Peregrine Falcon Semen: a Quantitative and Qualitative Examination

Collection frequencies and certain characteristics of Peregrine Falcon (Falco peregrinus) semen were investigated using semen from a falcon trained to copulate on a specially designed hat. Semen volume increased significantly when collections were increased from two to three times/day, but cells/ejaculate decreased. No significant difference in number cells/ejaculate or cells/microliter was detected between morning and evening samples with two collections/day. Three collections/day resulted in decreasing total cell numbers/collections and numbers/microliter with the most cells collected during the initial morning collection. Semen showed a high motility, with estimated 80 100% of sperm cells alive. The Peregrine Falcon (Falco peregrinus)continues to be a focal point of captive propagation efforts (Cade and Dague 1981). An important technique used in captive propagation is artificial insemination, since many captive falcoffs do not copulate (Boyd 1978). The technique of artificial insemination has been described by Boyd et al. (1977), but little attention has been directed toward quantitative or qualitative examination of falcon semen. We report here the affect of increasing frequency of semen collection upon semen volume and upon certain characteristics of peregrine semen, including concentration of sperm cells, total cells/ejaculate, motility and percent of viable sperm cells. MATERIALS AND METHODS We wished to know if daily semen volume could be increased significantly by collecting semen 3 times/d vs 2 times/d. Two periods were designated near the midpoint of the semen production cycle (Table 1). Period I comprised 9 d when semen was collected 2 times/d, between 0800 H and 1015 H, and between 1715 H and 1745 H. A third collection was accomplished between 1300 H and 1345 H in Period II. Three days separated the two 9-day collection periods. All semen in this study was collected from a 10-year-old peregrine. The falcon was behaviorally imprinted to humans and copulated on a specially constructed hat (Cade and Dague 1981). The falcon was handled and raised as described by Boyd and Schwartz (1981). The falcon was given the opportunity to copulate on the hat only during the period when semen was needed for artifiTable 1. Means (ranges in parentheses) of semen volume and sperm counts of a 10-year-old Peregrine Falcon. TIME VOL/DAY CELLS//.tl X l 0 3 CELLS/EJACULATE X 10 •