Geology topics

Robert E. Lovich

Publications and source records attributed to Robert E. Lovich.

7 recordsLinked to original sources

USGS2022

Range-wide persistence of the endangered arroyo toad (Anaxyrus californicus) for 20+ years following a prolonged drought

Prolonged drought due to climate change has negatively impacted amphibians in southern California, U.S.A. Due to the severity and length of the current drought, agencies and researchers had growing concern for the persistence of the arroyo toad ( Anaxyrus californicus ), an endangered endemic amphibian in this region. Range-wide surveys for this species had not been conducted for at least 20 years. In 2017–2020, we conducted collaborative surveys for arroyo toads at historical locations. We surveyed 88 of the 115 total sites having historical records and confirmed that the arroyo toad is currently extant in at least 61 of 88 sites and 20 of 25 historically occupied watersheds. We did not detect toads at almost a third of the surveyed sites but did detect toads at 18 of 19 specific sites delineated in the 1999 Recovery Plan to meet one of four downlisting criteria. Arroyo toads are estimated to live 7–8 years, making populations susceptible to prolonged drought. Drought is estimated to increase in frequency and duration with climate change. Mitigation strategies for drought impacts, invasive aquatic species, altered flow regimes, and other anthropogenic effects could be the most beneficial strategies for toad conservation and may also provide simultaneous benefits to several other native species that share the same habitat.

California↗

USGS2018

Biodiversity of amphibians and reptiles at the Camp Cady Wildlife Area, Mojave Desert, California and comparisons with other desert locations

We examined the biodiversity of amphibian and reptile species living in and near constructed ponds in the riparian area at the Camp Cady Wildlife Area (CCWA) in the Mojave Desert of San Bernardino County, California, based on field work from 1998-1999, 2016-2017, review of the literature, and searches for museum specimens using VertNet.org. A total of 11 species (201 captures), including two frogs and toads (one non-native frog), one turtle, three snakes, and five lizards were captured at terrestrial drift fences with pitfall traps encircling two ponds (0.5 hectares total) on the property in 1999. Four additional species (one frog, one lizard, and two snakes) were previously reported in 1978 from a ranch 1.6 km southwest from CCWA for a total of 15 species in the local area. The southwestern pond turtle (Actinemys pallida), was commonly observed at CCWA from 1998 to 1999 and documented as a breeding population. However, the species was extirpated at CCWA sometime after 2014 when the last individuals were photographed, and none have been detected since then despite significant efforts to do so. Biodiversity of amphibians and reptiles at CCWA is relatively low compared with sites elsewhere in the Mojave Desert with more elevational diversity. The 14 native species documented at CCWA accounts for approximately 21% of the native reptile and amphibian species reported by Stewart (1994) for the entire Mojave Desert, including peripheral species. Our smaller sample likely represents a group of easily detected species and is biased toward those found in or near water, especially amphibians. However, the relative proportion of amphibians vs. reptiles that inhabited CCWA in the last 40 years is not significantly different from the recently compiled proportions at five military installations in the California deserts. The herpetofauna inhabiting CCWA is notable for including riparian obligates like the western toad (Anaxyrus boreas), Northern Baja California treefrog (Pseudacris h. hypochondriaca), and A. pallida that are otherwise absent from large portions of the Mojave Desert. Other species are typical of those that are expected in the low-elevation creosote scrubdominated ecosystem in the area.

California↗

USGS2017

Using decision analysis to support proactive management of emerging infectious wildlife diseases

Despite calls for improved responses to emerging infectious diseases in wildlife, management is seldom considered until a disease has been detected in affected populations. Reactive approaches may limit the potential for control and increase total response costs. An alternative, proactive management framework can identify immediate actions that reduce future impacts even before a disease is detected, and plan subsequent actions that are conditional on disease emergence. We identify four main obstacles to developing proactive management strategies for the newly discovered salamander pathogen Batrachochytrium salamandrivorans ( Bsal ). Given that uncertainty is a hallmark of wildlife disease management and that associated decisions are often complicated by multiple competing objectives, we advocate using decision analysis to create and evaluate trade-offs between proactive (pre-emergence) and reactive (post-emergence) management options. Policy makers and natural resource agency personnel can apply principles from decision analysis to improve strategies for countering emerging infectious diseases.

Frontiers in Ecology and the Environment↗

USGS2016

Salamander chytrid fungus ( Batrachochytrium salamandrivorans ) in the United States—Developing research, monitoring, and management strategies

The recently (2013) identified pathogenic chytrid fungus, Batrachochytrium salamandrivoran s ( Bsal ), poses a severe threat to the distribution and abundance of salamanders within the United States and Europe. Development of a response strategy for the potential, and likely, invasion of Bsal into the United States is crucial to protect global salamander biodiversity. A formal working group, led by Amphibian Research and Monitoring Initiative (ARMI) scientists from the U.S. Geological Survey (USGS) Patuxent Wildlife Research Center, Fort Collins Science Center, and Forest and Rangeland Ecosystem Science Center, was held at the USGS Powell Center for Analysis and Synthesis in Fort Collins, Colorado, United States from June 23 to June 25, 2015, to identify crucial Bsal research and monitoring needs that could inform conservation and management strategies for salamanders in the United States. Key findings of the workshop included the following: (1) the introduction of Bsal into the United States is highly probable, if not inevitable, thus requiring development of immediate short-term and long-term intervention strategies to prevent Bsal establishment and biodiversity decline; (2) management actions targeted towards pathogen containment may be ineffective in reducing the long-term spread of Bsal throughout the United States; and (3) early detection of Bsal through surveillance at key amphibian import locations, among high-risk wild populations, and through analysis of archived samples is necessary for developing management responses. Top research priorities during the preinvasion stage included the following: (1) deployment of qualified diagnostic methods for Bsal and establishment of standardized laboratory practices, (2) assessment of susceptibility for amphibian hosts (including anurans), and (3) development and evaluation of short- and long-term pathogen intervention and management strategies. Several outcomes were achieved during the workshop, including development of an organizational structure with working groups for a Bsal Task Force, creation of an initial influence diagram to aid in identifying effective management actions in the face of uncertainty, and production of a list of potential management actions and key research uncertainties. Additional products under development include a Bsal Strategic Action plan, an emergency response plan, a monitoring and surveillance program, a standardized diagnostic approach, decision models for natural resource agencies, and a reporting database for salamander mortalities. This workshop was the first international meeting to address the threat of Bsal to salamander populations in the United States, with more than 30 participants from U.S. conservation and resource management agencies (U.S. Fish and Wildlife Service, U.S. Forest Service, U.S. Department of Defense, U.S. National Park Service, and Association of Fish and Wildlife Agencies) and academic research institutions in Australia, the Netherlands, Switzerland, the United Kingdom, and the United States.

Open-File Report↗

USGS2011

Habitat use and movement of the endangered Arroyo Toad ( Anaxyrus californicus ) in coastal southern California

Information on the habitat use and movement patterns of Arroyo Toads ( Anaxyrus californicus ) is limited. The temporal and spatial characteristics of terrestrial habitat use, especially as it relates to upland use in coastal areas of the species' range, are poorly understood. We present analyses of radiotelemetry data from 40 individual adult toads tracked at a single site in coastal southern California from March through November of 2004. We quantify adult Arroyo Toad habitat use and movements and interpret results in the context of their life history. We show concentrated activity by both male and female toads along stream terraces during and after breeding, and, although our fall sample size is low, the continued presence of adult toads in the floodplain through the late fall. Adult toads used open sandy flats with sparse vegetation. Home-range size and movement frequency varied as a function of body mass. Observed spatial patterns of movement and habitat use both during and outside of the breeding period as well as available climatological data suggest that overwintering of toads in floodplain habitats of near-coastal areas of southern California may be more common than previously considered. If adult toads are not migrating out of the floodplain at the close of the breeding season but instead overwinter on stream terraces in near-coastal areas, then current management practices that assume toad absence from floodplain habitats may be leaving adult toads over-wintering on stream terraces vulnerable to human disturbance during a time of year when Arroyo Toad mortality is potentially highest.

California↗

USGS2011

An inventory and monitoring plan for a Sonoran Desert ecosystem; Barry M. Goldwater Range-West

Marine Corps Air Station Yuma manages the Barry M. Goldwater Range-West, which encompasses approximately 2,800 square kilometers of Sonoran Desert habitat in southwestern Arizona. The Barry M. Goldwater Range is a major U.S. military installation designed as an air combat training location for the U.S. Marine Corps and U.S. Air Force, but it also includes some of the most pristine desert habitat in the United States. In an effort to ensure the long-term viability of this unique natural resource, the U.S. Geological Survey (USGS) has developed an Integrated Natural Resources Management Plan and Inventory and Monitoring Plan to guide natural resource management of the Barry M. Goldwater Range-West. This Inventory and Monitoring Plan provides a framework for long-term ecosystem monitoring on Barry M. Goldwater Range-West lands by identifying existing and potential threats to ecosystem function, prioritizing resources for monitoring, and providing information and protocols necessary to initiate a long-term ecosystem monitoring program. The Inventory and Monitoring Plan and related protocols were developed through extensive review of existing Sonoran Desert monitoring programs and monitoring literature and through a 2-day workshop with resource managers, monitoring experts, and other stakeholders. The Barry M. Goldwater Range-West Inventory and Monitoring Plan stresses the importance of regional monitoring partnerships and protocol standardization for understanding landscape-scale ecosystem changes in the Sonoran Desert; information and protocols contained within the plan may also be of interest to land managers engaged in large-scale ecosystem monitoring and adaptive management of other arid regions.

Open-File Report↗

USGS2009

Surface-dwelling and subterranean invertebrate fauna associated with giant reed ( Arundo donax Poaceae) in Southern California

In the southwestern United States giant reed, Arundo donax , is a non-native invasive plant that has become widely established in moist places and forms its largest stands along riparian corridors. The most widely reported negative effects include competition with native species, increased rate of transpiration, increased potential for wildfires, and stream channel and bank alteration. However, little is known about the faunal communities associated with this plant and the potential effects on native fauna. In this study, we focused our efforts on determining the faunal composition specifically from rhizome clumps of A. donax from a site located along the Santa Margarita River in San Diego County, California. A total of 2590 individual macro-invertebrates were collected and identified, and represented 64 species from 7 classes. No sensitive species and few vertebrates were found to be in association with A. donax rhizome clumps. Four non-native invertebrate species made up 43% of the total number of captured invertebrates, and 31% of the sampled invertebrates were confirmed as native species. This study demonstrates that A. donax rhizome clumps, and the soils associated with them, provide habitat for several native macro-invertebrate species, but can be dominated by a greater abundance of non-native species.

Bulletin, Southern California Academy of Sciences↗