Wild Neighbors: A Death in the Family

By Joe Eaton
Monday July 05, 2010 - 01:38:00 PM

A couple of days ago, I got word of the passing of another local celebrity. Although never the shot-blocker that Manute Bol was, she had her own dedicated following. She was a beaver, the matriarch of the Alhambra Creek clan in downtown Martinez. 

Heidi Perryman’s Martinez Beavers website has all the details. 

Mom, as she was generally known, was thought to be about six years old. (The longevity record for a North American beaver, according to the Animal Ageing and Longevity Database, is just over 23 years.) Recognizable by a distinctive notch in the side of her tail, she had been observed in the Alhambra watershed before she paired with her mate and got down to the business of dam construction in the fall of 2006. 

Mom and her mate produced three litters of four kits each, beginning in 2007. Two of the first batch succumbed to parasitic roundworms; the survivors took off on their own. Of the 2008 litter, one died, two dispersed, and the fourth hasn’t left the natal pond. All four of last year’s kits were killed by predators, possibly mink. 

The female lived just long enough to see a third litter enter the world. They were first reported June 9 and are thought to be old enough to feed themselves. The two-year-old sibling is keeping an eye on them. No word yet on Dad’s status. I can’t speculate about the grieving process in beavers. 

Perryman had noticed about the time the kits appeared that the mother was looking less well groomed than usual. Beavers are meticulous creatures, so that was cause for worry. Mom may have been applying the secretions from her castor gland to the new kits rather than her own fur. 

On June 24, Perryman wrote that “Mom beaver is looking much worse and appears to be near the end of her remarkable life…Beavers generally try not to die in the lodge, and mom appears to be staying to the banks, curling up weakly.” The beaver also seemed to be having difficulty eating. Perryman and other Martinez beaver advocates agonized over what to do. 

Last Saturday, the beaver was on the creek bank, listless, wet, and disoriented, staggering when she tried to move. Volunteers nudged her into a pet crate and drove her to the Lindsay Wildlife Museum’s hospital in Walnut Creek. 

On examination, she was emaciated—down to 34 pounds; normal weight could be as much as 60 pounds. Her magnificent wood-gnawing incisor teeth had finally failed her: one of her upper incisors was broken, and the two lower incisors had grown into her upper palate. (Incisor malocclusion and overgrowth can be a serious health issue for pet rodents and lagomorphs.) Too far gone for treatment, she was euthanized. 

In her short but prolific span, the female beaver was an effective good-will ambassador for her species. The Martinez family, just by being beavers, did a lot to enhance consciousness of the beaver’s role as an ecosystem engineer. Public support forced city officials to back off from an initial plan for lethal control and to work out a modus vivendi with the rodents. 

What happens now? Will the two-year-old sibling stay on as a parent-surrogate? Will the widowed male mate again? Will one of the dispersers return? Stay tuned.