Small Terrestrial Vertebrates Research Articles

Pitfall trap efficiency in sampling small vertebrates (Anura, Squamata, and Mammalia) in fragments of the Southeastern Atlantic Forest, Brazil

Pitfall traps are a sampling method broadly used in studies with small terrestrial vertebrates. In this paper, we compared the efficiency of modified pitfall traps in sampling anurans, squamates, and mammals. In two forest fragments of the Seasonal Semi-deciduous Atlantic Forest, we set up 26 arrays of drift fences and pitfall traps, composed of four 30-liter buckets, each set up arranged in a ‘Y’ shape linked by a fence of 4 m in length and 0.5 m in height. We tested for the effect of an internal rim on the border of the buckets by comparing buckets with and without a rim on capture efficiency. In general, we did not observe any effect of the rims in capture efficiency, independently of the bucket position where the rim was present. Still, terminal buckets with rims were less efficient in capturing rodents. We hypothesized that the use of buckets with rims did not increase the capture of small vertebrates due to the animal’s ability to perceive the rim due to substrate instability. However, the pitfall trap efficiently captures small vertebrates, and we do not recommend using the internal rims.

Comparing Effectiveness of AHDriFT Systems and Sherman Traps for Surveying Small Mammals in Northeastern Indiana

Abstract Traditional small mammal survey methods (e.g., Sherman traps) are beneficial in certain conditions but tend to require substantial effort and funds and can introduce various biases. The recently described adapted-Hunt drift fence technique (AHDriFT) camera trap system (i.e., camera traps combined with drift fences) can survey small terrestrial vertebrates and does not require much time in the field. Our objective was to compare the efficiency and effectiveness of AHDriFT systems and traditional Sherman traps for surveying small mammal communities. We conducted surveys with both methods in four sites of varying habitat types at the Eagle Marsh Nature Preserve (Fort Wayne, Indiana) from February to July in 2020 and May to August in 2021. We conducted 640 trap nights (one trap set on one calendar night) of Sherman trap surveys and 551 trap nights of AHDriFT system surveys. We captured 192 small mammals of three species with Sherman traps and obtained 532 images of unique small mammal individuals of seven species with AHDriFT systems. Our AHDriFT systems resulted in two times greater species richness (Z = −6.21, P < 0.01), 16 times greater species evenness (Z = −4.83, P < 0.01), and 23 times greater Shannon's diversity values (Z = −4.87, P < 0.01) than Sherman traps. The AHDriFT systems also documented the presence of four species that the Sherman traps did not (northern short-tailed shrew Blarina brevicauda, common shrew Sorex cinereus, long-tailed weasel Neogale frenata, eastern chipmunk Tamias striatus). Overall, AHDriFT system surveys provided 1.5–5 times more observations per dollar spent and required 90% less time in the field than Sherman trap surveys. These results suggest that AHDriFT systems may be a more efficient and effective method of surveying small mammal communities.

Annotated Checklist of Small Terrestrial Vertebrates at CFSII SL7 Ecological Corridor: Angsi Forest Reserve-Berembun Forest Reserve in Negeri Sembilan, Malaysia.

Surveys of small terrestrial vertebrates were conducted at identified Central Forest Spine (CFS) ecological corridor named CFSII SL7 (Secondary Linkage-7) involving Angsi Forest Reserve and Berembun Forest Reserve in Negeri Sembilan. The surveys were conducted in February, April, and September 2018. The main objective of these surveys is to update the checklist of small vertebrate species recorded in the corridor. Three plots were established, two located in Berembun FR, referred to as Berembun FR I and Berembun FR II, while one located at Angsi FR. A total of 100 collapsible cage traps, three harp traps, 10 mist nets, and 25 pitfall traps were deployed at each site. These traps were set for five consecutive nights per session, with two sampling sessions per site. In addition, direct observations and active searches were also conducted for arboreal species and herpetofauna respectively. A total of 326 individuals comprising 26 species of small mammals (eight families), 43 species of avifauna (19 families), and 22 species of herpetofauna (10 families) were recorded during the surveys. Berembun FR I harbor the highest number of small vertebrates (50 species), followed by Angsi FR and Berembun FR II with 43 and 39 species, respectively. In addition, 39 of the overall documented species are additionally recorded as small vertebrates compared to a compilation of previously listed species at both forest reserves. Through these results, it is hoped that the significance of these fragmented forests under CFSII SL7 as crucial habitats for small vertebrates can be further highlighted, and appropriate conservation measures must be taken to safeguard the small vertebrate population in these areas.

Optimizing monitoring of an endemic terrestrial salamander (Speleomantes ambrosii): comparing cost-effectiveness of different methods for abundance estimation

In order to correctly plan conservation and management of animal populations, it is fundamental to obtain reliable information on population abundance using cost-effective monitoring methods. In the case of small terrestrial vertebrates, capture–mark–recapture, removal sampling and counts of unmarked individuals have proven to be reliable techniques to estimate population abundance. In the present study, we applied a multinomial N-mixture modelling approach, performed through a double-observer sampling protocol, to estimate population size of the endemic terrestrial salamander Speleomantes ambrosii. We aimed at comparing cost-effectiveness of this protocol with those of other estimation methods (i.e., capture–mark–recapture and removal sampling), with particular attention to management and monitoring guidelines. The double-observer multinomial N-mixture protocol was the most cost-effective among the different methods: given its ease of application and cost-effectiveness, we encourage its employment for long-term monitoring and conservation plans of the near-threatened plethodontid salamander Speleomantes ambrosii.

Gamasid Mites (Gamasina) Associated with Small Terrestrial Vertebrates in the South of Non-Chernozem Center of Russia (Kaluga Province)

Gamasid Mites (Gamasina) Associated with Small Terrestrial Vertebrates in the South of Non-Chernozem Center of Russia (Kaluga Province)

Factors Affecting the Presence and Abundance of Amphibians, Reptiles, and Small Mammals under Artificial Cover in Southern California

Artificial cover objects (ACOs) are known to attract small terrestrial vertebrates, but the actual parameters that attract species to ACOs can vary across geographic regions and climates. For this study ACOs were placed in coastal sage scrub and grassland habitats in southern California and surveyed weekly for small terrestrial vertebrates over a 4-yr period. We observed 1643 individuals of 34 taxa during 143 survey sessions totaling 16,312 ACO days. Overall species richness and abundances under ACOs were highest from February to April. Our results showed that the probability of encountering a reptile under an ACO was highest in February and March under large wooden ACOs containing moist soil, when temperatures under the ACO were relatively mild, and when minimum air temperatures were low. At the community level, encounter probabilities for small mammals were highest for large wooden ACOs and ACOs with low soil moisture, with several species differences. Amphibians of three species were only captured in low numbers primarily under wooden ACOs from November to March. Use of ACOs in research and monitoring is an inexpensive and simple way to document and capture a wide variety of small terrestrial vertebrates. Species richness and abundance can be maximized over short periods using ACOs and can be equally important for long-term monitoring, particularly once the factors that make ACO use effective for small terrestrial vertebrates of a certain region have been investigated.

Население мелких наземных позвоночных животных памятника природы «Чеускинский бор» (Ханты-Мансийский автономный округ - Югра)

There are 25 specially protected natural areas of various status have been organized on the territory of the Khanty-Mansiysk Autonomous Okrug Ugra. Despite their great nature conservation value, the degree of study of flora and fauna, as well as the ecology of plants and animals in the territory of most of them, remains relatively low. Until now, special studies of small terrestrial vertebrates inhabiting the Cheuskinsky Bor have been carried out. In 2020, our research of small terrestrial vertebrates were carried out. The purpose of the study is to identify the species composition and some features of ecology (abundance, biotopic distribution) of small mammals, amphibians and reptiles. The research was carried out in July-September 2020. Metal cones were used to catch most of the vertebrate species. A total of 7400 cone-days have been worked out. 10 species of small mammals and 3 of amphibians are registered. The species composition of small mammals at the Cheuskinsky Bor site is relatively poor, 10 species were captured by cones, 3 were marked visually. The group of dominants included the common shrew and the red-backed vole. They accounted for 22% and 77%, respectively, of all recorded animals. Reptiles in the 2020 season were not registered in the counts, however, according to the literature, the habitat of the common European adder and viviparous lizard is known. Among amphibians, the moor frog and Siberian salamander are rare, the European toad is common. In the future, when conducting annual studies, the list of small mammals can be supplemented by 714 species of insectivores, bats and rodents, the list of amphibians 1 species.

Lined Snake (Tropidoclonion lineatum) Prescribed Fire Mortality

Functioning prairie ecosystems are characterized by periodic and cyclical disturbances (e.g., grazing, drought, fire, etc.). Grazing and fire were historically widespread drivers of habitat structure. Many native species are adapted to fire and rely on the diverse habitats it maintains in a range of successional states. Wildlife mortality is an inevitable result of many prescribed fires and various species of small terrestrial vertebrates with limited dispersal abilities are most commonly affected. Herein, we report on the detected mortality of an individual Lined Snake (Tropidoclonion lineatum) after a prescribed burn along a lowland tallgrass prairie - wet meadow ecotone in South Central Nebraska. Little information exists on this topic as our record is only the second published observation of T. lineatum mortality resulting from a prescribed burn to our knowledge. Land managers can limit the negative impacts of prescribed fire on native species of conservation concern by considering their natural histories during the planning process.

Reliability of multinomial N-mixture models for estimating abundance of small terrestrial vertebrates

Information on population abundance is important to correctly plan conservation and management of animal populations. In general, capture-mark-recapture (CMR) is considered the most robust technique to estimate population abundance, but it is costly in terms of time and effort. Recently, binomial N-mixture models, based on counts of unmarked individuals, have been widely employed to estimate abundance. These models have limits and their reliability has been criticized. In the majority of cases, multinomial N-mixture models based on multiple observer protocols, that are hierarchical extensions of simple CMR, are applied in estimating abundance of animals with large body size, conspicuous behavior or high detection probabilities. We applied and evaluated the reliability of a multinomial N-mixture modelling approach with multiple observer data to a small and cryptic terrestrial salamander, found in different habitats where populations possess different level of detectability. Estimates obtained with multinomial N-mixture models were compared to estimates obtained with classical methods, such as removal sampling, and their reliability has also been evaluated by simulations scenarios. Our results show that multinomial N-mixture models, applied within a multiple observer framework, give reliable and robust estimates of population abundance even when detection and density are relatively low. Therefore, multinomial N-mixture models appear efficient and cost-effective when planning and identifying management actions and conservation programs of small terrestrial animals such as amphibians and reptiles.

Integrative Framework for Long-Term Activity Monitoring of Small and Secretive Animals: Validation With a Cryptic Pitviper

The use of miniature accelerometer (ACT) data-loggers for remote and continuous recording of animal movement behavior is becoming increasingly common. Until recently, size constraints limited most animal-borne ACT applications to large-bodied species. We capitalized on the ongoing miniaturization and advancement of these technologies and associated computational techniques to develop a framework for long-term, low-frequency ACT monitoring of activity in small and secretive terrestrial species. We achieved this by internally implanting coupled radio transmitters and tri-axial ACTs in rattlesnakes (Crotalus atrox). Periodic field-validation observations of behavior were used to train and test supervised learning models (Random Forest, RF; Generalized Linear Elastic Net, GLMNET) for activity classification. The best performing RF model classified periods of movement and immobility in rattlesnakes with high accuracy (movement = 96%, immobile = 99%), and was applied to extensive ACT field datasets (median = 35 days, range = 6–289 days; N = 12) to produce activity budgets at multiple temporal scales. In general, these cryptic ambush predators were found to be highly sedentary, with activity budgets characterized by long periods of immobility interrupted by punctuated bouts of movement. The same temporal daily activity pattern was conserved across all active seasons (spring, summer non-mating, summer mating, fall), as most movement always occurred during the evening or nocturnal diel periods. Contrary to movement timing, daily movement duration was seasonally variable, as movement increased during the summer-mating season – possibly reflecting a combination of more favorable weather conditions (onset of rainy season) and mate-searching efforts by male rattlesnakes. This radio telemetry-accelerometry (RT-ACT) framework provides an objective and flexible set of data collection and processing procedures for long-term ACT field datasets. Expanding our coarse-scale behavioral classification scheme could provide a foundation for future investigations using the RT-ACT framework to explore relationships between individual behavioral decisions and performance in snakes and other small and secretive terrestrial vertebrates.

Long-term benefits and short-term costs: small vertebrate responses to predator exclusion and native mammal reintroductions in south-western New South Wales, Australia

Abstract ContextThe success of conservation fences at protecting reintroduced populations of threatened mammals from introduced predators has prompted an increase in the number and extent of fenced exclosures. Excluding introduced species from within conservation fences could also benefit components of insitu faunal assemblages that are prey for introduced predators, such as reptiles and small mammals. Conversely, reintroduced mammals may compete with smaller mammals and reptiles for resources, or even prey on them. AimsIn a 10-year study from 2008, we examine how small terrestrial vertebrates respond to the exclusion of introduced predators, the feral cat (Felis catus) and red fox (Vulpes Vulpes), introduced herbivores and the reintroduction of regionally extinct mammal species. MethodsDifferences in the yearly relative abundance of reptiles and mammals according to habitat type and whether sites were fenced or not, were tested using multivariate generalised linear models. Next, we calculated univariate P-values to identify individual species that showed significant relationships, positive and negative, with any of the explanatory variables. Key resultsTotal captures of reptiles were lower inside the conservation fence in all years, whereas total captures of small mammals were markedly higher inside the fenced area, notably in dasyurids. ConclusionOur results showed that conservation fences can deliver benefits for some fauna (but not all) beyond facilitating the reintroduction of highly threatened mammals. ImplicationsOur results demonstrated the consequential impacts of introduced predators on the Australian small mammal fauna, and showed that predator-exclusion fences can be an effective conservation intervention for this guild.

Seasonality and microhabitat selection in a forest-dwelling salamander.

Many small terrestrial vertebrates exhibit limited spatial movement and are considerably exposed to changes in local environmental variables. Among such vertebrates, amphibians at present experience a dramatic decline due to their limited resilience to environmental change. Since the local survival and abundance of amphibians is intrinsically related to the availability of shelters, conservation plans need to take microhabitat requirements into account. In order to gain insight into the terrestrial ecology of the spectacled salamander Salamandrina perspicillata and to identify appropriate forest management strategies, we investigated the salamander's seasonal variability in habitat use of trees as shelters in relation to tree features (size, buttresses, basal holes) and environmental variables in a beech forest in Italy. We used the occupancy approach to assess tree suitability on a non-conventional spatial scale. Our approach provides fine-grained parameters of microhabitat suitability and elucidates many aspects of the salamander's terrestrial ecology. Occupancy changed with the annual life cycle and was higher in autumn than in spring, when females were found closer to the stream in the study area. Salamanders showed a seasonal pattern regarding the trees they occupied and a clear preference for trees with a larger diameter and more burrows. With respect to forest management, we suggest maintaining a suitable number of trees with a trunk diameter exceeding 30cm. A practice of selective logging along the banks of streams could help maintain an adequate quantity of the appropriate microhabitat. Furthermore, in areas with a presence of salamanders, a good forest management plan requires leaving an adequate buffer zone around streams, which should be wider in autumn than in spring.

Population genetic structure of Grauer's Swamp Warbler Bradypterus graueri, an Albertine Rift endemic

The endangered warbler Bradypterus graueri is endemic to the Albertine Rift, where it is restricted to montane swamps above 1900 m across the region. We studied genetic structure among six populations sampled across the species' distribution in northern Burundi, Rwanda, Uganda and the eastern Democratic Republic of Congo. A total of 2117 base pairs of mitochondrial data were sequenced. Phylogenetic analyses and network reconstruction of B. graueri haplotypes recovered three clades with a defined geographical pattern: clade 1, Virunga Volcanoes and Kigezi Highlands; clade 2, Rugege Highlands; and clade 3, Kahuzi‐Biega Highlands; clades 2 and 3 are sisters to each other. Both landscape dynamics and historical climate are likely to have played a role in the diversification of this species. The divergence between clade 1 and clades 2 and 3 (168.5 ka, 95% HPD 108.5, 244.4) coincides with a prolonged period of aridity in tropical Africa between 130 and 270 ka. Similarly, the divergence between clades 2 and 3 (99.4 ka, 95% HPD 55.4, 153.8) corresponds with a period of aridity just prior to 94 ka. Populations sampled from the eastern arm of the central Albertine Rift (Kigezi and Rugege Highlands) show a coincident increase in effective population size after the Last Glacial Maximum at c. 15 ka, whereas those sampled from Kahuzi‐Biega on the western arm of the rift do not. Despite the perceived higher vagility of bird species relative to other vertebrates, the degree of phylogeographical structure among populations of B. graueri is similar to that reported for small mammals (Hylomyscus vulcanorum, Lophuromys woosnami, Sylvisorex vulcanorum) and a frog Hyperolius castaneus sampled across the central Albertine Rift. Collectively our results suggest that climate dynamics associated with late Pleistocene cycles had a significant influence on driving the population genetic structure and associated levels of genetic diversity in B. graueri and other small terrestrial vertebrates. Our results have implications for the conservation of B. graueri and other endemics to the Albertine Rift, particularly in the context of other phylogegeographical studies centred on this biodiversity hotspot.

Changes in the exploitation dynamics of small terrestrial vertebrates and fish during the Pleistocene–Holocene transition in the SW Iberian Peninsula: A review

The Pleistocene–Holocene transition c. 11.5 ka cal. BP is associated with dramatic climatic changes. These events led to fundamental shifts in landscape and have, therefore, been seen as responsible for a major impact on the human ecological behavior of the last hunter–gatherers in the Western European territory. In the case of Iberian Peninsula, it is commonly assumed that these human ecological adaptations are reflected in the new settlement and subsistence patterns that characterized the Late Upper Paleolithic–Mesolithic transition. Following the argument, the main aim of this paper is to present the state-of-the-art and consider this theoretical model using zooarchaeological data of small terrestrial vertebrates and fish from SW Portugal. Archaeological data are reviewed and discussed in order to analyze the change in the exploitation of small game, birds, and aquatic resources during this period. In this paper, we reinforce the idea that in SW Iberia, subsistence intensification and diversification precede the transition itself and are more likely to be related to other long-term phenomena, cultural and/or demographical, than to the changes in settlement behavior. The state-of-the-art discussed here led to new research questions related to the role of small vertebrates on the changes in human subsistence behavior during the Pleistocene–Holocene from Western Iberia.

The effects of multiple obstacles on the locomotor behavior and performance of a terrestrial lizard.

Negotiation of variable terrain is important for many small terrestrial vertebrates. Variation in the running surface resulting from obstacles (woody debris, vegetation, rocks) can alter escape paths and running performance. The ability to navigate obstacles likely influences survivorship through predator evasion success and other key ecological tasks (finding mates, acquiring food). Earlier work established that running posture and sprint performance are altered when organisms face an obstacle, and yet studies involving multiple obstacles are limited. Indeed, some habitats are cluttered with obstacles, whereas others are not. For many species, obstacle density may be important in predator escape and/or colonization potential by conspecifics. This study examines how multiple obstacles influence running behavior and locomotor posture in lizards. We predict that an increasing number of obstacles will increase the frequency of pausing and decrease sprint velocity. Furthermore, bipedal running over multiple obstacles is predicted to maintain greater mean sprint velocity compared with quadrupedal running, thereby revealing a potential advantage of bipedalism. Lizards were filmed running through a racetrack with zero, one or two obstacles. Bipedal running posture over one obstacle was significantly faster than quadrupedal posture. Bipedal running trials contained fewer total strides than quadrupedal ones. But on addition of a second obstacle, the number of bipedal strides decreased. Increasing obstacle number led to slower and more intermittent locomotion. Bipedalism provided clear advantages for one obstacle, but was not associated with further benefits for an additional obstacle. Hence, bipedalism helps mitigate obstacle negotiation, but not when numerous obstacles are encountered in succession.

It’s not all about the creeks: protection of multiple habitats will improve biodiversity conservation in a eucalypt forest

Understanding patterns in the distribution and abundance of wildlife across the landscape can aid in identifying the relative importance of habitats for biodiversity conservation. We aimed to identify whether riparian habitats were more important than other areas in the landscape to small terrestrial vertebrates. The study site was surveyed using 450 pit traps distributed across riparian, midslope and ridge top habitat. Riparian sites had the greatest abundance of small vertebrates of the three habitats. During some months of the year, there was a significant difference in the composition of the faunal assemblage between habitats. Unsurprisingly, riparian habitats were particularly important for frog species and it was these species that accounted for the greater abundance in this habitat. Riparian habitat was less important for other taxonomic groups and the more floristically rich midslope and ridge habitats, which had a greater abundance of leaf litter, fallen logs and rock cover, were favoured by mammal and reptile species. The conservation of riparian sites, without the protection of other habitats, overlooks a substantial proportion of the biodiversity in the landscape. This study may help inform management decisions in the Upper Warren region and other similar forested landscapes, regarding the location and timing of fauna monitoring and the frequency of fuel reduction burns.

Dry paths effectively reduce road mortality of small and medium-sized terrestrial vertebrates

Wildlife passages are widely used mitigation measures designed to reduce the adverse impacts of roads on animals. We investigated whether road kills of small and medium-sized terrestrial vertebrates can be reduced by constructing dry paths adjacent to streams that pass under road bridges. The study was carried out in southern Finland during the summer of 2008. We selected ten road bridges with dry paths and ten bridges without them, and an individual dry land reference site for each study bridge on the basis of landscape and traffic features. A total of 307 dead terrestrial vertebrates were identified during the ten-week study period. The presence of dry paths decreased the amount of road-killed terrestrial vertebrates (Poisson GLMM; p < 0.001). That was true also when considering amphibians alone (p < 0.001). The evidence on road-kills on mammals was not such clear. In the mammal model, a lack of dry paths increased the amount of carcasses (p = 0.001) whereas the number of casualties at dry path bridges was comparable with dry land reference sites. A direct comparison of the dead ratios suggests an average efficiency of 79% for the dry paths. When considering amphibians and mammals alone, the computed effectiveness was 88 and 70%, respectively. Our results demonstrate that dry paths under road bridges can effectively reduce road-kills of small and medium-sized terrestrial vertebrates, even without guiding fences. Dry paths seemed to especially benefit amphibians which are a threatened species group worldwide and known to suffer high traffic mortality.

The Implications of Increased Body Size in the Song Sparrows of the California Islands

We investigated morphological divergence between mainland and California Island populations of the Song Sparrow (Melospiza melodia). Body size in small terrestrial vertebrates has been hypothesized to be larger in island forms than in their mainland relatives. Previously, we established that although bill size in island populations was similar to that in mainland populations with similar climate, bill-size dimorphism averaged much greater on the islands. In this paper, we compare various measures of structural body size and body mass between the California Islands and the mainland. We found that average body mass is over 10% higher in island Song Sparrows than in comparable mainland populations. However, a lack of commensurate structural body size suggests that body condition might be better in island Song Sparrows. This higher size-corrected mass may be explained by the dominance hypothesis, greater food availability and/or reduced competition, or adaptive mass regulation in the face of reduced predation pressure on adults. Both greater sexual bill dimorphism and greater body mass suggest reduced competition for food for the island Song Sparrow: a possibility that invites further investigation.

Diet of Tonatia bidens (Chiroptera, Phyllostomidae) in an Atlantic Forest area, southeastern Brazil: first evidence for frugivory

The greater round-eared bat Tonatia bidens has a varied diet, consuming mostly insects, although it also feeds on small terrestrial vertebrates, such as rodents and birds. In 2008–2009, we expanded the knowledge of this species’ feeding ecology by analyzing the diet of a T. bidens population in an Atlantic Forest fragment in southeastern Brazil. Food remains found in day shelters and feeding roosts included insects, birds, mammals and fruits. Insects, Lepidoptera, Blattodea, Coleoptera and Orthoptera, were the main component of the diet. There was a preferential consumption of the soft parts of insects and vertebrates, possibly because these parts are more easily digested and are the most nutritious. This first evidence of fruit consumption is also discussed. This analysis indicates that T. bidens has a more general diet than previously reported.

Effects of grazing and invasive grasses on desert vertebrates in California

AbstractMuch of California's San Joaquin Valley is a desert and, like portions of other North American deserts, is experiencing an ecological shift from being dominated by ephemeral native forbs, with widely spaced shrubs, to fire‐prone non‐native annual grasses. Small terrestrial vertebrates, many of which are adapted to open desert habitats, are declining. One hypothesis is that the invasive plants contribute to the decline by altering vegetative structure. Although cattle may have originally been a factor in the establishment of these non‐native plants, their grazing may benefit the terrestrial vertebrates by maintaining an open structure, especially during average or wet winters when the exotic grasses grow especially dense. We experimentally tested the effect of cattle grazing on invasive plants and a community of small vertebrates at a site in the southwestern San Joaquin Desert. We established and monitored 4 treatment (grazed) and 4 control (ungrazed) plots from 1997 to 2006, and assessed the abundances of blunt‐nosed leopard lizards (Gambelia sila), giant kangaroo rats (Dipodomys ingens), short‐nosed kangaroo rats (Dipodomys nitratoides nitratoides), and San Joaquin antelope squirrels (Ammospermophilus nelsoni), all of which are listed as threatened or endangered by state or federal agencies. We also recorded abundances of the non‐protected western whiptail lizards (Aspidoscelis tigris), side‐blotched lizards (Uta stansburiana), San Joaquin pocket mice (Perognathus inornatus inornatus), and Heermann's kangaroo rats (Dipdomys heermanni). Based on repeated measures analysis of variance (ANOVA) and a 0.05 alpha level, only Heermann's kangaroo rats showed a treatment effect; they were more abundant on the control plots. However, this effect could be accounted for by the natural re‐establishment of saltbush (Atriplex spp.) on part of the study site. Saltbush return also favored western whiptail lizards and San Joaquin antelope squirrels. A regression analysis indicated that populations of blunt‐nosed leopard lizard and giant kangaroo rat increased significantly faster in grazed plots than the ungrazed controls, and abundances of 6 of 8 species were negatively correlated with increased residual dry matter. With relaxed alpha values to decrease Type II error, populations of blunt‐nosed leopard lizards (500% greater), San Joaquin antelope squirrels (85% greater), and short‐nosed kangaroo rats (73% greater) increased significantly on grazed plots over the course of the study compared to ungrazed plots. We did not find grazing to negatively affect abundance of any species we studied. When herbaceous cover is low during years of below average rainfall in deserts and other arid areas, grazing may not be necessary to maintain populations of small vertebrates. However, if cattle grazing is closely monitored in space and time to minimize adverse effects on the habitat, it could be an effective tool to control dense stands of non‐native grasses and benefit native wildlife. © 2011 The Wildlife Society.