Went to hear a biologist this evening re an ongoing study on blacktail deer and cougars. The deer study is in its 5th year and the cougar into its second year. I wish I'd gone prepared to take notes but didn't so this is from memory. Among predators, cougars had the most kills of blacktail deer, black bears the second and bobcats were third. Most of the bear kills apparently were fawns under 7 weeks old.
The biologist said that they started out to study cougar kills of deer but ran into so many bobcats and bobcat kills that they had to expand their study to include bobcats. Over the four years for which they have compiled deer mortality, my rough average of their data showed that bobcats killed about 1/3 as many deer as cougars did.
In the highest bobcat kill year, bobcats killed as many deer as cougars. In the low year, they killed 20% as many.
They had at least 27 cougars and 160 bobcats in the area studied, so the deer kills per bobcat are much lower, but total kills make bobcats a major predator on blacktail deer, in that area.
