INFLUENCE OF RADIO TRANSMITTERS ON PRAIRIE FALCONS

We examined the effect of backpack radio transmitters on Prairie Falco n (Falco mexicanus) reproduction (percentage of occupied territories p roducing young and number of nestlings produced) over four years. In a ddition, we observed falcon aeries during brood-rearing to determine a ttendance at the nest and in the territory, prey delivery rates, and p rey composition. We found no effect of radio tagging of Prairie Falcon productivity (nesting success and brood size) among years, although p roductivity varied significantly among years. The sex of the falcon ta gged did not affect productivity. Radio-tagged members of pairs did no t differ significantly from un-tagged members of pairs in territory at tendance, nest attendance, prey delivery rates, or caching rates. Nest lings raised by radio-tagged parents attained masses similar to those reared by control parents. During low prey years, radio-tagged males b rought a greater proportion of small birds and reptiles, and fewer mam mals to the nest area than control males.