The role of the Flehmen response in the behavioral repertoire of the stallion.

The role of the Flehmen response in equine behavior was investigated under field and laboratory conditions. In Experiment 1, a field study made of five stallions on pasture with between three and eighteen mares each during the season indicated the following: 1) The Flehmen response was most frequently preceded by nasal, rather than oral, investigation of substances; 2) The stallions' rate of Flehmen varied with the estrous cycles of the mares; 3) The rate of Flehmen response did not show a variation with time of day; and 4) The Flehmen response was most frequently followed by marking behaviors rather than courtship behaviors. The results suggest that the Flehmen response is not an immediate component of sexual behavior, e.g., courtship of the stallion but may be involved in the overall monitoring of the mare's estrous cycle. Therefore the Flehmen response may contribute to the chemosensory priming of the stallion for reproduction. In Experiment 2 stallions were presented with urine or feces of mares in various stages of the reproductive cycle as well as with their own or other males' urine or feces. The occurrence of sniffing and Flehmen was used to determine the discriminatory ability of the stallions. Stallions can differentiate the sex of a horse on the basis of its feces alone, but cannot differentiate on the basis of urine. This ability may explain the function of fecal marking behavior of stallions.

Twilight activity and antipredator behavior of young fowl housed in artificial or natural light.

Twenty-four-hr patterns of running wheel activity (Experiment 1) and death feigning, an antipredator behavior (Experiment 2), were studied in domestic chicks housed outside, in natural lighting, or indoors, with light onset and offset timed to coincide with the upper limbs of local sunrise and sunset, respectively. Although chicks housed outside were more active and displayed stronger death feigning reactions, the daily patterns of each activity were highly similar in the two groups. Activity peaked during the period corresponding to evening twilight and was negligible during the morning twilight period; in contrast, death feigning peaked during the morning twilight period. Activity measures indicated that chicks on the artificial light schedule had learned to anticipate dark by day 5, and subsequent ontogenetic changes in activity occurred exclusively in the evening twilight phase.

Use of taste repellants and emetics to prevent accidental poisoning of dogs.

Twelve taste repellents and 3 oral emetics were tested. The taste repellents were capsaicin, capsicum, oleoresin, sucrose octaacetate, quinine tonic, quassia wood extract, vanillamide, horseradish extract, caffeine, pepperoni enhancer, acorn extract, and commercially available bitter and hot flavors. The emetics tested were: antimony potassium tartrate, apomorphine, and copper sulfate. Intake of a 20% sucrose solution by Beagles was significantly depressed by addition of vanillamide at concentrations greater than 0.001%, by capsicum and capsaicin at concentrations greater than 0.01%, and by horseradish extract, pepperoni enhancer, and a commercially available hot flavor at concentrations greater than 0.1%. Antimony potassium tartrate, when added to the 20% sucrose solution at a concentration of 0.1%, produced emesis as did apomorphine at a concentration of 0.005% and copper sulfate at 1%. When the emetic antimony potassium tartrate was combined with vanillamide in a 20% sucrose solution, intake was reduced to less than 20 ml, and vomiting occurred within 15 minutes. Capsaicin (0.02%) inhibited intake of ethylene glycol to less than the lethal dose in 5 dogs tested. Incorporation of such taste repellents and/or emetics into potentially poisonous substances would reduce accidental poisoning of animals and children.