Using Camera Collars to Study Survival of Migratory Caribou Calves

Abstract

Monitoring survival of juveniles in wild populations of vertebrates is challenging because capture and marking of neonates may influence survival and induce biases. Camera collars have proven effective in resource and habitat selection studies, but their effectiveness to assess offspring survival is unknown. Our objective was to monitor the survival of neonates using camera collars installed on 24 preparturient female migratory caribou (Rangifer tarandus) of the Rivière‐aux‐Feuilles herd, from 2016 to 2018, in Nunavik, Canada. Females were captured with a net gun fired from a helicopter and pregnancy was confirmed by ultrasound. Cameras recorded a 10‐second video every 20 min from 1 June until 1 September 2017, when the collar detached automatically. We used Cormack‐Jolly‐Seber models to assess survival and resighting probabilities of calves based on their observation in the videos. Three collars failed, recording less than 30% of the expected videos, including one on a female that did not give birth. Among the 21 females wearing a functional collar, one gave birth to a stillborn calf. We analyzed 25,820 videos recorded from 20 collars. Calf sightings in videos were less frequent as the monitoring period advanced, but we estimated the probability of observing a live calf at 0.77 (SE = 0.42) over the sampling period. Videos indicated a survival rate of 0.67 (SE = 0.11) from birth to 1 September. Our results suggest that camera collars installed on adult females can be used to reliably assess offspring survival, and thus improve our understanding of caribou population dynamics. The application of camera collars should be useful for other large vertebrate species for which the assessment of neonate survival is lacking or difficult to obtain. © 2021 The Wildlife Society.

Machine Learning Methods and Visual Observations to Categorize Behavior of Grazing Cattle Using Accelerometer Signals

“…The use of camera collar technology to remotely observe free-ranging animal behavior is extensively used in difficult-to-observe animals [22]. Passive camera systems allow for observing specific animal behaviors and provide ecologists with a greater perspective of species life history, including patch selection and calf survival in Caribou [35]. Further, collar video data have been utilized in training accelerometer algorithms in the Gobi Khulan (Equus hemionus hemionus), a free-ranging wild horse in the Mongolian steppes [18].…”

Selection of summer feeding sites and food resources by female migratory caribou (Rangifer tarandus) determined using camera collars

“…Studies from direct observations of resource acquisition of wild caribou are, however, nearly inexistent [21,[25][26][27]. Cameras mounted on satellite collars is a new technology that can help observing wild animal behavior directly at the finest scale of analysis, without any risk of disturbing them in the process [28,29].…”

Critical summer foraging tradeoffs in a subarctic ungulate

“…Large herbivores are unique in that they spend a great deal of their time foraging, upwards of 14 h every day (e.g., Sukumar, 1989 ). Animal‐borne cameras have recently been applied to large herbivores across remote regions of Mongolia and Canada (Kaczensky et al, 2019 ; Vuillaume et al, 2021 ). Previous studies using video collars have measured foraging and diet, grooming and reproduction across cervids (e.g., Lavelle et al, 2015 ; Thompson et al, 2012 ; Viejou et al, 2018 ).…”