More carriers chimed in Tuesday after several major airlines began banning shipment of big game trophies amid outrage over the killing of Cecil the lion in Zimbabwe.
Air Canada announced that it would refuse to transport such big game animals as lions, leopards, elephants, rhinoceros or water buffalo, while the United Parcel Service (UPS) declined to follow suit.
Their decisions come just one day after US airlines Delta and American banned the shipment of big game trophies on flights.
"There are many items shipped in international commerce that may spark controversy," UPS said in a statement.
"UPS takes many factors under consideration in establishing its shipping policies, including the legality of the contents and additional procedures required to ensure compliance," it added.
"We avoid making judgments on the appropriateness of the contents," UPS said.
Despite Air Canada's ban, it said in a statement that it does not fly to Africa and so such shipments aboard its flights were rare to date.
United Airlines chimed in adding that its records showed it had not transported animal trophies in the past.
In a brief statement Monday, Delta said it would immediately "ban shipment of all lion, leopard, elephant, rhinoceros and buffalo trophies worldwide as freight."
It added that it would review its acceptance policies for other hunting trophies with the appropriate government agencies and other organizations.
Meanwhile, American tweeted that it would "no longer transport buffalo, elephant, leopard, lion or rhino trophies."
The decisions follow similar measures taken by Emirates and South African Airways.
The bans come during the peak hunting season in certain African countries and amid a worldwide outcry over the killing of Cecil by an American dentist and trophy hunter.
The lion, with a distinctive black mane, was a favorite with international visitors to Zimbabwe's Hwange National Park.
Authorities in Zimbabwe recently named another American alleged to have taken part in an illegal trophy kill of a lion in the country.
A government statement also said a safari organizer has been arrested as part of the crackdown on hunting near the big game reserve where Cecil lived.
American dentist Walter Palmer killed Cecil with a bow and arrow and paid some $50,000 for the hunt.
Hunting of such game has been suspended barring special permission from wildlife park authorities.