In 2005, a group of Russian, American and Indian zoologists published an analysis of historical and contemporary data on body weights of wild and captive tigers, both female and male across all subspecies. The data used include weights of tigers that were older than 35 months and measured in the presence of authors. Their comparison with historical data indicates that up to the first half of the 20th century both male and female Siberian tigers were on average heavier than post-1970 ones. The average historical wild male Siberian tiger weighed 215. 3 kg (475 lb) and the female 137. 5 kg (303 lb); the contemporary wild male Siberian tiger weighs 176. 4 kg (389 lb) on average with an asymptotic limit being 222. 3 kg (490 lb); a wild female weighs 117. 9 kg (260 lb) on average. Historical Siberian tigers and Bengal tigers were the largest ones, whereas contemporary Siberian tigers are on average lighter than Bengal tigers. The reduction of the body weight of today's Siberian tigers may be explained by concurrent causes, namely the reduced abundance of prey due to illegal hunting and that the individuals were usually sick or injured and captured in a conflict situation with people.