Cumulative Effects and Boreal Woodland Caribou: How Bow-Tie Risk Analysis Addresses a Critical Issue in Canada's Forested Landscapes

Abstract

Boreal caribou (Woodland Caribou, boreal population; Rangifer tarandus caribou) is a prominent mammal at the heart of a decades-long conflict between a growing resource sector and the associated risks to biodiversity. We employed the ISO 31010 Bowtie Risk Assessment Tool (BRAT) to evaluate the cumulative effects of anthropogenic and natural factors that may affect risks to self-sustainability in boreal caribou herds of Northeastern British Columbia. We used the BRAT to produce a visual synthesis of the cumulative effects causing the growth rate of boreal caribou herds to persistently fall below a level corresponding to a 60% chance of self-sustainability (λ < 1.025). The BRAT diagram provided the basis for a quantitative Layers of Protection Analysis (LOPA) of risk probabilities for three caribou herds. We combined threat assessments from the Species at Risk Act recovery strategy (Environment Canada, 2012) with data from published landscape experiments (e.g., restoration of seismic traces, maternal penning, and wolf culls) to parameterize the LOPA in three study areas. We report the implications of a combination of mitigation options vs. current risk conditions, as well as the implications of uncertainty in threat prevention. Our analysis indicates that a combination of mitigation scenarios will best facilitate caribou herd recovery, that barriers preventing predation threats could also aid in recovery success, and that compensatory predation may account for a significant proportion of both adult and juvenile female mortality across different herds. We estimated the minimum annual cost for effective mitigation and recovery to be $CDN 224K within any of the study areas. Bow-tie diagrams are a flexible and quantifiable tool that can translate resource management solutions to the diverse audience involved in conservation decision-making: scientists, land managers, policy makers, and concerned stakeholders.

Springtail coloration at a finer scale: mechanisms behind vibrant collembolan metallic colours

“…When viewed under sufficient magnification, the scales of all species show colourful patches and bands that generally run transverse to the ridges. The metallic coloration thus is likely to result from spatial mixing, as seen in metallic butterfly scales [8], and explains the observations of both broadband colour reflectance spectra and spectra with pronounced peaks in the violet to blue region of the spectrum. To increase our understanding of the colour production mechanisms, we performed optical modelling using three-dimensional models of lamina-only, ridge-only and lamina + ridge models.…”

“…colours of the rainbow), although there is increasing interest in the colour production mechanisms of scales with a broadband, metallic reflection (especially in butterflies). These studies reveal the importance of thin-film effects of upper/lower laminae and of the cross-ribs [8,[11][12][13][14][15][16][17]. By contrast, colour production of metallic scales of early Lepidoptera and basal arthropods which have many scaled representatives (e.g.…”

“…Structural colours in insect scales [4,5] (e.g. by thin films [6][7][8], photonic crystals [9,10], multilayers [6]) are well studied. However, most of these studies have focused on scales of extant, derived butterflies and beetles with distinct hues (i.e.…”

‘WildLift’: An Open-Source Tool to Guide Decisions for Wildlife Conservation

“…We also included scenarios with combined effects of recovery actions (i.e., multiple levers), which has been suggested to best improve caribou recovery (Serrouya et al, 2019;Winder et al, 2020). We assumed that combinations between demographic augmentations (i.e., MP, PE, and CB) and predator-prey population management (i.e., WR and MR) would result in simple additive effects on populations.…”

No evidence for individual recognition in threespine or ninespine sticklebacks ( Gasterosteus aculeatus or Pungitius pungitius )

“…discrimination between species and sexes, to differentiating kin from non-kin or familiars from unfamiliars, to the recognition of specific individuals [1][2][3]. Most researchers draw a distinction between class-level recognition and individual recognition [4,5].…”