Desert Populations Research Articles

Glomerular Filtration Rate and Blood Urea Nitrogen Levels between Coastal and Desert Regions within Libya

Background: Limited research exists on how geographic location and environmental factors influence kidney function. This study investigates potential variations in Glomerular Filtration Rate (GFR) and Blood Urea Nitrogen (BUN) levels between individuals residing in the coastal and desert regions of Libya. Methods: An observational, retrospective analysis was conducted using medical records. Participants (n=260) were recruited from Benghazi (coastal) and Jalu/Samnu/Sabha (desert) regions. Inclusion criteria included age range (18-90 years) and residency in the designated location. Exclusion criteria focused on factors affecting GFR (e.g., pre-existing kidney disease). GFR was estimated using the CKD-EPI formula. BUN levels were obtained from medical records. T-tests and Mann-Whitney U tests were used for statistical analysis. Results: The final sample size (after exclusions) and participant demographics was 134 participants. The study found no statistically significant difference in GFR between the coastal and desert groups (p-value = 0.238). However, BUN levels were significantly higher in the desert group (mean = 28.2 SD = 30.5) compared to the coastal group (mean = 15.5, SD = 10.5) with a p-value of (p-value = 0.026). Conclusion: This study did not identify a significant association between GFR and geographic location (coastal vs. desert) within Libya. However, BUN levels were significantly higher in the desert population, suggesting potential differences in kidney function or contributing factors that warrant further investigation.

For an Environmental Ethnography in Human and Physical Geography: Reenvisioning the Impacts and Opportunities of El Niño in Peru

In 2017 El Niño Costero devastated the northern coast of Peru. This article seeks to learn from this experience for future large central and eastern Pacific-driven El Niño events. It directs attention away from dominant disaster narratives to reflect on the opportunities that El Niño rains have generated for desert livelihoods over time. We make a call for and set out the key elements of a historical geographical ethnography approach in environmental geography, which, as well as examining climate dimensions (paleoclimatology, dendrochronological, and atmospheric changes) of El Niño, also aims to consider its impacts on the livelihoods and management strategies of desert communities over time. We take as a starting point the responses of people who themselves come directly into contact with environmental change, yet whose agency and experiences are often marginal in knowledge production about El Niño. Responding to recent calls for qualitative geography researchers to be more explicit about how data are collected and analyzed, we explain how and why it is important to compare stakeholder interviews and climate records with newspaper archives and community memories of the 1983 and 1998 El Niño events. We illustrate that for desert populations in northern Peru, El Niño can represent abundance as well as disaster and make visible their role in managing change after El Niño flooding.

Miners' diet in the Naḥal ‘Amram copper mines (southern ‘Arabah Valley) during the Roman-Byzantine periods

This study investigates the diet of copper miners at Naḥal ‘Amram (southern Negev Desert), through the examination of the well-preserved remains of plants, mammal and fish bones, dating to the Roman-Byzantine periods (1st–5th centuries CE), recovered during excavations undertaken in three different localities at this mining complex.Our analyses revealed that the miners enjoyed a varied and nutritious diet, comprising nine species of fruits and vegetables, alongside meat from two domestic animal taxa and representatives of eight different families of fish. While the fish and animal foods were brought to the mines from the Red Sea and neighboring regions, the vegetal food originated from a variety of different sources, some nearby, others quite distant.We suggest that since copper was traded from Naḥal ‘Amram, the foods arrived at the mines via the same trade routes, from settlements along the ‘Arabah, and these foodstuffs were likely bartered in exchange for copper. The results imply that the people engaged in copper mining were likely a local desert population, Nabataeans, supplementing their food needs from external sources and so enjoying improved nutritional status.Beyond its findings, the importance of this study lies in the combination of several disciplines, a methodology which can be useful for future research and provide a more reliable understanding of reconstructing the ancient diet.

Yesterday's problems are here to stay: Invisible exposure to geogenic metal (loid)s of arsenic, boron, and lithium in the Atacama Desert

AbstractIn this paper, we review the three natural contaminants (arsenic, boron, and lithium) that affected the ancient Andean populations of northern Chile. We debate the natural setting and the toxicity of these elements upon ancient populations exposed and their biocultural significance. This review demonstrates that recent advances in sensitive analytical atomic and mass spectrometry methods have immensely contributed to understanding the extent of exposure to geogenic metal (loid)s by ancient Andeans using well preserved tissues such as hair, bones, and teeth. In addition, the synthesized evidence shows that ancient Atacama Desert populations were significantly affected simultaneously by multiple potentially toxic chronic endemic regional hydro contaminants. Last, we suggest that future archaeometric and archaeological analysis need to consider ancient multicontaminants as an important factor when analyzing diet and health conditions.

High inter-population connectivity and occasional gene flow between subspecies improves recovery potential for the endangered Least Bell’s Vireo

Abstract Increasingly, genomic data are being used to supplement field-based ecological studies to help evaluate recovery status and trends in endangered species. We collected genomic data to address 2 related questions regarding the Least Bell’s Vireo (Vireo bellii), an endangered migratory songbird restricted to southern California riparian habitat for breeding. First, we sought to delineate the range limits and potential overlap between Least Bell’s Vireo and its sister subspecies, the Arizona Bell’s Vireo, by analyzing samples from the deserts of eastern California, southwestern Nevada, Utah, and Arizona. Second, we evaluated genetic structure among Least Bell’s Vireo populations in coastal California and estimated effective population size. Clustering analyses based on 10,571 single-nucleotide polymorphisms (SNPs) from 317 samples supported 2 major groups that aligned closely to the previously defined subspecies ranges. The first cluster included birds in the Central Valley, all coastal drainages, and westernmost deserts of California, with no further sub-structuring among coastal drainages. Almost all birds from the Amargosa River in eastern California and eastward assigned to the second cluster; however, low levels of gene flow were detected across the subspecies groups, with greater rates of gene flow from Arizona Bell’s Vireo to Least Bell’s Vireo than the reverse. Admixed individuals occurred in the California deserts; and although smaller than coastal populations, desert populations may be important for maintaining and replenishing genetic diversity and facilitating the movement of potentially adaptive genes between subspecies. Within Least Bell’s Vireo, local populations in coastal drainages comprised a single genetic population, with some evidence of close relatives distributed across drainages, suggesting that these could function as a well-connected metapopulation. These results are consistent with previous Least Bell’s Vireo banding studies that reported high rates of dispersal among drainages. Effective population size for both subspecies was high, suggesting that adaptive potential has been maintained despite previous declines.

The functional microclimate of an urban arthropod pest: Urban heat island temperatures in webs of the western black widow spider

Urbanization alters natural landscapes and creates unique challenges for urban wildlife. Similarly, the Urban Heat Island (UHI) effect can produce significantly elevated temperatures in urban areas, and we have a relatively poor understanding of how this will impact urban biodiversity. In particular, most studies quantify the UHI using broad-scale climate data rather than assessing microclimate temperatures actually experienced by organisms. In addition, studies often fail to address spatial and temporal complexities of the UHI. Here we examine the thermal microclimate and UHI experienced in the web of Western black widow spiders (Latrodectus hesperus), a medically-important, superabundant urban pest species found in cities across the Western region of North America. We do this using replicate urban and desert populations across an entire year to account for seasonal variation in the UHI, both within and between habitats. Our findings reveal a strong nighttime, but no daytime, UHI effect, with urban spider webs being 2–5 °C warmer than desert webs at night. This UHI effect is most prominent during the spring and least prominent in winter, suggesting that the UHI need not be most pronounced when temperatures are most elevated. Urban web temperatures varied among urban sites in the daytime, whereas desert web temperatures varied among desert sites in the nighttime. Finally, web temperature was significantly positively correlated with a spider's boldness, but showed no relationship with voracity towards prey, web size, or body condition. Understanding the complexities of each organism's thermal challenges, the “functional microclimate”, is crucial for predicting the impacts of urbanization and climate change on urban biodiversity and ecosystem functioning.

Defining the roles of local precipitation and anthropogenic water sources in driving the abundance of Aedes aegypti, an emerging disease vector in urban, arid landscapes

Understanding drivers of disease vectors’ population dynamics is a pressing challenge. For short-lived organisms like mosquitoes, landscape-scale models must account for their highly local and rapid life cycles. Aedes aegypti, a vector of multiple emerging diseases, has become abundant in desert population centers where water from precipitation could be a limiting factor. To explain this apparent paradox, we examined Ae. aegypti abundances at > 660 trapping locations per year for 3 years in the urbanized Maricopa County (metropolitan Phoenix), Arizona, USA. We created daily precipitation layers from weather station data using a kriging algorithm, and connected localized daily precipitation to numbers of mosquitoes trapped at each location on subsequent days. Precipitation events occurring in either of two critical developmental periods for mosquitoes were correlated to suppressed subsequent adult female presence and abundance. LASSO models supported these analyses for female presence but not abundance. Precipitation may explain 72% of Ae. aegypti presence and 90% of abundance, with anthropogenic water sources supporting mosquitoes during long, precipitation-free periods. The method of using kriging and weather station data may be generally applicable to the study of various ecological processes and patterns, and lead to insights into microclimates associated with a variety of organisms’ life cycles.

Whole-genome sequencing reveals adaptations of hairy-footed jerboas (Dipus, Dipodidae) to diverse desert environments

BackgroundEnvironmental conditions vary among deserts across the world, spanning from hyper-arid to high-elevation deserts. However, prior genomic studies on desert adaptation have focused on desert and non-desert comparisons overlooking the complexity of conditions within deserts. Focusing on the adaptation mechanisms to diverse desert environments will advance our understanding of how species adapt to extreme desert environments. The hairy-footed jerboas are well adapted to diverse desert environments, inhabiting high-altitude arid regions, hyper-arid deserts, and semi-deserts, but the genetic basis of their adaptation to different deserts remains unknown.ResultsHere, we sequenced the whole genome of 83 hairy-footed jerboas from distinct desert zones in China to assess how they responded under contrasting conditions. Population genomics analyses reveal the existence of three species in hairy-footed jerboas distributed in China: Dipus deasyi, Dipus sagitta, and Dipus sowerbyi. Analyses of selection between high-altitude desert (elevation ≥ 3000m) and low-altitude desert (< 500m) populations identified two strongly selected genes, ATR and HIF1AN, associated with intense UV radiation and hypoxia in high-altitude environments. A number of candidate genes involved in energy and water homeostasis were detected in the comparative genomic analyses of hyper-arid desert (average annual precipitation < 70mm) and arid desert (< 200mm) populations versus semi-desert (> 360mm) populations. Hyper-arid desert animals also exhibited stronger adaptive selection in energy homeostasis, suggesting water and resource scarcity may be the main drivers of desert adaptation in hairy-footed jerboas.ConclusionsOur study challenges the view of deserts as homogeneous environments and shows that distinct genomic adaptations can be found among desert animals depending on their habitats.

Defining Vascular Deserts to Describe Access to Care and Identify Sites for Targeted Limb Preservation Outreach

Access to care plays a critical role in limb salvage in chronic limb-threatening ischemia (CLTI). A "medical desert" describes a community lacking access to medical necessities, resulting in increased morbidity and mortality. We sought to describe vascular deserts, which we defined as regions with decreased access to specialty care. All California providers performing vascular surgery procedures were identified through online provider and health care facility searches. Facility participation in the Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) lower extremity bypass (LEB) and peripheral vascular intervention (PVI) modules was also determined. Addresses were geocoded with a 30-mile surrounding buffer using ArcGIS (Geographic information systems), creating maps based on care type, including all providers performing vascular procedures, board-certified vascular surgeons, and facilities participating in VQI modules. Public census data overlayed on the maps demonstrated population composition in desert versus nondesert regions. Subsequently, data from the Healthy Places Index (HPI) was overlayed, providing data regarding 25 social factors, comprising an overall HPI score and percent, with lower scores corresponding to poorer health and outcomes. Maps depicting care regions demonstrated decreased provider coverage with increasing specialty care, with the VQI provider map showing the most prominent "desert" regions. When comparing nondesert versus desert regions by care type, demographics including race, the percentage of the population 200% below the poverty line, and the rate of uninsured residents were described. Social determinants of health were then described for desert and nondesert regions by care type, including the HPI percentage and specific domain factors. The percentage of uninsured residents was significant only in the desert and nondesert areas served by board-certified vascular surgeons (19.6 vs. 16.8%, P<0.001). The mean HPI percentile was significantly lower in board-certified provider and VQI facility deserts than nondeserts (50.48% vs. 40.65%, P<0.001 and 52.68% vs. 43.12%, P<0.001, respectively). The economic and education factor percentiles were significantly lower in all desert populations, while the housing, social, and pollution factors were significantly higher in nondesert regions. Health care access, transportation, and neighborhood factor percentiles were significantly lower in board-certified and VQI facility deserts than in the nondesert areas. Access to vascular care plays a significant role in limb salvage. Through mapping vascular deserts, patient demographics, and social factors in desert regions are better understood, and areas that would benefit most from targeted outreach and limb preservation programs for CLTI are identified.

MODELING LONG-TERM HUMAN POPULATION DYNAMICS USING KERNEL DENSITY ANALYSIS OF 14C DATA IN THE ATACAMA DESERT (18º–21ºS)

ABSTRACTFood production is one of the most significant achievements in Andean history. The domestication of plants and animals presented an enormous challenge, relating to changing technologies, settlement patterns, and social organization. This paper aims to assess Atacama Desert population dynamics and their relationship to the domestication of plants and animals through chronological modeling using kernel density estimation on radiocarbon (14C) dates, assuming that a higher 14C probability density is related to more intense human occupation. The analysis is based on a 14C dataset comprising 1003 14C dates (between 11,000 and 150 BP) from 243 archaeological sites in the Arica and Tarapacá regions of northern Chile, collected from published data. We observed two population-dynamics inflection points for these regions. First, starting at ca. 3000 BP, constant population growth occurred, which was related to horticulture in the Arica region and to agriculture in the Tarapacá region. Second, between ca. 1000 and 400 BP, a general population rise occurred due to the consolidation of intensive agriculture in the lowlands and precordillera altitudinal belts in both regions and the integration of the coast and the altiplano into macro-regional population dynamics.

Testing the costs of defense against herbivores in ecotypes of Eruca sativa (Brassicaceae)

Abstract Plants of Eruca sativa from a desert population produce less vegetative biomass, flower earlier and possess higher density of trichomes than plants from a more mesic Mediterranean habitat. When eliciting plant defense mechanisms with methyl-jasmonate (MJ), trichome formation was exclusively enhanced in plants of the Mediterranean ecotype. To test the relative costs of defenses, ecologically-important traits were monitored in non-elicited plants of the two ecotypes and when defenses were induced by MJ. Opposing the expected tradeoffs of induced defense, MJ- elicitation significantly delayed bolting and flowering in plants of the desert ecotype but not in the Mediterranean ones. Moreover, MJ did not impose costs on fitness- related traits, i.e. fruit and seed production, nor differences between plants of the two ecotypes were found. It is suggested that early flowering in plants of the desert ecotype provide a mean to escape both the abiotic stressful environment as well herbivory, while induced defense in the Mediterranean ecotype was favored in habitats of more stressful biotic interactions. The results are discussed in light of the optimal defense theory and resource availability hypothesis.

Орёл-могильник на юго-востоке Казахстана в 2022–2023 годах: распространение, численность, угрозы

Орёл-могильник на юго-востоке Казахстана в 2022–2023 годах: распространение, численность, угрозы

Whole genome resequencing identifies local adaptation associated with environmental variation for redband trout.

Aquatic ectotherms are predicted to harbour genomic signals of local adaptation resulting from selective pressures driven by the strong influence of climate conditions on body temperature. We investigated local adaptation in redband trout (Oncorhynchus mykiss gairdneri) using genome scans for 547 samples from 11 populations across a wide range of habitats and thermal gradients in the interior Columbia River. We estimated allele frequencies for millions of single nucleotide polymorphism loci (SNPs) across populations using low-coverage whole genome resequencing, and used population structure outlier analyses to identify genomic regions under divergent selection between populations. Twelve genomic regions showed signatures of local adaptation, including two regions associated with genes known to influence migration and developmental timing in salmonids (GREB1L, ROCK1, SIX6). Genotype-environment association analyses indicated that diurnal temperature variation was a strong driver of local adaptation, with signatures of selection driven primarily by divergence of two populations in the northern extreme of the subspecies range. We also found evidence for adaptive differences between high-elevation desert vs. montane habitats at a smaller geographical scale. Finally, we estimated vulnerability of redband trout to future climate change using ecological niche modelling and genetic offset analyses under two climate change scenarios. These analyses predicted substantial habitat loss and strong genetic shifts necessary for adaptation to future habitats, with the greatest vulnerability predicted for high-elevation desert populations. Our results provide new insight into the complexity of local adaptation in salmonids, and important predictions regarding future responses of redband trout to climate change.

Population dynamics and the effect of drought in the threatened Nubian ibex

AbstractEstimating key state variables such as abundance, survival, and recruitment of wild populations, and their interaction with local conditions such as precipitation, is essential for state‐dependent decision making and management. Estimation of state variables remains challenging, especially in species such as mountain ungulates inhabiting rugged and remote terrains. Camera traps present a technological advance that can mitigate some of the challenges in state estimation and can be used to enhance existing methods. Here, we combined camera traps, individual markings, and GPS tracking to estimate abundance and survival for the threatened Nubian ibex (Capra nubiana) population of the Judean Desert, Israel. Since precipitation is a key determinant for recruitment in desert ungulates, we complemented our estimates with kid‐female ratios and regional precipitation records. Between 2016 and 2019, we individually marked 48 ibex of which 38 were also fitted with GPS collars within the Judean Desert. We performed 6 days of camera‐trap surveys each year to estimate abundance for the north Judean Desert population using mark‐resight in a robust‐design framework. Weight‐averaged abundance estimates for 2017–2019, respectively, were as follows: = 267 (95% CI = 117–418, SE = 51.27), 201 (95% CI = 115–288, SE = 36.85), and 226 (95% CI = 154–299, SE = 36.94) for females, and = 291 (95% CI = 154–299, SE = 36.94), 160 (95% CI = 108–212, SE = 25.19), and 283 (95% CI = 181–384, SE = 29.76) for males. By augmenting data from telemetry with camera traps, we estimated survival via known fates for the entire Judean Desert (north, mid, and south populations). Weight‐averaged survival estimates for 2016–2019, respectively, were: = 0.99 (95% CI = 0.97–1.00, SE = 0.012), 0.90 (95% CI = 0.24–0.99, SE = 0.153), 0.87 (95% CI = 0.62–0.97, SE = 0.081), and 0.88 (95% CI = 0.69–0.96, SE = 0.062) for females, and = 0.77 (95% CI = 0.26–0.97, SE = 0.203), 0.64 (95% CI = 0.33–0.86, SE = 0.151), 0.85 (95% CI = 0.60–0.96, SE = 0.087), and 0.88 (95% CI = 0.69–0.96, SE = 0.062) for males. The interannual trends of abundance and survival estimates corresponded with observed kid‐female ratios and the regional precipitation records, reflecting a population decline following 2017's drought and an increase following the increased precipitation in 2018. Our findings substantiate the efficacy of using camera traps to estimate Nubian ibex's key state variables, as well as detecting population trends driven by environmental conditions. Despite being costly, the capacity of statistically‐robust methods to estimate key state variables is indispensable, and camera traps make similar methods increasingly more feasible in remote and inaccessible populations.

The Origin and Character of God: Ancient Israelite Religion through the Lens of Divinity, Yahweh before Israel: Glimpses of History in a Divine Name and Yahweh: Origin of a Desert God

The Origin and Character of God: Ancient Israelite Religion through the Lens of Divinity, Yahweh before Israel: Glimpses of History in a Divine Name and Yahweh: Origin of a Desert God

Population Genetics of California Gray Foxes Clarify Origins of the Island Fox.

We used mitochondrial sequences and nuclear microsatellites to investigate population structure of gray foxes (Urocyon cinereoargenteus) and the evolutionary origins of the endemic island fox (Urocyon littoralis), which first appeared in the northern Channel Islands <13,000 years ago and in the southern Channel Islands <6000 years ago. It is unclear whether island foxes evolved directly from mainland gray foxes transported to the islands one or more times or from a now-extinct mainland population, already diverged from the gray fox. Our 345 mitochondrial sequences, combined with previous data, confirmed island foxes to be monophyletic, tracing to a most recent common ancestor approximately 85,000 years ago. Our rooted nuclear DNA tree additionally indicated genome-wide monophyly of island foxes relative to western gray foxes, although we detected admixture in northern island foxes from adjacent mainland gray foxes, consistent with some historical gene flow. Southern California gray foxes also bore a genetic signature of admixture and connectivity to a desert population, consistent with partial replacement by a late-Holocene range expansion. Using our outgroup analysis to root previous nuclear sequence-based trees indicated reciprocal monophyly of northern versus southern island foxes. Results were most consistent with island fox origins through multiple introductions from a now-extirpated mainland population.

Among-years rain variation is associated with flower size, but not with signal patch size in Iris petrana.

Among-years rain variation is associated with flower size, but not with signal patch size in Iris petrana.

Group-living carpenter bees conserve heat and body mass better than solitary individuals in winter

Environmental challenges are major drivers of the evolution of group living. In particular, harsh seasonal conditions can promote temporary or facultative social behaviour in primarily solitary animals. We asked how winter conditions might favour group living in a desert population of a facultatively social carpenter bee, Xylocopa sonorina Smith, that nests primarily in small groups during winter quiescence. We experimentally manipulated the social condition (social versus solitary) of bees living in observation nests in ambient winter conditions and measured effects of group living on temperature and body condition. Social bees experienced significantly warmer temperatures than solitary bees in identical nests. Furthermore, social bees experienced smaller reductions in body mass than solitary bees over the course of the 1-month observation period. These results suggest important benefits of group living in cold and resource-scarce conditions, which may allow X. sonorina to reduce risk of freezing and emerge from winter quiescence in better physiological condition. Seasonal associations such as these provide opportunities for extended social interactions among nestmates, an important context for the evolution of more complex cooperative behaviours.

Microbiome Variation Across Populations of Desert Halophyte Zygophyllum qatarensis.

Microbial symbionts play a significant role in plant health and stress tolerance. However, few studies exist that address rare species of core-microbiome function during abiotic stress. In the current study, we compared the microbiome composition of succulent dwarf shrub halophyte Zygophyllum qatarensis Hadidi across desert populations. The results showed that rhizospheric and endosphere microbiome greatly varied due to soil texture (sandy and gravel). No specific bacterial amplicon sequence variants were observed in the core-microbiome of bulk soil and rhizosphere, however, bacterial genus Alcaligenes and fungal genus Acidea were abundantly distributed across root and shoot endospheres. We also analyzed major nutrients such as silicon (Si), magnesium, and calcium across different soil textures and Z. qatarensis populations. The results showed that the rhizosphere and root parts had significantly higher Si content than the bulk soil and shoot parts. The microbiome variation can be attributed to markedly higher Si – suggesting that selective microbes are contributing to the translocation of soluble Si to root. In conclusion, low core-microbiome species abundance might be due to the harsh growing conditions in the desert – making Z. qatarensis highly selective to associate with microbial communities. Utilizing rare microbial players from plant microbiomes may be vital for increasing crop stress tolerance and productivity during stresses.

Spatial ecology of female bighorn sheep in a prairie landscape in Nebraska

AbstractUnderstanding the spatial ecology of small populations at the periphery of their range is important for identifying factors limiting population growth and developing sound management strategies. Bighorn sheep were reintroduced to Nebraska in 1981 and persist in a small population at the easternmost extent of the distribution of the species, where 1 of the 2 subpopulations is declining. Bighorn sheep space use and movement has been studied extensively in mountain and desert populations, but information is sparse from prairie populations in the Northern Great Plains. We investigated the spatial ecology of female bighorn sheep in Nebraska, USA, with global positioning system (GPS) telemetry. We tested the hypothesis that space use and movements would vary across seasons, years, and individuals but predicted that migration would involve relatively short distances in this translocated population (relative to native populations) occupying a fragmented landscape. Overall, females used smaller seasonal home ranges (3.3–7.8 km2) than most of those reported previously for the species and exhibited a high degree of variability in space use and movements across seasons, subpopulations, and individuals. Most females (92–100%) exhibited fidelity to their home ranges across seasons and years. Six females migrated between spatially distinct core lambing and winter ranges, although the distances (range = 7.9–8.7 km) and mean elevations (range = 31–41 m) between these core seasonal ranges were less than those reported for most native, migratory bighorn sheep populations. After accounting for variation in season, subpopulation, and years, home range size was positively associated with road density in both subpopulations (P &lt; 0.001), suggesting that females incur greater energetic costs associated with greater space use in areas of higher fragmentation. Our results establish the basic spatial ecology of female bighorn sheep in Nebraska where their behavior appears to reflect the isolated nature of suitable habitat in this fragmented prairie landscape.