Implications of intraguild predation for sea turtle nest protection

In the United States, raccoons Procyon lotor are often removed from sea turtle nesting beaches to decrease egg mortality. However, raccoons also consume ghost crabs Ocypode quadrata, another common egg predator. Reducing predator populations can benefit secondary predators, inflating total predation pressure and leading to a decline in prey species. We used track and burrow counts to compare raccoon and ghost crab abundance at four beaches in Florida, USA, that differ in management activity and determined predation rates on loggerhead Caretta caretta nests by each predator. Mean raccoon abundance (range 0.12-0.46 tracks plot⁻¹ night⁻¹) and ghost crab density (0.09-0.19 burrows m⁻²) were inversely correlated. Ghost crabs were largest at the site with the fewest raccoons. The stable nitrogen isotope ratios of ghost crabs (mean 9.8‰) were positively correlated with body mass, indicating larger ghost crabs feed at a higher trophic level and suggesting large ghost crabs may consume more loggerhead eggs. The highest rates of egg predation by both predators (31%) occurred where raccoon abundance was lowest and ghost crab abundance was highest, suggesting ghost crab burrows may facilitate predation by raccoons. Our data suggest that predation by raccoons limits ghost crabs and that removing raccoons can increase ghost crab abundance and sea turtle egg mortality. Although predator removal can be effective when nest predation rates are quite high, maintaining moderate raccoon densities may be important for controlling ghost crabs. These results highlight the importance of understanding food web connectivity in developing management strategies to achieve conservation goals, especially when the species of concern are threatened or facing extinction.     

Habitat succession, hardwood encroachment and raccoons as limiting factors for Lower Keys marsh rabbits

The Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri), a marsh rabbit subspecies endemic to the Lower Keys, Florida was protected in 1990, however, populations continue to decline despite recovery efforts. We hypothesized on-going habitat loss and fragmentation due to succession and hardwood encroachment has lead to increased edge, reduced habitat quality, and increased activity by native raccoons (Procyon lotor). These factors reduce the suitability of patches in a later successional state, thus threatening LKMR recovery and metapopulation persistence. We surveyed 150 LKMR patches in 2008, tallying adult and juvenile rabbit pellets, estimating measures of habitat succession and quality (woody and herbaceous ground cover, distribution of herbaceous species) and recording raccoon activity (number of raccoon signs). We calculated patch edge (patch shape index) using ArcGIS. We evaluated the relationship between patch and habitat attributes and LKMR using regression analysis and model selection. We found both adult and juvenile LKMR pellet counts were lower in patches with higher shape indices and higher in patches with greater occurrence of bunchgrasses and forbs. We also found adult LKMR pellet counts were lower in patches with higher raccoon activity. Our results suggest patch edge, habitat succession and quality, and raccoons pose a threat to the persistence and recovery of LKMR populations. Recovery efforts should focus on reducing these trends through habitat management and raccoon removal implemented in carefully controlled experiments with proper monitoring. Measures of patch and habitat attributes important to LKMR should be incorporated into long-term metapopulation monitoring and used to evaluate recovery actions.     

Large scale predator control improves the productivity of a rare New Zealand riverine duck

Declines in avian populations are often attributed to the presence of introduced predators but conservation managers frequently lack good information about the effectiveness of potential predator control regimes for protecting threatened species. Whio, Hymenolaimus malacorhynchos, are a threatened New Zealand waterfowl that has been declining in both distribution and abundance. We conducted a six-year study using a paired-catchment experiment in New Zealand Nothofagus forest as part of an adaptive management programme to assess whether whio populations responded positively to stoat (Mustela erminea) control. Video monitoring identified stoats as the primary nest predator. Year-round low-intensity stoat control (10 traps per linear km) significantly reduced the stoat abundance index in trapped sites compared with untrapped sites. As a result, whio nesting success and productivity, the number of fledglings produced per pair, increased significantly in the trapped compared to the untrapped area. However, survival rates and the number of pairs did not change significantly between the treatments. These findings indicate stoats are the primary agent of decline for whio in this Nothofagus forest system, and show that low-intensity stoat control is sufficient to improve the productivity of whio populations. Overall, the study demonstrates the value of an adaptive management approach whereby management techniques can be evaluated to ensure that the primary agent of decline is clearly identified and that predator densities are kept sufficiently low.     

Predator control for protecting kaki (Himantopus novaezelandiae)—lessons from 20 years of management

In New Zealand, the endemic kaki or black stilt (Himantopus novaezelandiae) has been the focus of intensive conservation management for the past 20 years. Threatened by predation and habitat loss, the population fell to as low as 23 birds before management was implemented to reverse the decline. Predator trapping has been one form of management intervention in the wild, yet despite 20 years of control, there is only limited evidence to suggest that predator trapping is beneficial for the survival of kaki. Lack of adequate experimental design and understanding of the predator-prey dynamics in the system in which kaki live appear to be the main reasons why the benefits of predator control are not consistently clear. An adaptive management approach would have provided more information on the efficacy of predator trapping and increased understanding of the inter-relationships between kaki survival and predator abundance.     

Monitoring predators to optimize their management for marine turtle nest protection

The fundamental conservation focus for Hobe Sound National Wildlife Refuge (HSNWR), Florida is to provide protected nesting habitat for three threatened or endangered marine turtle species. Turtle nesting and hatching spans from early spring to fall each year. Left unchecked, nest predation by raccoons and armadillos would destroy most turtle nests. Predators are removed to protect nests, primarily with a one person-month contract using control specialists. We maximized the efficiency of predator removal by using a passive tracking index to: (1) optimize the timing and strategy for predator removal, (2) minimize labor by identifying areas where predator removal would have maximal effect, (3) examine beach invasion patterns of predators, (4) assess efficacy of removal efforts, (5) provide anticipatory information for future turtle nesting seasons, and (6) serve as a detection method for invasion by additional species known to depredate turtle nests. An overall nest predation rate of 28% resulted, whereas the rate for the previous year was 42% when the same level of contracted predator removal was applied, but without monitoring predators. One year before that, predator removal was done without contracts with specialists and predation was 48%. Up to 95% of the nests were destroyed in the years prior to predator removal. Using 2000 data on numbers of nests, clutch sizes, and emergence rates, we estimated the number of hatchlings that would have been lost assuming that the predation rates observed from four predator removal scenarios at HSNWR would have occurred in 2000. Historical predation of 95% would have resulted in 120,597 hatchlings lost in 2000. Predator removal as part of regular refuge operations would have reduced this number to 62,481. Addition of a contract with control specialists would have further reduced the number lost to 53,778. Addition of temporal and spatial monitoring for predator removal reduced losses to 36,637.     

Does invasive plant management aid the restoration of natural ecosystems?

Invasive alien plants of natural ecosystems, commonly referred to as weeds, can reduce the abundance and diversity of native flora and fauna, and alter ecosystem processes. Using Australia’s 20 ‘Weeds of National Significance’ (WoNS), we investigated how natural ecosystems responded following their management. We reviewed the literature and surveyed land managers involved in WoNS management programs by distributing a questionnaire through various e-mail networks. While most of the 95 papers reviewed measured the effect of management on the target WoNS, only 18 assessed the response of other plant species. In these studies, native plant species did not necessarily recover following management and in many instances the managed WoNS was replaced by other weed species. Three other studies investigated the response of invertebrate communities and an ecosystem process following WoNS management but none examined the response of vertebrates or microbial communities. A total of 168 replies were received to the land manager survey. Of the 142 land managers who evaluated their WoNS management program, 86 monitored the response of native plant species and/or other weeds, mostly using qualitative assessments. These managers reported no vegetation response after management of the WoNS (7%) or re-colonisation by a combination of native and weed species (52%) or only by native plants (33%) or the targeted WoNS (2%). Our results emphasise the need to select sites for weed management that are less degraded and thus have a higher likelihood of natural recovery and/or to incorporate activities that facilitate recovery of native plant communities in conjunction with weed removal.     

Positive and negative effects of exotic Erodium cicutarium on an arid ecosystem

Many exotic species negatively affect native species and alter ecosystem function. Erodium cicutarium, an exotic annual plant, can attain high densities, but little is known about its effects on native plant communities. We first examined patterns of abundance of E. cicutarium and native annuals over a 16-year period at a long-term study site in southeastern Arizona. In years of high E. cicutarium abundance, the correlations between the abundance of E. cicutarium and native annuals in small-scale local communities were typically negative, suggesting a competitive interaction. To further examine the interaction between E cicutarium and native annuals, we conducted a short-term field experiment at the same location using plots that contained pairs of quadrats. One quadrat in each pair was subjected to E. cicutarium removal during the winter of 2003-2004 while the other served as a control. At the end of the growing season, E. cicutarium removal quadrats contained significantly higher abundance and richness of native annual plants. However, control plots contained significantly higher abundance of all annuals due to the presence of E. cicutarium. Thus, in the single growing season examined, while E. cicutarium appears to suppress the diversity and abundance of native species, its presence significantly increases community productivity.     

Phytoremediation Potential of Vetiver Grass (<Emphasis Type="Italic">Vetiveria zizanioides</Emphasis>) for Treatment of Metal-Contaminated Water

Phytoremediation using vetiver grass (Vetiveria zizanioides) has been regarded as an effective technique for removing contaminants in polluted water. This study was conducted to assess the removal efficiency of heavy metals (Cu, Fe, Mn, Pb, Zn) using vetiver grass (VG) at different root lengths and densities and to determine metals uptake rate by plant parts (root and shoot) between treatments (low and high concentration). Removal efficiency for heavy metals in water by VG is ranked in the order of Fe>Pb>Cu>Mn>Zn. Results showed that VG was effective in removing all the heavy metals, but removals greatly depend on root length, plant density and metal concentration. Longer root length and higher density showed greater removals of heavy metals due to increased surface area for metal absorption by plant roots. Results also demonstrated significant difference of heavy metals uptake in plant parts at different concentrations indicating that root has high tolerance towards elevated concentration of heavy metals. However, the effects were less significant in plant shoot suggesting that metals uptake were generally higher in root than in shoot. The findings have shown potential of VG in phytoremediation for heavy metals removal in water thus providing significant implication for treatment of metal-contaminated water.     

Lessons about extinction and translocation: models for eastern barred bandicoots (Perameles gunnii) at Woodlands Historic Park, Victoria, Australia

In 1998 the protected population of Perameles gunnii (eastern barred bandicoot) at Woodlands Historic Park, Victoria, Australia became functionally extinct following removals of individuals for translocation between 1994 and 1996. Population viability analysis and data collected whilst the population was in decline are used to explore the impact that these removals had on the decline of the P. gunnii population at Woodlands. Due to some ambiguities in the life history of P. gunnii at Woodlands, two structurally different population models were used. Explicitly including the removal of animals in the analysis indicates that there may be at least a three-fold increase in the risk of quasiextinction due to removals. In some scenarios, over 17% of the trajectories decrease to a level less than or equal to 10 females within the observed time period of the collapse of the population, that is by April 1998. The modelling approach identified a number of critical factors in the decline of the population, such as variation in survival rates. By representing the life history strategy using two alternate models, quantitative statements about the impact that removals had on the population decline at Woodlands are made. While removals probably contributed to the collapse of the population, removals were not the sole cause of population decline. The real reasons for decline remain unknown; however, it is likely to be closely linked to habitat decline, difficult environmental conditions and predation. If P. gunnii are reintroduced to Woodlands again, then the models presented here may help to develop management strategies to establish a self sustaining population, as well as exploring translocations options.     

Can threatened species survive where the top predator is absent?

Top predators have been described as highly interactive keystone species. Their decline has been linked to secondary extinctions and their increase has been linked to ecological restoration. Several authors have recently argued that the dingo Canis lupus dingo is another example of a top predator that maintains mesopredators and generalist herbivores at low and stable numbers, thereby increasing biodiversity and productivity. Due to the sensitivity of many Australian species to introduced mesopredators and herbivores, the top predator hypothesis predicts that threatened species will not survive where dingoes are rare or absent. However, several threatened species have survived inside the Dingo Barrier Fence (DBF). We present a new view on the survival of the yellow-footed rock-wallaby Petrogale xanthopus xanthopus and the malleefowl Leipoa ocellata inside the DBF where the dingo is considered very rare, or in areas where the dingo is believed to have been eradicated several decades ago. We found that dingoes co-occurred with both threatened species. Dingoes were present at all wallaby colonies surveyed and occurred throughout their range. The most common predator detected in areas inhabited by the wallabies was in fact the dingo, and we found no significant difference between dingo abundance inside compared to outside the DBF. Malleefowl nests were found to be scent marked by dingoes at the three sites that we surveyed, despite these sites being close to human settlement and sheep farms, and in small and fragmented patches of wilderness. These findings provide further evidence for an association between the presence of dingoes and the survival of threatened species, which is in agreement with the top predator hypothesis. The results of this study challenges the current assumption that the presence and ecological consequence of dingoes in sheep country are negligible and we suggest that wildlife managers verify whether dingoes are present before predator control is initiated.     

Can Vegetal Biopolymers Work as Coagulant–Flocculant Aids in the Treatment of High-Load Cosmetic Industrial Wastewaters?

The aim of this work was to evaluate the role of three biopolymers used as coagulant?Cflocculant aids in the treatment of a high-load cosmetic industry wastewater (WW) located in Mexico. Discussion is based on a surface response methodology. When using guar, locust bean gum, and Opuntia mucilage, conductivity and turbidity removals as high as 20.1 and 67.8?% were found, respectively. Chemical oxygen demand (COD) removals as high as 38.6?% were observed. The maximum removal efficiency was found for mucilage, with 21.1?mg?COD/mg polymer. At the end of the process, pH was in the range of 5.8?C7.3 for an initial wastewater pH value of 5.6. The production of sludge was very dependent on the WW organic load. An analysis of some metal content in the sludges is presented. From the response surface analysis, it was observed that the parameter which strongly affected the removal of COD, turbidity, oil and greases (O&G), and the amount of sludge including their metal contents was the polymer dose. Only in the case of O&G removal was a combination of dose?Cwastewater organic load responsible for the removals. The values of R ² for the correlation process were between 0.5451 (O&G) and 0.7989 (COD). The p values for the different expressions were between 0.1985 (COD) and 0.7195 (O&G). The values of adequate precisior (AP) indicate how feasible it is to use the surface response analysis (AP?>?4). Most of the analysis indicated that AP?>?4, except in the case of the O&G removal analysis where AP?=?2.9.     

Removal of introduced predators, but not artificial refuge supplementation, increases skink survival in coastal duneland

Exotic predators can have detrimental impacts on indigenous fauna. Lethal predator control is commonly used to reduce predator impacts, but is not always feasible, effective or ethical. A promising non-lethal alternative is refuge supplementation for prey. We conducted a Before-After Control-Impact (BACI) experiment over 3 years to determine the relative effects of predator removal (by exclosure fencing) and artificial refuge supplementation on survival of McCann’s skink (Oligosoma maccanni) in duneland on Kaitorete Spit (South Island, New Zealand). Skink populations on 0.0625 ha-grids were randomly assigned to four treatment groups, each replicated four times: (a) predator exclosure only; (b) artificial retreats only; (c) exclosure + artificial retreats, and (d) control (no exclosure or artificial retreats), and monitored annually by pitfall trapping. Capture-recapture analysis was used to estimate the difference in annual survival probability between pre- and post-treatment periods. On average, survival increased only at grids that received the exclosure-only treatment (effect size of 0.03 (0.017-0.043; unconditional 95% CI)). Reduction in predator abundance (by lethal predator control or predator exclusion), but not artificial refuge supplementation, is predicted to benefit McCann’s skink. Our findings add to other studies highlighting the detrimental impacts of exotic predators on indigenous prey and calls for improved means of reducing predator impacts.     

Nesting activity of the loggerhead turtle caretta caretta in South Carolina,II. protection of nests from raccoon predation by transplantation

Small mammals are significant predators of unhatched marine turtle nests in many parts of the world. Raccoons Procyon lotor destroy over 95% of the loggerhead turtle nests laid on some South Carolina beaches. To remove developing eggs from nest-associated clues which could aid raccoons, we transplanted whole and partially preyed-upon nests on Kiawah or Cedar Islands in 1972, 1973, 1977 and 1978. Eggs were moved to man-made cavities near the original nest cavities in erosion-free areas. Care was taken not to transfer clues from the original nest. Predation on wild (control) nests ranged from 55·1% (Cedar, 1978) to 93·8% (Kiawah, 1972). Transplant predation was significantly lower in all cases, ranging from 6·1% (Kiawah, 1972) to 18·7% (Kiawah, 1973). Hatching success of transplant was not significantly different from that of hatchery-reared or control clutches (60–81%). Transplanting may be an easier, less expensive method for protection of nests from predation or erosion than other procedures such as predator control, chemical aversion conditioning, or hatcheries, and merits further testing at other turtle rookeries.     

Surplus killing by introduced predators in Australia—evidence for ineffective anti-predator adaptations in native prey species?

Australian examples of surplus killing by mammalian predators were collated. These included surplus killing of native mammals and birds by foxes (Vulpes vulpes) and stock, native mammals and native birds by dingoes (Canis lupus dingo). We found no examples of surplus killing by feral cats (Felis catus). Incidents collated include historical anecdotes of surplus killing by foxes as they colonised the Australian mainland, recent examples where foxes killed threatened native species at sites despite intensive management to exclude foxes, and recent examples of the killing of native species on formerly fox-free islands to which foxes gained entry. Episodes of surplus killings by foxes, other than predation on captive or closely confined animals, appeared different in kind and frequency to those documented for co-evolved predator-prey systems on the large continental landmasses. They did not appear to be uncommon events associated with synchronised births of prey species, unusual or extreme weather that disadvantaged prey species, or seasonal food caching by a predator. Rather, surplus killing events appeared to reflect ineffective anti-predator defences by prey species when encountering a novel and efficient predator to which they have had no evolutionary exposure. We suggest that surplus killing by foxes may have been a feature of, and major contributor to, the rapid mainland extinction or contraction in range of many native species in Australia. In contrast to foxes, examples of surplus killing by dingoes relate mostly to domestic stock (calves and sheep). The arrival of dingoes to the Australian continent preceded that of foxes by 3500-4000 years, but they appear not to have had the dire impact on native mammals that we attribute to foxes. This may be due to fundamental differences in hunting styles and prey size and to their sparse populations in pre-European Australia. Active persecution of non-commensal dingoes by Aborigines, the lack of free-water, and the absence of European rabbits (Oryctolagus cuniculus) as an alternative food supply would have limited their numbers and their impact on native mammals.     

Which uncertainty? Using expert elicitation and expected value of information to design an adaptive program

Natural resource management is plagued with uncertainty of many kinds, but not all uncertainties are equally important to resolve. The promise of adaptive management is that learning in the short-term will improve management in the long-term; that promise is best kept if the focus of learning is on those uncertainties that most impede achievement of management objectives. In this context, an existing tool of decision analysis, the expected value of perfect information (EVPI), is particularly valuable in identifying the most important uncertainties. Expert elicitation can be used to develop preliminary predictions of management response under a series of hypotheses, as well as prior weights for those hypotheses, and the EVPI can be used to determine how much management could improve if uncertainty was resolved. These methods were applied to management of whooping cranes (Grus americana), an endangered migratory bird that is being reintroduced in several places in North America. The Eastern Migratory Population of whooping cranes had exhibited almost no successful reproduction through 2009. Several dozen hypotheses can be advanced to explain this failure, and many of them lead to very different management responses. An expert panel articulated the hypotheses, provided prior weights for them, developed potential management strategies, and made predictions about the response of the population to each strategy under each hypothesis. Multi-criteria decision analysis identified a preferred strategy in the face of uncertainty, and analysis of the expected value of information identified how informative each strategy could be. These results provide the foundation for design of an adaptive management program.     

Biodegradation Kinetics and Effects of Operating Parameters on the Performance of a Methyl Tert-Butyl Ether Degrading Biofilter

The goals of the study were to determine the effectiveness of a laboratory-scale biofilter on the removal of methyl tert-butyl ether (MTBE) and investigate the operating parameter effects on biofilter performance. The experimental results show that average MTBE removals of 53.6–93.2% were observed at loads of 2.5–20.1 gm^?3 h^?1 and an empty-bed residence time of three minutes, after continuous operation for four months throughout the biofilter acclimation period. After a one-day recovery period operation, the biofilter system recovered from the introduction of a shock load. More than 99% removal efficiencies were achieved for the inlet MTBE concentration at 50 ppmv and with the highest residence time. MTBE removals at the bottom section of the biofilter were consistently lower than for the top section, which was attributed to insufficient microorganism growth in the bottom section. The parameters estimated by using the Michaelis-Menten equation were 1.116 ± 0.51 ppmv s^?1 for the maximum removal rate (V _m ), and 26.38 ± 17.21 ppmv for the half-saturation constant (Ks), evaluated at the biofilter exit.     

Factors influencing survival and long-term population viability of New Zealand long-tailed bats (Chalinolobus tuberculatus): Implications for conservation

A population viability analysis is important for the management of endangered populations and requires the estimation of survival parameters. The long-tailed bat (Chalinolobus tuberculatus) is one of only two native terrestrial mammals currently found in New Zealand and is classed as vulnerable. Its viability in temperate beech (Nothofagus) forest, Eglinton Valley, Fiordland, New Zealand was estimated using mark-recapture data collected between 1993 and 2003 using the Program MARK. Survival was estimated based on a total of 5286 captures representing 1026 individuals. Overall annual survival varied between 0.34 and 0.83 but varied significantly among three sub-populations and with sex and age. Females generally had a higher survival rate compared to males; and adults had higher survival relative to juveniles. Survival of all bats was lower in years when the number of introduced mammalian predators was high and when the winter temperature was warmer than average. High numbers of introduced predators occurred during three of the 10 years in the study. Climate change may mean that the conditions that promote high predator numbers may occur more frequently. A preliminary population viability analysis using a projection matrix on the overall adult female population showed an average 5% decline per year (λ = 0.95). Increased predator control targeting a range of predators is required in years when their numbers are high in order to halt the decline of this population of long-tailed bats. Population estimates using minimum number alive estimates supported the population estimates derived from Program MARK and a population viability analysis using matrices.     

Conservation action in the Galàpagos: feral pig (Sus scrofa) eradication from Santiago Island

Introduced mammals are major drivers of extinction and ecosystem change. As omnivores, feral pigs (Sus scrofa) are responsible for wholesale adverse effects on islands. Here, we report on the eradication of feral pigs from Santiago Island in the Galápagos Archipelago, Ecuador, which is the largest insular pig removal to date. Using a combination of ground hunting and poisoning, over 18,000 pigs were removed during this 30-year eradication campaign. A sustained effort, an effective poisoning campaign concurrent with the hunting program, access to animals by cutting more trails, and an intensive monitoring program all proved critical to the successful eradication. While low and fluctuating control efforts may help protect select native species, current eradication methods, limited conservation funds, and the potential negative non-target impacts of sustained control efforts all favor an intense eradication effort, rather than a sustained control program. The successful removal of pigs from Santiago Island sets a new precedent, nearly doubling the current size of a successful eradication, and is leading to more ambitious projects. However, now we must turn toward increasing eradication efficiency. Given limited conservation funds, we can no longer afford to spend decades removing introduced mammals from islands.     

Evaluating barriers to native seedling establishment in an invaded Hawaiian lowland wet forest

Many tropical island forest ecosystems are dominated by non-native plant species and lack native species regeneration in the understorey. Comparison of replicated control and removal plots offers an opportunity to examine not only invasive species impacts but also the restoration potential of native species. In lowland Hawaiian wet forests little is known about native species seed dynamics, recruitment requirements, or the effects of management. In a heavily invaded lowland wet forest, we examined the relationship between seed presence and seedling establishment in control and removal plots. Non-native species were competitively superior because they had higher germination percentages and dominated the seed bank; only seven out of 33,375 seedlings were native. In contrast, the seed rain contained native seed, but native seedling recruitment was almost exclusively limited to removal plots, suggesting that optimum establishment conditions are not met in the presence of a dense mid-storey of non-native species. Non-native species dominance was altered and biomass significantly decreased over time resulting in a reduced weeding effort (12.38-0.77 g day⁻¹). We suggest that with opening of the canopy through non-native species removal and subsequent weeding, it may be possible to reduce the seed bank enough to skew the regeneration potential towards native species. Our results suggest that germination success and lack of a seed bank are the main bottlenecks for native species. We conclude that without invasive species control, future regeneration of Hawaiian lowland wet forests is likely to be almost entirely non-native.     

Body size, niche breadth, and ecologically scaled responses to habitat fragmentation: mammalian predators in an agricultural landscape

The ability to make a priori assessments of a species' response to fragmentation, based on its distribution in the landscape, would serve as a valuable conservation and management tool. During 1997-1999, we monitored 717 scent stations to examine seasonal use of forest patches, corridors, and crop fields by coyotes (Canis latrans), domestic cats (Felis catus), foxes (Vulpes vulpes and Urocyon cinereoargenteus), raccoons (Procyon lotor), striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and long-tailed weasels (Mustela frenata). For each species we developed landscape-based ecologically scaled landscape indices (ELSI), and we modeled species spatial distribution across three spatial scales (landscape-level, element-level, and local habitat-level). Our results suggest that these predators view landscape fragmentation at different spatial scales and demonstrate strong interspecific differences in their response to elements of the landscape. All species except coyotes and domestic cats avoided agricultural fields. In general, predator species that were more mobile (i.e. high ESLI for landscape connectivity; coyotes) were characterized by landscape- and element-based logistic models. In contrast, models including local habitat features generally were most appropriate for less mobile or more stenophagous predators (e.g. long-tailed weasels). Our analysis extends the application of the ESLI concept to species assemblages that do not appear to function as metapopulations, and it highlights the importance of examining spatial scale and species-specific responses to habitat fragmentation. We discuss the relevance of these findings for defining ecological landscapes, understanding predator-prey interactions at multiple spatial scales, and conserving predator and prey populations in fragmented landscapes.