Fig 5 - uploaded by Livia Spadetto
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Correlation between the ranks for prothrombin time (PT) and for ΣSGAR values detected in barn owls (n = 39) from the Region of Murcia (SE Spain). Ranks were assigned to both variables to visualize their relationship, highlighting the relative position of observations.
Source publication
Second-generation anticoagulant rodenticides (SGARs) are commonly used for rodent control, affecting various non-target wildlife species. Here, blood samples from common kestrels (Falco tinnunculus, n = 70 chicks) and barn owls (Tyto alba, n = 54 chicks and 12 adults) from Southeastern Spain were analysed using HPLC-TQ. SGAR prevalence was 68.6% in...
Contexts in source publication
Context 1
... SGAR-detected individuals were very similar, 15.0 ± 0.8 and 15.2 ± 0.3 s, respectively. We cannot assert acute intoxication as all samples coagulated, which is consistent with our expectations according to the ΣSGAR levels in the blood. However, a positive and significant correlation was found between ΣSGARs and PT (Rho = 0.395, p = 0.006) (see Fig. 5), which is an interesting finding in free-ranging nestlings given that the initial AR dose and time of exposure were unknown. Surprisingly, variations in PT were observed, including samples testing negative for SGARs (Fig. 5). It remains unclear whether these variations fall within a physiological range for barn owls or indicate recent ...
Context 2
... in the blood. However, a positive and significant correlation was found between ΣSGARs and PT (Rho = 0.395, p = 0.006) (see Fig. 5), which is an interesting finding in free-ranging nestlings given that the initial AR dose and time of exposure were unknown. Surprisingly, variations in PT were observed, including samples testing negative for SGARs (Fig. 5). It remains unclear whether these variations fall within a physiological range for barn owls or indicate recent exposure. In fact, while plasma half-life of ARs is relatively short in bird species (16.5 ± 10.0 h for warfarin in Eastern barn owl Tyto javanica; Khidkhan et al., 2024), experimental studies suggest that PT returns to ...
Citations
... Our hypotheses were that AR exposure could be widespread in this species, and that the rate of AR exposure is higher in eagle owls exposed to the considered risk variables, compared to those inhabiting more natural or protected areas. Additionally, we hypothesised that the coagulation capacity decreases proportionally to the levels of ARs detected in blood samples, as previously demonstrated in other bird of prey species (Spadetto et al., 2024a(Spadetto et al., , 2024b. By providing critical insights into the extent of AR contamination and its impact on the eagle owl, this study seeks to provide information for the development of conservation strategies and regulatory measures to mitigate the risks posed by these chemicals. ...
... They are also preferred for their ability to overcome the widespread resistance that rodent populations have developed against FGARs. Flocoumafen was also detected at very high prevalence in other nocturnal and diurnal raptors in the Region of Murcia sampled during the same study years (Spadetto et al., 2024a(Spadetto et al., , 2024b. These results are remarkable given that, in Spain, only one product containing flocoumafen is registered for non-professional use, and two are intended for use by specialized personnel (Carrera et al., 2024). ...
... Eagle owls in our study area often reside in the wildland-urban interface (zones where urban or residential development is directly adjacent to or mixed with natural vegetation), where it has been recently shown that the risk of AR exposure can be significant (Hofstadter et al., 2021;Silveira et al., 2024). In another research conducted on common kestrels in the same study area, higher ΣSGAR levels have been observed in the more urbanised study site, surrounding the city of Murcia (Spadetto et al., 2024a), which suggests that in heavily anthropized areas, the residential use of ARs is widespread among the local population. These findings are also consistent with other studies in which the degree of urbanisation has been found to be a strong predictor of AR exposure (Geduhn et al., 2015;Lohr, 2018;López-Perea et al., 2019;Musto et al., 2024). ...
Anticoagulant rodenticides (ARs) are widely used for pest control, resulting in their pervasive presence in the environment and posing significant toxicological risks to a range of predatory and scavenging species. Our study mainly aimed to evaluate AR exposure and effects in nestlings of eagle owl (Bubo bubo) from the Region of Murcia (southeastern Spain). We analysed ARs in blood samples (n = 106) using high-performance liquid chromatography-triple quadrupole (HPLC-TQ), assessed the influence of potential anthropogenic (presence of livestock farms, landfills and human population density) and environmental (land uses and proximity to watercourses) variables, and measured prothrombin time (PT) and plasma biochemical parameters as biomarkers of effects. Our results showed the presence of AR residues in 91.5% of the nestlings, with 70.8% exhibiting multiple ARs (up to six compounds in a single individual). Second-generation ARs (SGARs) were the most prevalent compounds. The analysis of biochemical parameters indicated that the sampled individuals were in good physiological condition. Although PT was positively correlated with total AR concentration (ΣARs), the relationship was not significant (Rho = 0.04; p = 0.49). Regarding environmental factors, higher ΣARs were associated with the most urbanised study site and the presence of landfills, likely due to the increased availability of rodent prey. The prevalence of two SGARs (brodifacoum and difenacoum) was linked to closer proximity to riverbeds, suggesting a contamination pathway associated with inland aquatic ecosystems, where these AR compounds may concentrate due to water scarcity. This study underscores the widespread exposure of eagle owls to ARs and highlights the importance of effective monitoring and management of these pollutants to protect conservation-concern wildlife in Mediterranean semiarid regions.
