Science Spotlight

Volunteers from the Society for the Conservation of Bighorn Sheep install the second of three 2,300-gallon water tanks to provide water for wildlife in the Southern California desert.

SCBS volunteer Glenn Sudmeier and Steve Marschke install plumbing fixtures for the sheep drinker at the Cady Mountains guzzler project in San Bernardino County.

Pipes bolted into the rocks coming from a catch pond going to the original guzzler installed in the desert.

Plumbing pipes leading from the catch ponds to the storage tanks at the 40-year-old Cady # 1.

The completed project: Drinkers are covered by fiberglass simulated rocks that shade the water to slow evaporation and to stop algae growth in the opening of the drinker.

Entire scope of the project, with the 150-foot-long catch field in the background that feeds water to the underground tanks.

One of the most elusive species in California is the desert bighorn sheep (Ovis canadensis nelsoni) that live in the dry, desert mountains of southeastern California. Desert bighorn are far from fragile – males are about five feet long and can weigh up to 200 pounds, while the females weigh up to about 150. Despite their size, their keen eyesight and the agility to escape predators up steep rocky slopes, they still face many threats, including disease, human development, expansion and – more recently—a changing climate. Water is critical to their survival in this extreme environment.

The Society for the Conservation of Bighorn Sheep (SCBS), an all-volunteer organization in Southern California, has been working since 1964 for the conservation and management of the desert bighorn sheep. Over the last 40 years, SCBS and CDFW have been installing drinking systems (also called guzzlers) across the sheep’s habitat to help counteract these challenges. Now the populations rely on these water sources to survive and there is a responsibility to keep them functional and maintained.

In September 2017, SCBS rallied the volunteers to install a new drinking system to provide sheep and other animals life-supporting water in the hot summers. The project took place in the desert east of Barstow, and began with the removal and replacement of the very first guzzler ever installed in California.

The old system had two cement catch ponds, each similar to a small swimming pool lined with plastic. The catch ponds collected rain water and funneled it though pipes and valves to three tanks, where it was stored and fed to a small stainless steel drinker box. Due to its age and condition, after being exposed to the desert air and sun for more than 40 years, the system needed constant maintenance, and – more importantly – SCBS members had to haul hundreds of gallons of water across the desert each summer in order to keep the tanks full during the hottest parts of the year.

To improve efficiency and reduce the impact on the habitat, engineers and scientists devised a new approach to the design and installation of the new system. They created a 150-foot-long catch field, laying down three sections of overlapping matting, like tiles on a roof. The mats were then covered with rocks to help it blend into the surrounding area. The mats are made of non-absorbent material that funnels water down a slope where it’s collected and fed into two 2,300-gallon plastic tanks buried in the ground.

SCBS members did all the work to design and engineer the site, dig out the large holes to bury the tanks and install the plumbing and other equipment, including a solar powered satellite telemetry system that will allow scientists to monitor the water levels, ambient temperatures, water flow and other measurements at the remote site.

After four days of morning-to-night labor, the project was completed and the site returned to its near-natural state. Most of the old system was removed with one tank still operating to give the sheep time to find the new water source about 1,000 feet away. The new system is more efficient, requires very little maintenance, and has a higher storage capacity that should eliminate water hauling efforts. The tanks provide enough water for all wildlife in the area, not just the sheep, and they are less visually intrusive from both land and the air, blending well into the desert surroundings.

All this equipment comes at a cost and this construction was paid for with a grant from the CDFW Big Game Management Account (BGMA) that provides money to fund projects that benefit big-game populations and the habitats upon which they depend.

The careful planning and work done will provide a stable and reliable water source for the sheep and other wildlife in this area for decades to come.

To watch volunteers install the new drinking system, watch a video on the CDFW YouTube channel.

Photos of installation courtesy of SCBS. CDFW photos of finished project by Andrew Hughan.

Does the Western pond turtle (Actinemys marmorata), a freshwater species native to the Pacific Coast, hold secrets to survive climate change and adapt to rising sea levels? CDFW biologists want to know and have partnered with UC Davis and the Department of Water Resources to conduct a long-term study in Solano County’s Suisun Marsh to better understand the aquatic reptiles.

Officially, the Western pond turtle is a Species of Special Concern in California because of declining populations brought about by habitat loss, degradation and competition from that pet store favorite – the non-native, red-eared slider. The pet slider turtles are often released into the environment by their owners after outgrowing or outliving their welcome. They also outgrow and out-compete the medium-sized western pond turtles for food and critical basking spots. Western pond turtle populations are faring even worse in Oregon and Washington.

And yet in the Suisun Marsh, with its brackish water and high salinity, the Western pond turtle appears to be thriving. The Suisun Marsh, ironically, may now be home to one of the strongest populations of Western pond turtles on the West Coast.

“It’s just a really unique population in a place where we didn’t expect to see a freshwater species,” said Mickey Agha, the UC Davis Ph.D. student leading the university’s turtle research with Dr. Brian Todd, an associate professor in the UC Davis Department of Wildlife, Fish and Conservation Biology.

As if to underscore the point, researchers this summer collected a turtle with a barnacle attached to its shell – a testament to the marine-like environment to which the Suisun Marsh turtles have adapted.

Researchers also have been impressed with the age, health and size of the individual turtles. At 1 ½ to 2 pounds and with an upper shell that stretches up to 8 inches in length, researchers are discovering some of the largest Western pond turtles ever recorded in California.

“Looking at the ones we’ve collected, we’re seeing a lot of healthy turtles in good body condition,” said Environmental Scientist Melissa Riley, who is leading CDFW’s efforts.

The research began in the summer of 2016 with scientists trying to get a basic sense of turtle population numbers. The turtles are trapped in baited, floating hoop nets, their size, weight and age recorded. Before being released, each turtle is marked by filing a unique pattern of small notches along the edges of the upper shell. More than 125 turtles have been recorded in the project’s database.

Turtle trapping is taking place on three sites at the Suisun Marsh in and around the Grizzly Island Wildlife Area. Biologists are particularly interested in turtles at the Hill Slough Wildlife Area along Grizzly Island Road as 500 acres there will soon be restored to tidal marshland. Biologists plan to affix tiny, solar-powered, GPS tracking devices to some of the turtles to study their movements and see how they respond to the increasingly saltwater environment at Hill Slough and other parts of the marsh.

“That’s one of the many questions we have,” Agha said. “If sea level rise occurs, what happens to these turtles?”

If you’re an avid marine sport angler, you have most likely seen the smiling faces and brown polo shirts of California Recreational Fisheries Survey (CRFS) samplers. Since its inception in 2004, CRFS has grown into one of the state’s largest and most important survey efforts. Survey samplers are tasked with collecting data about both recreational fishing catch and effort.

Annually, CRFS samplers make direct contact with 68,000 fishing parties at over 400 sampling sites between the California-Oregon state line to the California-Mexico border. A separate but related telephone survey effort contacts an additional 26,000 anglers. A program of this large scale is necessary because recreational fishing effort and success rates are highly dynamic – a large sample size is needed to adequately estimate catch and effort. Recreational fishing effort is also very challenging to predict, as it can be affected by many factors (weather, gas prices, time of year, fishing seasons, etc.). But the recreational sector accounts for a significant portion of overall marine harvest, so it’s essential to collect that data to produce reliable estimates of harvest.

CRFS is part of a larger effort to estimate recreational catch and effort on the west coast and is integral to the national effort conducted by the National Marine Fisheries Service’s Marine Recreational Information Program. This partnership allows CRFS methods to be periodically peer reviewed by expert consultants throughout the country. This review provides certification that the methods meet or exceed national standards and fisheries management needs, and can recommend the use of new methods to address changing needs or to capture emerging fisheries.

There are three parts to the survey. The first is the field sampling component. This consists of in-person interviews conducted for four different fishing modes – beaches and banks, man-made structures, private/rental boats, and commercial passenger fishing vessels. Field survey questions are specific to catch and effort data during daylight hours at publicly accessible sites. The second part of the survey is the telephone survey. Anglers are randomly selected monthly through the state’s online Automated License Data System (ALDS) and asked about effort data (the number of fishing trips taken) at beach and bank sites. The telephone survey also collects data from private boats returning to sites not sampled during the field survey, and private boats returning at night. The third part of the survey is collection of data from commercial passenger fishing vessel logs. Captains submit this information for every trip, and the data is used together with field sampling data to estimate overall fishing effort.

All of this information is used in many ways. In addition to CDFW, the Fish and Game Commission and the Pacific Fishery Management Council use the data to:

• Track in-season catches against annual harvest limits, especially for certain over-fished groundfish species, such as Yelloweye and Cowcod rockfish.
• Produce in-season salmon estimates in coordination with the CDFW Ocean Salmon Project.
• Aid the development of regulations, including fishing season, bag limits, minimum size limits and depth limits.
• Assess stocking needs for individual fish species.

How can you help? There are two ways! If you encounter a CRFS sampler in the field, please cooperate and answer the interview questions truthfully. Take the time to allow the sampler to examine and measure any catch. Recreational anglers, particularly those who fish frequently, are more likely to encounter CRFS samplers. Every fishing trip is unique — different target species, success rates, different locations, different gear, etc. — so we ask anglers, “Even if you have completed this survey before, please cooperate each time you are asked!”

Secondly, if you receive a phone call, please say “yes” to the CRFS telephone surveyor. Data collected through this telephone survey is used to estimate fishing effort that cannot be estimated any other way.

Personal contact information is always kept confidential, and the information that is collected becomes part of a public database. To learn more about the CRFS, access the database or download related flyers and brochures, please visit www.wildlife.ca.gov/Conservation/Marine/CRFS.

Deer population estimates are an important element of the California Department of Fish and Wildlife’s (CDFW) management decisions regarding the species – including setting quotas for deer-hunting seasons, acquiring land and identifying habitat improvement projects. Historically, CDFW has relied upon helicopter surveys to obtain these population estimates, but such surveys can be problematic. While they are effective in open and largely flat areas, they are less so in tree-laden areas where deer are hidden from sight. They can also be extremely expensive.

Now, thanks to emerging DNA technology, scientists are exploring a less invasive, cost-effective alternative: Analysis of what the deer leave behind.

The use of DNA is not new, of course – CDFW has used hair or tissue samples to extract DNA and identify individual animals for years. But scientists are finding that the painstaking collection and analysis of deer droppings is particularly useful because it allows them to gather the necessary information without physically touching (or stressing) the animals. And that, one might say, is the “bottom line.”

Fecal DNA analysis is being used by wildlife biologists in the North Central Region as part of a six-year region-wide study of mule deer (Odocoileus hemionus) that will provide population estimates in areas where data has previously been lacking. CDFW scientists, in cooperation with UC Davis, will use the deer pellets to take a genetic “fingerprint” designed to help estimate deer populations.

Starting in 2016, a crew began setting transects for pellet collection in the standardized sampling locations (known to hunters as deer zones X6a/b, X7a/b and X8) which are located in Lassen, Plumas, Sierra, Nevada, Placer and Alpine counties. After starting points were randomly selected, habitat information and pictures were collected along with fresh pellets. After the pellets were removed from the area in an initial sweep, scientists revisited the transect once a week for three more weeks to collect new samples. Between July and September of 2016, biologists visited 43 different transects in the summer range and collected and analyzed 458 fresh pellet samples. Staff also captured 20 does and seven bucks and fit them with satellite collars that produced data that helped identify summer home ranges.

CDFW will also use DNA to identify individual deer to help gather buck/doe/fawn ratios. Biologists will then combine the DNA data with home range data from collared deer to calculate the estimated number of deer in the population. This year staff have already completed another 36 plots and collared 18 more deer. Another series of pellet collections is scheduled next year, with a goal of continuing until all 17 counties in the region have been sampled.

Although several DNA projects are occurring across the state, this project is the largest landscape-level study for deer in California. The study is funded through CDFW’s Big Game Account, a dedicated account that provides research and management funds for game species. The University of California will conduct the laboratory work and statistical analysis.

The California Department of Fish and Wildlife (CDFW) recently launched the first phase of a multi-year study of tule elk in Colusa and Lake counties. In partnership with the University of California, Davis and the Rocky Mountain Elk Foundation, and with the assistance of capture specialists from Leading Edge Aviation, researchers used helicopter net guns to capture and place satellite collars on 45 tule elk.

The technique of using DNA extracted from fecal pellets to study wildlife populations is a relatively new, non-invasive approach that minimally disturbs animals and enables surveys in low-visibility habitats where sight-based surveys would be relatively ineffective. It is also less costly than other survey methods, and therefore can be used more frequently.

While fecal DNA analysis has been used to estimate abundance and other population parameters in deer herds in California since 2011, this study will be the first application of the technique to free-ranging tule elk. The study results will guide future elk conservation planning efforts.

Tule elk are a native subspecies of elk unique to California. Prior to the arrival of European settlers, they numbered more than half a million statewide, but the population rapidly declined in the mid-1800s due to unregulated market hunting and habitat loss. In 1875, a ranch owner in Kern County took efforts to protect the last remaining tule elk and allowed them to multiply on his property, likely saving them from extirpation.

Since 1975, CDFW has captured and relocated more than 1,500 elk. As a result, there are an estimated 5,100-plus tule elk distributed in 22 herds throughout California today. See more information about the distribution, range and history of this unique animal in California.