The Catalina Bison Roundup (October to November 2011)
As I’ve mentioned, Catalina Island sports a fairly robust population of American Bison. Yes, THOSE American Bison, the ones that were nearly eradicated in the late 1800’s by wildly overzealous hunting. Normally native to the plains-states of the United States they have nevertheless made themselves quite at home on the rugged face of Catalina.
Introduced in the 1920’s for the filming of the not-exactly-classic movie “The Vanishing American.” After filming concluded fourteen individuals were left on the island due to budget constraints. With no natural predators and (if not abundant) sufficient food, the herd eventually swelled beyond its means.
Over time, Bison watching became a staple of the Catalina Island tourist experience. However, large grazing animals can devastate fragile grassland and sedge communities with ease and it eventually became clear that something needed to be done to control their burgeoning population. The current target Bison population for the island is (a somewhat arbitrary) ~150 individuals. A removal effort conducted several years ago achieved that number by relocating many of the females to the mainland (the bulls were deemed too large and aggressive to safely move) the resulting population is therefore heavily male-dominated a circumstance that benefits both tourists (everyone wants to see the bulls fighting during the rut) and the Conservancy (Reducing the number of females on the island greatly reduces the amount of work needed to carry out species management).
The current plan on the island is to administer a contraceptive (via dart-gun if necessary) to all viable females every year. The contraceptive in question reduces the ability of the target females eggs to interact with spermatozoa, thus making breeding impossible without the physiological effects of sterilization. The catch, of course, is that this requires all of the islands Bison to be rounded up every year for processing.
That was my job while on the island.
Broken down into simple steps, my days basically went like this.
Arrive at work at Seven in the morning and feed the Bison we’ve already captured and penned. They weren’t, as a general rule, too happy about being stuck in the corals, getting out of the truck wasn’t a very good idea most of the time.
Once feeding is finished either head to the last known location of a herd or set out blindly in an attempt to find an unreported group.
IF we found a group half of us would stay with the trucks while the other half bailed out, grabbed backpacks, and attempted to herd the Bison in the direction of the pens using only strong language and thrown rocks. This worked about as well as you might expect it to. Bison are surprisingly quick, even on incredibly steep slopes, and could easily out distance us.
IF we managed to get them back to the catch pens then everyone would get back in trucks and attempt to herd them manually into more secure locations. Again, this involved a lot of trial and error.
IF we didn’t manage to get them back to the catch pens (as was the case most days) we’d lay out a trail, Hansel and Gretel style, of alfalfa between where ever they were ignoring us from and the pens in the hopes of luring them closer before the next day.
IF we didn’t manage to find any on a given day we’d instead busy ourselves repairing the damage that the captive Bison were constantly inflicting upon the pens and hoping that tomorrow we’d have better luck.
All in all we managed to capture ~90 of the Bison roaming free on the island – that number including all but ~18 of the mature females – before our time ran out. Enough to call the whole operation a success, but not a particularly resounding one.
Especially since the last sizable herd of females managed to evade us with a newborn in tow.
Posted on December 1, 2011, in Catalina Island and tagged Animals, Bison, California, Catalina, Invasive Species, Land Management, Nature, Photography, Places I've worked. Bookmark the permalink. Leave a comment.