How the Harvest Mouse Came to Suisun Bay

A long, long time ago there was a family of harvest mice. Mice are common, but these were unique – born to those who had lived in the salty, marshy bay for many generations, these mice ate and drank from the sea as well as the land and rivers. For generations, there were only the southern families, scattered along the marshes of Corte Madera and in the San Francisco Bay (U.S. Fish & Wildlife, 2013). One family, however, would undergo strife and conflict before reaching a whole new world. What became of them after is another tale entirely – but this is how their story begins.

Lightfoot, Longtail, Peasprout, Sharpteeth, and Splittail lived in a pickleweed forest for most of their lives. Mother, father, two daughters, and a son, respectively, they happily shared their marsh with many other harvest mice families, nesting in dry grass and sedges just beyond the waters’ reach (Fisler, 1965). For a time, things were peaceful – until they weren’t.

Lightfoot’s parents’ parents spoke of a time before the floating wooden beasts, carrying upon their backs and within their bellies bare-skinned, long-limbed creatures cloaked in the fur and hide of others, but even that was told to them secondpaw from their elders. Lightfoot and her family knew not of these times, but they knew plenty of the wooden beasts. Boats, they were called, steered by humans to carry one another and their food. It was mainly the food Lightfoot was interested in.

Since the arrival of the humans and their boats, the marshes had grown smaller, fields of pickleweed replaced by sprawling wooden platforms and shacks, the beginnings of civilization – not that Lightfoot or her family were cognizant nor caring of this fact. All Lightfoot and Longtail knew was that they had less food, less shelter, and more dangers to worry about in their homeland. As families do in times of strife, they draw closer together and focus on the necessities – sometimes regardless of potential risk.

One day, a boat approached their marsh and – rather than stop at one of the platforms – moored itself directly into their hummock. The crashing of waves and shouting of commands woke Peasprout – always a light sleeper and in search of opportunities for snacks – whose startled squeaks stirred the rest of the family into scattering to higher ground just in time. A resounding thud disturbed several other families, who scurried deeper into the brush as several humans began trodding down into their marsh carrying barrels and other bundles of supplies.

Sensing an opportunity – humans always kept more food on their boats – Peasprout hesitated for only a second before squeaking out her idea and darting up the gangplank as soon as it was clear. Exasperated but not surprised, the rest of her family – and a few others lucky enough to be in earshot of Peasprout – followed quickly behind. Thus, the southern harvest mice found themselves stowaways upon The Diantha, unknowing of the fate it was destined for.

Onboard The Diantha, the families of harvest mice were easy to miss. Smaller than the palm of your hand and almost the same color as wood, they blended in perfectly to the nooks and crannies of the boat. At night, they emerged and scurried across the back rocking and swaying beast, while the humans it contained dozed, oblivious to the flurry of activity around them. The humans stored grains, plants, and all sorts of things in the belly of the wooden creature, without much security at all. It made it a simple matter for Peasprout and her siblings to forage to their hearts’ content, while Longtail and Lightfoot snuck away more morsels to hide in their makeshift nest.

They knew they were traveling away from their home, but they knew not which direction nor how long they would travel, so they prepared. Lightfoot and Longtail began to grow older, move slower, and their dark brown fur began to turn gray and thin. Most harvest mice lived for 12 Moons (years), give or take, and Lightfoot and Longtail were both approaching their tenth (U.S. Fish & Wildlife, 2013). Their family had survived owls and snakes, floods and droughts, but time is the fire in which everything burns – they could only hope that they would see their offspring reach this new land, or protect them as best they could until then.

It was early in the morning when The Diantha shook, a violent quake that immediately awoke all those on board. Lightfoot and Longtail were slower to rise than Peasprout and her siblings, but they made their way to the exposed deck and were equally ecstatic and terrified at what they saw. They were near the shore – near a salt marsh, even! - but the wooden vessel was caught on a sandbar separated by a wide inlet, and while the humans were only up to their chests as they caught ropes thrown to them and lowered smaller boats to the surface of the water, the depth and breadth of the water was not something they could traverse. They would have to wait, and stow away on one of the smaller boats, or they would be trapped and left to the whims of the ocean, the humans, and whatever new creatures awaited them in this new land.

It was several days until they had their opportunity. The humans had begun tearing apart The Diantha, starting at the highest point and working their way down. There were conversations of “scuttling,” and “Josiah Wing’s new storefront and homestead,” but all the harvest mice knew was that their temporary home was crumbling around them and they had to reach the land now, or they never would.

With the railings broken down and the smaller boats hung along the side to take away reusable wood and supplies, Lightfoot and Longtail led their children through the shadows to their quarry – a boat packed full of bundles of dried pickleweed and other grasses, several covered barrels fastened to the front and rear. Peasprout, Sharpteeth, and Splittail all managed to scurry over the edge and into the dinghy, but it was then that they heard and felt the dreaded footsteps of a human approaching.

Nearing their 11th Moon each, Longtail and Lightfoot knew what they had to do. Drawing attention to themselves, they squeaked and scurried in circles as fast as their aging bodies could, forcing the human to look away from the dinghy and call out to the other humans as they tried to shoo away the mice from their cargo. Not realizing that the two mice were not alone, and that their offspring had hidden away in the very boat the humans were trying to “protect,” one human ordered the dinghy to be lowered to the water and sent ashore while they made sure no other mice had gotten into their stores. Harvest mice were not burrowers, so they hid their tracks very well, but they were still big enough to be seen if out in the open (US EPA, 2010). Lightfoot and Longtail knew this, and so they gladly led the humans away while their children escaped, knowing that even if they never saw them again, they had done their duty and protected their family as best they could.

When Peasprout, Sharpteeth, and Splittail came ashore in the salt marsh, it was a bittersweet experience. They discovered that several other harvest mouse families had escaped as well, stowaways like them on the Diantha who had been hidden in the small boats themselves or in bundles and barrels taken ashore. The hurt of their parents’ sacrifice was dulled by their understanding of its necessity, and the newfound company of kin and kith. Many had been lost at sea, but enough had survived to see this new land and make it their new home, and the elders that fell to ensure that remained in the memory and stories of their kin for generations to come. Sharpteeth and Splittail in particular exalted the actions of their parents, telling the story again and again to any who would listen, while Peasprout agreed and took advantage of everyone’s distraction to sneak away food whenever she could.

Over time, the red bellies of the harvest mice began to turn white and tan, southern families becoming northern families and spreading further and further along the shore. Thanks to their journey at sea, they found that they could drink from the ocean as well as fresh water, to no ill effect (US Fish & Wildlife, 2013). They learned the name of their new home – Suisun Bay, or ‘Where the West Wind Blows.’ To this day, families of harvest mice live and call the Bay their home, nesting in the highlands of salt marshes amongst the cordgrass. They live alongside shrews, moles, and other smaller mammals, as well as larger ones such as foxes and tule elks. They are often hunted by hawks and kestrels as well as carnivorous mammals, particularly cats in more human populated regions (US Fish & Wildlife, 2013).

Because of their reliance on the saltwater marshes, climate change and habitat loss has been significantly impactful on the harvest mouse. Much of their land has been lost from rising ocean levels or repurposed to suit human needs – roughly 193,000 acres reduced to 30,000 in less than two centuries (US EPA, 2010) – but much like Longtail, Lightfoot, and their family, the harvest mouse endures and lives on.

References

Dingler, N. (2003). The three josiah wings: Shipping merchant, Pioneer, mayor. http://www.bellavistaranch.net/suisun_history/josiah_wing-dingler.html

Endangered species facts - salt marsh harvest mouse. US EPA. (2010, February). https://www.epa.gov/sites/default/files/2013-08/documents/salt-marshharvest-mouse.pdf

Salt-Marsh Harvest Mouse (Reithrodontomys Raviventris): U.S. Fish & Wildlife Service. FWS.gov. (n.d.). https://www.fws.gov/species/salt-marsh-harvest-mouse-reithrodontomys-raviventris

Smith, J., & Fisler, G.F. (1966). Adaptations and speciation in harvest mice of the marshes of San Francisco Bay. Systematic Biology, 15, 240.

Sustaita, D., Quickert, P.F., Patterson, L., Barthman-Thompson, L. and Estrella, S. (2011), Salt marsh harvest mouse demography and habitat use in the Suisun Marsh, California. The Journal of Wildlife Management, 75: 1498-1507. https://doi-org.ezproxy.library.wwu.edu/10.1002/jwmg.187