Preferred Patches Research Articles

Preferences and feasibility of long-acting technologies for treatment of hepatitis C virus in low- and middle-income countries: A survey of providers and policymakers.

Long-acting technologies (LATs) for hepatitis C virus (HCV) are under development as a strategy to improve linkage to care, treatment adherence and outcomes. We conducted a survey of HCV treatment prescribers and HCV policymakers in low- and middle-income countries (LMICs) regarding acceptability and feasibility of HCV LATs. We included one-time intramuscular injection, subdermal implant and transdermal patch as potential LAT options. We surveyed participants regarding optimal health system and patient characteristics, concerns, potential barriers, overall feasibility and preferences for HCV LAT as compared to daily oral medication. Overall, 122 providers and 50 policymakers from 42 LMICs completed the survey. Among providers, 93% (113/122) expressed willingness to prescribe LAT and 72% (88/120) of providers preferred LAT if provided at comparable efficacy, safety and cost as current oral treatments. Of providers preferring HCV LAT to daily oral medication, 67% (59/88) preferred injection, 24% (21/88) preferred patch and 9% (8/88) preferred implant. Only 20% (24/122) would prescribe LAT if it were more costly than oral treatment. In regression analysis, no provider characteristics were associated with preference for LAT over oral treatment. Policymakers reported high likelihood that LAT would be included in treatment guidelines (42/50; 84%) and national drug formularies (39/50; 78%) if efficacy, safety and cost were similar to oral treatment. HCV LATs could advance progress to HCV elimination in LMICs by diversifying treatment options to improve treatment coverage and outcomes. Provider preferences from LMICs are a critical consideration in the development of HCV LATs to ensure its early and equitable availability in LMICs.

Landscape Dynamics and Ecological Risk Assessment of Cold Temperate Forest Moose Habitat in the Great Khingan Mountains, China.

The change in habitat pattern is one of the key factors affecting the survival of the moose population. The study of the habitat landscape pattern is the key to protecting the Chinese cold-temperate forest moose population and monitoring the global distribution of moose. Through the ecological risk assessment of the moose habitat landscape pattern in a cold-temperate forest, we hope to assess the strength of habitat resistance under stress factors. This study provides a theoretical basis for the protection of the moose population in the cold-temperate forest in China and the establishment of the cold-temperate forest national park. In the study, the MaxEnt model, landscape index calculation and ecological risk assessment model construction were used to analyze the field survey and infrared camera monitoring data from April 2014 to January 2023. The habitat suitability layer of the moose population in the Nanwenghe National Nature Reserve of the Great Khingan Mountains was calculated, and the range of the moose habitat was divided based on the logical threshold of the model. The landscape pattern index of the moose habitat was calculated by Fragstats software and a landscape ecological risk assessment model was established to analyze the landscape pattern and ecological risk dynamic changes of the moose habitat in 2015 and 2020. The results showed that under the premise of global warming, the habitat landscape contagion index decreased by 4.53 and the split index increased by 4.86 from 2015 to 2020. In terms of ecological risk: the area of low ecological risk areas increased by 0.88%; the area of medium ecological risk areas decreased by 1.11%; and the area of high ecological risk areas increased by 0.23%. The fragmentation risk of the landscape pattern of the moose habitat tends to increase, the preferred patch type is dispersed, the degree of aggregation is low, and the risk of patch type transformation increases. The middle and high ecological risk areas are mainly concentrated in the river area and its nearby forests, showing a fine and scattered distribution. Under the interference of global warming and human activities, the fragmentation trend of the moose habitat in the study area is increasing, and the habitat quality is declining, which is likely to cause moose population migration. For this reason, the author believes that the whole cold temperate forest is likely to face the risk of increasing the transformation trend of dominant patch types in the cold-temperate coniferous forest region mainly caused by global warming, resulting in an increase in the risk of habitat fragmentation. While the distribution range of moose is reduced, it has a significant impact on the diversity and ecological integrity of the whole cold-temperate forest ecosystem. This study provides theoretical references for further research on the impact of climate warming on global species distribution and related studies. It is also helpful for humans to strengthen their protection awareness of forest and river areas and formulate reasonable protection and sustainable development planning of cold-temperate forests. Finally, it provides theoretical references for effective monitoring and protection of cold-temperate forests and moose population dynamics.

Individual Network Topology of Patch Selection Under Influence of Drifting Site Fidelity

Network theory has led to important insight into statistical-mechanical aspects of systems showing scaling complexity. I apply this approach to simulate the behavior of animal space use under the influence of memory and site fidelity. Based on the parsimonious Multi-scaled random walk model (MRW) an emergent property of self-reinforcing returns to a subset of historic locations shows how a network of nodes grows into an increased hierarchical depth of site fidelity. While most locations along a movement path may have a low revisit probability, habitat selection is maturing with respect to utilization of the most visited patches, in particular for patches that emerge during the early phase of node development. Using simulations with default MRW properties, which have been shown to produce space use in close statistical compliance with utilization distributions of many species of mammals, I illustrate how a shifting spatio-temporal mosaic of habitat utilization may be described statistically and given behavioral-ecological interpretation. The proposed method is illustrated with a pilot study using black bearUrsus americanustelemetry fixes. One specific parameter, the Characteristic Scale of Space Use, is here shown to express strong resilience against shifting site fidelity. This robust result may seem counter-intuitive, but is logical under the premise of the MRW model and its relationship to site fidelity, whether stable or shifting spatially over time. Thus, spatial analysis of the dynamics of a gradually drifting site fidelity using simulated scenarios may indirectly cast light on the dynamics of movement behavior as preferred patches are shifting over time. Both aspects of complex space use, network topology and dynamically drifting dispersion of site fidelity, provide in tandem important descriptors of behavioral ecology with relevance to habitat selection.

Do habitat preferences improve fitness? Context-specific adaptive habitat selection by a grassland songbird.

Animals are predicted to prefer high-quality over low-quality habitats, but adaptive habitat selection is less straightforward than often assumed. Preferences may improve only specific fitness metrics at particular spatial scales, with variation across time or between sexes. Preferences sometimes even reduce fitness. We investigated the context specificity of adaptive habitat selection, studying dickcissels (Spiza americana)-a polygynous songbird-as a model. From 2014 to 2015, we measured male and female habitat preferences at two scales (territories and landscape patches) on 21 grassland patches in Ringgold County, Iowa, USA. We tested whether preferences improved four fitness metrics-polygyny, avoidance of brood parasitism by brown-headed cowbirds (Molothrus ater), fledgling productivity, and offspring condition. Both sexes preferred territories where offspring attained superior condition and patches where parasitism was infrequent. Females preferred patches where nests produced more fledglings, and in 2014, males on preferred (i.e., early-established) territories attracted more mates and produced more fledglings. However, males on non-preferred (i.e., late-established) territories were more successful in 2015. This inconsistency may have arisen because females were abundant and nest-predation rates were low in May-June 2014, allowing early-settling males to produce many young. In 2015, however, females were more abundant and nests more successful later in the breeding season. Our results show that habitat preferences do not uniformly improve fitness, and some benefits differ between sexes. Moreover, preference-fitness relationships only manifest at specific scales, and annual variation in population and predation dynamics can limit consistency. Detecting adaptive habitat selection thus requires multi-year measurements and careful consideration of relevant scales.

CAR 4. Modifiable Factors That Reduce Postoperative Complications After Carotid Endarterectomy

The benefit of prophylactic carotid endarterectomy (CEA) is reduced by postoperative complications. The purpose of this study was to define modifiable factors that could improve outcomes after CEA. The Vascular Quality Initiative CEA registry was analyzed for modifiable factors associated with reduced postoperative complications (neurologic events [ie, transient ischemic attack or stroke] and return to operating room [RTOR] for a bleeding or neurologic event). A multivariate logistic regression analysis was used to account for baseline differences. There were 70,986 patients in the registry who were analyzed for RTOR and postoperative neurologic events. The preferred patch material was bovine pericardium in 77%, Dacron in 19%, vein in 2%, and polytetrafluoroethylene (PTFE) in 2%. Type of closure and use of protamine were found to correlate with complications. PTFE and primary closure had a higher rate of RTOR than bovine pericardium, Dacron, or vein (Table). PTFE, primary closure, and vein had higher rates of neurologic events than bovine pericardium or Dacron (Table). After clustered multivariable analysis, the use of bovine pericardium compared with Dacron, PTFE, vein, and primary closure was associated with reduced RTOR (odds ratio [OR], 0.70; 95% confidence interval [CI], 0.56-0.89; P < .01), as was protamine use (OR, 0.74; 95% CI, 0.60-0.91; P < .01). Bovine pericardium (OR, 0.59; 95% CI, 0.47-072; P < .01) and Dacron closure (OR, 0.56; 95% CI, 0.43-0.74; P < .01) were both associated with reduced postoperative neurologic events. The use of bovine pericardium for closure and protamine for heparin reversal is associated with reduced rates of postoperative complications after CEA.TableIncidence of postoperative events analyzed by type of closureRTOR, %Stroke or TIA, %Bovine pericardium (n = 51,460)1.81.5Dacron (n = 12,349)2.01.5Vein (n = 1459)1.81.9PTFE (n = 1638)2.82.8Primary closure (n = 4051)2.62.8P value<.01<.01PTFE, Polytetrafluoroethylene; RTOR, return to operating room; TIA, transient ischemic attack. Open table in a new tab

Implementation of Basal–Bolus Therapy in Type 2 Diabetes: A Randomized Controlled Trial Comparing Bolus Insulin Delivery Using an Insulin Patch with an Insulin Pen

Background: Barriers to mealtime insulin include complexity, fear of injections, and lifestyle interference. This multicenter, randomized controlled trial evaluated efficacy, safety, and self-reported outcomes in adults with type 2 diabetes, inadequately controlled on basal insulin, initiating and managing mealtime insulin with a wearable patch versus an insulin pen.Methods: Adults with type 2 diabetes (n = 278, age: 59.2 ± 8.9 years), were randomized to patch (n = 139) versus pen (n = 139) for 48 weeks, with crossover at week 44. Baseline insulin was divided 1:1 basal: bolus. Using a pattern-control logbook, subjects adjusted basal and bolus insulin weekly using fasting and premeal glucose targets.Results: Glycated hemoglobin (HbA1c) change (least squares mean ± standard error) from baseline to week 24 (primary endpoint) improved (P < 0.0001) in both arms, −1.7% ± 0.1% and −1.6% ± 0.1% for patch and pen (−18.6 ± 1.1 and −17.5 ± 1.1 mmol/mol), and was maintained at 44 weeks. The coefficient of variation of 7-point self-monitoring blood glucose decreased more (P = 0.02) from baseline to week 44 for patch versus pen. There were no differences in adverse events, including hypoglycemia (three severe episodes per arm), and changes in weight and insulin doses. Subject-reported treatment satisfaction, quality of life, experience ratings at week 24, and device preferences at week 48 significantly favored the patch. Most health care providers preferred patch for mealtime insulin.Conclusions: Bolus insulin delivered by patch and pen using an algorithm-based weekly insulin dose titration significantly improved HbA1c in adults with type 2 diabetes, with improved subject and health care provider experience and preference for the patch.

A forest canopy as a living archipelago: Why phylogenetic isolation may increase and age decrease diversity

AbstractAimAn individual tree resembles a living island, a small spatially distinct unit upon which colonizers maintain populations. However, several differences exist compared to oceanic islands: a tree is relatively young, is composed of numerous differently aged branches, may be phylogenetically isolated from neighbours, and some of its colonizers are specific to particular tree lineages. We suggest that these specificities strongly affect both alpha‐ and beta‐diversity within trees, including positive effects of isolation on the diversity of generalists, and strengthening of the effect of isolation with tree age.LocationRennes, Bretagne, Western FranceTaxonLittle‐dispersive, generalist oribatid mites (Acari) and highly dispersive, specialist gall wasps (Hymenoptera: Cynipidae) on oak (Quercus sp.) trees.MethodsWe tested the effects of tree and branch age, tree and branch habitat diversity, and tree phylogenetic isolation on per‐branch and per‐tree alpha‐diversity, and on within‐tree beta‐diversity of both taxonomic groups.ResultsFor gall wasps, no variable explained diversity patterns at any level. In contrast, for oribatid mites, we found that high phylogenetic isolation of trees and high branch age increased alpha‐diversity per tree and per branch (in young trees) as well as turnover among branches. High tree age decreased alpha‐diversity per branch (in phylogenetically isolated trees) and increased turnover among branches. Increasing habitat diversity increased alpha‐diversity per tree, but decreased alpha‐diversity per branch (in young trees).Main conclusionsFor mites, contrary to common expectation, we suggest that: (a) phylogenetically distant neighbours are a source of immigration of distinct species and (b) with the increase of tree age, species‐sorting results in a few species colonizing and dominating their preferred patches. In gall wasps, strict specialization on oaks, and efficient dispersal may render oak age or isolation unimportant. The positive relationship between isolation and within‐tree turnover is a new contribution to biogeography in general.

User- and Health Care Provider–Reported Outcomes for a Wearable Bolus Insulin Delivery Patch

User- and Health Care Provider–Reported Outcomes for a Wearable Bolus Insulin Delivery Patch

Are Landscape Configuration Metrics Worth Including When Predicting Specialist and Generalist Bird Species Density? A Case of the Generalised Additive Model Approach

Due to the complexity of factors that influence species density on a large geographical scale, the effectiveness of the species distribution model (SDM) is still debatable. That is why the buffer zone (the area within 100 m from the outside edge of the patch), the core, i.e. (patches excluding the 100 m buffer zone from the patch’s edge) and patch shape are explored in this study to see how they affect the density of habitat specialist and generalist bird species. Two sets of generalised additive models were generated separately for each of the four bird species: One set of models contained landscape configuration metrics as an additional predictor variable, and the other did not. The results showed that models including the core, the buffer zone and the shape of patches turned out to be definitely better than models without them. Specialist species, the Corn bunting and the Wood nuthatch, are more likely to occur in the core of the preferred patches, and they choose those of a simple shape; while generalist species, the Whinchat and the Tree pipit, are more probable to be present in the buffer zone of a more complicated shape. Thus, the results clearly show that specific landscape configuration models can improve the predictive power of SDMs and can be used as an effective tool for predicting species density and functional bird diversity (specialist and generalist). Furthermore, from the applied ecology perspective, detailed landscape configuration metrics can be considered as a surrogate of elusive habitat conditions.

Habitat selection and range use of little owls in relation to habitat patterns at three spatial scales

AbstractUnderstanding the rules of habitat selection and the individual behavioural routines in the home‐range is crucial for developing evidence‐based conservation action. We investigated habitat selection and range use of adult little owls Athene noctua in relation to landscape configuration, habitat structure and resource distribution. We determined the preference of habitat structures by VHF‐telemetry. Large‐ and fine‐scale distribution patterns of voles – the main prey during the breeding season – were assessed by transect counts of signs of vole presence. An experiment using artificial perches was carried out to determine the fine‐scale adjustment of the owls' range use in relation to prey abundance and vegetation height. Habitat selection and resource exploitation by little owls were structured at all spatial levels: (1) at the landscape scale, orchards were highly preferred over other areas. This accords with the patchy large‐scale occurrence of voles, which were absent in cropland, but abundant in orchards and grassland; (2) within home‐ranges, the spatial distribution of voles was highly inhomogeneous and structures with high prey abundance were used over‐proportionally; (3) at the scale of foraging sites, little owls preferred patches with low vegetation over those with high prey abundance, establishing that prey availability is the crux. The results suggest that all levels of habitat selection and range use were related to farming practices and affected by current cultivation. Conservation measures should focus on the conservation and restoration of orchards on the landscape level and habitat management measures should focus on grasslands – the main food providers – by creating a mosaic of patches with short grass and tall grass. Together with other habitat structures providing food resources such as field edges, wildflower areas and structures facilitating access to prey, the quality of habitat patches in terms of food availability may be highly improved.

The distribution of digenean metacercariae within bream (Abramis brama) gill apparatus: preferences, co-occurrence and interactions of parasites.

Species-specific microenvironmental preferences and interactions between parasite species have been the focus of many ecological studies. Here, we studied the distribution of ectoparasite species within the gill apparatus of bream (Abramis brama) from Lake Lubāns (Latvia) to establish whether digenean metacercariae: (1) prefer specific patches within the gill apparatus; (2) co-occur in the same patches with monogeneans and copepods within a host individual; and (3) interact with monogeneans and copepods. We recorded all parasites on gill arches of the same host species and used null models to analyse co-occurrences of digenean metacercariae, monogeneans and copepods. Zero-inflated mixture models were used to define the preferred patches of parasites. We found that digenean metacercariae (Bucephalus polymorphus) prefer specific patches of the gill apparatus to encyst, and shared these preferences with monogeneans and copepods, but did not interact with them. We concluded that digenean metacercariae have a species-specific microenvironmental preference to encyst in the gill apparatus and their occurrence (even in high numbers) does not reduce the success of attachment of monogeneans and copepods in the same gill patches.

Predatory interactions between prey affect patch selection by predators

When predators can use several prey species as food sources, they are known to select prey according to foraging efficiency and food quality. However, interactions between the prey species may also affect prey choice, and this has received limited attention. The effect of one such interaction, intraguild predation between prey, on patch selection by predators was studied here. The predatory mite Neoseiulus californicus preys on young larvae of the western flower thrips Frankliniella occidentalis and on all stages of the two-spotted spider mite Tetranychus urticae. The two prey species co-occur on several plant species, on which they compete for resources, and western flower thrips feed on eggs of the spider mites. A further complicating factor is that the thrips can also feed on the eggs of the predator. We found that performance of the predatory mite was highest on patches with spider mites, intermediate on patches with spider mites plus thrips larvae and lowest on patches with thrips larvae alone. Patch selection and oviposition preference of predators matched performance: predators preferred patches with spider mites over patches with spider mites plus thrips. Patches with thrips only were not significantly more attractive than empty patches. We also investigated the cues involved in patch selection and found that the attractiveness of patches with spider mites was significantly reduced by the presence of cues associated with killed spider mite eggs. This explains the reduced attractiveness of patches with both prey. Our results point at the importance of predatory interactions among prey species for patch selection by predators.Significance statementPatch selection by predators is known to be affected by factors such as prey quality, the presence of competitors and predators, but little is known on the effects of interactions among prey species present on patch selection. In this paper, we show that patch selection by a predator is affected by such interactions, specifically by the feeding of one prey species on eggs of the other.

Living on the boundary of a post-disturbance forest area: The negative influence of security cover on red deer home range size

In the face of climate change and the probable rise in the frequency of severe natural disturbances, successful management of forest ecosystems requires profound knowledge, including the one connected with the temporal and spatial relations between populations of wild herbivores and their habitats. Animal location data collected with VHF collars and spatial GIS data were used to investigate home range size of red deer living along the boundary of two contrasting forest environments which were created after a large-scale (10,000ha) stand-replacing fire in south-western Poland. We found male home ranges to be nearly twice as large as female ones. Surprisingly, the percentage of the burned area (less penetrated by humans, although of lower food availability) was negatively correlated with deer home range sizes in all seasons. The conditions in the post-disturbance forest were relatively stable during the year, which could explain the lack of differences between seasonal home ranges. Our findings suggest that the relationship between home range size and open habitats may be determined by the distribution of the latter: patches offering the best forage seem to be worth the effort of travelling, even at the cost of home range expansion. Heterogeneity features (patch and edge density) of forest interior habitats in this study did not emerge as an important determinant of the total size of home ranges. When burned and unburned areas were analysed separately, the results revealed that their size could be at least seasonally adjusted to habitat heterogeneity: in the burned area, deer seemed to travel longer distances between preferred patches (an increase in patch density was positively correlated with home range size), whereas the opposite was observed in the undisturbed forest in winter and spring. Our findings suggest that in populations under strong hunting pressure, security cover is a key resource, determining deer space use, especially in post-disturbance forests. We concluded that large areas of cover-offering habitats may lead to local increase in deer population and higher browsing pressure also in surrounding forests. Proper planning and introduction of feeding places (open areas) might help to control the population size by hunters and thus mitigate this effect.

Spatial memory or food cues; which do horses use to locate preferred forage patches?

Spatial memory or food cues; which do horses use to locate preferred forage patches?

Biotic interactions affect the colonization behavior of aquatic detritivorous macroinvertebrates in a heterogeneous environment

It has previously been suggested that macroinvertebrates actively search for suitable patches to colonize. However, it is not well understood how the spatial arrangement of patches can affect colonization rates. In this study, we determined the importance of the environmental factors (distance, connectivity and resource availability) for patch colonization in an experimental system using Gammarus aequicauda (Amphipoda), Lekanesphaera hookeri (Isopoda) and Ecrobia ventrosa (Gastropoda). Furthermore, we also assessed how the relative importance of each of these environmental factors differed in interactions between the three species. The single species experiments showed that distance was the most important factor for G. aequicauda and E. ventrosa. However, while E. ventrosa preferred patches close to the release point, G. aequicauda strongly preferred patches further from the release point. High resource availability was a strong determinant for the patch colonization of G. aequicauda and L. hookeri. Connectivity was only of moderate importance in the study system for L. hookeri and E. ventrosa. The effects of the environmental factors were strongly affected by interspecific interactions in the multispecies experiments. For G. aequicauda, the distance preference was lowered in the presence of E. ventrosa. Moreover, while for L. hookeri the effect of resource availability was ruled out by the species interactions, resource availability gained importance for E. ventrosa in the presence of any of the other species. Our results suggest a strong link between environmental factors and biotic interactions in the colonization of habitat patches and indicate that the effect of biotic interactions is especially important for species sharing similar traits.

Cattle make two-stage discriminations in patch choice

Discrimination among vegetation patches differing in quantity and quality is crucial to the foraging success of grazing animals living in grasslands. Animals are assumed to discriminate preferred patches from others first, before they visit patches to eat, and then when they are eating patches. We conducted six experiments to test the ability of cattle (Bos taurus) to discriminate among vegetation patches at these two stages during foraging. In each experiment, a group of Japanese Black cows was allowed to graze a tropical grass (Paspalum notatum) for 30 min in a 20 × 20 m area comprising 4, 6 or 9 types of patches. Animals almost always visited and grazed the patches selectively, with a longer residence (grazing) time per visit in more frequently visited patches. Allocation of grazing time was correlated more closely with allocation of visits than with residence time per visit. Faced with patchy vegetation, cattle can discriminate preferred patches from less-preferred and non-preferred patches at two stages during foraging. The first-stage discrimination (pre-visit-and-eating discrimination) is more important than the second (eating discrimination) as a determinant of grazing time allocation to patches.

Remarks on the number of persistent states to a fragmented predator–prey model system

We consider a predator–prey model system for spatially distributed species over patches. Each predator species has a unique preferred patch (shelter and reproduction site) and travel for chasing prey. Its individuals are split into resident from the preferred patch and travelers. Further there is at most one resident predator species per patch. Depending on the availability of local anthropized resources not related to local prey on the preferred patch, one distinguishes between well-fed and starving predators. We assume prey species do not disperse at the predator scale.In this study we are interested in the number of persistent stationary states for the resulting ordinary differential equations model system. There exists at most one persistent predator–prey stationary state when there is exactly one starving resident predators per patch provided all functional responses to predation are Lotka–Volterra like or when a single starving resident predators is available. Else multiple persistent predator–prey stationary state are likely to exist. A specific emphasis is put on toy-model systems with 2 or 3 patches. Slow–fast dynamical methodology is also used for locally asymptotically stable purposes.Numerical experiments suggest that several scalings may govern the dynamics at stabilization.

Size-at-age and body condition of juvenile American lobsters (Homarus americanus) living on cobble and mud in a mixed-bottom embayment in the Bay of Fundy

American lobsters, Homarus americanus, prefer structurally complex cobble bottom for settlement and early development, but this habitat is sparse and some juveniles are likely forced to exploit other habitats, such as mud bottom. Size-at-age and body condition of juvenile lobsters may vary between cobble and mud habitats, due to differences in food and shelter the habitats provide. In this study, we used cobble-filled collectors deployed on mud and cobble bottom to capture juvenile lobsters occupying cobble and mud seafloor in a mixed-bottom embayment in the southwestern Bay of Fundy, Canada. We compared their size-at-age using a recently developed age-determination technique, and their body condition using mass–length relationship, RNA/DNA ratio and protein content. Individuals 3 and 4 years of age inhabiting mud bottom had greater carapace length than same-age conspecifics on cobble, which could be due to greater growth of juveniles in the less preferred mud habitat. We also found that for a similar carapace length lobsters on mud had slightly lower body mass than those on cobble. RNA/DNA ratio and protein content did not differ between juveniles sampled from the two habitats. Our results suggest that mud bottom represents a more important habitat for young lobsters than is currently appreciated. We hypothesize that mud bottom has become a more important juvenile habitat in recent years due to high lobster abundance, which may be forcing some juveniles to move from preferred but saturated cobble patches to other habitats, such as mud.

Nest site characteristics and nesting success of the Western Burrowing Owl in the eastern Mojave Desert

We evaluated nest site selection at two spatial scales (microsite, territory) and reproductive success of Western Burrowing Owls (Athene cunicularia hypugaea) at three spatial scales (microsite, territory, landscape) in the eastern Mojave Desert. We used binary logistic regression within an information-theoretic approach to assess factors influencing nest site choice and nesting success. Microsite-scale variables favored by owls included burrows excavated by desert tortoise (Gopherus agassizii), burrows with a large mound of excavated soil at the entrance, and a greater number of satellite burrows within 5 m of the nest burrow. At the territory scale, owls preferred patches with greater cover of creosote bush (Larrea tridentata) within 50 m of the nest burrow. An interaction between the presence or absence of a calcic soil horizon layer over the top of the burrow (microsite) and the number of burrows within 50 m (territory) influenced nest site choice. Nesting success was influenced by a greater number of burrows within 5 m of the nest burrow. Total cool season precipitation was a predictor of nesting success at the landscape scale. Conservation strategies can rely on management of habitat for favored and productive nesting sites for this declining species.

Biased correlated random walk and foray loop: which movement hypothesis drives a butterfly metapopulation?

Animals in fragmented landscapes have a major challenge to move between high-quality habitat patches through lower-quality matrix. Two current mechanistic hypotheses that describe the movement used by animals outside of their preferred patches (e.g., high-quality habitat or home range) are the biased, correlated random walk (BCRW) and the foray loop (FL). There is also a variant of FL with directed movement (FLdm). While these have been most extensively tested on butterflies, they have never been tested simultaneously with data across a whole metapopulation and over multiple generations, two key scales for population dynamics. Using the pattern-oriented approach, we compare support for these competing hypotheses with a spatially explicit individual-based simulation model on an 11-year dataset that follows 12 patches of the federally endangered Fender's blue butterfly (Plebejus icarioides fenderi) in Oregon's Willamette Valley. BCRW and medium-scale FL and FLdm scenarios predicted the annual total metapopulation size for ≥ 9 of 12 patches as well as patch extinctions. The key difference, however, was that the FL scenarios predicted patch colonizations and persistence poorly, failing to adequately capture movement dynamics; BCRW and one FLdm scenario predicted the observed patch colonization and persistence with reasonable probabilities. This one FLdm scenario, however, had larger prediction intervals. BCRW, the biologically simplest and thus most parsimonious movement hypothesis, performed consistently well across all nine different tests, resulting in the highest quality metapopulation predictions for butterfly conservation.