An analysis of threats and factors that predict trends in Canadian vertebrates designated as at-risk

Abstract

The identification of factors that predict trends in population abundance is critical to formulate successful conservation strategies. Here, we explore population trends of Canadian vertebrates assessed as “at-risk” by the Committee on the Status of Endangered Wildlife in Canada and the threats affecting these trends using data from the Canadian Living Planet Index. We investigate how threat profiles—the combination of threats for a given species—vary among species and taxonomic groups. We then investigate threat profile as a predictor of temporal trends—both exclusively and in combination with additional biotic and abiotic factors. Species had 5.06 (±2.77) threats listed on average, and biological resource use (BRU) was the most frequently cited. Our analysis also revealed an association between taxonomic group and population trends, as measured by the proportion of annual increases (years with a positive interannual change). By contrast, the predictive power of threat profile was poor. This analysis yielded some useful insight for conservation action, particularly the prioritization of abating BRU. However, the predictive models were not as meaningful as originally anticipated. We provide recommendations on methodological improvements to advance the understanding of factors that predict trends in population abundance for prioritizing conservation action.

Threats to Neglected Biodiversity: Conservation Success Requires More Than Charisma

“…However, we found that the probabilities of each of those four threats being included in mollusk listing decisions have been decreasing since the mid-2000s. Similarly, two out of the three pollution threats for which year was a predictor for arthropods and two out of the six pollution threats for which year was a predictor for chordates have also been decreasing since the mid-2000s, even though pollution was regarded to be a prominent threat for these phyla (Wilcove et al, 1998;Sánchez-Bayo and Wyckhuys, 2019;Currie and Marconi, 2020;Wagner et al, 2021). Our findings supported those of Leu et al (2019), who found the broad-resolution threat of pollution shifted from increasing to decreasing in the mid-2000s.…”

“…Our findings were in agreement with studies which have identified invasive species as problematic for angiosperms (Wilcove et al, 1998;Hernández-Yáñez et al, 2016), arthropods (Wilcove et al, 1998;Sánchez-Bayo and Wyckhuys, 2019;Wagner et al, 2021), and mollusks (Lydeard et al, 2004;Johnson et al, 2013;Lopes-Lima et al, 2014;Böhm et al, 2020). While the species interaction threats were not escalating and topmost for chordates as they were for the other three phyla, there is evidence that they are still having noteworthy impacts on this phylum (Wilcove et al, 1998;Ducatez and Shine, 2017;Currie and Marconi, 2020). One reason our findings may have differed from the literature was that we considered chordates as a phylum as opposed to breaking them down into classes as is common for comparative studies (e.g., Ducatez and Shine, 2017).…”

Past, present, and future of the Living Planet Index

“…Protected areas and protected area management [96][97][98][99] Impacts of conservation management on species 40 and threatened species 36,100 Living Planet Index for recovering populations of European mammals and birds 37 Living Planet Index for utilized species 101,102 Trends in target and bycatch species (oceanic sharks and rays) 103 Other influences of the LPI Index of Linguistic Diversity 104,105 The Wetland Extent Trends Index 106,107 Sustainability Policy Transparency Toolkit (SPOTT) Index 108 The Species Awareness Index (SAI) 109 Table 1…”

“…In particular, the threat and management data at population-level allows for more fine-grained analysis compared with using species-level data. Recent applications of the data include: measuring the effectiveness of protected areas [96][97][98] ; evaluating the correlates of abundance trends in subsets of species such as mammals, reptiles, forest specialists, freshwater megafauna and migratory species 90,92,93,95,115 ; the nature of population dynamics in response to threats or management [99][100][101]116,117 ; the effects of land use and climate on species 118 and exploring linkages between human development variables and wildlife population trends 119 .…”

Assessing the representation of species included within the Canadian Living Planet Index

“…Thus, targeted monitoring programs may be required for missing species and specific biotic traits to further enhance representation in the absence of publicly available abundance data. This work builds upon the taxonomic and spatial representation of the dataset analyzed in Marconi et al (2021), which has been used to assess threats to at-risk vertebrates in Canada and potential management actions for their recovery (Currie and Marconi 2020). Moreover, variations on the approach outlined in this analysis could be useful for evaluating a representative sample of vertebrates needed for calculating an LPI at national and (or) regional scales beyond Canada-a frequent question that has yet to be remedied, though studies are underway (Pata et al, A sampled approach to the Living Planet Index; in preparation).…”