Work

Birds as Environmental Bioindicators of Genotoxicity in Brazilian Cerrado Farmlands: An In Situ Approach

Year: 2025

Type: article

Abstract: Birds have played a crucial role as environmental monitors through-out history, ranging from the use of canaries to detect methane and carbon monoxide in mines to the decline of raptors and seabirds dur-ing the DDT era due to widespread organochlorine pesticide contami-nation. Owing to their high diversity and capacity for bioaccumulation, birds are widely recognized as effective indicators of environmental change and pollutant exposure. Cytogenetic techniques have been in-creasingly applied over the past two decades to assess micronuclei formation resulting from interactions with clastogenic and aneugenic chemical compounds. The main goals of this study were: (a) to evalu-ate a subset of the bird community in the southeastern Brazilian Cer-rado as potential environmental indicators of pesticide exposure using the erythrocyte micronucleus test; and (b) to investigate possible asso-ciations between bird morphometric traits and micronuclei frequency. Birds were sampled from three groups of coffee farms in the Brazilian Cerrado. Blood samples were collected from 122 individuals via the brachial vein, followed by slide preparation for micronucleus analysis. The species Leptotila rufaxilla, Volatinia jacarina, Galbula ruficauda, Gnorimopsar chopi, Molothrus bonariensis, Passer domesticus, Turdus leu-comelas, and Turdus rufiventris exhibited six or more micronuclei per 1,000 erythrocytes, indicating the highest potential as bioindicators of environmental contamination. Micronuclei frequency in erythrocytes was positively correlated with the use of mixed pesticides, with varia-tion depending on the size of the coffee farms. Although a slight nega-tive biological trend was observed between micronuclei frequency and certain morphometric traits, particularly bill length, no statistically significant correlations were found. Similarly, birds from large farms exhibited a slight reduction in certain morphometric features, though these differences were also not statistically significant. These results highlight the utility of selected bird species as early-warning bioindi-cators for pesticide exposure in tropical agroecosystems.

Source: Animals

DOI: 10.3390/ani15213208