facebook pixel
Bay Nature magazineOctober-December 2004

Scientist: Howard Shellhammer

Voices from the Field

by on October 01, 2004


Howard Shellhammer is known as the champion of a very rare mouse. A world expert on the endangered salt marsh harvest mouse, the former San Jose State biology professor has studied these diminutive rodents for over four decades, and spoken out often on their behalf. Defending the mouse “is a way to defend marshes,” Shellhammer says. “Because if the marsh supports this mouse, it will also likely support the California clapper rail and salt marsh wandering shrew, two other species of concern.”

Since Shellhammer began studying them in 1961, the mouse’s numbers have dwindled at an alarming rate. Small populations survive today in isolated marshes scattered around the Bay. The primary reason for their decline is loss of habitat. Even though they are good swimmers, the mice need a zone of upper marsh thick with salt-tolerant plants in which to take cover during high-high tides. This habitat has been reduced by development and subsidence to strips just a few feet wide on the steep sides of levees.

According to Shellhammer, the pending large-scale conversion of salt ponds back to marsh is the potential life raft that could keep the salt marsh harvest mouse—and its complex wetland habitat—alive.

“I hope it will hang on,” Shellhammer says. “I’m arguing as much as I can for complete marshes with adequate escape cover for the mice. I’d like to see fairly large marshes with complete habitat zones included in this restoration process. Right now, small populations disappear in bad years and since they are often separated by too much unsuitable habitat the marshes don’t get restocked. Increasing the size and connectivity of the marshes would prevent genetic stagnation and increase the mouse’s effective population numbers.”

Shellhammer says he can finally see the light at the end of the tunnel. “I think of them as the ‘once and future marshes.’ Once they were much bigger and more complex than today, but I think someday in the future they will be that way again. And as I get older, I get more confident that this will happen.”

Most recent in Habitats: Freshwater, Bay, Marine

See all stories in Habitats: Freshwater, Bay, Marine

one comment:

Linda Alioto on July 27th, 2014 at 8:09 pm

You were my professor a number of years ago. I was a student at Fresno High School (graduated 1960), then attended San Francisco State 1960-61, then Fresno State and a few other schools after that. I’ve been interested in ecology from my very first college semester. Wildlife habitats are being wiped out at an alarming rate.

I live in Missouri now and have a large set of yards for a city dwelling. I try to be eco-friendly with my yardwork and plantings. The house I bought when I retired has no trees on it, but it has one tree root mound left and I can’t bring myself to rip it out of the ground because there are creatures who make their home underground in those roots an tunnels. My yard man has stopped grousing around about it and just looks the other way, mows it the best he can and doesn’t argue with me about it anymore. :-) Take care and enjoy life! Linda (Bales) Alioto

Leave a Comment





Bay Nature