Acute oral toxicity and tissue residues of saxitoxin in the mallard (Anas platyrhynchos)

•Median lethal dose of saxitoxin in mallards was estimated to be 167 µg kg−1.•Detection of saxitoxin in tissues, not including the gastrointestinal tract, was inconsistent in mallards that died acutely.•No specific abnormalities or tissue pathology was associated with saxitoxin exposure.•Weight loss was associated with saxitoxin exposure in surviving mallards.