Neurophysiological and Behavioral Changes in Non-Target Wildlife Exposed to Organophosphate and Carbamate Pesticides: Thermoregulation, Food Consumption, and Reproduction

SYNOPSIS. Originally utilized or developed as human poisons, anticholinesterase compounds are among the most widely used pesticides in the world and non-target wildlife are frequently exposed. Because these compounds primarily act by inhib- iting acetylcholinesterase at synapses within the central and peripheral nervous systems, the potential for altering physiological and behavioral responses essential for survival and reproduction in exposed animals is great. We review the effects of acute but sublethal exposure to organophosphates and carbamates on thermo- regulation (hypothermia), food consumption (anorexia and altered foraging be- havior), and reproduction (altered hormone levels, reductions in clutch and litter size, and alterations in reproductive behavior), and the mechanisms believed to cause them. We believe these are the direct toxic effects most likely to reduce populations of free-living birds and mammals within treated areas. Data from studies of captive birds and laboratory mammals and free-living individuals given controlled dosages are included with an emphasis on information published within the last 5 years. The limitations of existing data for determining the biological and regulatory significance of these effects are discussed.