Posts Tagged: bats
Do you know where your pollinators are? Think bees, birds, butterflies, bats and beetles.
And think flies. Especially syrphid flies, also known as "flower flies" and "hover flies."
The UC Davis Department of Entomology and Nematology is hosting an open house during National Pollinator Week from 11 a.m. to 2 p.m. at its bee garden, Häagen-Dazs Honey Bee Haven on Bee Biology Road, west of the central UC Davis campus.
Here's what you can expect to see or do:
- learn how to catch and observe bees up close
- see honey bees at work in an observation beehive
- learn about bee diversity and identification
- learn about what and how to plant for bees
- learn about growing and good pollination in home fruit gardens
- see easy-to-grow bee plants and solitary bee houses available for a donation to the garden.
The Häagen-Dazs Honey Bee Haven, installed in the fall of 2009 and located next to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, off Hopkins Road, is a half-acre garden devoted to bee pollinator conservation and education. It was founded and sprang to life during the term of interim department chair, Professor Lynn Kimsey, director of the Bohart Museum of Entomology, who coordinated the entire project. Kimsey was singled out for her work when the Pacific Branch of the Entomological Society of America honored her and four others – "The Bee Team"– with the 2013 outstanding team award.
A Sausalito team – landscape architects Donald Sibbett and Ann F. Baker, interpretative planner Jessica Brainard and exhibit designer Chika Kurotaki – won the design competition. The judges were Professor Kimsey; founding garden manager Missy Borel (now Missy Borel Gable), then of the California Center for Urban Horticulture; David Fujino, executive director, California Center for Urban Horticulture at UC Davis; Aaron Majors, construction department manager, Cagwin & Dorward Landscape Contractors, based in Novato; Diane McIntyre, senior public relations manager, Häagen-Dazs ice cream; Heath Schenker, professor of environmental design, UC Davis; Jacob Voit, sustainability manager and construction project manager, Cagwin and Dorward Landscape Contractors; and Kathy Keatley Garvey, communications specialist, UC Davis Department of Entomology and Nematology.
Others with a key role in the founding and "look" of the garden included the UC Davis Art/Science Fusion Program, founded and directed by the duo of entomologist/artist Diane Ullman, professor and former chair of the UC Davis Department of Entomology, and self-described "rock artist" Donna Billick of Davis. Miss Bee Haven, a six-foot long worker bee sculpture, the work of Billick, anchors the garden. The art in the garden is the work of their students, ranging from those in Entomology 1 class to community residents. Eagle Scout Derek Tully planned, organized and built a state-of-the-art fence around the garden.
Why are pollinators so crucial? Take it from the Xerces Society for Invertebrate Conservation:
"Pollinators are essential to our environment. The ecological service they provide is necessary for the reproduction of over 85 percent of the world's flowering plants, including more than two-thirds of the world's crop species. The United States alone grows more than 100 crops that either need or benefit from pollinators, and the economic value of these native pollinators is estimated at $3 billion per year in the U.S. Beyond agriculture, pollinators are keystone species in most terrestrial ecosystems. Fruits and seeds derived from insect pollination are a major part of the diet of approximately 25 percent of all birds, and of mammals ranging from red-backed voles to grizzly bears. In many places, the essential service of pollination is at risk from habitat loss, pesticide use, and introduced diseases."
So, on Saturday, June 23, you won't see any red-backed voles or grizzly bears. But you'll see bees, butterflies, birds and beetles.
And flies. Syprhid flies.
For more information on the open house, access https://hhbhgarden.ucdavis.edu/wp-content/uploads/2018/01/Pollinator-week-flyer-2018-1.pdf
California is in the middle of the Pacific Flyway, a major north-south flyway for migratory birds, and also bats, that extends from Alaska to South America.
“Every autumn, migratory bats, such as the Mexican free-tailed bats, travel to their overwintering grounds in Southern California and Mexico, where there's plenty of bugs to eat; they come back each spring to raise their families,” said Rachael Long, a UC Cooperative Extension advisor who studies bats.
Bats are beneficial because they feed on insects, including mosquitoes and pests such as codling moths that damage fruit and nut crops. The economic value of bats for pest control on farms has been estimated by some studies to exceed $23 billion per year. Long, who serves Sacramento, Solano and Yolo counties, is studying the value of bats for pest control in walnut orchards.
In the city of Davis, officials recently warned people to stay away from bats after bats found on the UC Davis campus tested positive for rabies. Long agrees with the warning, but worries that it might also result in healthy bats being killed.
“This is most unfortunate for people and bats, but not a surprise at this time of year. Right now, thousands of bats are flying through our great Central Valley, migrating south for the winter, just like ducks and geese, so there's a higher chance of contact,” she said “We just don't see bats as much because they are flying at night, using the stars, earth's magnetic field, and landscapes to navigate.”
Their journey south is lengthy, from as far north as Washington state to Mexico, and exhausting, so bats need to rest along the way.
“Sometimes you'll see one or more tucked up in the corner of your house, such as under an eave,” Long said. “If so, use this as an opportunity to share with others the amazing life of a bat that can fly over a thousand miles to their overwintering grounds and back again in the spring. Leave them alone, let them rest, and they will fly away after they've rested and recovered.”
If you have to move a bat, she notes you should wear gloves and not handle a bat with bare hands because they will bite in self-defense.
“If you find a bat on the ground, place a box over the bat and using a piece of card, slip it under, then gently and carefully slide the bat into the box,” Long said. “Place the box at 4 to 5 feet off the ground and open it (bats usually can't take off from the ground). The bat can then crawl out of the box in its own time and fly away.”
“If the bat does not fly away within 30 minutes, it is probably sick or injured. In this case, contact a wildlife rescue unit in your area.”
Long noted that animal control officers have to euthanize bats to test for rabies.
“The bat may be perfectly healthy, just tired,” she said. “If no people or pets have obviously touched the bat, you can call a wildlife rescue organization. If in doubt, call animal control.”
If a bat does have rabies, Long said, “Rabies dies within five to 10 minutes after the bat dies.”
For more information on the benefits of bats, see Long's post in UC ANR's Green Blog, “Bats in the Belfry? No, Bats in Walnut Orchards” at //ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=17395.
What's the economic value of bats to the agricultural pest control? It probably exceeds $23 billion per year, according to recent studies. However, very little data exists on the benefits of bats for individual crops, such as walnuts.
UC Agriculture and Natural Resources researchers, together with UC Davis, are launching a survey to better understand the value of bats (and birds) on managed lands. The voluntary survey, focused on growers and landowners in California's Central Valley, may be completed online.
Work is already underway to assess the pest-control impact of bats on walnut production in the Central Valley with a grant from the U.S. Environmental Protection Agency STAR (Science to Achieve Results).
California produces almost all of the nation's walnuts. Farmers grow some 500,000 tons of walnuts on 290,000 acres, with the annual crop valued at $1.8 billion. Due to popular demand, new orchards are planted every year, calling for more intensive farming practices to manage costly crop pests. For walnuts, the key pest is the codling moth, a larva that feeds on developing nuts. The adult moths begin to fly and lay eggs on the nutlets in May and produce up to four generations per year.
Bats forage in walnut orchards for codling moths and other insects. Colonies of bats double their activity on farms when they roost in bat houses attached to barns in the orchards. The Mexican free-tailed bat is the most abundant species, followed by the Yuma and California myotis, and five other species, including the pallid bat.
In an effort to quantify the economic impact of bats' consumption of codling moths, we captured 36 Mexican free-tailed bats over a three-night period in an 80-acre walnut orchard in Yolo County. Some 3,000 bats live in the bat houses in an abandoned shop on the property.
The research procedure: We opened our mist net from 11 p.m. to 2 a.m. to correspond with codling moth flights and bat activity, and captured the bats as they returned to the roost after feeding. We placed the bats individually in sterile cloth sacks and kept them there until they defecated, then we released them. We quickly froze the guano pellets and shipped them to a USDA lab, where scientists genetically tested them for the presence of codling moths.
Our preliminary data suggest that 5 percent of these bats – about 150 bats from this colony of 3,000 – consumed at least one codling moth per night. We calculated 30 nights per generation for the codling moth, and four generations per year, with each female moth laying 60 viable eggs on individual nuts.
The next steps: we are refining our economic data and determining whether these insect-hunting bats help reduce pesticide use in walnut orchards.
Bats provide these pest control services for free while farmers enjoy a decrease of pests in their orchards and an increase in profits.
Co-authors: Rachael Long, UC ANR advisor; and Katherine Ingram, Department of Wildlife, Fish and Conservation Biology, UC Davis.
Working with campus experts (such as faculty and staff in the Department of Wildlife, Fish and Conservation Biology) and local environmental and conservation organizations, the volunteer students are improving the habitats for local wildlife and engaging the public in hands-on activities.
This is an extraordinary program that gives the students real-world environmental management skills, along with leadership opportunities and communications experience. Professor John Eadie, Department of Wildlife, Fish and Conservation Biology at UC Davis, said of the Wild Campus program, “Hands-on activity is a huge part of the educational experience.”
A past project — Build a Wild Home Day — involved working with the UC Davis Arboretum on a successful public outreach program to build bird and bat boxes for installation on campus. (Great photos of this program are on the group’s Facebook page.)
The Wild Campus organization has a large cadre of eager and dedicated students who are improvising and making the most of limited resources. However, they are in need of donated field equipment (used equipment is fine) and financial contributions.
Visit the Wild Campus website and Facebook page for a feel-good look at what these ambitious students are doing to improve the environment, along with ways you can help them succeed.
California is home to 25 species of bats. All are insectivorous, with the exception of two species in the Southern California desert that feed on pollen and nectar. Here in the Central Valley there are seven common species of bats including red, hoary, pallid, big brown, and Mexican freetailed bats, as well as California myotis, and Yuma myotis, sometimes referred to as little brown bats.
Farmers welcome bats to their farms every year because they are voracious predators of pests including stinkbugs, cucumber beetles, and moths such as cutworms and armyworms that plague crops. Mosquitoes, midges and flies are also a favorite prey. Studies by UC Cooperative Extension in Yolo County and the UC Davis Department of Wildlife, Fish, & Conservation Biology are looking at the impact of bats on codling moth control in walnuts, a serious exotic pest that costs the walnut industry tens of thousands of dollars every year to control. Current data suggest that orchards with colonies of bats have higher bat activity than those without bats.
Sometimes bats roost where they are not wanted. If this occurs, excluding them from the area is the best way to remove them. However, this should not be done between the end of May and early August when bats have their young. Generally they have one offspring per year, with many weeks before the pups can fly. Insectivorous bats generally live for at least 10 to 15 years. Contact the UC Cooperative Extension Service in Yolo County for more information on excluding bats from buildings. If one is found in your house, simply turn out the lights and open the doors or windows and it will fly right out (they’re as scared as you are!).
Injured and orphaned bats are occasionally found on the ground. Never touch a bat with bare hands as they can carry rabies. If one is found on the ground, use gloves or a dustpan and broom to gently pick it up and put it in an area where predators such as cats or dogs cannot get to it. The bat will usually fly away at some point. If a bat is obviously injured or sick, contact the California bat rescue unit and someone will come get the bat to try to nurse it back to health to release it back in the wild.
Migration is the most dangerous time for bats because they become concentrated as they move, making them more vulnerable to dangers, such as wind turbines. Since little is known about the migratory movement of bats, it is crucial that we develop a better understanding of their seasonal whereabouts so hazards are minimized. Wind turbines especially should not be placed in their migratory pathways.
For those interested in learning more about bats, contact the Yolo Basin Foundation. Every summer they lead tours to watch several hundred thousand bats leaving their roost at dusk under the Sacramento causeway to forage for insects, helping farmers with natural pest control.