Noninvasive Genetic Assessment Is an Effective Wildlife Research Tool When Compared with Other Approaches

Abstract

Wildlife research has been indispensable for increasing our insight into ecosystem functioning as well as for designing effective conservation measures under the currently high rates of biodiversity loss. Genetic and genomic analyses might be able to yield the same information on, e.g., population size, health, or diet composition as other wildlife research methods, and even provide additional data that would not be possible to obtain by alternative means. Moreover, if DNA is collected non-invasively, this technique has only minimal or no impact on animal welfare. Nevertheless, the implementation rate of noninvasive genetic assessment in wildlife studies has been rather low. This might be caused by the perceived inefficiency of DNA material obtained non-invasively in comparison with DNA obtained from blood or tissues, or poorer performance in comparison with other approaches used in wildlife research. Therefore, the aim of this review was to evaluate the performance of noninvasive genetic assessment in comparison with other methods across different types of wildlife studies. Through a search of three scientific databases, 113 relevant studies were identified, published between the years 1997 and 2020. Overall, most of the studies (94%) reported equivalent or superior performance of noninvasive genetic assessment when compared with either invasive genetic sampling or another research method. It might be also cheaper and more time-efficient than other techniques. In conclusion, noninvasive genetic assessment is a highly effective research approach, whose efficacy and performance are likely to improve even further in the future with the development of optimized protocols.

Novel frontier in wildlife monitoring: Identification of small rodent species from fecal pellets using near‐infrared reflectance spectroscopy (NIRS)

“…In conclusion, fNIRS can facilitate rodent population censuses with larger sample sizes, combining large spatial extent with small grain if combined with pellet‐count‐based abundance indices (Engeman & Whisson, 2006 ; Jareño et al, 2014 ; Karels et al, 2004 ). The wide array of data (e.g., diet, disease, and stress) discernible through fNIRS suggests that developing monitoring schemes based on pellet counts and fNIRS could meet the need for ecosystem‐ and interaction‐based approaches to monitoring (Ehrich et al, 2019 ) and for this purpose complement genetic methods (Zemanova, 2021 ). Further steps in this direction involve increasing the spatial scope of calibrations, extending the calibration exposure times to meet the needs of field sampling intervals, as well as continuous development of the calibration model algorithm and outlier detection.…”

“…Feces—and the chemical and genetic information they store—could therefore allow for the determination of diverse ecological and physiological variables indicative of species interactions (c.f. Ehrich et al, 2019 ; Vance et al, 2016 ), if combined with suitable molecular, endocrinological, or spectral methods (Galan et al, 2012 ; Schwarzenberger, 2007 ; Zemanova, 2021 ). Indeed, realizing the potential of fecal data for large‐scale ecological monitoring calls for a set of cost‐effective high‐throughput analytical methods (Vance et al, 2016 ; Zemanova, 2021 ).…”

“…Ehrich et al, 2019 ; Vance et al, 2016 ), if combined with suitable molecular, endocrinological, or spectral methods (Galan et al, 2012 ; Schwarzenberger, 2007 ; Zemanova, 2021 ). Indeed, realizing the potential of fecal data for large‐scale ecological monitoring calls for a set of cost‐effective high‐throughput analytical methods (Vance et al, 2016 ; Zemanova, 2021 ). Such methods, if embedded in appropriate monitoring schemes (Yoccoz et al, 2001 ), could provide access to questions pertinent to ongoing biodiversity shifts and ecosystem changes (Lenoir & Svenning, 2015 ; Pecl et al, 2017 ; Wintle et al, 2010 ).…”

“…Analytical methods that are nondestructive for the fecal samples themselves increase their utility by allowing subsequent application of further analytical methods. For instance, rapid advances in noninvasive and nondestructive genetic methods allow for increasingly cost‐effective taxonomic analysis of feces (Zemanova, 2021 ), given sufficiently preserved genetic material.…”

Comparison of Minimally Invasive Monitoring Methods and Live Trapping in Mammals

“…This provides a distinct advantage over live trapping for both animal well-fare and researcher injury risk. In addition, the total cost and effort for less invasive methodologies tends to be less than for invasive or lethal approaches, providing quantitative monetary and time advantages for these methods [ 20 ]. Combined with the relative similarity in detection of individuals that occurs with live trapping compared to less invasive methods, the advantages of minimally invasive approaches suggests that these methods should be considered at least as often as live trapping when population monitoring is the goal.…”