LAUSR

Artificial insemination (AI) is the most frequently used assisted reproductive technique for captive propagation of rare avian species. As semen quality is critical for reproductive success, baseline data are needed for evaluating and selecting the best male bird donors. To this end, we used computer-assisted semen analysis to assess male eastern imperial eagles (n = 7), northern goshawks (n = 24) and peregrine falcons (n = 20). While imperial eagles and northern goshawks donate ejaculate voluntarily, peregrine falcons required cloacal massage. Eight peregrine falcon females were inseminated with semen from eight males, with fresh ejaculates (15 to 50 μl) applied to the pars uterina of the oviduct immediately after collection and examination. All females were inseminated within 2 h of laying an egg. A fertilization rate of 70% was achieved using this method. Minimum semen characteristics associated with egg fertilization included a semen concentration of 115.12 × 106/ml, 33.52% total motility, 1.92% spermatozoa with progressive motility and 0.17% with rapid motility. Comparative data on spermatozoa concentration and kinematics suggest that eastern imperial eagles concentrate on high quality semen investment at the start of the breeding season, northern goshawks compensate for a decrease in motilityassociated parameters with increased semen concentration and peregrine falcons maintain semen production standards throughout the breeding season. Our data show that, in birds of prey, levels of egg fertilization following AI with fresh semen can be almost as successful as after natural mating. Raptors, ejaculate quality, artificial insemination, fertilization rate, endangered avian species conservation Despite some limitations, captive propagation is an essential ex situ strategy for breeding birds of prey, whether for endangered species conservation or falconry purposes (Snyder et al. 1996; Bailey and Lierz 2017). Indeed, such methods have proved important for the recovery of wild populations of critically endangered and charismatic species, such as the Californian condor (Meretsky et al. 2000), peregrine falcon (Fleming et al. 2011) and Mauritius kestrel (Jones et al. 1995). In addition to loss of habitat and resources and over-exploitation, declines in these species are frequently associated with environmental pollutants that induce deleterious effects on avian reproduction (Fry 1995; Pikula et al. 2013; Hruba et al. 2019). Furthermore, as the number of captive-bred birds of prey increases, the international demand on birds for the falconry trade has been saturated, with native species benefiting from a drop in illegal capture of wild birds. In captivity, birds of prey are either allowed to mate naturally or are subjected to assisted reproduction (Bailey and Lierz 2017). To prevent failures in breeding projects, a good knowledge of reproductive physiology is necessary in order to ensure breeding pair quality and general state of health, species-specific differences, male and female synchronization, sperm characteristics, fertilization processes, egg formation, laying cycle and fertilized egg incubation. The most common assisted reproductive technique utilised in birds of prey is artificial insemination (AI) using fresh semen, or semen after no more than two days of ACTA VET. BRNO 2020, 89: 291–300; https://doi.org/10.2754/avb202089030291 Address for correspondence: Veronika Seidlová, Jiří Pikula University of Veterinary and Pharmaceutical Sciences Brno Palackého tř. 1946/1 E-mail: [email protected]; [email protected] http://actavet.vfu.cz/