Are we truly helping those in need: A comprehensive assessment of semen technologies in wild bird species

Semen technologies (STs) have been increasingly used in birds as a resource to overcome difficulties commonly faced by conservation breeding programs. Yet their application endures challenges not only related to avian physiology but also in terms of efficiency and welfare of the animals being handled. Advances have been made in some taxonomic groups in recent decades, even though the dissemination of these approaches is not as widespread as in mammals. Here, we gathered data from 178 scientific articles on STs to better understand the distribution of research among taxonomic groups and reproductive areas, the reasons for this arrangement, and discuss what the future priorities for making these tools more effective within global bird conservation. Most available information refers only to semen collection (42%, i.e., methods, parameters, etc.), while a small fraction of the literature describes the use of the complete cycle of STs (16%). These figures highlight that, despite decades of research, refinement in avian STs remains unbalanced with more emphasis on acquiring basic knowledge about semen/sperm than on integrative application of biotechnologies. Our screening becomes even more astonishing when we observed that STs have been applied to less than 2% of bird species, mostly targeting non-threatened species often chosen for their charisma, monetary value, or ease of maintenance in captivity. This survey provides insights for researchers, breeders, zoos, organizations and funding agencies worldwide to reflect on future paths and guidelines for the development of reproductive technologies in birds making them more useful in preserving species truly in need.