Recolonizing wolves influence the realized niche of resident cougars.

摘要: Background: Niche differentiation may betray current, ongoing competition between two sympatric species or reflect evolutionary responses to historic that drove apart. The best opportunity test whether contributes niche is for behavioral shifts by the subordinate competitor in controlled experiments which abundance of dominant manipulated. Because these circumstances are difficult coordinate natural settings wide-ranging species, researchers seize opportunities presented reintroductions. We tested new reintroduced wolves and resident cougars Southern Yellowstone Ecosystem assess might be impacting realized cougars. Results: Between 2002 2012, a period during increased from 15 as high 91 study area, significantly percentage deer decreased elk their diet summer. Our top models explaining changes identified availability, defined number per wolf each year, strongest predictor changing cougar prey selection. Both were simultaneously declining system, though more quickly than elk, numbers exponentially same time frame. Therefore, we concluded availability did not explain switching with at least partially explained deer. also recorded 5 marked kittens killed 2 an undetermined predator. In addition, 2005 9 adult 10 died starvation, part wolves. Conclusions: Direct interspecific predation shifting selection system provided evidence recolonizing Through competition, have impacted (SYE), current now exhibit reflective era when previously Ecosystem.