Featured Scientist

Krista Hoffmann at North Table Mountain.


Conducting fieldwork for a Suisun Marsh restoration project.


Conducting fieldwork for a Suisun Marsh restoration project.

Krista Hoffmann is CDFW’s Integrated Pest Management Coordinator. She works in CDFW’s Lands Program coordinating the management of invasive vegetation and invasive species on state wildlife areas and ecological reserves. Krista attended the University of California, Davis (UC Davis), where she earned an undergraduate degree in ecology and evolutionary biology and a doctoral degree in pharmacology and toxicology. Before joining CDFW in 2020, Krista worked for the California Department of Water Resources and prior to that served in the Peace Corps in Palau, Micronesia.

What is your role as Integrated Pest Management Coordinator?

I coordinate weed management which includes ensuring that staff who use herbicides have the correct certifications and training, and that as a department we are following regulations and internal guidelines. I provide information on best management practices and help land managers with problem solving to find the best solution for invasive species on the properties they manage. I read a lot of scientific literature to keep up with new research. I compile data and review weed management plans, among other things. But one of my favorite parts of the job is when I get to do field work. The hands-on restoration work, getting my hands dirty and getting the field experience, is one of the most important parts of my job that helps me understand what’s really happening on the ground.

Integrated pest management is an ecosystem-based strategy to control or eradicate invasive species and includes prevention, treatment and monitoring of invasive species populations. It’s “integrated” in that multiple tools are typically used to enhance efficacy and reduce non-target impacts. The approach also includes active or passive restoration with native, desirable plants to help outcompete or prevent reinvasion by unwanted species.

What motivated you to follow this career path?

I was always interested in science and nature. I was one of those kids who caught and played with most of the critters I could find around my neighborhood, from pill bugs and spiders to lizards and snakes. I was always really fascinated by animals and plants and loved being outside. I also loved learning about science and nature and how things work. I knew I wanted to go into science when I started college. I was also really interested in cultures and the idea of traveling to learn about cultures around the world.

How did you start working on invasive species and toxicology?

I did an undergraduate research project in Dr. Donald Stong’s Spartina Lab at UC Davis. I worked with one of his researchers, Dr. Debra Ayres, who was looking at the hybridization (crossing) between the native Spartina foliosa cordgrass and the non-native Spartina alterniflora from the East Coast and how the resulting hybrid species was more vigorous and more competitive than either of the parent species. Now, the Invasive Spartina Control Project, primarily led by Dr. Drew Kerr, has eradicated over 90 percent of the invasive or hybrid species in the San Francisco Bay Area. It’s a major success story in the world of invasive species management.

Studying toxicology was inspired by a job I had prior to graduate school where I collected water samples from agricultural fields to test for pesticide residues. That’s how I became aware of all the chemicals that are in our waterways and interested in how they might affect aquatic species like fish. Now as a scientist at CDFW I’ve been able to put my two interests together. A lot of what I do now is determining both where herbicides are needed to control invasive species and how to protect non-target species at the same time.

Can you describe the approach to managing invasive plants on CDFW-managed lands?

We use a variety of methods on our lands. For example, grazing by cows, sheep or goats can remove invasive species while promoting native species if it’s done right. We also are looking into using prescribed (planned) fire to remove some species, or flooding for others, and physical methods like mowing and hand pulling are commonly used. There are cool new tools using drones to monitor species or even to control species in a very targeted way. Herbicides are also an important tool that we use, often in combination with other approaches. Decisions on which tools are most appropriate for a given target and setting are based on a combination of information from the scientific literature and hands-on experience, and we adapt our approaches as needed as new tools or evidence become available.

What are some of the most problematic species you work on?

There are lots of them! However, not all non-native species are invasive. “Invasive” plants are those that cause harm to the environment or the economy. A few that cause a lot of problems on our lands are yellow starthistle, perennial pepperweed, cheatgrass and European beachgrass. Some aquatic invasive plants are Phragmites (common reed), Spartina (smooth cordgrass), giant reed, water hyacinth and water primrose. I’m fortunate that I’ve been able to work with regional staff on a few hands-on restoration projects addressing some of these especially problematic plants. At the Hallelujah Junction Wildlife Area in Sierra County, we are studying different control methods for cheatgrass, and how to put a stop to the fire cycle that it perpetuates such as using herbicides and planting native species that compete with cheatgrass. I’m also assisting with a large-scale restoration project in our Northern Region, aiming to control European beachgrass in the dune habitat and Spartina in the tidal wetlands. In Suisun Marsh, there’s been a recent surge in the alkali Russian thistle population, which is impacting waterfowl habitat. I’m working with the Suisun Resource Conservation District to develop a Russian Thistle Control Plan for the region.

Do you have any advice for young scientists?

Do lots of different things. Don’t think you need to stick to one direct career path to be successful. It’s a great idea to get a diversity of experience when you’re starting out. It’s the best way to figure out what you enjoy doing and you never know what skills might come in handy down the road.

Banding wild turkeys and collecting samples in Davis .


Field work in Carrizo Plain National Monument.


Selfie with giant kangaroo rat, Elkhorn Plateau in Carrizo Plain.

Biologist Matt Meshriy assists with statewide coordination on issues affecting a broad group of species that includes upland game birds. His job also focuses on small game mammals and predators and competitors of upland game species like badgers, skunks, coyotes, and racoons. Meshriy provides support on a range of issues impacting upland game species including regulations, harvest estimates, disease surveillance, habitat assessment and grant research.

Educated at San Francisco State University, Meshriy has an undergraduate degree in ecology and evolution and a master’s degree in animal behavior and physiology with a focus in mammalogy. In 2004, he landed his first professional biology job banding spotted owls for the U.S. Forest Service in Plumas National Forest. His next professional stop was at the University of California, Berkeley, where he was a research associate in a forest pathology and mycology laboratory. There he maintained culture collections and learned to use molecular techniques like DNA extraction and amplification that later helped him in acquiring grants to fund his master’s thesis work.

Meshriy returned to San Francisco State University and taught biology laboratories and conducted field and genetic investigations of the federally endangered giant kangaroo rat in the Carrizo Plain National Monument. His thesis, titled “Kinship associations of a solitary rodent, Dipodomys ingens, at fluctuating population densities,” described behavioral adaptations of this unique species that facilitate population maintenance and dispersal under unpredictable conditions in their desert environment. After earning his graduate degree in 2009, Meshriy worked for the U.S. Geological Survey en route to being hired by CDFW in 2012.

What led you to a career in wildlife science?

First and foremost, I wanted to do something that felt meaningful. As a kid, my dad got me interested in space. He told me about the moon landings and of future missions to Mars. I grew up with Star Wars in the movie theaters. Although I was raised in the urban landscape of San Francisco and the bay Peninsula, I have always enjoyed being outside in the natural world and regularly explored the coastal mountains on my bicycle and the Sierra Nevada once I could drive.

I worked during my senior year of high school and for a year before and while attending college. I was initially interested in astronomy, astrophysics and meteorology but I came to realize that they required more math than I was comfortable with. I started looking into botany as an alternative area of study, and one semester of calculus seemed more do-able than three. As I enrolled in more elective coursework in the biological sciences, I found my way to biogeography and ecology. I’m fascinated by the relationships between organisms and I’m always curious about the ways that larger groups of organisms and systems are constantly struggling to find or maintain states of equilibrium, and how humans and our activities are increasingly affecting these systems.

Why did you apply for the upland game position?

Before applying for the position, I had very much been involved with the field aspects of data collection and processing of biological samples and data analysis. However, I didn’t have much experience or exposure to other areas of public science like policy, regulation and public outreach. When the job opening was advertised, I was leading a crew in field surveys of the federally threatened giant garter snake in the Sacramento Valley. While I enjoyed the physical work, the idea of being exposed to different aspects of wildlife management was appealing.

What’s your favorite part of your job?

In my experience, our collective progress toward solving problems and improving our understanding of issues moves forward in an uneven manner, in bits and spurts. My favorite parts of the job are the occasions when I feel connected to one of those instances of a shift to forward momentum, when new information becomes available or something new becomes possible.

This might be because a needed regulation gains enough support that it is prioritized for development, or a research need is filled through a new grant or collaboration. It’s the ability to see different facets of issues as I progress in my career. For example, how agencies work together to deliver the science that drives the policy. I like seeing how science is adapted to meet the needs of the public and how each agency and partner is involved. There’s not always a map for that process. Sometimes it takes creative thinking.

What should people know about upland game?

The term “upland game” relates to a group of species that are generally widespread in the state. Many upland game species are versatile and adaptable to a broad range of habitats whereas others occupy more specialized or geographically limited niches in California, like the rock ptarmigan and greater sage grouse.

As a group, upland game species and habitats are fairly ubiquitous in California. There are lots of opportunities for wildlife watchers and hunters alike to pursue upland game birds and mammals without having to travel too far around the state.

What advice would you have for young people interested in science careers?

Explore every opportunity that interests you. The more opportunities you can become involved with, the more likely you’ll find things that satisfy you personally and that you can make a living doing. I don’t think people should spin their wheels in internships or volunteer opportunities that don’t interest them at the outset, on the hope of landing a lucrative job that they assume will fulfil them. Instead, find the pursuits that you really enjoy and then figure out how to string together that set of knowledge, skills and experiences into something that is profitable and unique to you over time. For me, the value in casting a wide net is the broad exposure to issues and species and being able to recognize emergent properties or similarities in different areas of biology and the environment.

Setting up camera trap at Pixley National Wildlife Refuge.


O’Leary working at Sandridge Bakersfield Cactus Preserve.


O’Leary measuring a blunt-nosed leopard lizard at Semitropic Ecological Reserve.

Environmental Scientist Reagen O'Leary monitors wildlife and plant species on CDFW ecological reserves in the Central Valley. She’s part of a small team that helps protect and recover threatened and endangered species and their habitats on about 50,000 acres of CDFW-owned lands. O’Leary studied biology at Fresno State University and held several part-time jobs, including zookeeper at Fresno Chaffee Zoo, veterinary assistant at an animal hospital and scientific aid for CDFW’s Fishing in the City program. She also conducted owl surveys and worked in CDFW’s Lands Unit. Her first full-time position with the state was as an environmental planner for Caltrans. She was hired by CDFW as an environmental scientist in 2011.

When did you know you wanted to be a scientist?

When I was a kid, I enjoyed watching Mutual of Omaha’s Wild Kingdom and Jacques Cousteau documentaries. I was very curious about the natural world and wanted to know how it worked. I was the type of kid who could sit in a field by myself and be entertained by my fascination with the plants and wildlife around me. Growing up, I thought I wanted to be a marine biologist and work with whales and sharks. In my 20s, I worked at a veterinary clinic and realized I liked animals more than people – but not in a clinical setting. That led to my interest in field biology.

What do you enjoy about your job at CDFW?

I love monitoring and taking inventory of the listed species, whether they be plants or wildlife. The wildlife species we typically work with include the blunt-nosed leopard lizard, kangaroo rat species, San Joaquin kit fox, Swainson's hawk and San Joaquin antelope squirrel. I also really enjoy teaching young scientists about the different species and habitats they depend on. I like seeing lightbulbs go off in people’s minds when they learn something new and correlate that knowledge to what they already knew but maybe couldn’t put to words. Young people can be transformed by what they learn, and I enjoy nurturing an appreciation for nature.

What does your job look like on a day-to-day basis?

It depends on the time of year. The field work is varied. For example, we have a long-term lizard monitoring grid that we’ve kicked off for this year that will run in the spring, summer and fall. On hot days we’ll be out in the field early to beat the heat and get back home at a reasonable time. I oversee our annual winter resident bird surveys. I also monitor the status of multiple rare plants on our ecological reserves during the species blooming period. Other duties include setting up camera traps throughout the lands for species detections. We conduct kangaroo rat trapping in the summer, which consists of night work, and during winter we conduct fairy shrimp surveys. Overall, I’ve logged a lot of walking miles in the San Joaquin desert doing all sorts of activities.

As far as day-to-day office work, I coordinate new land acquisitions, write reports, present on our work at conferences, mentor and guide our scientific aids and conduct work funded by grants. I’m the lead staff for coordinating land acquisitions on a Habitat Conservation Plan. I sometimes joke with my colleagues and say, “Who knew we’d need to understand real estate documents to do this job?”

Do you have any recommendations for aspiring scientists?

I would encourage students to be curious about nature and not be scared to ask professionals questions. What I’m discovering with young people is that they sometimes don’t ask enough questions, or they don’t know what questions to ask. Don’t ever think you’re going to learn it all; as a matter of fact, the more you learn, the more you discover what you don’t know. If you are a person with a curious nature, the scientific field is definitely for you. Find folks that like to explore nature and let your curiosity blossom.