 2016).…”

A three-step approach to minimise the impact of a mining site on vicuña (Vicugna vicugna) and to restore landscape connectivity

“…water, wood, energy) depletion, spillage of waste rock and pollutants, and the introduction of alien species (Weaver and Caldwell 1999;Barrow 2000;Franks et al 2010;IFC 2012;Wickham et al 2013). Due to the large extent of perturbation, some impacts reach regional dimensions through the modification of ecological processes, like vertebrate migrations (Sawyer et al 2013;Blum et al 2015). In parallel to negative effects on biodiversity and the physical environment, affected communities suffer risks and impacts in health, safety, cultural heritage and livelihood, potentially leading to physical or economic displacement.…”