"We think ... in terms of the stress and fear and pain the animal is subjected to, it is the worst event at the Stampede, and we're hoping our campaign will continue to raise the concerns about that event," Peter Fricker, the humane society's communications officer, said in an interview with The Canadian Press.
The event features a running calf and a rider mounted on a horse. The rider must catch the calf by throwing a loop of rope from a lariat around its neck. He then dismounts from the horse, runs to the calf and restrains it by tying three legs together in as short a time as possible.
"We have written to Mayor Nenshi in Calgary asking him to urge the Stampede's board to consider dropping calf roping, as he is a member of the Stampede board. We think he has a reputation as a very progressive and compassionate man," Fricker said.
"He has a lot of respect in the community and we think if he were to speak to the board about this that they would be obliged to listen."
The letter was sent to Nenshi last spring. He received over 1,300 emails from concerned citizens encouraging him to use his position to help ban the sport. The mayor politely declined.
"Although the mayor of Calgary has a seat on the board of the Calgary Stampede, the Calgary Stampede has ultimate authority over animal care at the Stampede rodeo," Nenshi replied in a letter to the humane society.
"Your inquiries and campaign should be directed toward that organization. However, I can say that the Calgary Stampede takes animal care very seriously and has been recognized across North America for its commitment to ensuring the health and safety of all the animals that participate in Stampede-related events."
The letter, dated April 13, included a short note at the bottom in the mayor's handwriting. "Thank you for your interest in the matter and your continued advocacy for animals."
Nenshi pointed out the Calgary Humane Society and the Alberta SPCA are working with the Stampede to make sure animals are well looked after.
It's not the first time Nenshi has been approached about banning calf roping. He received a letter last July from the mayor of Surrey, B.C., who encouraged him to follow the example set by the her city's annual Cloverdale Rodeo in 2007.
Mayor Dianne Watts said a decision to ban calf roping, steer wrestling and team roping has not hurt the event's popularity.
"Thank your for your thoughtful consideration of this request, which would improve animal welfare and serve as an example for the rodeo world," she wrote.