Genetic analysis reveals demographic fragmentation of grizzly bears yielding vulnerably small populations

摘要: Ecosystem conservation requires the presence of native carnivores, yet in North America, distributions many larger carnivores have contracted. Large live at low densities and require large areas to thrive population level. Therefore, if human-dominated landscapes fragment remaining carnivore populations, small demographically vulnerable populations may result. Grizzly bear range contraction conterminous USA has left four fragmented three which remain along Canada–USA border. A tenet grizzly is that viability these demographic linkage (i.e. inter-population movement both sexes) Canadian bears. Using individual-based genetic analysis, our results suggest this connection been severed across their entire southern Canada by a highway associated settlements, limiting female reducing male movement. Two resulting are vulnerably (≤100 animals) one completely isolated. Our trans-border be more threatened than previously thought efforts must expand include international connectivity management. They also demonstrate ability analysis detect gender-specific fragmentation recently disturbed systems, traditionally intractable increasingly important ecological measurement worldwide.