STATE BAT MANAGEMENT: The Arizona Advantage

Five years ago, Arizona citizens turned state lottery profits into one of the country’s most innovative conservation programs, and bats have been winners too . . .

BY DEBRA C. NOEL

WHAT happens when a state wildlife management agency wins the lottery? For starters, money to fund research and conservation programs is suddenly available, people learn more, and animals benefit. To make sound decisions about the conservation and recovery of wildlife, a management agency must have enough information about an animal or group of animals. In an ideal world, for example, we would know where all important bat roosts are located, what species uses a roost, how many bats use it, when they use it, what threatens the roost, and what the population trend is.

But the reality for bats is far from this perfect world. The reasons are many; an important one is that “glamour” species like bald eagles, peregrine falcons, and black-footed ferrets have long taken precedence over animals like bats, which often don’t inspire the same kind of public sympathy or interest. And because interest in the plight of bats has been comparatively low— on both a public and an official level— funding and adequate personnel with the necessary expertise have also been lacking.

Before 1990, management of Arizona’s 28 species of bats was no different. The Arizona Game and Fish Department employed one nongame mammalogist responsible for managing 134 nongame mammals in the state, including bats. Clearly it was impossible for only one person to focus much attention on any one group of animals. Bats weren’t entirely overlooked, however, and some surveying and population monitoring was done by independent bat specialists around the state. But with limited money available from the Arizona Nongame Wildlife Tax Checkoff and other state and federal funding programs, the Department itself was able to conduct only a few surveys on only a few bat species.

Then in 1990, wildlife management in Arizona changed. Citizens placed an initiative on the ballot to allocate Arizona lottery profits to a variety of conservation, education, recreation, and access and acquisition purposes. The new “Heritage” program would provide $10 million to the Arizona Game and Fish Department and $10 million to Arizona State Parks every year. The Arizona voters passed it by a landslide.

Suddenly, the Game and Fish Department had to plan for the best use of this money. A committee of broad thinkers was assigned the task of developing a department-wide plan. One of the first things they did was to set aside money to fund private contracts for wildlife inventory, research, urban habitats, and education. Luckily, they also recognized that bats had long been ignored and set aside annual funds for their management as well. The Arizona Game and Fish Department’s Bat Management Program was officially born.

The program is ambitious. Designed to manage Arizona’s great diversity of bats, it also promotes bat conservation and education. In addition, the program conducts statewide bat surveys and is developing a cooperative network among bat biologists, cave specialists, and other experts from across the nation. The Department hired me as the coordinator, and I hired two wildlife biologists, Shawn Castner and Tim Snow, to help me. At the time, I had no idea that this program was the only one of its kind, making Arizona the most progressive state in the nation with regard to its bats.

Our first job was to learn about the life history of bats, how to identify different species, and how to conduct surveys to assess their presence and numbers. We started by talking to bat specialists, attending bat study workshops, and learning how to enter mines and caves safely. We absorbed every bit of information we could get our hands on. By the winter of 1992, with a lot of help from many people, we were— more or less— ready to go.

The next task was to set priorities for conducting surveys. Mines and caves appeared to be the most critical place to start because of bat sensitivity to human disturbance and because of the increased number of abandoned mines being closed in Arizona. With an estimated 80,000-100,000 mines in the state, many slated for closure, we had adequate cause to be concerned about the safety of resident bats.

We began our first surveys of abandoned mines on public land along the Bill Williams River in west-central Arizona in November 1992. Little was known about bats in the area, and it was
within the winter range for California leaf-nosed bats (Macrotus californicus), a species on the candidate list for endangered or threatened status. Many of the mines along the river are geothermally heated, making them ideal habitat for these nonhibernating bats.

Because of the time of year, we expected to find active winter colonies of leaf-nosed bats and temporarily vacant nursery roosts for a number of other species. We used the accumulation of guano as evidence that an empty mine might accommodate a nursery colony during the summer; the quantity of guano present indicated how great the use might be. From November until March the following year, Tim and Shawn surveyed 514 mines along the river. Forty-two percent showed some evidence of bat use, and 14 percent of these showed significant use. Two of the roosts contained California leaf-nosed bats with over 500 individuals each— important discoveries.

Between April and September 1993, we surveyed an additional 711 mines on public land managed by the Bureau of Land Management (BLM). In contrast with the geothermally heated mines along the Bill Williams River, only 19 percent of the BLM mines showed evidence of bat use, with 3 percent showing significant use. We speculated that the number of bat roosts along the river was higher than in some other areas of the state because the warmer mines provide better habitat year-round for the overwintering California leaf-nosed bats, as well as for summer nursery colonies of many other bat species.

During that first summer, we also conducted a survey on the U.S. Army Yuma Proving Ground. We discovered five significant bat roosts, one of which contained 200 California leaf-nosed bats. But the most important discovery was the identification of several key flight corridors for bats using the nearby Colorado River for food and water. Even before we completed the survey, our work achieved results. Data gained from mist-netting bats over Yuma Wash showed that, even though the wash was dry, it was the most important flight corridor on the entire range and that bats used it for foraging. In 10 hours we had captured 36 bats of four species over this dry wash. The Army had proposed using it as a test site, which would result in some disturbance to vegetation and the ground. But because of what we learned, plans are now underway to locate the test site in a less sensitive area.

That summer we also found a mine that contained a nursery roost of about 350 Townsend’s big-eared bats (Plecotus townsendii)— the largest such roost known for this species in Arizona. These bats are being considered for federal endangered or threatened status. Several months later, we learned that the site would be lost to open-pit mining operations. When we informed officials at Consolidated Mines of the risk to an important bat roost, they were extremely cooperative and supportive. They waited to break into the roost until late in fall, when the colony was at its lowest population size, and we were able to exclude the few remaining bats. Other nearby sites, where we had discovered small groups of big-eared bats, were available as alternative roosts. True, the original roost was lost, but these animals would surely have died had we not discovered them through the survey and recommended a way to save them.

LAST YEAR, the second summer, we focused on mines within the Imperial National Wildlife Refuge along the Colorado River in southwestern Arizona. We surveyed 111 mines during this project. The most important find was an abandoned mine containing a mixed maternity colony of about 10,000 California leaf-nosed bats and Yuma myotis (Myotis yumanensis). Barriers had been placed over all five openings of the mine sometime in the past, and all had been breached by visitors. Although human disturbance at bat roosting sites ranks as one of the greatest causes of decline, in this case it may have been fortunate for the bats because it meant they could still enter the mine. Plans are now being made to replace the old barriers with bat gates, which will prevent people from entering but will allow bats unrestricted access.

This winter, we conducted a similar survey in the Prescott National Forest in north-central Arizona. Because the survey was conducted during the colder months, the number of bats and species we caught in our nets was low, as we expected. But the project was valuable in another way because it directly affected the management of a group of abandoned mines located on forest lands. The U.S. Forest Service had requested that the mine operators close the inactive sites. Our survey of these mines indicated that one was a hibernating site for Townsend’s big-eared bats and that none were important nursery roosts. Our recommendation was to gate the hibernaculum and close the remaining mines. Other similar projects have shown that the few bats occasionally using nearby mines will likely move to the protected site.

Another survey conducted in response to proposed mine closures resulted in discovering a transitory roost of about 20,000 lesser long-nosed bats (Leptonycteris curasoae), an endangered species. These stopover roosts allow the bats to rest, replenish their energy, and prepare for the next leg of their journey south to Mexico, where they reside during the winter months. Even though transitory roosts are used for a mere six to eight weeks every year, they can be extremely important. The newly identified site is on National Park Service lands and is one of only two known transitory roosts for the species in Arizona. The National Park Service has recently approved funding to replace the existing barriers with approved bat gates. The roost will be monitored and a survey of the surrounding habitat will be conducted to locate and eventually protect agave plants, one of the bats’ main food sources.

Other protective measures also resulted from last year’s work. At a cave owned by the Arizona State Land Department, two independent bat specialists contracted by the Arizona Game and Fish Department began a long-term survey of the cave’s bat populations. For the past 40 to 50 years, the cave has been a very popular site for recreational spelunkers. It is also home to a summer nursery colony of Townsend’s big-eared bats and a winter colony of California leaf-nosed bats. Evidence showed a direct correlation between greater visitation to the cave in recent years and a decline of the big-eared bat colony-a species extremely sensitive to disturbance. The bats have declined by 50 percent in the cave, and perhaps even mor-e alarming, the females failed to reproduce in 1994.

The State Land Department was also concerned about the liability brought on by increased recreational use. We recommended installing bat gates on all three entrances to the cave to reduce liability and to protect the bats. The Department agreed, and last November, heavy-duty bat gates were installed on all three entrances to the cave. We are now developing a management plan for the cave with the help of three Arizona grottoes (local chapters of the National Speleological Society). Many options are being considered, including limited visitation. The Arizona Game and Fish Commission has also approved the use of Heritage funds to purchase the property from the State Land Department.

A MAJOR BENEFIT of the Heritage monies is a greatly expanded capacity to collect data. In addition to surveying caves and mines, we have also been inspecting artificial structures for possible bat use, finding colonies beneath bridges, in the crevices of dams, and in buildings. Bats roosted in half of the 32 bridges thus far inspected, nine of which harbor significant roosts. Surveying just two dams resulted in locating a roost of about 2,700 Yuma myotis, and one of the 15 buildings we examined contained about 2,000 of these bats. Another way we have increased the amount of information available is by providing grants to knowledgeable independent biologists.

By analyzing the data collected from all of these projects, we have discovered some important things about bats in our state. Over the last two years, we have completed surveys at 1,895 mines and caves. Overall, 32 percent show some evidence of bat use, and 8 percent show use we consider significant. In geothermal areas, the percentage of bat use is much greater, making these sites even more critical to bats. Heritage has now funded bat surveys in 11 areas of the state, with an additional four pending approval.

One of these Heritage-funded projects was the extremely successful forest bat survey, which has been conducted for the last two years [BATS, Summer 1994]. This cooperative project by the Department, the U.S. Forest Service, and BCI uses radiotelemetry technology to follow bats to their roosts. Using this technique has resulted in locating many tree roosts for bat species we previously knew nothing about. Some of what we learned the first year was groundbreaking. BCI member volunteers returned to this project last year and are enthusiastic about helping for as long as they are needed. In return, the Forest Service is receiving valuable data about bats; the information is having a direct effect on forest management practices such as logging, snag removal, and controlled burns

CONDUCTING SURVEYS AND collecting data helps promote sound bat management. But education increases the public’s awareness and understanding of these animals, and their awareness in turn supports further conservation efforts. Realizing this, we have also been extremely involved in bat education, both for the public and for biologists.

During the summer of 1993, we focused on bats in an issue of the Department’s monthly magazine, Wildlife Views. In conjunction with the Department’s Education Branch, we also published a poster featuring the state’s bats. Using BCI photos, the poster includes a brief natural history summary on the back of each photo, so that teachers can also use them as flash cards. The response to both these publications has been enthusiastic. We have received many positive comments from students, teachers, biologists, and the general public.

We have also cosponsored several bat study training workshops, directed toward Department and other agency biologists, teachers, and the general public. Some of these workshops have been presented in cooperation with the BLM and the Department’s Education and Habitat branches, training hundreds of biologists from Arizona. Other workshops have been co-hosted with BCI, whose field-study workshop program trains people from across the nation in bat natural history, survey protocol, mine assessment, potential threats, and bat management and conservation strategies.

The citizens’ initiative that made the Heritage program a reality has been the single most important catalyst in improving wildlife management in Arizona. On a statewide level, the funding has allowed us to take the lead in the kind of management that anticipates future needs for our wildlife. For bats it means that each year a wealth of new information is being gathered and analyzed, for the first time enabling us to make informed decisions about their conservation. And it means that many important new bat roosts have not only been identified but have also been protected.

But adequate funding alone is not the only advantage Arizona’s bats have. The Game and Fish Department’s Bat Management Program is truly a cooperative effort: our accomplishments wouldn’t have been possible without help and support from biologists, the citizens of Arizona, private businesses, and conservation organizations like BCI. We are looking forward to continued success stories in the years to come.

(Bio)
Debra C. Noel is a wildlife biologist and the bat management coordinator for the Arizona Game and Fish Department’s Bat Management Program.

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Arizona’s new Bat Management Program has led to the discovery and protection of previously unknown but important roosts. Biologists found the state’s largest known roost for Townsend’s big-eared bats just in time to save them.

State biologists discovered significant roosts for California leaf-nosed bats in abandoned geothermally heated mines. By finding the bats before the mines are permanently sealed, such roosts can instead be protected.

One of the most important discoveries last year was a large maternity colony of Yuma myotis in an abandoned mine that was being disturbed by curious people entering the tunnels. The mine will now receive protective gates.

A critical stopover roost for endangered lesser long-nosed bats was found when biologists responded to a proposed mine closure. As a result, the site is being protected. The roost is one of only two such roosts known for the species in the state.

For the past two years, a joint study with BCI, the Arizona Game and Fish Department, and the U.S. Forest Service, has been yielding important information about Arizona’s forest bats. (Top left) Kei Yasuda, a BCI member volunteer, and Tom Morrell, an Arizona Game and Fish Dept. biologist, prepare to release a bat with radio transmitter that they have just attached to the bat’s back. Bert Grantges (below), field coordinator for the project, listens for the sound of the radio-tagged bat so that researchers can discover its roost.