Vector-Borne Disease in Wild Mammals Impacted by Urban Expansion and Climate Change.

Ecologies of zoonotic vector-borne diseases may shift with climate and land use change. As many urban-adapted mammals can host ectoparasites and pathogens of human and animal health concern, our goal was to compare patterns of arthropod-borne disease among medium-sized mammals across gradients of rural to urban landscapes in multiple regions of California. DNA of Anaplasma phagocytophilum was found in 1-5% of raccoons, coyotes, and San Joaquin kit foxes; Borrelia burgdorferi in one coyote, rickettsiae in two desert kit foxes, and Yersinia pestis in two coyotes.

Potential impact of diphacinone application strategies on secondary exposure risk in a common rodent pest: implications for management of California ground squirrels.

Anticoagulant rodenticides are a common tool used to manage rodents in agricultural systems, but they have received increased scrutiny given concerns about secondary exposure in non-target wildlife. Rodenticide application strategy is one factor that influences exposure risk. To understand the impact of application strategy, we tested residues of a first-generation anticoagulant (diphacinone) in liver tissue of radiotransmittered California ground squirrels (Otospermophilus beecheyi) following spot treatments, broadcast applications, and bait station applications in rangelands in central California during summer and autumn 2018-2019.

Use of rodenticide bait stations by commensal rodents at the urban-wildland interface: Insights for management to reduce nontarget exposure.

Background: Pest management professionals use anticoagulant rodenticides, usually placed in tamper-resistant bait stations, to control commensal rodents, but significant concerns remain about exposure of nontarget species, especially at the urban-wildland interface. We deployed digital cameras to monitor use of bait stations placed in 90 residential yards across Orange County, California, USA. Two bait stations, supplied with nontoxic bait, were monitored in each yard for approximately 30 consecutive days during two camera-trapping sessions between December 2017 and March 2019.

Effectiveness of rodenticides for managing invasive roof rats and native deer mice in orchards.

Roof rats (Rattus rattus) and deer mice (Peromyscus maniculatus) are occasional pests of nut and tree fruit orchards throughout California and in many other parts of the USA and beyond. In general, the most practical and cost-effective control method for rodents in many agricultural environments is the use of rodenticides (toxic baits), but little or no information exists on the efficacy of current rodenticides in controlling roof rats and deer mice in orchards. Therefore, our goals were to develop an index of rodent activity to monitor efficacy of rodenticides and to subsequently test the efficacy of three California Department of Food and Agriculture rodenticide baits (0.