Just to give you guys a few references for null plurals in elephant and lion. This is quite a common form for all game animals. I have only listed a few examples here.
Hunting the Elephant in Africa, and Other Recollections of Thirteenyears' Wanderings: and other... - Page 52
by C. H. (Chauncy Hugh) Stigand - 1913
"Two days later, while waiting for the canoe to be brought down, I followed a herd of elephant, and they took me past the spot at which the last elephant had ..."
Teaching and Hunting in East Africa - Page 67
by Dan McNickle - Biography & Autobiography - 2004
"Hunters pay attention to the wind. Hunters do not wade into a bog upwind of a herd of Elephant. The local..."
Elephant Protection Act of 1979 and the International Wildlife Resources Conservation Act of... - Page 73
by United States. Congress. Senate. Committee on Environment and Public Works. Subcommittee on Resource Protection - 1980
"... The elephant is of vital economic importance to the country whether from management programs or from safari hunting, and it is this fact ..."- Clearly not talking about one elephant. Oddly it uses the singular 'is' rather than 'are.' Maybe the US Senate need more time in school.
Heart Shots: Women Write about Hunting - Page 191
by Mary Zeiss (EDT) Stange - Sports & Recreation - 2003
"I think I am the first person ever to scout elephant by plane, ... The reaction of a herd of elephant to my Avian was, in the initial instance, always ..."
A Novice on the Nile - Big Game Hunting in the Sudan - Page 20
by Frank Weber - 2005
"... our elephant experiences of 19th, for steaming up river through the sudd ... herd of elephant on the left bank ..."
H.R. 1006 and H.R. 1472: Legislative Hearing Before the Subcommittee on Fisheries Conservation,... - Page 57
by Wildlife, and Oceans United States. Congress. House. Committee on Resources. Subcommittee on Fisheries Conservation - 2003
"... just due to encroaching civilization, sports hunting, and, of course, ... and a pride of lion moved in and it grew to be the largest pride in all of ..."