Trapping vs Depredation

Yesterday was a lovely day of post conference glow, but now it is monday and the ominous week awaits us all. There is never enough time to do all the things for beavers that we imagine. Yesterday I poured my free time into puzzling over the trapping records which were meticulously maintained since 1950. I got thinking about it listening to Mike Settell’s presentation about trapping in Idaho.

You see, fur-bearer trappers have to report their take of species by county at the end of the season. And Fish and Game has been compiling these records back since 1950. They have to also indicate how many of the furs they sold and for what price. Over the years the very most lucrative fur has been muskrat, with a decade of interest in bobcat as well. Beaver prices have never been worth much, varying in price from a high of 21 in 1980 to a low of 4 in 1970.

If we were to take these beaver trapping records and plot them on a graph they would look like fairly steady slope downwards. There were 1686 beaver reported trapped the year I was born and only 60 last year. Now you might be thinking, wow that’s great! Less beaver killed! But you’d be wrong. Because while trapping has gone down, depredation has gone UP.

It is illegal to sell fur after depredation. And you can imagine that the rugged outdoorsy trapping has gone down as we’ve become more urbanized. Clearly the conflicts with landowners has gone up as we moved into every nook and cranny of wild space.Theoretically the two systems are independent and have different unredeeming qualities For example, there is no limit of ‘take’ on beaver so you could trap all you want. But there is a limit to ‘depredation’ and you can only kill what you have permission to remove.  However, when you trap there is at least some record of how many were killed because you need to report what you took and where it was from, whereas no one has to report their totals in beaver depredation at all. Trapping records, such as they are; are public and online. They are fairly comprehensively organized by county and species. Depredation permits are private, hard to access and cryptically maintained.

In fact, I would argue that depredation is the vast black hole into which our beaver resources are being poured today.They disappear and no one records the loss. Robin and I will be working on a spread sheet of the declining trapping business on beavers, but here is a little taste of the numbers.

You can see the pattern fairly clearly here. The big surprises for me were the numbers taken in specific counties. The year I was born  there were a whopping 96 beaver trapped in Contra Costa County. The 60 year record goes to Plumas county with 282 beaver trapped in 1955. Butte county is a consistent high water mark regardless of year, Stanislaus and Sacramento are high until depredation takes over.

The shocker to me came in the very first record for 1950. when it reports an impossible 182 beavers were trapped in Riverside county in Southern California. The arid region boasts .3 square miles of water. And zero depredation permits in our last accounting. There are minimal numbers of beavers all the years since. So where does this boom come from? I can only conclude it’s a data entry error. Riverside is right next to Plumas in the list, and Plumas often has large numbers. So that’s probably what happened.

Unless there was a beaver invasion in Southern California in the 50’s?