Short‐term effect of helicopter‐based capture on movements of a social ungulate

Abstract

Capture and handling of wildlife is often an important component of studies where detailed demographic, behavioral, physiological, or health data are required. Yet, capturing and handling wildlife is sometimes controversial and lacking public support because of concern about effects on individuals. Investigating potential effects of capturing wildlife is also important to inform data-censoring protocols when using information obtained from captured animals. We investigated the short-term effect of helicopter-based capture and handling on movements of free-ranging bison (Bison bison) that were chemically immobilized in Yukon, Canada. We examined daily movement rates, home range size, and displacement of global positioning system-collared individuals immediately after capture and for 20 days thereafter. Our results indicate that there is a minimal short-term effect of helicopter-based capture on bison movements. Significant differences from apparent pre-capture movement behavior were observed only within 24 hours after capture. We observed variation among individuals, however, with some animals taking up to 10 days to return to apparent pre-capture movement rates, whereas others had no measurable response to capture. Despite individual variation, >80% of individuals had returned to apparent pre-capture movement behavior within the first 5 days after capture. Furthermore, sex-based effects were evident: females increased their daily movement rates, home range size, and displacement after capture, whereas males had either no effect or decreased movement rates. Our results suggest that movement rates are altered for only a short period after capture and, therefore, should not have severe negative effects on bison using our protocols. Accordingly, researchers should censor the first 10 days after capture from their analyses to avoid using biased information. Our study should also help inform public discourse regarding capturing and handling wildlife for research or management purposes. Ó

Short-term effects of GPS collars on the activity, behavior, and adrenal response of scimitar-horned oryx (Oryx dammah)

“…While we are unable to disentangle the effects of animal handling from the effects related solely to GPS collars themselves, we illustrate that significant effects in behavior, activity, and FGMs dissipate quickly after animals are fitted with a GPS collar. We encourage further investigation into the long-term effects of these revolutionary devices to the field of movement ecology, but concur with similar studies ( [14][15][16][17]39,80]) that find no evidence that should preclude their use.…”

“…ongoing discussion with the general public, providing quantitative information on the time it takes for animals to adjust to being fitted with tracking devices (see also [13][14][15][16][17]39]). Although our sample sizes are small, our results were consistent across individuals monitored and are the first to quantify the time it takes for headshaking to return to normal levels after GPS collaring fitting.…”

“…Since the inception of animal tracking, scientists have recognized the ethical concerns of fitting animals with tracking devices, providing general guidelines (e.g., devices should weigh <5% of total animal body weight) and in most cases, requiring tracking studies to undergo a thorough review from animal care and use committees before being initiated [11]. While various studies investigating potential adverse effects resulting from animals wearing telemetry devices exist (for a review, see [12]), most mammalian studies (~85% reported in [12]) have focused on small-to medium-sized animals (< 15 kg), which are easier (and less expensive) to monitor and manipulate in laboratory settings than studies on large animals (although see [13][14][15][16][17]). Prevailing results of these studies illustrate that the effects of fitting tracking devices on animals are generally minimal, although severe and study-specific impacts have been reported [12,18].…”

“…Prevailing results of these studies illustrate that the effects of fitting tracking devices on animals are generally minimal, although severe and study-specific impacts have been reported [12,18]. And while research into the effects on large mammals do exist (see [13,[15][16][17]19]), these studies are mostly focused on the effects that result from capture and/or chemical immobilization, rather than the impact of collars themselves.…”

Effects of linear features on resource selection and movement rates of wood bison (Bison bison athabascae)

“…Prior to analyses, we screened the data for potential errors. To do so, we first removed the initial two weeks of GPS locations after capture to reduce effects of capture-related behavioural alterations (Jung et al 2019). Second, we removed all locations with low positional accuracy (i.e., two-dimensional GPS locations (or fixes) with positional dilution of precision values > 5; Lewis et al 2007).…”