Variation In Range Size Research Articles

Diel variation in home range size and precise returning ability after spawning migration of coral reef grouper Epinephelus ongus: implications for effective marine protected area design

Diel variation in home range size and precise returning ability after spawning migration of coral reef grouper Epinephelus ongus: implications for effective marine protected area design

Home ranges of Cape porcupines on farmlands, peri-urban and suburban areas in KwaZulu-Natal, South Africa

Cape porcupines, Hystrix africaeaustralis, are one of the South African mammalian species that are increasing their distribution range and abundance with anthropogenic changing land-use. Knowledge of the home range of this species can provide important ecological information and explain their ability to persist in a range of land-use types. We investigated the home ranges of 15 radio-tagged Cape porcupines on farmlands, peri-urban and suburban areas in KwaZulu-Natal, South Africa. Using the 95% Kernel Density Estimator (KDE), Cape porcupines had an overall estimated mean home range of 39.37 ± 6.33 ha (n = 9) which ranged from 13.19 to 67.19 ha. When compared with other Hystrix species, Cape porcupines had the lowest estimated home range size. Individuals on farmlands had the smallest mean estimated home range area (24.57 ha), relative to peri-urban (34.61 ha) and suburban (45.18 ha) sites. Variation in the home range sizes of Cape porcupines with differing anthropogenic land-use type showed their behavioural flexibility in response to habitat heterogeneity and forage availability in each. Our results suggest that Cape porcupine ranging ecology is influenced by food resource distribution and availability in various land-use types.

Implications of male breeding-season home range movements for population monitoring and minimum reserve area of the Ocellated Turkey (Meleagris ocellata), a threatened Yucatán endemic

ABSTRACT Information on home range size and movements can inform the design of protected areas for bird species of conservation concern. Populations of the Ocellated Turkey (Meleagris ocellata), a heavily hunted Yucatan endemic, appear to be declining rapidly throughout its small geographic range, despite large protected areas. We radio-tagged adult males during the breeding season in a protected, mixed-use area in Belize to describe individual and annual variation in home range size and use. Our objectives were to (1) determine the minimum reserve area necessary to sustain a population of this species, (2) evaluate use of data from related species for home range parameters in conservation plans, and (3) help design species-specific survey methods suitable for distance sampling and camera trapping. There were no differences in mean minimum convex polygon (969 ha), 95% fixed kernel (692 ha), and 50% fixed kernel (90 ha) due to breeding strategy or habitat disturbance. The core home ranges of some individua...

The biogeography of home range size of woodland caribou Rangifer tarandus caribou

AbstractAimPopulation‐limiting factors represent the core of conservation biology. Because animal space use is affected by ecological constraints that can vary among populations, limiting factors might be revealed from intraspecific variation in home range size. We evaluated biogeographic variation in the home range size of woodland caribou (Rangifer tarandus caribou), a threatened species inhabiting the boreal forest, in relation to land cover, topography, snowcover and disturbance across the species’ range.LocationTwenty‐five populations in Canada, spanning the contiguous boreal forest (an east–west extent of 4,400 km), including the southern fringe of the species’ range, adjacent to a broad region of extirpation.MethodsWe compiled the average annual home range size of adult female caribou (5–68 home ranges per population) and 18 putative predictor variables in each population range. We uncovered major gradients using principal components analysis and then evaluated models of home range size using multiple regression, with orthogonal variables representing vegetation, human disturbance and snowcover.ResultsAverage home range size varied 28‐fold among populations (range: 312–8,838 km2). Home range area was most strongly and negatively correlated with anthropogenic disturbance in the population range (R2 = 0.391), a variable in all seven top models (ΔAICc ≤ 5.99). Among populations, where human disturbance in the population range was low (≤10%), mean home range sizes consistently exceeded 1,400 km2. Conversely, where human disturbance was high (>55%), especially at the species’ southern range margin, mean home range sizes did not exceed 1,500 km2.Main ConclusionsIn the boreal forest, female caribou may constrict their home ranges amid human‐caused disturbances. We speculate that smaller home ranges may lower the risk of encounter by predators, a key limiting factor. Among populations, smaller home ranges may serve as a signal of anthropogenic habitat loss.

A regional scale assessment of habitat selection and home range of the eastern rat snake in pine-dominated forests

An animal’s spatial ecology may provide insight into how resources are distributed or potentially limiting across its home range. Some species with broad geographic distributions may exhibit intraspecific variation in space use among populations given the spectrum of available habitat across their range. Animals may need to move further in habitats with limited resources thereby lowering survival. Species, like the eastern rat snake (Pantherophis alleghaniensis), occur throughout the eastern USA and are thought to be strongly tied to hardwood forests. However, their occurrence in pine-dominated forests in the southeastern USA suggests they have broader habitat requirements than previously noted. Our objective was to investigate patterns of habitat use and spatial ecology for eastern rat snakes across multiple pine-dominated forests in Southern Georgia and Northern Florida to capture regional differences in eastern rat snake resource use. We examined home range and habitat use at multiple spatial scales for 30 radio-telemetered snakes from three sites; one in Georgia (Pebble Hill) and Florida (Tall Timbers) during 2004–2005 and one more northern site in Georgia (Ichauway) during 2010–2012. Snakes tracked on Ichauway had a mean home range size that was 3.9 times larger (95% Mean Convex Polygon [MCP], 13.6 ± 8.2 ha) than the estimate for Tall Timbers (3.5 ± 3.2 ha) and 2.6 times larger than the estimate for Pebble Hill (5.3 ± 3.2 ha). Snakes at all three sites selected primarily open edge and pine habitat at the landscape scale and were most likely to be found in large, mature oak trees (Quercus spp.). At Ichauway, hardwood removal activities associated with longleaf pine (Pinus palustris) restoration reduced the number of hardwood trees per hectare by 33% in hardwood removal areas from 1998 to 2014. This management approach included limiting suitable large oak trees that rat snakes use and may help explain the variation in home range size and the number of snakes captured at Ichauway (n = 14) compared to the other two sites (Tall Timbers, n = 154, Pebble Hill, n = 127).

Spatial autocorrelation inflates niche breadth–range size relationships

AbstractAimSpecies with broader environmental tolerances are expected to be more widely distributed than specialist species, implying a positive correlation between niche breadth and geographic range size. When this relationship is evaluated using data derived from broad‐scale geographic distributions of species, spatial autocorrelation of species distribution data and environments may inflate niche breadth–range size relationships, bringing into question the causal relationship between environmental tolerance and range size. Using null models, we quantify the contribution of spatial autocorrelation to the frequently reported relationship between species’ range size and niche breadth.LocationSouth Africa.Time periodCurrent.Major taxa studiedEighty species in the genus Pelargonium.MethodsUsing phylogenetic least squares regression, we examined the extent to which variation in range size of Pelargonium species is related to temperature and precipitation niche breadths. We developed null models that randomized the spatial distribution of the climatic variables, but retained their broad spatial autocorrelation structure. We tested whether observed niche breadth–range size relationships were stronger than expected, given spatial autocorrelation of climatic variables.ResultsWe found the expected positive relationships between measures of niche breadth and range size, but these were no stronger than expected based on our spatial null models. Including spatial structure in simulations reduced expected niche breadths compared to simulations based on fully randomized environmental variables, resulting in steeper slopes for the simulated niche breadth–range size relationships.Main conclusionOur results indicate that spatial autocorrelation may positively bias niche breadth–range size relationships. This bias suggests that previously reported relationships between range size and niche breadth based on broad‐scale distributional data may be, at least in part, artefactual. Future studies need to explicitly account for spatial autocorrelation, and inferences on the role of environmental tolerance in driving patterns of species range size variation should be derived in conjunction with laboratory and field‐based experiments.

Characteristics of Nanocarbon Pyrolyzed from Coconut Shell

In this work, coconut shell was used as raw material to. Dried coconut shells were burned in a close compartment to form coconut charcoal. The dried carbon was further washed with hot distilled water to obtain a pH 7 and was dried again in an oven at 100 °C for 12 hours. The carbon was further pyrolyzed at two temperature variations, i.e. at 400 °C and 1400 °C, under argon environment for two hours before being cooled to room temperature and ready for characterization. The X-ray diffraction result showed that there are two prominent peaks centred around 2θ 25° and 43°, whereas the scanning electron microscopy result showed the flakes microstructure with long range size variation. The energy dispersive X-ray spectroscopy showed that the composition of sample pyrolyzed at 400° C has 59-85 % carbon 7-37 % oxygen and 0.02-0.93 other elements (Si, P, Cl, K, Ti and Ni), whereas the sample pyrolyzed at 1400 °C has 88-92 % carbon, 7.8-11.7 % oxygen and 0.01-0.4 % other elements. This result showed that the coconut shell has the potential to be used as a cheap raw material for synthesizing nanocarbon using a simple method.

Species invasions and the phylogenetic signal in geographical range size

AbstractAimAccelerating rates of anthropogenic introductions are leading to a dramatic restructuring of species distributions globally. However, the extent to which invasions alter the imprint of evolutionary history in species geographical ranges remains unclear. Here, we provide a global assessment of how the introduction, establishment and spread of alien species alters the phylogenetic signal in geographical range size using birds as a model system.LocationGlobal.Time periodContemporaneous.TaxaBirds.MethodsWe compare the phylogenetic signal in alien range size with that of native distributions of species globally (n = 9,993) and across different stages in the invasion pathway, from introduced (n = 965) to established species (n = 359). Using stochastic simulations, we test whether differences in phylogenetic signal arise from nonrandom patterns of species introduction, establishment or spread.ResultsGeographical range size in birds exhibits an intermediate phylogenetic signal, driven by the spatial clustering of closely related species. Nonrandom introductions, biased towards wide‐ranging species from particular clades and regions, produce an anomalously strong phylogenetic signal in the native range size of introduced species. In contrast, the phylogenetic signal in alien range size is substantially weaker than for native distributions. This weak phylogenetic signal cannot be explained by a lack of time for dispersal but is instead regulated by phylogenetic correlations across species in the location and number of introduction events.Main conclusionsWe demonstrate that the effects of anthropogenic introductions on the phylogenetic signal in range size vary across different stages in the invasion pathway. The process of transport and introduction amplifies the phylogenetic signal in the pool of potential invaders, whereas the subsequent pattern of spread decouples variation in alien range size from phylogenetic ancestry. Together, our findings suggest that evolutionary relatedness is likely to be a relatively weak predictor of the spread of invasive species.

Variation in home range size and patterns in adult female American crocodiles Crocodylus acutus

Variation in home range size and patterns in adult female American crocodiles Crocodylus acutus

Home Range Size and Resource Use of Breeding and Non-breeding White Storks Along a Land Use Gradient

Biotelemetry is increasingly used to study animal movement at high spatial and temporal resolution and guide conservation and resource management. Yet, limited sample sizes and variation in space and habitat use across regions and life stages may compromise robustness of behavioral analyses and subsequent conservation plans. Here, we assessed variation in (i) home range sizes, (ii) home range selection, and (iii) fine-scale resource selection of white storks across breeding status and regions and test model transferability. Three study areas were chosen within the Central German breeding grounds ranging from agricultural to fluvial and marshland. We monitored GPS-locations of 62 adult white storks equipped with solar-charged GPS/3D-acceleration (ACC) transmitters in 2013-2014. Home range sizes were estimated using minimum convex polygons. Generalized linear mixed models were used to assess home range selection and fine-scale resource selection by relating the home ranges and foraging sites to Corine habitat variables and normalized difference vegetation index in a presence/pseudo-absence design. We found strong variation in home range sizes across breeding stages with significantly larger home ranges in non-breeding compared to breeding white storks, but variation between regions. Home range selection models had high explanatory power and well predicted overall density of Central German white stork breeding pairs. Also, they showed good transferability across regions and breeding status although variable importance varied considerably. Fine-scale resource selection models showed low explanatory power. Resource preferences differed both across breeding status and across regions, and model transferability was poor. Our results indicate that habitat selection of wild animals may vary considerably within and between populations, and is highly scale dependent. Thereby, home range scale analyses show higher robustness whereas fine-scale resource selection is not easily predictable and not transferable across life stages and regions. Such variation may compromise management decisions when based on data of limited sample size or limited regional coverage. We thus recommend home range scale analyses and sampling designs that cover diverse regional landscapes and ensure robust estimates of habitat suitability to conserve wild animal populations.

Mass‐independent maximal metabolic rate predicts geographic range size of placental mammals

Abstract Understanding the mechanisms driving geographic range sizes of species is a central issue in ecology, but remarkably few rules link physiology with the distributions of species. Maximal metabolic rate (MMR) during exercise is an important measure of physiological performance. It sets an upper limit to sustained activity and locomotor capacity, so MMR may influence ability to migrate, disperse and maintain population connectivity. Using both conventional ordinary least squares (OLS) analyses and phylogenetically generalized least squares (PGLS), we tested whether MMR helps explain geographic range size in 51 species of placental mammals. Log body mass alone (OLS r2 = .074, p = .053; PGLS r2 = .016, p = .373) and log MMR alone (OLS r2 = .140, p = .007; PGLS r2 = .061, p = .081) were weak predictors of log range size. However, multiple regression of log body mass and log MMR accounted for over half of the variation in log range size (OLS R2 = .527, p < .001). The relationship was also strong after correcting for the phylogenetic non‐independence (PGLS R2 = .417, p < .001). In analyses restricted to rodents (34 species), neither log body mass alone (OLS r2 = .004, p = .720; PGLS r2 = .003, p = .77) nor log MMR alone was useful in predicting log geographic range size (OLS r2 = .008, p = .626; PGLS r2 = .046, p = .225), but multiple regressions of log body mass and log MMR accounted for roughly a third to a half of the variation in log range size (OLS R2 = .443, p < .001, PGLS R2 = .381, p < .001). Mass‐independent MMR is a strong predictor of mass‐independent geographic range size in placental mammals. The ability of body mass and MMR to explain nearly 50% of the variation in the geographic ranges of mammals is surprising and powerful, particularly when neither variable alone is strongly predictive. A better understanding of MMR during exercise may be important to understanding the limits of geographic ranges of mammals, and perhaps other animal groups. A plain language summary is available for this article.

Geography, environment and organismal traits in the diversification of a major tropical herbaceous angiosperm radiation.

The generation of plant diversity involves complex interactions between geography, environment and organismal traits. Many macroevolutionary processes and emergent patterns have been identified in different plant groups through the study of spatial data, but rarely in the context of a large radiation of tropical herbaceous angiosperms. A powerful system for testing interrelated biogeographical hypotheses is provided by the terrestrial bromeliads, a Neotropical group of extensive ecological diversity and importance. In this investigation, distributional data for 564 species of terrestrial bromeliads were used to estimate variation in the position and width of species-level hydrological habitat occupancy and test six core hypotheses linking geography, environment and organismal traits. Taxonomic groups and functional types differed in hydrological habitat occupancy, modulated by convergent and divergent trait evolution, and with contrasting interactions with precipitation abundance and seasonality. Plant traits in the Bromeliaceae are intimately associated with bioclimatic differentiation, which is in turn strongly associated with variation in geographical range size and species richness. These results emphasize the ecological relevance of structural-functional innovation in a major plant radiation.

Variation in range size and dispersal capabilities of microbial taxa.

Geographic range size can span orders of magnitude for plant and animal species, with the study of why range sizes vary having preoccupied biogeographers for decades. In contrast, there have been few comparable studies of how range size varies across microbial taxa and what traits may be associated with this variation. We determined the range sizes of 74,134 bacterial and archaeal taxa found in settled dust collected from 1,065 locations across the United States. We found that most microorganisms have small ranges and few have large ranges, a pattern similar to the range size distributions commonly observed for macrobes. However, contrary to expectations, those microbial taxa that were locally abundant did not necessarily have larger range sizes. The observed differences in microbial range sizes were generally predictable from taxonomic identity, phenotypic traits, genomic attributes, and habitat preferences, findings that provide insight into the factors shaping patterns of microbial biogeography.

Rainfall predicts seasonal home range size variation in nyala

Rainfall predicts seasonal home range size variation in nyala

Rapoport's rule and determinants of species range size in snakes

AbstractAimUnderstanding determinants of species' range size is paramount to explaining global ecological patterns and estimating extinction risk of species. Here, we examined whether a sample of 536 snake species exhibits a latitudinal gradient of range size in support of Rapoport's rule, and determined predictors of range size from a set of environmental and biological factors.LocationGlobal.MethodsBased on a priori hypotheses about the effects of latitude, environmental and biological factors on species' range, we calculated mid‐latitudes of species ranges, and collected data on environmental factors (altitude, temperature, precipitation, size and number of ecoregions occupied) and biological traits (body size, fecundity, habitat breadth and species age) to construct multivariate models of snake range size. We used a recently published dated consensus phylogeny to determine minimum adequate models of range size using phylogenetic generalized least squares models and establish correlations between range size and time since species' description.ResultsRange size increased significantly with latitude, consistent with Rapoport's rule, especially across mid‐ and high latitudes in the Northern Hemisphere. Habitat breadth, body size and altitudinal range had a significant positive effect on range size, with minor negative effects on range size from mean altitude and reproductive output. Biological variables explained more variation in range size than environmental variables. Species' range size had a significant effect on species' description, with larger‐ranged species having been described earlier.Main conclusionsPrediction of range size in lesser‐known species such as snakes relies on a suite of factors. Species with restricted habitat breadth, small body size and at high altitudes generally have smaller ranges, and are thus likely to have higher extinction risk. [Correction added on 10 October 2017, after first online publication: The preceding sentence has been rephrased for clarity.] Our work illustrates that it is these species we are likely to under‐report in extinction risk assessments.

Thermal barriers constrain microbial elevational range size via climate variability.

Range size is invariably limited and understanding range size variation is an important objective in ecology. However, microbial range size across geographical gradients remains understudied, especially on mountainsides. Here, the patterns of range size of stream microbes (i.e., bacteria and diatoms) and macroorganisms (i.e., macroinvertebrates) along elevational gradients in Asia and Europe were examined. In bacteria, elevational range size showed non-significant phylogenetic signals. In all taxa, there was a positive relationship between niche breadth and species elevational range size, driven by local environmental and climatic variables. No taxa followed the elevational Rapoport's rule. Climate variability explained the most variation in microbial mean elevational range size, whereas local environmental variables were more important for macroinvertebrates. Seasonal and annual climate variation showed negative effects, while daily climate variation had positive effects on community mean elevational range size for all taxa. The negative correlation between range size and species richness suggests that understanding the drivers of range is key for revealing the processes underlying diversity. The results advance the understanding of microbial species thermal barriers by revealing the importance of seasonal and diurnal climate variation, and highlight that aquatic and terrestrial biota may differ in their response to short- and long-term climate variability.

How climatic variability is linked to the spatial distribution of range sizes: seasonality versus climate change velocity in sphingid moths

AbstractAimTo map the spatial variation of range sizes within sphingid moths, and to test hypotheses on its environmental control. In particular, we investigate effects of climate change velocity since the Pleistocene and the mid‐Holocene, temperature and precipitation seasonality, topography, Pleistocene ice cover, and available land area.LocationOld World and Australasia, excluding smaller islands.MethodsWe used fine‐grained range maps (based on expert‐edited distribution modelling) for all 972 sphingid moth species in the research region and calculated, at a grain size of 100 km, the median of range sizes of all species that co‐occur in a pixel. Climate, topography and Pleistocene ice cover data were taken from publicly available sources. We calculated climate change velocities (CCV) for the last 21 kyr as well as 6 kyr. We compared the effects of seasonality andCCVon median range sizes with spatially explicit models while accounting for effects of elevation range, glaciation history and available land area.ResultsRange sizes show a clear spatial pattern, with highest median values in deserts and arctic regions and lowest values in isolated tropical regions. Range sizes were only weakly related to absolute latitude (predicted by Rapoport's effect), but there was a strong north‐south pattern of range size decline. Temperature seasonality emerged as the strongest environmental correlate of median range size, in univariate as well as multivariate models, whereas effects ofCCVwere weak and unstable for both time periods. These results were robust to variations in the parameters in alternative analyses, among them multivariateCCV.Main conclusionsTemperature seasonality is a strong correlate of spatial range size variation, while effects of longer‐term temperature change, as captured byCCV, received much weaker support.

Explaining biogeographical range size and measuring its effect on species diversification in bark beetles

AbstractAimTo test whether geographical range size is influenced by ecological factors and whether species diversification increases with range sizes in bark beetles.LocationGlobalMethodsHere, we (1) evaluate how several predictors – namely mode of reproduction, symbiotic associations with fungi, host‐plant type, utilization of specific host‐plant clades, and level of host‐plant specialization – influence geographical range size, and (2) explicitly test whether range size is associated with species diversification. Analyses were performed with a dataset of 109 genera using Ornstein‐Uhlenbeck adaptation models which control for phylogenetic constraints.ResultsWe found regular inbreeding by sibling mating to predict an increase in geographical range size, whereas angiosperm hosts type predicted smaller geographical ranges compared to gymnosperm associated lineages. Variation in range size was also associated with utilization of specific host‐plant clades, with conifers being the strongest predictor. Furthermore, the number of utilized host‐plant clades showed a positive association with genera level range size. Our analyses also found fungus farming to predict a reduction in geographical range size, but with a smaller effect size than for inbreeding and host‐type. Lastly, we found a strong positive association between biogeographical range size and species diversification rates.Main conclusionsWe conclude that allopatric speciation is an important contributor to the distribution of species richness in bark beetles. Our study supports the idea that range expansion and speciation are intrinsically linked, and that reproductive behaviour and host‐type preference – through their influence on biogeographical dispersal ability – are ultimately determining factors of species diversification in bark beetles.

Woodland features determining home range size of roe deer

Use of ecotones by ungulates may be mediated by their movements between main feeding areas and woodland, where they locate their shelter. The roe deer Capreolus capreolus has been termed as a woodland species, although we suggest that it did not evolve as a forest ungulate, but depending on forest glades. Roe deer feed on a wide range of vegetal species, although their diet is mainly dominated by woody plants. Our study was carried out in a fragmented area covered with small forest patches of Mediterranean “macchia” scrubwood, interspersed in an agricultural matrix. Aim of our study has been to test how ranging movements of roe deer are influenced by landscape heterogeneity and to evaluate which features of woodland affect home range size. Radio-locations of 22 female and 12 male adult roe deer, monitored for three years, were used to assess home range size. A linear mixed model was fitted to investigate variation in home range size according to eleven spatial parameters estimated to describe home range size and composition. Throughout the year, no significant difference was found between home range sizes of males (median: 16.70ha, Q1–Q3: 13.20–31.60ha) and females (median: 23.52ha, Q1–Q3: 13.30–44.00ha: lme: F=0.9; P=0.35). Habitat density, edge density, percentage of woodland within home range and woodland structure determined home range size. Home ranges with few habitat types and a small amount of wood were large, while roe deer occupied small home ranges when habitat density was high and when a high proportion of wood was concentrated in a single large patch. Woodland covered a mean±SE of 36.2±17.9% in each home range. In conclusion, roe deer seem to be particularly well adapted to live in human transformed, peripheral habitats, e.g. farmlands, as long as a minimum quantity of woodland is included within their HR.

Variation in home range size of red foxes Vulpes vulpes along a gradient of productivity and human landscape alteration.

Home range size is a fundamental concept for understanding animal dispersion and ecological needs, and it is one of the most commonly reported ecological attributes of free-ranging mammals. Previous studies indicate that red foxes Vulpes vulpes display great variability in home range size. Yet, there has been little consensus regarding the reasons why home range sizes of red foxes vary so extensively. In this study, we examine possible causes of variation in red fox home range sizes using data from 52 GPS collared red foxes from four study areas representing a gradient of landscape productivity and human landscape alteration in Norway and Sweden. Using 90% Local Convex Hull home range estimates, we examined how red fox home range size varied in relation to latitude, elevation, vegetation zone, proportion of agricultural land and human settlement within a home range, and sex and age. We found considerable variation in red fox home range sizes, ranging between 0.95 km2 to 44 km2 (LoCoH 90%) and 2.4 km2 to 358 km2 (MCP 100%). Elevation, proportion of agricultural land and sex accounted for 50% of the variation in home range size found amongst foxes, with elevation having the strongest effect. Red foxes residing in more productive landscapes (those in more southern vegetation zones), had home ranges approximately four times smaller than the home ranges of foxes in the northern boreal vegetation zone. Our results indicate that home range size was influenced by a productivity gradient at both the landscape (latitude) and the local (elevation) scale. The influence of the proportion of agriculture land on home range size of foxes illustrates how human landscape alteration can affect the space use and distribution of red foxes. Further, the variation in home range size found in this study demonstrates the plasticity of red foxes to respond to changing human landscape alteration as well as changes in landscape productivity, which may be contributing to red fox population increases and northern range expansions.