Roe Deer (Capreolus capreolus) Hair as a Bioindicator for the Environmental Presence of Toxic and Trace Elements

Abstract

The return to pasture use as an alternative to intensive livestock farming implies some risks with the lack or the excessive presence of potentially toxic elements; in this regard, wild animals have been used as bioindicators for decades. Thus, the purpose of this study is quantifying Cu, Cr, Mn, Zn, Se, As, Cd, Ni, Pb, Al, Fe, and Mg in fur from roe deer and understanding if it is a valid bioindicator tool. Hair was collected from 39 hunted roe deer and divided by age (<36 months old/≥36 months old), sex (male/female), and area of origin (urbanized/rural area). The mean concentrations of Fe, Mg, Mn, Al, Cr, and Pb were higher (p < 0.05) in the urbanized group; the mean levels of Mg and Cr were higher (p < 0.05) in older animals; and Cu, Fe, Mg, Cd, and Cr showed a higher accumulation in females. Our findings showed an age-related variation of elements, with higher concentrations in adult animals and females. In conclusion, our findings prove that hair is a valid matrix for this type of survey, and wild animals are good bioindicators for monitoring the presence of trace elements in pastures.

Portable X-ray Fluorescence for Measuring Lead in the Hair of Wild Mammals

“…Lead levels in devil hair, in both the validation study (mean 1.65 ± 4.61 SD) and the plantation landscape study (mean 1.05 ± 1.02 mg/kg), were comparable to other published research on lead exposure in mammals (both wild and domestic). The levels we found were lower than those found in the hair of domestic dogs ( Canis familiaris ) used for hunting in Argentina (mean 2.37 ± 6.21 mg/kg) (Fernández et al, 2021), similar to those in hair from fruit bats in eastern Australia (medians for three species: 1.26/1.64/2.26 mg/kg) (Sánchez et al, 2022) and roe deer in Italy (mean 1.39 ± 1.63 mg/kg) (Draghi et al, 2023), and higher than those found in hair from Malay civets sampled in Malaysian Borneo (mean 0.52 ± 1.08 mg/kg) (Evans et al, 2022). Similar to several of these studies (Draghi et al, 2023; Evans et al, 2022; Sánchez et al, 2022), there was no evidence of variations in lead levels in devil hair among sexes and age classes.…”

“…One non-invasive approach to investigating heavy metal exposure in mammals is through hair analysis, a technique used by some recent studies on non-scavenging mammal species such as fruit bats ( Pteropus spp.) (Sánchez et al, 2022), Malay civets ( Viverra tangalunga ) (Evans et al, 2022) and roe deer ( Capreolus capreolus ) (Draghi et al, 2023). Collecting hair samples from wild animals can be done remotely using hair snares (Azad et al, 2019) or through minimal handling of trapped wild animals.…”

Goat hair as a bioindicator of environmental contaminants and adrenal activation during vertical transhumance

“…Different anthropogenic activities are responsible for the Al soil enrichment and consequent increase in the bioavailability of this compound in plants (45). In a study on roe deer hair (32), the animals that fed near urban areas had higher hair concentrations of Al than animals feeding in rural areas (32). In the same way, we could hypothesize that the difference in Al values before and after vertical transhumance could be due to the different origins of the feed.…”

Evaluation of the Difference in the Content of Essential and Non-Essential Elements in Wild Boar and Swine Tissues Sampled in the Same Area of Northern Italy

“…The differences between these studies could be explained not only by differences in the contamination of the regions due to anthropogenic activity, but also by differences in the geological characteristics of the areas. Indeed, As is naturally present in rocks and sediments [ 37 ].…”

“…Contrary to our results, a study by Kasprzyk et al on the content of micro and macro elements in the liver of wild boars reported significant differences between sexes [ 58 ]. Also, in different studies on roe deer muscle, liver and hair, differences between the sexes in the contents of essential and non-essential elements were highlighted [ 37 , 59 ]. A possible explanation for the lack of statistically significant sex-related differences in our study is that, unlike the roe deer in other studies, whose females, due to the hunting season, could be in lactation or diapause, the female wild boars used in this study were neither pregnant nor lactating; these are physiological states that are known to greatly mobilize both essential and non-essential elements [ 60 ].…”