RMA Bison Roundup


“Chutes and Ladders” Bison are moved through chutes while those working the roundup open and close doors from the walkways above the bison.

Rocky Mountain Arsenal National Wildlife Refuge conducted their annual bison roundup on Tuesday, the 17th. The bison herd, now at 86 animals, is rounded up, cajoled into chutes, and tested for a variety of things such as DNA, diseases, and contamination. It’s a facinating process to watch and in spite of the pros working the roundup, bison still go where they want to go. There’s a lot of bison psychology applied to moving a 1,500 pound wild animal through steel chutes and keeping them calm while taking blood, clipping hair, and extracting a piece of meat from their hind end. Other than a few bloody noses and a broken horn, everything went smoothly for the USFWS team.


“Roundup” Bison are pushed from a large holding pasture to a much smaller holding pen before entering the chutes. Bison like to stay in a group and can easily double back on whomever is trying to move them. They’re very athletic and can run at speeds over 30 mph. This pass caught about 35 bison, with a few breaking free to stay in the pasture awhile longer. The guy in the cherry picker basket is a National Geographic photographer.


“In Chute” Bison are moved into the first open chute in small groups.


“Bull Bison In The Hub” This 1,500 pound bull was extremely pissed off about being moved from a grassy pasture to this metal enclosure. The paddles are used to get the bison to move through a door and into one of the chutes. Three doors were open at one point and the bull pawed the ground, snorted, and kicked the sidewalls, but wouldn’t go through. He was allowed to go back into a bigger holding area to cool off.


“Bison Squeeze” There’s a lot of activity around the machine that holds the bison for blood, hair, and fat samples. Once a bison is in this squeeze machine, the sides are slowly closed in to apply pressure, the head secured to prevent injury, and the bison is processed in a few minutes. If they have a chip (rice-sized under skin) the chip is read to add data about the animal. If not, a chip is inserted while the bison is in this machine.


“Bison Head Secure” Some bison calm down in the machine, others fight the whole process, start to finish. For the latter, this guy goes in and turns the head, securing it with a rope. He holds the bison there until processing is complete and the animal is freed.


“Squeeze” This juvenile was held still by the steel bar until release in just a few minutes.

Rocky Mountain Arsenal NWR, bison

Frosty Bison Bull : Prints Available

A bull bison is covered with frost in a landscape of hoar frost. The temperature was zero degrees the day after Christmas. Bos bison

The RMA bison are now free to graze the winter grassland.

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