Characteristics for evaluating the conservation value of species hybrids

The extent and rationale for protecting species hybrids in North America is inconsistent, leading to gaps in species conservation. Currently, neither the Canadian Species at Risk Act nor the U.S. Endangered Species Act provide protection or management guidelines for hybrids. Hybrids are often viewed negatively, but occur frequently and do not always result in negative ecological or genetic consequences. With the global decline in biodiversity and potential importance of hybrids in maintaining and preserving biodiversity, it is essential that conservation and management guidelines for hybrids be established. Therefore, we analyzed 62 hybrids of potential conservation concern in Canada and the United States to identify cases where opportunities for hybrid conservation are being overlooked in policy. Hybrids were classified by cause of hybridization (natural, intentional anthropogenic, or unintentional anthropogenic), parent taxa origin (native or non-native), taxonomic class, genetic background, parent taxa protection status, hybrid conservation status (protected or managed), and prevailing attitude toward the hybrid (positive, neutral, or negative). Generally, attitudes toward hybrids depended largely on the real or perceived effect the hybrid has on human life or other highly valued species. These attitudes are influenced by the cause of hybridization and the origin of the parental taxa. Based on these findings, we identify specific gaps in current hybrid conservation research and suggest opportunities for hybrid conservation based on relevant hybrid characteristics.