Pacific Southwest Research Station

Pacific Southwest Research Station
800 Buchanan Street
West Annex Building
Albany, CA 94710-0011

(510) 559-6300

Research Topics Wildlife & Fish

Mammals

Developing Quantitative Methods for Assessment of Bat Populations: Bats are important components of biodiversity and, as primary predators of nocturnal insects, play an important role in ecosystem function, especially in forests. Nevertheless their contributions are often overlooked because their activities take place out of sight from humans: they roost in inconspicuous places and emerge from them at night to forage under the cover of darkness.

Uncovering the mysteries of bat ecology often requires the use high-tech tools such as echolocation detectors to determine their activity patterns and radio-transmitters as small as 0.33 g (0.01 oz) to gain information about roost locations and foraging areas. In addition, the activity patterns of bats are anything but regular or predictable. Bats in forests switch roosts every 2-3 days and alter the timing and location of their foraging activities on a nightly basis in response to weather conditions and availability of insects. Yet, against the backdrop of these challenges, Bill Zielinski and Ted Weller found that "a growing number of government agency personnel, and others, require more information about the species of bats that occur in their area", their conservation needs, and methods that can be used to assess the status of their populations (Weller and Zielinski 2006).

Mitigating Impacts of Wind Energy Development on Populations of Migratory Bats: Energy development and distribution promises to be a major global challenge during the 21st century. In the US, there are increasing calls to achieve greater "energy independence" and there is general agreement that renewable sources of energy will be an important component of our energy portfolio. Because wind energy is able to generate electricity without many of the environmental impacts associated with other energy sources, it is expected to produce a net benefit to wildlife species. However, in some situations, wind energy developments have produced large impacts to bats in the form of direct mortality from collision with moving turbines. The majority of bats killed, worldwide, are migratory species, which in California are represented by hoary bats, red bats, silver-haired bats, and Mexican free-tailed bats. A number of hypotheses exist for why bats collide with wind turbines (Cryan 2008, Kunz et al. 2007), but from a practical standpoint there are two important avenues of exploration that may increase compatibility between wildlife and wind energy. First, predictive tools must be developed that allow us to ascertain whether proposed wind energy developments are likely to be a threat to bats. Second, once facilities are built, we must take steps to minimize impacts to bat populations.

Carnivore Survey: The integrity of an ecosystem may be measured by the health of its vertebrate carnivore populations. Carnivores influence the structure and reflect the vigor of trophic levels on which they depend, and are sensitive to the abundance and behavior of the human populations with which they coexist.