got-peckers

C. c. acadicus Bailey	c. frondator Mearns Sonora beaver	C. c. pallidus
C. c. baileyi Nelson	C. c. idoneus	C. c. phaeus Heller Admiralty beaver
C. c. belugae Taylor\Cook Inlet beaver	C. c. labradorensis	C. c. rostralis
C. c. caecator Bangs Newfoundland beaver	C. c. leucodonta Gray Pacific beaver	C. c. repentinus Goldman Sonora beaver
C. c. canadensis Kuhl Canadian beaver	C. c. mexicanus Bailey Rio Grande beaver	C. c. sagittatus
C. c. concisor	C. c. michiganensis Bailey Woods beaver	C. c. shastensis Taylor Shasta beaver
C. c. carolinensis Rhoads Carolina beaver	C. c. missouriensis Bailey Missouri River beaver	C. c. subauratus California Golden beaver
C. c. duchesnei	C. c. pacificus Rhoads Washington beaver	C. c. taylori Davis

So theoretically there are 25 subspecies of beaver in the united states. The three in yellow are native to California. These subspecies are supposed to have slightly different skull morphology and slightly different ‘habits’. When subspecies don’t look noticeably different, or act noticeably different, they are defined as a variety of the species that is separated by some geological feature but generally could, if it weren’t for circumstances, breed comfortably with others outside its subspecies. Different races of humans are not called ‘subspecies’ for obvious reasons, but different types of dog are. There is some early description of golden beaver only knowing how to make ‘bank lodges’ instead of island lodges. In his famous chapter that is often cited, Grinnell noted that these beavers have lost their skill at making canals, somewhat at damming, and even that they are less likely to leave footprints!

Grinnell speculated that the golden beaver wasn’t ideally suited to the higher elevations, and even though they were eventually reintroduced and did fine (thank you very much) there are some who have argued that is because of their cross breeding with other beavers from heartier strains. Importantly, Grinnell did much of his research at a time when there weren’t many beaver left in california to get an adequate sample. Remember that way back in Morgan’s writing there was discussion of “slave beavers” based on the observation that some skins had dented heads, and were obviously the ones that did the damming work by breaking boards with their skulls.

Nowhere does he mention that regional and terrain differences might have more to do with varied behavior than genetics. For example, beavers on wide bodies of water like the colorado river build bank lodges and do not build dams, regardless of subspecies. When Rick saw our ‘bank lodge’ with built up wood atop he was confused. Was this a ‘bank lodge’ or an ‘Island lodge’? His work on the Shasta subspecies in the lassen area occurred very soon after the last volcanic eruption, and probably isn’t a good read of what is ‘typical’ either.

So one discussed goal of the “Historic Range of Beaver in California work group” (still working on the acronym) is proposing a “Lets Investigate Early Subspecies’ (LIES) paper as well. An interesting conversation is taking place with several genetic experts to see what testing would involve. A very important caution is that most historic beaver skins were preserved using arsenic, so care must be taken when collecting samples. Interestingly, we just had word that beavers were also ‘reintroduced’ in other states, some of the very states that supposedly were used to ‘reintroduce’ heartier california beavers. What this means is that whose beavers are whose might be anyones guess!

Okay, I woke up this morning ready to write a somber introduction to the fur trade in California with all the exciting new beaver murder mysteries I’ve been reading, but instead I got immersed in this paper sent to me this morning by our wikipedia friend. It is Grinnell’s chapter on the Beaver in the 1937 UCB zoology departement’s “Fur Bearing Mammals of California“. Grinnell is a very important author, recognized for his conservation, and an early advocate for beaver. I especially liked his illustration of the interior of a bank lodge.

The lovely conclusion of his paper says,

The beaver is one of our most popularly appealing native mammals and should be conserved and encouraged for this reason alone, when other considerations permit. It might be advisable, even, in certain districts where they are somewhat detrimental to the works of man, to condone their shortcomings on the score of their esthetic and educational value-to maintain them so·that they will be accessible for observation by the public at large, both adultsartd children. The latter, especially, find in beavers and their works a keen stimulus to wholesome enquiry.

Ahhh that pretty accurately describes our experience here in Martinez. I’d like it embroidered into the lining of the suits of our council members. Obviously the author had an affection for beavers and enjoyed watching them from time to time. He writes beautifully about kits and the experiences of folks who had the fortune to raise them. He describes what its like to see a beaver making a “V” in the water as it approaches and it is clear he’d feel right at home in Martinez.

Of course, he also notes that Golden Beaver don’t live above 300 feet elevation in California, that our beavers have lost their construction skills and don’t leave footprints, that dam building indicates no signs of intelligence in general and that beaver males fight to the death to mate with the “herd”. He added that, while females were home-loving and family oriented, males mated with everything they could score and had more injuries because of this.

Sigh. More beaver myths.

He ultimately talks about the good that beavers do in the environment and notes that some ranchers were particularly fond of their presence. When beaver dams caused damage to their crops or roads, they tried to discourage building by using a pipe to drain water. Apparently the clever creatures dammed up the pipe pronto. He writes of a particular landowner taking some rather usual measures,

Steel traps were then set in the shallow water of the irrigation canal where the beavers had a dam, and several of the animals were caught. These trapped beavers were soundly spanked by the rancher, who used a good stout board for this purpose. He had protected them on his ranch for years and still did not want to kill them. After they had been spanked and turned loose they stayed away for a while, but a few weeks later some of the same beavers, identified by the trap marks on their toes, were again caught in this canal.

For the record, beating a prone, helpless 40 lb animal with a board is called “clubbing” not “spanking”, and thank God it didn’t work…Good lord, don’t let the council read this. I can see one particular property owner right now out there with a paddle. This goes into the next article on “the history and invention of flow devices”. I’m sending it to Mike and Skip right away! Mind you, it’s all relative. Yes the beavers rebuilt the dam, but I’m sure they were really sorry about it.

Can we just say that there are flaws with the Grinnell article and leave it at that? Obviously California beavers build dams, leave footprints, eat vegetables, care for young, and lived in elevations over 300 feet. All those trappers weren’t in our rivers for the view. If you’re interested in my longer notes on the article drop me a line and I’ll send them to you.

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