- Author: Rebecca Ozeran
A few months ago, I was asked about the toxicity of various plants in a horse pasture after the death of a miniature horse using that pasture. While many of the identified plants were chemically harmless (such as filaree [Erodium spp] and some native clovers), the pasture did have fiddleneck (Amsinckia spp) and popcorn flower (Plagiobothrys spp), two native forbs with potentially toxic chemistry.
Popcorn flower (above) has small white flowers. Fiddleneck (below) has slightly larger yellow flowers. Both plants have similar overall shapes: slender flowering stems, relatively small leaves, and hairs on all parts except the flowers themselves.
Fiddleneck is a known alkaloid accumulator and popcorn flower is similarly suspected to accumulate alkaloids. There are no cases that I have found where popcorn flower was identified as a cause of toxicity, however. Most research on popcorn flower chemistry focuses on insect herbivores which like to eat plants with alkaloids, to protect themselves against predation (e.g. Hartmann et al. 2004) – but that's a topic for another blog!
Alkaloids are secondary organic compounds produced by many plants. Different types of alkaloids have different interactions with animal biology, some of which are benign or beneficial, and others which are harmful. Some alkaloids you may have heard of include morphine, nicotine, and quinine. Pyrrolidizine alkaloids, the type found in fiddleneck and popcorn flower, have harmful effects. Toxicity often occurs when animals eat feed or hay contaminated with fiddleneck seeds, and some cases have been documented from animals grazing the plant in a pasture. Fiddleneck alkaloids can cause liver disease and death of horses, cattle, and pigs, but sheep seem to be less vulnerable (Craig et al. 1985).
Both fiddleneck and popcorn flower may also accumulate nitrates. Nitrates convert into nitrites once the animal eats the plant. Nitrites then react with hemoglobin in the blood and make it unable to carry oxygen. This oxygen deficiency can cause death in a matter of hours depending on the concentration of nitrates in the animal's diet. Sheep, pigs, and horses seem more resistant to nitrate poisoning while cattle are most vulnerable (Tucker et al. 1961).
How to avoid livestock poisoning by fiddleneck and popcorn flower
The best way to prevent livestock poisoning by these forbs is to make sure there is plenty of good forage available. Livestock don't typically seek out fiddleneck or popcorn flower. Fiddleneck and popcorn flower have more stem than leaf, so they aren't very palatable, and they are densely covered in hairs that tend to discourage grazing. In a pasture with plenty of grasses and desirable forbs, then, animals will easily avoid these harmful plants.
The risk of poisoning arises when there is little else for the animals to eat. As a pasture that has been overgrazed or a pasture experiencing a drought therefore might have too few plants for the animals to be able to avoid popcorn flower and fiddleneck. When possible, having more than one pasture can help keep animals safe. Animals should be moved out of pastures where the only available plants may be toxic.
Body size is also a factor in many cases of toxicity. A fully grown 1,000-lb animal may be unaffected by a small amount of these toxins in their diet (such as this horse, pictured above, who ate a mouthful of grass plus a single fiddleneck plant right in front of me), while a young or small animal might become seriously ill after eating just a few plants. Whether an animal develops clinical signs of toxicity or poisoning depends on the concentration of toxin in the forage, the quantity of forage consumed, and the animal's size. However, any amount could be harmful and if you notice your animals are consuming toxic plants, please contact your veterinarian.
Can fiddleneck and popcorn flower be controlled?
You are not likely to eradicate them, but there are ways to control these plants if you are concerned about them.
Both fiddleneck and popcorn flower can be hand-pulled – gloves recommended to protect against the hairs – if present in small patches. On small acreages, mowing an infested pasture before the plants produce seeds in the spring can help reduce the population. Some herbicides can also help kill these plants; generally speaking, you will need to apply herbicides when the plants are young and small, to prevent seed production for the year. Contact your local UCCE office for more specifics if you want to consider chemical treatments.
Long-term, re-seeding bare patches in pastures and ensuring moderate grazing can also help outcompete these species. Because they have relatively small leaves, popcorn flower and fiddleneck rely on plenty of open space and sunshine to grow. As a result, they are less common in pastures that are densely populated by desirable forages that shade smaller plants.
For more on establishing a healthy pasture, even if you have dryland pastures or pastures with animals other than horses, the free guide here is a great place to start: Establishing and Managing Irrigated Pasture for Horses.
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If you are concerned that your animals may have been exposed to toxic plants, contact your veterinarian. If you have concerns about plants in your pastures, feel free to contact your local UCCE office for assistance with plant ID.
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Check out CalFlora to see the geographic distribution of these and many other plant species in California
References:
Craig, A.M., L.L. Blythe, E.D. Lassen, and M.L. Slizeski. 1985. Resistance of sheep to pyrrolizidine alkaloids. Israel Journal of Veterinary Medicine 42:376-384.
Hartmann, T., C. Theuring, T. Beuerle, L. Ernst, M.S. Singer, and E.A. Bernays. 2004. Acquired and partially de novo synthesized pyrrolizidine alkaloids in two polyphagous arctiids and the alkaloid profiles of their larval food-plants. Journal of Chemical Ecology 30(2):229-254.
Tucker, J.M., D.R. Cordy, L.J. Berry, W.A. Harvey, and T.C. Fuller. 1961. Nitrate Poisoning in Livestock. California Agricultural Experiment Station. Circular 506, 12p.
Invasive species are non-native plants, animals, or pathogens that can cause economic or environmental harm. This year, we will be spotlighting several different invasive species that are established in California to raise awareness and help reduce their spread. Stay tuned—we will be showcasing a different invasive species each day and where you can find more information.
Want to learn more about California Invasive Species Action Week? Check out the full schedule of events on their website.
- Author: Ben Faber
There is a wild world in those avocado orchards. A study was done locally of some of the carnivores besides humans that show up there.
Carnivore Use of Avocado Orchards Across and Agricultural-Wildland Gradient
Wide-ranging species cannot persist in reserves alone. Consequently, there is growing interest in the conservation value of agricultural lands that separate or buffer natural areas. The value of agricultural lands for wildlife habitat and connectivity varies as a function of the crop type and landscape context, and quantifying these differences will improve our ability to manage these lands more effectively for animals. In southern California, many species are present in avocado orchards, including mammalian carnivores. We examined occupancy of avocado orchards by mammalian carnivores across agricultural-wildland gradients in southern California with motion-activated cameras. More carnivore species were detected with cameras in orchards than in wildland sites, and for bobcats and gray foxes, orchards were associated with higher occupancy rates. Our results demonstrate that agricultural lands have potential to contribute to conservation by providing habitat or facilitating landscape connectivity.
Read on:
http://www.avocadosource.com/journals/plos_one/nogeiretheresa2013.pdf
- Author: Anne Schellman
- Contributor: Karey Windbiel-Rojas
Did you know that every 60 days, a new and potentially damaging invasive species enters California?
California residents can help in the fight against invasive species by learning and participating next week (June 2-10) in the California Invasive Species Action Week.
What is an invasive species?
Invasive species are non-native plants, animals, or pathogens that can cause economic or environmental harm. These invading species can damage:
- Native plants and animals—especially those that are endangered
- Agriculture—both farming and ranching operations
- The environment—waterways and parks/recreational areas
- Human health—through viruses and other pathogens
Find out more about invasives at the Center for Invasive Species Research.
How do invasive species get into California?
Invasive species are often native to a country or area different to that in which they have invaded and are now causing problems. For hundreds of years and people have traveled throughout the United States and from other countries, they brought species of plants and animals with them from their native lands to California, either accidentally or intentionally. Some introductions had positive outcomes (food and horticultural crops) while others did unexpected damage (certain invasive plants). Many invasive plant problems began as ornamental plants for sale by nurseries and garden centers. Today, exotic and invasive plants are still available in commercial nurseries. Other exotic species arrive in products brought into California shipped through commercial trade or by travelers.
Want to help?
Stay tuned to this blog each day to learn more. Starting Monday, June 4, we will be highlighting several exotic and invasive plant, insect, disease, and vertebrate pests along with things you can do to limit their spread such as:
- Learning about which species are threats to California.
- Using native plants in your landscape.
- Not moving firewood from place to place.
And many other ways to help!
Take action now!
In addition to learning about invasives, you can also take action by joining an event near you. Check the 2018 Schedule of Events link on the California Invasive Species Action Week for more information.
- Author: Kathy Keatley Garvey
DAVIS--Crowds will "explore the diversity of life" at 13 museums or collections during the seventh annual UC Davis Biodiversity Museum Day on Saturday, Feb. 17. The event, set from 9 a.m. to 4 p.m. is free and open to the public.
Displays will range from ancient dinosaur bones to live praying mantises, from hawks to honey bees and from California condor specimens to carnivorous plants. Last year's Biodiversity Museum Day drew more than 4000 visitors to campus.
This is a family friendly, science-based event, said Biodiversity Museum Day chair Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology. All 13 museums or collections are within walking distance on campus except for the Häagen-Dazs Honey Bee Haven on Bee Biology Road and the Raptor Center on Old Davis Road. Openings vary from 9 a.m. to 1 p.m. and from noon to 4 p.m.
The following will be open from 9 a.m. to 1 p.m.:
- Arboretum and Public Garden, Good Life Garden, next to the Robert Mondavi Wine and Food Science Institute, 392 Old Davis Road, on campus
- Bohart Museum of Entomology, Room 1124 of the Academic Surge Building, Crocker Lane
- California Raptor Center, 340 Equine Lane, off Old Davis Road
- Museum of Wildlife and Fish Biology, Room 1394, Academic Surge Building, Crocker Lane
- Paleontology Collection, Earth and Physical Sciences Building, 434 LaRue Road
- Phaff Yeast Culture Collection, Robert Mondavi Institute of Wine and Food Science, 392 Old Davis Road, on campus
- Viticulture and Enology Culture Collection, Robert Mondavi Institute of Wine and Food Science, 392 Old Davis Road, on campus
The following will be open from noon to 4 p.m.:
- Anthropology Museum, 328 Young Hall and grounds
- Design Museum, 124 Cruess Hall, off California Avenue
- Botanical Conservatory, Greenhouses along Kleiber Hall Drive
- Center for Plant Diversity, Sciences Laboratory Building, off Kleiber Hall Drive
- Häagen-Dazs Honey Bee Haven, Bee Biology Road, off Hopkins Road (take West Hutchison Drive to Hopkins)
- Nematode Collection, Sciences Laboratory Building, off Kleiber Hall Drive
All participating museums and collections have active education and outreach programs, Yang said, but the collections are not always accessible to the public. In the event of rain, alternative locations are planned for the outdoor sites. Maps, signs and guides will be available at all the collections, online, and on social media, including Facebook and Twitter, @BioDivDay.
Capsule information about each museum or collection:
The Arboretum and Public Garden display will be from 9 a.m. to 1 p.m. at the Good Life Garden, next to the Robert Mondavi Wine and Food Science Institute, 392 Old Davis Road, on campus. It will join two other collections: Phaff Yeast and Viticulture and Enology. The Arboretum activities will be interactive; Learning-by-Leading Students are creating the content that will be featured on the day of Biodiversity Day. Coordinator: Melissa Cruz, outreach and leadership program coordinator.
Bohart Museum of Entomology
The Bohart Museum of Entomology will be open from 9 a.m. to noon in Room 1124 of the Academic Surge Building on Crocker Lane, off LaRue Road. The Bohart is the home of a global collection of nearly 8 million insect specimens. Highlights will include the 500,000-specimen butterfly/moth collection, curated by entomologist Jeff Smith; display of praying mantises, including orchid mantises, by UC Davis entomology student Lohit Garikipati; and a Belize insect collection display by Smith and fellow Bohart Museum associates Fran Keller and Dave Wyatt from their latest expedition. "You'll be able to see the tremendous diversity of butterflies, moths and mantids, and talk to the scientists who have just returned from there," said Tabatha Yang, education and outreach coordinator. "There will be orchids and orchid bees connecting the Bohart Museum's work with plant biology and science."
California Raptor Center
The California Raptor Center on 1340 Equine Lane, Davis, just off Old Davis Road, will be open from 9 a.m. to 1 p.m. A living collection of non-releasable raptors will be on exhibit. The center's educational ambassador birds will be out "on the fist" in the fenced yard by the museum, so visitors can get a close look at wild raptors while talking to the volunteers and learning about the magnificent birds of prey that live in this area, said Julie Cotton, volunteer and outreach coordinator. The on-site museum, recently renovated, features redesigned exhibits and a new touch-screen display. Coordinator: Julie Cotton, volunteer and outreach coordinator.
Museum of Wildlife and Fish Biology
The Museum of Wildlife and Fish Biology, in Room 1394 of the Academic Surge Building, Crocker Lane (off LaRue Road) will be open from 9 a.m. to 1 p.m. Visitors can view the bird and mammal museum specimen taxidermy demonstrations; explore the research collections with museum docents; see the newly acquired California condors on display, and see other specimens on display, including Papua New Guinea birds and mammals, reptiles and amphibians, primates and marine fishes. Note that strollers are not allowed in classroom or museum, they can be parked them under adjacent stairwell. Visitors are also asked to wash their hands before entering museum. Coordinator: Andrew Engilis Jr., director.
The Paleobiology Collection will be open from 9 a.m. to 1 p.m. in the Earth and Physical Sciences Building, 434 LaRue Road. Visitors can view fossil specimens dating from as old as 550 million years ago to more recent animal skeletons. Paleontology graduate students in invertebrate and vertebrate paleontology will answer questions and provide interesting factoids. Coordinator: Mark Deblois, Department of Earth and Planetary Sciences.
Phaff Yeast Culture Collection and Viticulture and Enology Culture Collection
These collections will be open from 9 a.m. to 1 p.m. in the Robert Mondavi Institute for Wine and Food Science, 392 Old Davis Road, on campus. Visitors can learn about the importance of microbes in research, biotechnology, and food and beverages, and about the proud history of two of the world's prominent microbe collections. The Phaff Yeast Culture Collection is part of the Department of Food Science and Technology department, and the Viticulture and Enology Culture Collection is part of the Department of Viticulture and Enology. Visitors can see and smell dozens of yeast species, learn how yeasts and bacteria are important for making fermented foods and beverages (even clothes can be made from microbes), taste vegemite, marmite and kombucha tea; learn about cutting edge research using these microbe collections; and tour the UC Davis teaching winery and brewery.
The microbe collection activities will be in the Robert Mondavi Institute Brewery, Winery and Food Processing building, which is in the southwest area of the complex of orange buildings at Old Davis Road and Hilgard Lane. Coordinators: Kyria Boundy-Mills, Phaff collection curator and specialist, Food Science and Technology, and Lucy Joseph, Viticulture and Enology collection curator and senior museum scientist.
Anthropology Museum
The Department of Anthropology Museum in 328 Young Hall will be open from noon to 4 p.m. The Anthropology Museum curates collections of archaeological, ethnographic, biological and archival materials. The theme is "Year of the Dog" and there will be a scavenger hunt for kids to find all the hidden dogs in the exhibits, and people can test their skills as an ancient hunter and toss an atlatl dart or learn to make a tool from volcanic stone, says zooarchaeologist Christyann Darwent. The Anthropology Museum curates collections of archaeological, ethnographic, biological and archival materials. The museum maintains a teaching collection that includes casts and reproductions of artifacts from a variety of prehistoric human groups. Coordinator: Christyann Darwent, associate professor.
Design Museum
The Design Museum will be open from noon to 4 p.m. in Room 124 of Cruess Hall. Professor Timothy McNeil and curator Adrienne McGraw will staff the exhibit, It's Bugged: Insects' Role in Design, which explores the connections between people and insects. This is a special opening just for Biodiversity Museum Day. (The exhibit opened Jan. 8 and continues through April 22; regular hours are weekdays from noon to 4 p.m. and Sundays from 2 to 4 p.m.) "It's Bugged" includes art from hornet nest paper; beetle-gallery sculptures, and insect-themed clothing from the Department of Design faculty and graduate students; and insect specimens from the Bohart Museum of Entomology and insect photos from UC Davis alumnus Alex Wild, curator of entomology at the University of Texas, Austin. Coordinators: Timothy McNeil, professor, and Adrienne McGraw, exhibition curator.
The Botanical Conservatory
The Botanical Conservatory, greenhouses on Kleiber Hall Drive, will be open from noon to 4 p.m. Visitors can expect a multi-sensory experience of a plethora of plants primarily from the tropical and subtropical biomes. Featured plants and displays include the always popular carnivorous plants, fruiting specimens of Chocolate (Theobroma) and Coffee (Coffea), various Amorphophallus species at various stages of leaf and possibly flowering individuals, an assortment of cacti, succulents and other desert dwellers, and finally an assortment of winter blooming South African Bulbs to further entice the senses. Coordinator: Ernesto Sandoval, collections manager.
Center for Plant Diversity Herbarium
The Center for Plant Diversity Herbarium, open from noon to 4 p.m. in Room 1026 of the Sciences Laboratory Building, central campus (off Kleiber Hall Drive), will exhibit Hmong medicinal and culinary herbs. Viewers can view and identify plants under the microscope and watch plant pressing and mounting demonstrations. A kids' area activity will include pressed plants/glue/paper. Coordinator: Ellen Dean, curator.
Häagen-Dazs Honey Bee Haven
Häagen-Dazs Honey Bee Haven, a half-acre bee demonstration garden next to the Harry H. Laidlaw Jr. Honey Bee Research Facility, Bee Biology Road, will be open from noon to 4 p.m. Activities include catch-and-release bee viewing and making "Feed the Bees" seed cookies. The haven was installed in the fall of 2009. A six-foot-long bee sculpture, Miss Beehaven, by artist Donna Billick, co-founder and co-director of the UC Davis Art/Science Fusion Program, anchors the haven. Other art, coordinated by entomology professor Diana Ullman, co-founder and director of the Art/Science Fusion Program, and Billick, also graces the haven. Guests will see bee condos occupied by leafcutter bees and mason bees. Robbin Thorp, distinguished emeritus professor of entomology, has recorded more than 80 different species of bees in the garden. Coordinator: Christine Casey, academic program management officer.
Nematode Collection
The nematode collection will open from noon to 4 p.m. in the Science Laboratory Building, central campus (off Kleiber Hall Drive). Visitors can expect to see live and preserved nematode specimens. Highlights include the huge jars of whale intestinal worms. Nematodes, also called worms, are elongated cylindrical worms parasitic in animals or plants or free-living in soil or water. They exist in almost every known environment. The many different species eat everything from bacteria and fungi to plant and animal tissue. Coordinator: Corwin Parker, nematology doctoral student.
For further information about the Biodiversity Day, access the UC Davis Biodiversity Museum Day website.