Organismal effects of pesticide exposure on meadow voles (Microtus pennsylvanicus) Living in golf course ecosystems: Developmental instability, clinical hematology, body condition, and blood parasitology

Abstract

This is the second of two articles reporting the results of a nonlethal biomonitoring study that quantified the effects of pesticide exposure on meadow voles (Microtus pennsylvanicus) living in golf course ecosystems of the Ottawa/Gatineau region (ON and PQ, Canada, respectively). In the present article, we describe results of measurements regarding developmental instability (e.g., fluctuating asymmetry), congenital birth defects (e.g., skeletal terata), clinical hematology (e.g., differential counts), general body condition (e.g., body mass-length relationships), and blood parasite load (Trypanosoma sp. and Bartonella spp.). Voles were captured during the year 2001 to 2003 at six golf courses and two reference sites. Once voles were fully sedated using isoflurane, blood was collected, radiographs taken, and morphometric measurements recorded. Three animals from each course were euthanized to determine body burdens of historically used organochlorine (OC) and metal-based pesticides. Exposure to in-use pesticides was determined from detailed golf course pesticide-use records. None of the endpoints measured was significantly related to body burdens of OC pesticides and metals historically used, nor did any endpoint significantly vary among capture sites in relation to total pesticide application to the capture site or to the number of days since the last application of pesticide. Based on these findings, it appears that voles from golf courses were no less healthy than their conspecifics from reference sites.

Can Body Condition and Somatic Indices be Used to Evaluate Metal-Induced Stress in Wild Small Mammals?

“…However, the attribution of these effects to TMs, other pollutants, or a combination of both remained speculative. The authors of several other studies failed to detect any significant differences in body condition/body weight in small mammals from polluted and reference sites [36], [37]. The present results reveal complex relationships of SMI with both individual (age, gender, TM concentrations in tissues) and environmental (high intra- and inter-site variability) variables.…”

Monitoring exposure of northern cardinals,Cardinalis cardinalis, to cholinesterase‐inhibiting pesticides: enzyme activity, reactivations, and indicators of environmental stress

“…However, our study could not differentiate between contributions of envi-ronmental stressors, such as food limitation, and contaminants to FA. It is feasible that exposure to ChE-inhibiting compounds did not contribute to FA patterns at all [21]. Future studies must be designed carefully to differentiate between FA as a result of contaminant exposure versus noncontaminant environmental stressors (e.g., habitat or food limitation).…”

“…Eeva et al [19] found that the degree of FA in the pied flycatcher ( Ficedula hypoleuca ) and great tit ( Parus major ) was related inversely to a contaminant gradient, and a similar response has been reported for another vertebrate taxa [20]. However, recent field and laboratory studies report that contaminant stressors did not result in increased FA, nor was there a detectable dose‐response relationship between contaminants and FA [21,22]. Thus, the efficacy of FA as a bioindicator for contaminant stress remains unknown.…”