going unreported, the Nile crocodile along with the saltwater crocodile is estimated to kill hundreds (possibly thousands) of people each year, which is more than all other crocodilian species combined. While these species are much more aggressive toward people than other living crocodilians (as is statistically supported by estimated numbers of crocodile attacks), Nile crocodiles are not particularly more likely to behave aggressively to humans or regard humans as potential prey than saltwater crocodiles. However, unlike other "man-eating" crocodile species, including the saltwater crocodile, the Nile crocodile lives in close proximity to human populations through most of its range, so contact is more frequent. This combined with the species' large size creates a higher risk of attack. Crocodiles as small as are capable of overpowering and successfully preying on small apes and hominids, presumably including children and smaller adult humans, but a majority of fatal attacks on humans are by crocodiles reportedly exceeding in length. In studies preceding the slaughter of crocodiles for the leather trade, when there were believed to be many more Nile crocodiles, a roughly estimated 1,000 human fatalities per annum by Nile crocodiles were posited, with a roughly equal number of aborted attacks. A more contemporary study claimed the number of attacks by Nile crocodiles per year as 275 to 745, of which 63% are fatal, as opposed to an estimated 30 attacks per year by saltwater crocodiles, of which 50% are fatal. With the Nile crocodile and the saltwater crocodile, the mean size of crocodiles involved in non-fatal attacks was about as opposed to a reported range of or larger for crocodiles responsible for fatal attacks. The average estimated size of Nile crocodiles involved in fatal attacks is . Since a majority of fatal attacks are believed to be predatory in nature, the Nile crocodile can be considered the most prolific predator of humans among wild animals. In comparison, lions, in the years from 1990 to 2006, were responsible for an estimated one-eighth as many fatal attacks on humans in Africa as were Nile crocodiles. Although Nile crocodiles are more than a dozen times more numerous than lions in the wild, probably fewer than a quarter of living Nile crocodiles are old and large enough to pose a danger to humans. Other wild animals responsible for more annual human mortalities either attack humans in self-defense, as do venomous snakes, or are deadly only as vectors