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

Abstract

28GPS collars have revolutionized the field of animal ecology, providing detailed information on 29 animal movement and the habitats necessary for species survival. GPS collars also have the 30 potential to cause adverse effects ranging from mild irritation to severe tissue damage, reduced 31 fitness, and death. The impact of GPS collars on the behavior, stress, or activity, however, have 32 rarely been tested on study species prior to release. The objective of our study was to provide a 33 comprehensive assessment of the short-term effects of GPS collars fitted on scimitar-horned oryx 34 (Oryx dammah), an extinct-in-the-wild antelope once widely distributed across Sahelian 35 grasslands in North Africa. We conducted behavioral observations, assessed fecal glucocorticoid 36 metabolites (FGM), and evaluated high-resolution data from tri-axial accelerometers. Using a 37 series of non-standard regression models, we illustrate clear but short-term effects to animals 38 fitted with GPS collars. Behavioral observations highlighted a significant increase in the amount 39 of headshaking from pre-treatment levels, returning below baseline levels during the post-40 treatment period (>3 days post-collaring). Similarly, FGM concentrations (i.e., stress hormones) 41 increased after GPS collars were fitted on animals but returned to pre-collaring levels within 5 42 days of collaring. Lastly, tri-axial accelerometers, collecting data at eight positions per second, 43 indicated a > 480 percent increase in the amount of hourly headshaking immediately after 44 collaring. This post-collaring increase in headshaking was estimated to decline in magnitude 45 within 4 hours after GPS collar fitting. These effects constitute a handling and/or habituation 46 response (model dependent), with animals showing short-term responses in activity, behavior, 47 and stress that dissipated within several hours to several days of being fitted with GPS collars. 48Importantly, none of our analyses indicated any long-term effects that would have more pressing 49 animal welfare concerns. 3 | Stabach et al. 3 50 51 52 Global Positioning System (GPS) devices have revolutionized the field of animal ecology [1-3], 53 providing detailed information about how animals move and utilize space across diverse and 54 often rapidly changing landscapes [e.g., 4-7]. A variety of taxa can now be monitored, ranging 55 in size from pint-sized ovenbirds (Seiurus aurocapilla; [8]) to multi-ton elephants (Loxodonta 56 africana; e.g., [9]). In some instances, animals are now being monitored over their entire 57 lifespans [10], a result of technological innovations (e.g., solar rechargeable batteries) or re-58 tagging efforts, and at temporal resolutions (minutes to seconds) that would have been 59 unimaginable just a few decades ago. 60Since the inception of animal tracking, scientists have recognized the ethical concerns of 61 fitting animals with tracking devices, providing general guidelines (e.g., devices should weigh 62 <5% of total animal body weight) and in most ca...

Using piecewise regression to identify biological phenomena in biotelemetry datasets

“…Alternatively, quantifying behavioural responses post‐capture can provide useful species‐specific information on altered behaviour and inform future studies (Dechen Quinn et al, 2012; Picardi et al, 2022). For example, Stabach et al (2020) examined effects of GPS collar deployment on scimitar‐horned oryx Oryx dammah to quantify the short‐term responses in activity, behaviour, stress levels and the length of time before these effects subsided.…”

Using Piecewise Regression to Identify Biological Phenomena in Biotelemetry Datasets

“…Alternatively, quantifying behavioral responses post-capture can provide species-specific information on altered behavior and inform future studies (Dechen Quinn et al, 2012). For example, Stabach et al (2020) examined effects of GPS collar deployment on scimitar-horned oryx ( Oryx dammah ) to quantify the short-term responses in activity, behavior, and stress levels, and the length of time before these effects subsided. Visual observation showed headshaking significantly increased post-capture but returned to pre-capture levels within 3 days, and random forest classification of tri-axial accelerometer data indicated a 480% increase in headshaking compared to stable baseline levels that resumed after 24 hours.…”

“…Visual observation showed headshaking significantly increased post-capture but returned to pre-capture levels within 3 days, and random forest classification of tri-axial accelerometer data indicated a 480% increase in headshaking compared to stable baseline levels that resumed after 24 hours. Using piecewise regression, Stabach et al (2020) found that fecal glucocorticoid metabolite levels were elevated for five days following collar deployment, suggesting a stress response, before returning to baseline levels.…”

Forces experienced by instrumented animals depend on lifestyle

“…(8) (9)), drag is negligible in terrestrial (though not aerial) systems even though tag detriment in terrestrial animals has been widely reported and is multi-facetted (10). For example, cited issues range from minor behavioral changes (11) through skin-, subcutaneous-and muscle damage with ulceration (12,13) to reduced movement speed (14) and dramatically increased mortality (15). As with drag, we advocate that a force-based framework is necessary to help understand such detriment.…”