Landscape condition influences energetics, reproduction, and stress biomarkers in grizzly bears

Abbey E Wilson,Gordon Stenhouse,David M Janz,Dan Wismer,Nicholas C Coops

doi:10.1038/s41598-021-91595-4

Abstract

Environmental change has been shown to influence mammalian distribution, habitat use, and behavior; however, few studies have investigated the impact on physiological function. This study aimed to determine the influence of landscape condition on the expression of target proteins related to energetics, reproduction, and stress in grizzly bears. We hypothesized that changes in landscape condition explains protein expression. Skin biopsies were collected from free-ranging grizzly bears in Alberta, Canada from 2013–2019 (n = 86 individuals). We used an information theoretic approach to develop 11 a priori candidate generalized linear mixed models to explain protein expression. We compared models using Akaike Information Criteria (AICc) weights and averaged models with ΔAICc < 2 for each protein. Food resources, represented by increased distance to coal mines and decreased crown closure, positively influenced energetic proteins (adiponectin and alpha-1-acid glycoprotein). Proteins related to reproduction (ceruloplasmin and serpin B5) were positively associated with increased wetland and upland food resources in addition to movement, but negatively associated with increased distance to roads. One stress related protein, complement C3, was positively influenced by increased percent conifer. Given the need to detect emerging threats to wildlife, we suggest the assessment of physiological function will lead to improved monitoring of species in rapidly changing landscapes.

Highlights

Environmental change has been shown to influence mammalian distribution, habitat use, and behavior; few studies have investigated the impact on physiological function
Variables related to food resources with corresponding hypotheses associated with foods, individual behavior, and terrain influenced the expression of the greatest number of proteins, those related to energetics, reproduction, and stress
Variables related to anthropogenic disturbance with hypotheses associated with foods, mortality risk and human use influenced the expression of proteins related to metabolism and reproduction, while biology influenced one protein related to reproduction

Summary

Introduction

Environmental change has been shown to influence mammalian distribution, habitat use, and behavior; few studies have investigated the impact on physiological function. In the province of Alberta, grizzly bear (Ursus arctos) populations reside in areas with an increasing demand for natural resources, agriculture, and recreation, all of which lead to increasing fragmentation and loss of h abitat[2] This species was listed as threatened by the province in 20103, which prompted extensive research on the conservation strategies needed to inform policy makers and management activities in the r egion[4,5,6]. The use of contemporary molecular tools to determine physiological function may provide novel approaches to detect parameters that indicate declining health status in a population These methods offer a means to understand the physiological mechanisms that influence health in this species, thereby aiding scientists and managers with the identification of conservation strategies prior to critical population thresholds, as declining health may influence population performance (e.g., number of cubs produced). There has been increased interest and success in the identification and use of protein biomarkers to predict clinical outcomes in h umans[26], as specific proteins can serve as indicators of physiological or pathological states and provide information for the early detection of poor health and/or disease[27]

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