Finally Watched the Bats on Yolo Causeway

IMG_2627Most of us are afraid of bats at an almost instinctual level. Unlike snakes and spiders though, I am hardpressed to name a species of bat. The other night I learned there are more species of bat of any other type of mammal except rodents. I might have known at one time in Jr High biology that bats are mammals, but it was good to be reminded.

I wasn’t prepared for the bat expert, Corky Quirk, to have live bats on display in small plastic carriers. They were fascinating to look at up close and watch as they stretched a wing or moved about. However, I was still pretty creeped out. Corky gives a great presentation including playing a rap on echolocation. She uses a camera to give us an larger than life view of the bats eating.

After a quick last bathroom break and a chance to buy a t-shirt, we piled into the van and our cars and drove out to the public entrance to the Yolo Bypass Wildlife Area and drove the loop until we needed to turn off onto some farm roads to reach where the bats live during the day. You cannot go there without the Foundation volunteers, although you can watch a smaller colony of 15,000 bats fly out from the first parking lot.

IMG_2629The best time to see them leave is about 30 minutes before sundown. The sun had already mostly gone down when the ribbon of bats started exiting from under the Yolo Causeway. It was impressive. The colony we watched fly out to eat insects all night under the Yolo County sky was a mix of mothers and adolescent pups. Bats do us a great service by eating their weight in insects every night (and twice that when moms are nursing). I was happy to learn so much about this small but mighty member of our ecosystem.

C715A256-2067-4134-87D6-DE8AA07FA297I’ve been a supporter of the Yolo Basin Foundation for 5 years and have heard various people extol the niftiness of watching the bats leave their “cave” under the Yolo Causeway. Finally I helped to organize a group of colleagues so I participate in one of the Bat Talk and Walks. You can sign up for a public Bat Talk and Walk on the Foundation’s website. Or you can contact Corky and arrange a private tour for your group, $12 per adult and a minimum $240 donation. You must have at least 12 and they can accommodate up to 60 people.



Hooray for Floodplains, Food Webs and Fish!

This excellent video describes the Nigiri Project at Knaggs Ranch in the Yolo Bypass. Watch as these students explain the importance of floodplains to producing food for salmon fry. These young fish move from the gravel spawning beds on the Sacramento and Feather Rivers toward the ocean. Due to our flood control levees they have lost 95% of their floodplain feeding grounds.

Lulu the Wonder Dog sniffing out the fish at Knaggs Ranch.

Lulu the Wonder Dog sniffing out the fish at Knaggs Ranch.

Farmers in the Yolo Bypass have been working with UC Davis and government scientists to prove that fish will grow at record rates on rice fields when flooded in the winter time. As the fields are drained, the fish continue their journey to the ocean and the food is flushed into the Delta where it provides food for Smelt and other native fish.

Local stakeholders have worked out an integrated plan that meets flood, fish, farm and waterfowl needs. It is now before government agencies to seize the opportunity for breakthrough.

Wild Rice a Boon to Wildlife in Yolo Bypass

Wild rice harvestI had the good luck to tour the Yolo Bypass one morning when the farmer who has the lease on the Yolo Bypass Wildlife Area was harvesting the wild rice. It is fascinating to watch as the fields are kept wet and a special harvester picks up the rice to lop off the heads.

It leaves in its wake a field with insects and crayfish exposed. The ibis and egrets enjoy a feast.

ibis and egretsThe Yolo Bypass is in the Pacific Flyway. In a few months ducks, and geese and other waterfowl will return to the 16,800 acres of the Yolo Basin Wildlife Area to feed and breed over winter. The wildlife area is a short distance from Davis and West Sacramento, and yet when I stood there with the Causeway within site, it felt like miles away from civilization.

The Wildlife Area offers designed wetlands with plants that provide food for waterfowl. Another section is leased to farmers who raise rice–both white and wild–that provides an income to the Wildlife Area and leaves behind a lot of rice grains for the birds.

Giant Garter Snake habitat could be quite extensive with good management practice like only mowing half the ditch.

Giant Garter Snake habitat could be quite extensive with good management practice like only mowing half the ditch.

Rice farmers also provide other habitat benefits. Some stage the draining of their fields to provide shorebird habitat. Others mow just one side of the ditch to benefit giant garter snakes.

The Yolo Basin Foundation provides tours of the Wildlife Area to over 4,000 school children a year and special events, such as bat tours and bird watching walks. You can also access the Wildlife Area during daylight hours. Start at Parking Lot A at the exit closest to the Causeway and drive up and over the levee. No dogs or bicycles allowed.

Nigiri Project Wraps Up Another Successful Year

You can read about the conclusion of another successful year of salmon fish fattening on Knaggs Ranch rice fields on this San Francisco Chronicle cover story.  Or…

Salmon ready for their journey to the PacificOnce upon a time the California native salmon population was dwindling. Every year the fish hatcheries would release hundreds of thousands of salmon to have a miniscule return because the river was so channelized that the fish could not find the important floodplain habitat where they need to put on weight and delay their migration to sea to a time when the upwelling off the coast of San Francisco provides food.

Then one day a Department of Water Resources scientist Ted Sommers had an idea. He placed a 100,000 tagged hatchery fish in the main stem of the Sacramento River and 100,000 tagged hatchery fish in the Toe Drain of the Yolo Bypass (a flood control area that can still operate like a floodplain). He caught 16 fish in the Bay trawls at the end of a few weeks and the Bypass fish were noticeably bigger. And then Carson Jeffres, a grad student at UC Davis decided to build off of this with an experiment on one of the few remaining undammed rivers in NorCal. He created an experiment on the Cosumnes River, which resulted in the now “famous” cooler picture of floodplain salmon three times the size of the other salmon. This resulted in the National Marine Fisheries Service requiring 17,000 acres of floodplain habitat in the Sutter and Yolo Bypasses as part of the Biological Opinions for the water agencies to continue pumping water through the Delta.

In some ways this seemed like an “all is lost” moment because the agencies interpreted that as flooding the Bypasses wall-to-wall for long periods of time and this would have made it tough for the farmers and duck clubs in the Bypass to survive and then this would have compromised the Bypasses as a flood control structure.  Until one day John Brennan, a farm manager/appraiser/rice drier owner put together a group to buy Knaggs Ranch and experiment with using rice fields as surrogate salmon floodplain habitat. And now 3 years later the experiment has proven that the rice fields with water held for up to 6 weeks create “Floodplain Fatties”. And a coalition of farmers, scientists, fish advocates, county folks, wildlife area managers, and agencies are proposing a management system that is compatible with all of the existing uses in the Yolo Bypass. This year is a drought year and naturally really tough on fish. Access to the floodplain will give them resiliency to survive this kind of water year and in the future sea-level rise and warmer temps. It is also Conservation Measure 2 in the Bay Delta Conservation Plan.

Birding at the Yolo Bypass Wildlife Area

On a bright and beautiful day in April I drove out to the Yolo Bypass Wildlife Area to see the birds.  There are many, many more birds in winter.  In April, most have migrated north to their nesting grounds where they will raise another generation.  There are still many, many birds to see including red wing blackbirds, egrets, Swainson hawks, among others.

I made this little video to give you a taste:

The Yolo Bypass Wildlife Area is just off Interstate 80 at the E. Chiles Road exit (by the fruitstand).  You may also recognize it as the place where Davis youth write messages in stone on the side of the levee.

You can download this map from the Yolo Basin Foundation’s website to find your way through the Bypass:

There are picnic tables and port-a-potties at each of the parking lots.  If you do picnic, please keep the refuge tidy.

There is no entry fee for enjoying the Wildlife Area, however, if you enjoy birding or picnicking, consider a donation to the Yolo Basin Foundation at

Also, you are in a floodplain that serves as the release valve for Sacramento’s flood protection.  So if you are going to see the birds after a big storm or while it is raining, the area may be closed.

Nigiri Project: salmon on rice

The Yolo Bypass is tucked between Woodland and Sacramento and yet when you are in the middle of it you feel a million miles away.  My car stirred great blue herons and snowy white egrets as I drove along the levee to meet John Brennan and Emily James.  I had forgotten just how great is the wingspan of these birds so I slowed and paid attention to their elegant flight.

John and Emily directed me to park my car and I hopped into their truck. Our first stop was at the top of the property where they operate a  seasonal earthen dam to direct water from the Ridge Cut Canal at the bottom of the Colusa Drain into the fields. This is the water that floods up the rice fields in winter to decompose rice stubble and provide waterfowl habitat. With duck season over at the end of January,most rice farmers or duck club managers have pulled out the boards on the fields and drained them. They’ll go on vacation with their duck club widows and then return to begin prepping the fields for planting rice in April.

There are other crops grown in the Bypass–safflower, sunflowers, tomatoes–and cattle and sheep graze, but in this section the predominance of clay soils makes it good for growing rice.  And there is a long established symbiosis between waterfowl and rice.   What seems like a new idea is that this seasonal floodplain might also be ideal for fish.

In 2001 Ted Sommers and colleagues published a paper about the importance of floodplains as temporary Chinook salmon habitat.  It caused some excitement at the time, but it took just over 10 years before he was able to stage an experiment with hatchery salmon fry in the Yolo Bypass.

Before the levees, when the salmon runs were much higher than today’s 50,000 fish, the young salmon would regularly find themselves out on the various floodplains that bordered the Sacramento River where they were  able to find a safe place to feed and grow before heading out to sea.

This year the seasonal floodplain was recreated on the lower five acres of a Yolo Bypass rice field. Ted’s crew with the Department of Water Resources (DWR) and a crew from UC Davis set up experiments with 10,000 hatchery fish: releasing them to eat and grow from the end of January to mid-March.

Recently I was able to visit the intentional floodplain to see the conclusion of the experiment.  The two crews worked together to catch and count the fish before they released them into the Bay Delta.

A portion of the fish had microchips inserted that made it possible to wand them and record their growth rates. The DWR study is straightforward: fish in, fish out, fish size and fish health.Their preliminary findings showed very healthy fish that had doubled in length and quadrupled in size.  The UC Davis study designed by Peter Moyle and Jacob Katz prepared various rice stubble treatments and made fish pens within the floodplain to hold fish and see if their growth and survival rates varied with the various treatments. These are the black pens in the midst of the flooded field.

The UC Davis grad students were also taking random samples of fish to measure and a few were packed to take back to the lab to check for other growth indicators.

On the day I visited the mood was jubilant.  Everyone was working to count the fish before the forecasted storm made it harder to get into the site.  They were also having a good time doing what they love most.

John Brennan the farm manager for the Cal Marsh & Farm Ventures where this project is taking place is one of the most enthusiastic and well-spoken of the team members.  He has spent hours explaining the project to reporters and others who need to understand what the potential is for fish in the Yolo Bypass.

John can envision a wayto manage for fish on the their rice fields on a seasonal basis. And he explains how this 5 acre project can be incrementally expanded until 1,000,000 small salmon safely grow to a size where they have a better shot at making it to adulthood.  If they can improve the return rate of the fish to 2% , then this site can potentially grow the salmon run from 50,000 to over 70,000 and so on.

John thinks the project is important because it stresses the integrated management of a working landscape, which he sees as the path forward, with the agricultural community, as the true stewards of the land, taking a lead role in the designing and implementing the environmental solutions of the next generation.

It is also an important lynchpin in the conservation strategy for managing the water supply operations in the Delta under the current Biological Opinion (that is the opinion by the fish agency NMFS about what steps must be taken to keep the salmon from becoming extinct). It becomes even more important in the proposed Bay Delta Conservation Plan.

The idea is controversial.  Yet, the Yolo Basin has long had multiple uses as farmers and wildlife refuge managers have worked together to provide flood protection, food, and habitat.  This is another benefit that can be accommodated if good will can prevail.