I know that most predators like tigers, wolves and lions don’t always catch their prey. which predator is the best at catching prey when compared to other mammalian species? Do reptile, fish and avian predators have the same success rates?
Pack hunters like wild dogs are usually pretty successful (relatively speaking)
I would guess insectivorous bats. They have to catch a huge number of very small prey to meet the energy demands of non-gliding flight.
Regards,
Shodan
Niko Tinbergen describes the hunting of water shrews in one of his books. They sound fearsomely aggressive, and they’d have to be – shrews have to eat a huge proportion of their body weight to maintain themselves – much more than larger mammals like dogs. I’d give them a vote for “most effective” 9out of necessity).
Hedgehogs are mammals; they prey on slugs which aren’t terribly agile; result: near to 100% success rate on hunts.
I’d think that man would be up there, too. 
I’ll second the shrew idea…
I would guess the polar bear would be up there since its main prey is seals, which are relatively abundant and mostly defenseless.
I don’t think so. I have friends who take time off during deer season. They drive to their or a friend’s “camp” where they drink a huge volume of beer. If one or two hunters out of a group of 10 gets a deer, they are all happy. If nobody winds up maimed, it is a successful hunt.
While I know of hunters similar to vetbridge’s group, those that I know consider any injury a minor failure of the trip… it means they left the cabin! 
I on the other hand actually hunt, both at camp, and locally to my home. 6 years hunting, 1 deer. Not a very good percentage. Granted, I don’t really know what I’m doing yet, not having grown up in a hunting family. I also won’t starve if I don’t get a deer in a given season, so I’ve the luxury of sleeping in when it’s too rainy, windy, hot/cold, tired, or whatever…
While a single deer would make a lot of meat, human hunters don’t need to be sucessful every trip out.
-Butler
I’m going to say one of the baleen whales. If swimming along and smiling counts as a “hunt”, then each whale catches millions of prey per hunt.
Seals actually manage to elude polar bears quite a bit of the time; usually by slipping into the water (either off the edge of an ice shelf, or through a hole in the bottom of an ice cave), where they are more agile than their attacker.
This is true, although I guess I was thinking more of calving season where there are a lot of baby seals.
I wouldn’t really class that as hunting. It’s more equivalent, I think, to the large mammalian browsers and grazers on land. The whales don’t go out hunting, they just gulp down the food that’s all around them.
Now toothed whales will actually hunt, but I have no idea how successful they usually are at it.
Even fairly young seals can elude polar bears (although probably not newborn ones) - some seals raise their young in snow caves with the only entrance being a hole through the ice, into the water - polar bears can break through the top and kill the seals, but only if they’re really quick and stealthy; in many cases, the seals escape by diving through the hole into the water - on balance, I think the hedgehog still enjoys a greater success rate.
Perhaps a bad example but it points out the difficulting in answering this. Is a successful hunter one that consumes large numbers of virtually defenseless prey or one that routinely kills prey much larger and physically capable than itself? In that category I’d put coyotes, wolves, large cats and humans. Of those humans had to invent tools to make up for lack of claws and fangs but managed to make huge impacts in animal populations without metal weapons. Look at it this way, is the man shooting fish in a barrel a more successful because he has a better hit ratio than a bowhunter? I’d say that is a good analogy to comparing moles and bats to wolves and tigers.
ARGH! Hedgehog. My bad.
Your basic housecat is a pretty fearsome predator. Especially when you consider that it’s efficient enough at hunting to get away with sleeping 20 hours a day or so.