Space Habitat Research Articles

Bigger machines make houses and rockets

While most three-dimensional printers are put to work making small parts or prototypes, start-ups are developing techniques to make much larger things, including houses and rockets. Construction technology company Icon and housing nonprofit New Story used a large-format printer to build the concrete foundation and walls of a small, 32.5-m2house in Austin, Texas. The house was constructed in 48 hours at a cost of about $10,000. Icon says it aims to build houses of up to 75 m2 and to refine the process to make it faster and more affordable. While its first mission is to build affordable housing in developing regions, Icon says its printers could also be used to make habitats in space. Icon’s 3-D house printer could someday catch a ride on a 3-D-printed rocket made by another start-up, Relativity Space. The company raised $35 million in a second round of funding led by venture fund Playground

At which spatial and temporal scales can fungi indicate habitat connectivity?

Isolation of habitats in space and time affects species globally and in a multitude of ecosystems. It is however often difficult to assess the level of isolation from the point of view of the focal species. Indicator species are often used to assess ‘conservation value’ of habitats. One such approach involves the use of wood-decaying fungal species as indicators of near-natural forests, continuity in old-forest characteristics over time, and/or presence of red-listed species, but not of spatial connectivity. The indicator species were commonly assigned based on expert opinions, but few scientific evaluations have been performed of what these species actually indicate. Building on previous classifications of wood-decaying fungal indicator species on Norway spruce, we hypothesized that indicator species would differ from non-indicator species in how they respond to local temporal connectivity (forest age, the intensity of historical selective logging and the presence of well-decomposed large logs), and to local and landscape-scale spatial connectivity (local forest area, local amount of deadwood and the connectivity to old forest in the surrounding landscape). Based on fungal occurrence data from a fixed number of spruce logs at 28 sites distributed across the Scandinavian Peninsula, we explored the spatiotemporal scales at which the local communities were affected by connectivity. Indicator species showed the strongest response to connectivity of old forest (≥80 years) within 100 km, while non-indicator species depended on connectivity of younger forest (≥40 years) at a smaller spatial scale (≤25 km). Indicator species increased and non-indicator species decreased in total abundance with the increasing age of the local forest stand. Landscape-scale old-forest connectivity was beneficial for indicator species in all sites except those with relatively low amount of deadwood, while non-indicator species showed the opposite pattern. We identify a threshold of around 29 m3 ha−1 in the amount of spruce logs where indicator species become abundant enough to influence non-indicator species through competitive interactions. There was a pronounced uniformity within each species group in the connectivity responses. We conclude that the studied indicator species indicate high forest age, high amount of resources and, given that the resources are plentiful, also high old-forest connectivity, but they do not indicate a long history without any logging operations or local deadwood continuity. The studied non-indicator species did not indicate any of the studied spatiotemporal connectivity variables. Indicator species are usually red-listed and may continue to decline in the future without habitat restoration efforts.

Assessment of ecosystem functioning from space: Advancements in the Habitats Directive implementation

The Habitats Directive (HD) and the Natura 2000 network establish a common framework for maintaining European natural habitats in a favourable conservation status and represent the main instrument used by conservation decision makers in the European Union. Habitat conservation status depends on the sum of the influences acting upon the habitat and its typical species that may affect its long-term natural distribution, structure and functions. Thus, ecosystem functioning is influenced by the diversity, number and functional traits of the species occurring in a habitat. Although the HD establishes that representative species should be selected to reflect favourable structure and functioning of the habitat type, it would not be realistic to associate species with all aspects of structure and functioning given the variability of Annex I habitats. This constraint led us to seek new approaches that allow a more direct assessment of the ecosystem functioning for natural habitats in space and time. We propose a remote sensing-based approach to characterize and assess the ecosystem functioning of habitats. As a case study, we applied our approach to three Mediterranean natural habitat types from the Iberian Peninsula included in Annex I of the Habitats Directive, i.e., Mediterranean sclerophyllous forest, Mediterranean deciduous forest and Sub-Mediterranean and temperate scrub. First, we estimated two key descriptors of ecosystem functioning derived from the Enhanced Vegetation Index and related them to primary production dynamics by using satellite images captured by the MODIS sensor for each year between 2001 and 2012. Second, we arranged these functional descriptors in two-dimensional space and calculated the distances from the habitats assessed to the reference sites, i.e., habitat patches that showed an optimal conservation status of composition and structure. Then, the distances were averaged over the period, and the habitats were categorized according to their mean distances as favourable or unfavourable-inadequate or unfavourable-bad, as outlined in the reporting guidelines under Article 17 of the Directive. Our approach provides new procedures to assess ecosystem functions across space and time, while complying with reporting obligations derived from the HD.

Hazardous Gas Detection Sensor Using Broadband Light-Emitting Diode-Based Absorption Spectroscopy for Space Applications

As space travel matures and extended duration voyages become increasingly common, it will be necessary to include arrays of early fire detection systems aboard spacefaring vessels, space habitats, and in spacesuits. As gasses that are relevant to combustion and pyrolysis have absorption features in the mid-infrared range, it is possible to utilize absorption spectroscopy as a means of detecting and quantifying the concentration of these hazardous compounds. Within this work, a sensor for detecting carbon dioxide has been designed and tested autonomously on a high-altitude balloon flight. The sensor utilizes a 4.2-μm light-emitting diode source, amplitude modulation to characterize species concentrations, and frequency modulation to characterize ambient temperature. Future work will include expanding the sensor design to detect other gases, and demonstrating suborbital flight capability.

Among‐species overlap in rodent body size distributions predicts species richness along a temperature gradient

Temperature is widely regarded as a major driver of species richness, but the mechanisms are debated. Niche theory suggests temperature may affect richness by filtering traits and species in colder habitats while promoting specialization in warmer ones. However, tests of this theory are rare because niche dimensions are challenging to quantify along broad thermal gradients. Here, we use individual‐level trait data from a long‐term monitoring network spanning a large geographic extent to test niche‐based theory of community assembly in small mammals. We examined variation in body size among 23 communities of North American rodents sampled across the National Ecological Observatory Network (NEON), ranging from northern hardwood forests to subtropical deserts. We quantified body size similarity among species using a metric of overlap that accounts for individual variation, and fit a structural equation model to disentangle the relationships between temperature, productivity, body size overlap, and species richness. We document a latitudinal gradient of declining similarity in body size among species towards the tropics and overall increase in the dimensions of community‐wide trait space in warmer habitats. Neither environmental temperature nor net primary productivity directly affect rodent species richness. Instead, temperature determines the community‐wide niche space that species can occupy, which in turn alters richness. We suggest a latitudinal gradient of trait space expansion towards the tropics may be widespread and underlie gradients in species diversity.

Long-term distribution and habitat changes of protected wildlife: giant pandas in Wolong Nature Reserve, China.

Changes in wildlife habitat across space and time, and corresponding changes in wildlife space use, are increasingly common phenomenon. It is critical to study and understand these spatio-temporal changes to accurately inform conservation strategy and manage wildlife populations. These changes can be particularly large and complex in areas that face pressure from human development and disturbance but are also under protection and/or restoration regimes. We analyzed changes in space use and habitat suitability of giant pandas in Wolong Nature Reserve, China, over three decades using kernel density, spatio-temporal analysis of moving polygons (STAMP), and MaxEnt methods, and data from three national censuses. Between 2001 and 2012, there was a slight retraction in total range, and more area of significant space use decreases than increases. Habitat suitability varied spatially and temporally, with a 4.1% decrease in average suitability between 1987 and 2001 and a 3.5% increase in average suitability in between 2001 and 2012. Elevation and bamboo were the most important habitat predictors across the three censuses. Human and natural disturbance variables such as distance to household and the distance to landslide variable in the 4th census were also important predictors, and likely also negatively influenced important habitat variables such as bamboo and forest cover. We were able to measure changes in space utilization and habitat suitability over a large time scale, highlighting the achievements and challenges of giant panda conservation. Long-term monitoring of the changes in distribution and habitat of threatened species, and an analysis of the drivers behind these changes such as undergone here, are important to inform the management and conservation of the world's remaining wildlife populations.

Vegetation mapping above tree line in Nandiar valley, western Himalayas. A multivariate approach

This paper communicates an analytical exploration of the vegetation above tree line in Nandiar valley western Himalayas with respect to climatic, edaphic and topographic factors. The alpine pasture stretches above the tree limits between elevations of 2850–3800m. Thirteen stands were selected on the basis of physiognomy of vegetation in 2014–15. The leading life form and leaf spectra were therophytes and microphyll respectively. Four plant communities were identified through two ways indicator species analysis at cut level 2. Bray-Curtis ordination showed that maximum stands have common species. Detrended correspondence analysis grouped species having similar habitats in ordination space. Canonical correspondence analysis constrained species along different environmental variables. The significant result were contribution by phosphorous (P=0.01) and wind speed (P=0.08). Few plant species like Betula utilis and Podophyllum emodi are threatened due to its medicinal collection. The alpine pasture of Nandiar valley is under severe stress due to anthropogenic and grazing factors. Overall, this research article call for greater attention to the types of conservation actives occurring and the ways they are working together to protect and recover the global alpine biodiversity.

Changes in the porosity induced by tillage in typical Argiudolls of southeastern Buenos Aires Province, Argentina, and its relationship with the living space of the mesofauna: a preliminary study

The study of structure is essential to understand the effects of natural and anthropogenic degradation of the environment. Continuous tillage has negative effects on soil structure. The structural heterogeneity of the soil is a key element which makes it possible for several functional groups of organisms to coexist in the soil. Thus, the soil provides a habitat for a vast array of small and large organisms residing permanently or temporarily within it. The aim of our work is to analyze the effect of tillage in typical Argiudolls of Los Padres Pound, in the pores morphology, size and roughness, and its relationship with the potential available habitat space of the mesofauna. We worked on a cultivated plot, for over 40 years, and referencing a plot with non-farmed soils. Size, number, and roughness of pore were determined. For mesofauna, they were taken into account previous studies in these soils. The results of this study proved such influence of tillage on soil structure in the cultivated plot. The modifications of physical properties resulting from tillage are due to the decrease in total porosity and the modification in the type, size, and roughness of the pores. The decrease in total porosity might influence the abundance and diversity of mesofauna in these typical Argiudolls.

Home range estimator method and GPS sampling schedule affect habitat selection inferences for wild turkeys

ABSTRACTUnderstanding patterns in the spatial distribution of individuals in a population is a central question in ecology. Concurrent with advances in biotelemetry devices, development of home range estimator methods incorporating the temporal component of locational fixes are increasingly used to investigate these patterns at finer scales. However, these methods may necessitate sampling schedules that limit battery life and study period length. Practically, evaluating how home range estimator methods affect calculations of space use and habitat selection prior to deployment of biotelemetry devices could help researchers optimize data acquisition schedules. We quantified spatial overlap between a home range estimator using temporal information (dynamic Brownian bridge movement model [dBBMM]) and home range estimators not incorporating the temporal component of fixes (ad hoc and href kernel density estimator [KDE]) across differing sample schedules, and the resulting error in habitat selection ratios using data collected from wild turkeys (Meleagris gallopavo) equipped with Global Positioning Systems units in Texas, Georgia, South Carolina, and Louisiana, USA, during February–May 2015. When comparing ranges created from KDEs to dBBMM, commission errors were large (20–80%) and did not diminish with increased sampling rates. In contrast, omission error rate declined quicker and improvements were minimal when fix rates increased beyond 4/day. Compared with ranges estimated with dBBMM, KDEs poorly defined the spatial bearings of an individual's range, overestimated areas of use, underestimated areas avoided, and showed different patterns of habitat selection. Our results suggest home range estimator methods incorporating temporal information seem capable of estimating ranges encompassing nearly all area used by an individual and should be used even at relatively low‐frequency collection schedules to assess home ranges of wild turkeys. If researchers are interested in describing habitat selection of wild turkeys, we recommend a sampling schedule of ≤1 location/hour during daytime and dBBMM for range estimation. © 2018 The Wildlife Society.

Transformation of polyhedrons

Polyhedral transformation enables large volumetric change amongst Platonic and Archimedean solids. It has great potential in applications where transportability and protection of payload are critical design features, e.g., small or micro satellites, space habitats or planetary rovers. However, existing designs introduce many degrees of freedoms, making the control of transformation process extremely difficult and cumbersome, and thus the practical applicability of the mechanisms is restricted. This paper develops a kinematic method to enable polyhedral transformation with a single degree of freedom. The approach has been implemented for the transformation between truncated octahedron and cube. Motion analysis indicates that transformation path is unique without singularity, which is further demonstrated with physical validation models. We envisage that our method could be suitable for extension to other paired polyhedron sets.

Impacts of Downtown Developments to Facilitate Environmental Sustainability and Presence of Core and Frame: A Case Study of Saddar, Karachi, Pakistan

A real sustainable world and a livable environment for everyone is currently needed and becoming an extraordinarily challenging task. Sustainability for whom-who benefits and who loses? The increasing environmental problems are also hampering the sustainability. The remarkable increase in population and severe food shortages has brought unprecedented burden on land.Land is considered as space, territory, location, ecosystem, reserve and human habitat above all. Land-use provides a basis for identification of different functional zones in the city thus providing a framework for shaping the internal structure of a city. The best-planned development of any area is possible when the problems of that area are well understood, well documented and closely monitored. Systematic information on land-use / land cover classes, environmental problems and the available arrangement is critically important for future planning of an area.The rationale of this study is to indicate the presence of core and frame in the downtown area of Saddar, Karachi and to examine how finished downtown developments are designed to facilitate environmental sustainability. The field inventory has been conducted to find out the functional and physical developments and sustainability of the study area. In addition the process models have been applied to find out the environmental sustainability. The results of filed investigations show that Saddar does not fulfill the requirement of any of the classical land use models. With reference to the planned development of the core area, zoning laws should be applied to place the functions properly to their respective location. The main problems should be considered as prime matters for the city planners and agencies.

Fuels Management and Habitat Restoration Activities Benefit Eastern Hognose Snakes (Heterodon platirhinos) in a Disturbance-Dependent Ecosystem

Abstract Eastern Hognose Snakes (Heterodon platirhinos) are considered a species of conservation concern in the northeast United States because of their association with rare and declining habitats such as pine barrens and shrublands. These are disturbance-dependent habitats that currently require management to persist. We studied Eastern Hognose Snakes on a pitch pine–scrub oak barren in western Massachusetts from 2008 to 2013 to describe patterns of space use, habitat selection, and survival of this species and to evaluate the effects of habitat restoration and fuels management. We monitored 12 snakes with radio telemetry during the months of May to October 2008–2010. We examined habitat use versus availability using paired logistic regression analyses in which availability was temporally and spatially explicit in relation to radio-tracked snakes' previous use location and likely movements. We found that radio-tracked snakes significantly avoided closed-canopy forests and power line corridors, and inste...

The Impact of Oxidative Stress on the Bone System in Response to the Space Special Environment.

The space special environment mainly includes microgravity, radiation, vacuum and extreme temperature, which seriously threatens an astronaut’s health. Bone loss is one of the most significant alterations in mammalians after long-duration habitation in space. In this review, we summarize the crucial roles of major factors—namely radiation and microgravity—in space in oxidative stress generation in living organisms, and the inhibitory effect of oxidative stress on bone formation. We discussed the possible mechanisms of oxidative stress-induced skeletal involution, and listed some countermeasures that have therapeutic potentials for bone loss via oxidative stress antagonism. Future research for better understanding the oxidative stress caused by space environment and the development of countermeasures against oxidative damage accordingly may facilitate human beings to live more safely in space and explore deeper into the universe.

Microphone arrays for efficient communications during long-duration space missions

The astronauts' ability to communicate easily among themselves or with the ship's computer should be a high priority for the success of the mission. Long-duration space habitats—whether spaceships or surface bases—will likely be larger than present-day Earth-to-orbit/Moon transfer ships. Hence an efficient approach would be to free the crew members from the relative burden of having to wear headsets throughout the spacecraft. This can be achieved by placing microphone arrays in all crew-accessible parts of the habitat. Processing algorithms would first localize the speaker and then perform speech enhancement. The background ``noise'' in a spacecraft is typically fan and duct noise (hum, drone), valve opening/closing (click, hiss), pumps, etc. We simulate such interfering sources by a number of loudspeakers broadcasting various sounds: real ISS sounds, a continuous radio stream, a poem read by one author, etc. To test the concept, we use a linear 30-microphone array driven by a zero-latency professional au...

Effects of high-intensity static magnetic fields on a root-based bioreactor system for space applications

Static magnetic fields created by superconducting magnets have been proposed as an effective solution to protect spacecrafts and planetary stations from cosmic radiations. This shield can deflect high-energy particles exerting injurious effects on living organisms, including plants. In fact, plant systems are becoming increasingly interesting for space adaptation studies, being useful not only as food source but also as sink of bioactive molecules in future bioregenerative life-support systems (BLSS).However, the application of protective magnetic shields would generate inside space habitats residual magnetic fields, of the order of few hundreds milli Tesla, whose effect on plant systems is poorly known. To simulate the exposure conditions of these residual magnetic fields in shielded environment, devices generating high-intensity static magnetic field (SMF) were comparatively evaluated in blind exposure experiments (250 mT, 500 mT and sham -no SMF-). The effects of these SMFs were assayed on tomato cultures (hairy roots) previously engineered to produce anthocyanins, known for their anti-oxidant properties and possibly useful in the setting of BLSS. Hairy roots exposed for periods ranging from 24 h to 11 days were morphometrically analyzed to measure their growth and corresponding molecular changes were assessed by a differential proteomic approach. After disclosing blind exposure protocol, a stringent statistical elaboration revealed the absence of significant differences in the soluble proteome, perfectly matching phenotypic results. These experimental evidences demonstrate that the identified plant system well tolerates the exposure to these magnetic fields.Results hereby described reinforce the notion of using this plant organ culture as a tool in ground-based experiments simulating space and planetary environments, in a perspective of using tomato ‘hairy root’ cultures as bioreactor of ready-to-use bioactive molecules during future long-term space missions.

Human Assisted Robotic Vehicle Studies - A conceptual end-to-end mission architecture

With current space exploration roadmaps indicating the Moon as a proving ground on the way to human exploration of Mars, it is clear that human-robotic partnerships will play a key role for successful future human space missions. This paper details a conceptual end-to-end architecture for an exploration mission in cis-lunar space with a focus on human-robot interactions, called Human Assisted Robotic Vehicle Studies (HARVeSt). HARVeSt will build on knowledge of plant growth in space gained from experiments on-board the ISS and test the first growth of plants on the Moon. A planned deep space habitat will be utilised as the base of operations for human-robotic elements of the mission. The mission will serve as a technology demonstrator not only for autonomous tele-operations in cis-lunar space but also for key enabling technologies for future human surface missions. The successful approach of the ISS will be built on in this mission with international cooperation. Mission assets such as a modular rover will allow for an extendable mission and to scout and prepare the area for the start of an international Moon Village.

Exploring innovative radiation shielding approaches in space: A material and design study for a wearable radiation protection spacesuit

We present a design study for a wearable radiation-shielding spacesuit, designed to protect astronauts’ most radiosensitive organs. The suit could be used in an emergency, to perform necessary interventions outside a radiation shelter in the space habitat in case of a Solar Proton Event (SPE). A wearable shielding system of the kind we propose has the potential to prevent the onset of acute radiation effects in this scenario. In this work, selection of materials for the spacesuit elements is performed based on the results of dedicated GRAS/Geant4 1-dimensional Monte Carlo simulations, and after a trade-off analysis between shielding performance and availability of resources in the space habitat. Water is the first choice material, but also organic compounds compatible with a human space habitat are considered (such as fatty acids, gels and liquid organic wastes). Different designs and material combinations are proposed for the spacesuits. To quantify shielding performance we use GRAS/Geant4 simulations of an anthropomorphic phantom in an average SPE environment, with and without the spacesuit, and we compare results for the dose to Blood Forming Organs (BFO) in Gy-Eq, i.e. physical absorbed dose multiplied by the proton Relative Biological Effectiveness (RBE) for non-cancer effects. In case of SPE occurrence for Intra-Vehicular Activities (IVA) outside a radiation shelter, dose reductions to BFO in the range of 44–57% are demonstrated to be achievable with the spacesuit designs made only of water elements, or of multi-layer protection elements (with a thin layer of a high density material covering the water filled volume). Suit elements have a thickness in the range 2–6 cm and the total mass for the garment sums up to 35–43 kg depending on model and material combination. Dose reduction is converted into time gain, i.e. the increase of time interval between the occurrence of a SPE and the moment the dose limit to the BFO for acute effects is reached. Wearing a radiation shielding spacesuit of the kind we propose, the astronaut could have up to more than the double the time (e.g. almost 6 instead of 2.5 h) to perform necessary interventions outside a radiation shelter during a SPE, his/her exposure remaining within dose limits. An indicative mass saving thanks to the shielding provided by the suits is also derived, calculating the amount of mass needed in addition to the 1.5 cm thick Al module considered for the IVA scenario to provide the same additional shielding given by the spacesuit. For an average 50% dose reduction to BFO this is equal to about 2.5 tons of Al. Overall, our results offer a proof-of-principle validation of a complementary personal shielding strategy in emergency situations in case of a SPE event. Such results pave the way for the design and realization of a prototype of a water-filled garment to be tested on board the International Space Station for wearability. A successful outcome will possibly lead to the further refining of the design of radiation protection spacesuits and their possible adoption in future long-duration manned missions in deep space.

Toward a community ecology of landscapes: predicting multiple predator-prey interactions across geographic space.

Community ecology was traditionally an integrative science devoted to studying interactions between species and their abiotic environments in order to predict species' geographic distributions and abundances. Yet for philosophical and methodological reasons, it has become divided into two enterprises: one devoted to local experimentation on species interactions to predict community dynamics; the other devoted to statistical analyses of abiotic and biotic information to describe geographic distribution. Our goal here is to instigate thinking about ways to reconnect the two enterprises and thereby return to a tradition to do integrative science. We focus specifically on the community ecology of predators and prey, which is ripe for integration. This is because there is active, simultaneous interest in experimentally resolving the nature and strength of predator-prey interactions as well as explaining patterns across landscapes and seascapes. We begin by describing a conceptual theory rooted in classical analyses of non-spatial food web modules used to predict species interactions. We show how such modules can be extended to consideration of spatial context using the concept of habitat domain. Habitat domain describes the spatial extent of habitat space that predators and prey use while foraging, which differs from home range, the spatial extent used by an animal to meetall of its daily needs. This conceptual theory can be used to predict how different spatial relations of predators and prey could lead to different emergent multiple predator-prey interactions such as whether predator consumptive or non-consumptive effects should dominate, and whether intraguild predation, predator interference or predator complementarity are expected. We then review the literature on studies of large predator-prey interactions that make conclusions about the nature of multiple predator-prey interactions. This analysis reveals that while many studies provide sufficient information about predator or prey spatial locations, and thus meet necessary conditions of the habitat domain conceptual theory for drawing conclusions about the nature of the predator-prey interactions, several studies do not. We therefore elaborate how modern technology and statistical approaches for animal movement analysis could be used to test the conceptual theory, using experimental or quasi-experimental analyses at landscape scales.

Unraveling the onset of Cretaceous Oceanic Anoxic Event 2 in an extended sediment archive from the Tarfaya‐Laayoune Basin, Morocco

AbstractWe investigated the onset and development of Cretaceous Oceanic Anoxic Event 2 (OAE2) in a newly drilled core (SN°4) from the Tarfaya Basin (southern Morocco), where this interval is unusually expanded. High‐resolution (centimeter‐scale equivalent to centennial) analysis of bulk organic and carbonate stable isotopes and of carbonate and organic carbon content in combination with XRF scanner derived elemental distribution reveal that the ocean‐climate system behaved in a highly dynamic manner prior to and during the onset of OAE2. Correlation with the latest orbital solution indicates that the main carbon isotope shift occurred during an extended minimum in orbital eccentricity (~400 kyr cycle). Shorter‐term fluctuations in carbonate and organic carbon accumulation and in sea level related terrigenous discharge were predominantly driven by variations in orbital obliquity. Negative excursions in organic and carbonate δ13C preceded the global positive δ13C shift marking the onset of OAE2, suggesting injection of isotopically depleted carbon into the atmosphere. The main δ13C increase during the early phase of OAE2 in the late Cenomanian was punctuated by a transient plateau. Maximum organic carbon accumulation occurred during the later part of the main δ13C increase and was associated with climate cooling events, expressed as three consecutive maxima in bulk carbonate δ18O. The extinctions of the thermocline dwelling keeled planktonic foraminifers Rotalipora greenhornensis and Rotalipora cushmani occurred during the first and last of these cooling events and were likely associated with obliquity paced, ocean‐wide expansions, and intensifications of the oxygen minimum zone, affecting their habitat space on a global scale.

Hedgehogs on the move: Testing the effects of land use change on home range size and movement patterns of free-ranging Ethiopian hedgehogs.

Degradation and alteration of natural environments because of agriculture and other land uses have major consequences on vertebrate populations, particularly on spatial organization and movement patterns. We used GPS tracking to study the effect of land use and sex on the home range size and movement of a typical model species, the Ethiopian hedgehogs. We used free-ranging hedgehogs from two areas with different land use practices: 24 from an area dominated by irrigated farms (12 ♂♂, 12 ♀♀) and 22 from a natural desert environment within a biosphere reserve (12 ♂♂, 10 ♀♀). Animals were significantly heavier in the resource-rich irrigated farms area (417.71 ±12.77SE g) in comparison to the natural desert area (376.37±12.71SE g). Both habitat and sex significantly influenced the home range size of hedgehogs. Home ranges were larger in the reserve than in the farms area. Total home ranges averaged 103 ha (±17 SE) for males and 42 ha (±11SE) for females in the farms area, but were much larger in the reserve averaging 230 ha (±33 SE) for males and 150 ha (±29 SE) for females. The home ranges of individuals of both sexes overlapped. Although females were heavier than males, body weight had no effect on home range size. The results suggest that resources provided in the farms (e.g. food, water, and shelters) influenced animal density and space use. Females aggregated around high-resource areas (either farms or rawdhats), whereas males roamed over greater distances, likely in search of mating opportunities to maximize reproductive success. Most individual home ranges overlapped with many other individuals of either sex, suggesting a non-territorial, promiscuous mating. Patterns of space use and habitat utilization are key factors in shaping aspects of reproductive biology and mating system. To minimize the impacts of agriculture on local wildlife, we recommend that biodiversity-friendly agro-environmental schemes be introduced in the Middle East where the transformation from dry lands to ‘islands of fertility’ is often extreme.