Hexachlorocyclohexane in Non-breeding Populations of American Kestrel (Falco sparverius) in Central Mexico

Area of Science:

• Environmental Toxicology
• Avian Ecology
• Wildlife Contaminant Analysis

Background:

• Hexachlorocyclohexane (HCH) is a persistent organic pollutant with known toxic effects.
• Agricultural areas can be sources of HCH contamination, impacting wildlife.
• Migratory birds can transport contaminants across long distances.

Purpose of the Study:

• To determine the concentration and presence of HCH isomers in American kestrels during the non-breeding season in central Mexico.
• To investigate potential differences in HCH levels based on sex and geographic location (Tlaxcala and Hidalgo).

Main Methods:

• Blood samples were collected from 36 American kestrels (Falco sparverius) in agricultural fields.
• Concentrations of total HCH (∑HCH) and its isomers (α-HCH, β-HCH, γ-HCH) were analyzed.
• Statistical analysis was performed to compare contaminant levels between sexes and states.

Main Results:

• The mean concentration of ∑HCH was 0.07 µg/mL in both Tlaxcala and Hidalgo.
• HCH presence did not significantly vary between sexes or between the two studied states.
• β-HCH and γ-HCH (lindane) were detected in 97% and 80% of samples, respectively; α-HCH was found in one sample.

Conclusions:

• The study confirms the presence of HCH contamination in overwintering American kestrel populations in central Mexico.
• Results suggest widespread exposure, with no significant variation by sex or location within the study area.
• Further research is needed to understand the sources, timing, and intake routes of HCH in this migratory raptor population.