Maximum Movement Distance Research Articles

Movement ecology of amphibians: from individual migratory behaviour to spatially structured populations in heterogeneous landscapes,

Both genetic cohesion among local populations of animals and range expansion depend on the frequency of dispersers moving at an interpatch scale. Animal movement has an individual component that reflects behaviour and an ecological component that reflects the spatial organization of populations. The total movement capacity of an individual describes maximum movement distance theoretically achievable during a lifetime, whereas its variation among the members of a local population determines the magnitude of interpatch movements and thus of gene flow between neighbouring patches within metapopulation or patchy population systems. Here, I review information on dispersal and migration as components of the movement capacity of juvenile and adult pond-breeding amphibians and discuss how these components inform the spatial structure of populations. Amphibians disperse as juveniles and adults, but movement distances detected in tracking or capture–mark–recapture studies are usually far below the corresponding estimates based on molecular gene-flow data. This discrepancy reflects the constraints of available tracking methods for free-ranging individuals leading to inappropriate surrogates of annual movement capacity, but can be resolved using probabilistic approaches based on dispersal functions. There is remarkable capacity for and plasticity in movements in amphibians. Annual within-patch movements (migrations) of individuals can be large and likely represent an underestimated capacity for movement at the interpatch scale. Landscape resistance may influence the paths of dispersing amphibians, but rarely impedes interpatch movements. Juveniles emigrating unpredictably far from the natal pond and adults switching from within-patch migrations to dispersal to another patch demonstrate the plasticity of individual movement behaviour. Three basic conclusions can be drawn with respect to the linkage of individual movement behaviour and spatial or genetic structure of local amphibian populations embedded in a heterogeneous landscape: (1) individual movements or consecutive short-term series of movements are misleading surrogate measures of total movement capacity; (2) probabilistic modelling of movement capacity is the best available behavioural predictor of interpatch gene flow; (3) connectivity of local populations in heterogeneous landscapes is less affected by landscape resistance than previously expected.

Large‐scale movements in European badgers: has the tail of the movement kernel been underestimated?

Characterizing patterns of animal movement is a major aim in population ecology, and yet doing so at an appropriate spatial scale remains a major challenge. Estimating the frequency and distances of movements is of particular importance when species are implicated in the transmission of zoonotic diseases. European badgers (Meles meles) are classically viewed as exhibiting limited dispersal, and yet their movements bring them into conflict with farmers due to their potential to spread bovine tuberculosis in parts of their range. Considerable uncertainty surrounds the movement potential of badgers, and this may be related to the spatial scale of previous empirical studies. We conducted a large-scale mark-recapture study (755 km(2); 2008-2012; 1935 capture events; 963 badgers) to investigate movement patterns in badgers, and undertook a comparative meta-analysis using published data from 15 European populations. The dispersal movement (>1 km) kernel followed an inverse power-law function, with a substantial 'tail' indicating the occurrence of rare long-distance dispersal attempts during the study period. The mean recorded distance from this distribution was 2.6 km, the 95 percentile was 7.3 km and the longest recorded was 22.1 km. Dispersal frequency distributions were significantly different between genders; males dispersed more frequently than females, but females made proportionally more long-distance dispersal attempts than males. We used a subsampling approach to demonstrate that the appropriate minimum spatial scale to characterize badger movements in our study population was 80 km(2), substantially larger than many previous badger studies. Furthermore, the meta-analysis indicated a significant association between maximum movement distance and study area size, while controlling for population density. Maximum long-distance movements were often only recorded by chance beyond the boundaries of study areas. These findings suggest that the tail of the badger movement distribution is currently underestimated. The implications of this for understanding the spatial ecology of badger populations and for the design of disease intervention strategies are potentially significant.

Movement patterns of small benthic fish in lowland headwater streams

Summary Understanding the mechanism governing the movements of stream‐dwelling fish is a fundamental issue associated with a diverse range of ecological processes. We examined the movement pattern of a small benthic species, Lefua echigonia, using a mark–recapture technique in small headwater streams. Our main objectives were as follows: (i) to assess the movement range and direction of L. echigonia; (ii) to examine how biotic and abiotic factors affect emigration and immigration patterns and (iii) to assess movement patterns at the stream scale. Stationary fish accounted for the greatest proportion of recaptured adult L. echigonia. Seventy‐five per cent of recaptured individuals moved <100 m in 12 months after release, and the maximum movement distance was 500 m upstream. Moreover, adult L. echigonia showed significant upstream bias in movements. According to the results of the generalised linear mixed model GLMM analysis, movement of adult L. echigonia was associated mainly with the density of conspecifics, rather than with habitat quality and body size. Adult L. echigonia were mainly stationary in relatively high‐density sections, and emigration tended to increase with decreasing density. Moreover, mobile individuals were prone to move into relatively high‐density sections. The proportion of mobile fish showed a strong positive correlation with catchment area at the stream scale. This result indicates that stream discharge can influence the mobility of adult L. echigonia. During baseflow, the water was static in a number of stream sections, which suggests that the influence of catchment area on mobility may be more a function of freshets than normal water flow.

Mate-Searching Behaviour of Common and Rare Wasps and the Implications for Pollen Movement of the Sexually Deceptive Orchids They Pollinate

Pollinator behaviour directly affects patterns of pollen movement and outcrossing rates in plants. In orchids pollinated by sexual deception of insects, patterns of pollen movement are primarily determined by the mate-searching behaviour of the deceived males. Here, using a capture-mark-recapture study (CMR) and dietary analysis, we compare mate-searching behaviour in relation to local abundance of two pollinator species and explore the implications for pollen movement in sexually deceptive Drakaea (Orchidaceae). Drakaea are pollinated solely by the sexual deception of male thynnine wasps. The rare Drakaea elastica and widespread D. livida occur sympatrically and are pollinated by the rare but locally common Zaspilothynnus gilesi, and the widespread and abundant Z. nigripes, respectively. Local abundance was significantly different with Z. nigripes twice as abundant as Z. gilesi. For the 653 marked wasps, there was no significant difference in median movement distance between Z. gilesi and Z. nigripes. However, the maximum movement distance was twice as high for Z. gilesi (556 m) compared with Z. nigripes (267 m). This is up to three times greater than previously reported for thynnines in CMR studies. Recapture rates were six times higher in Z. gilesi (57%) compared to Z. nigripes (9%). Pollen loads and wasp longevity were similar, suggesting that this difference in recapture rate arises due to differences in the number of males moving at a scale >500 m rather than through diet or mortality. Differences in the frequency of longer movements may arise due to variation in the spatial distribution of the wingless females. We predict that pollen movement will largely be restricted to within populations of Drakaea (<500 m), with few movements between populations (>500 m).

年龄、性别及季节因素对千岛湖岛屿社鼠最大活动距离的影响

Chinese white-bellied rats,Niviventer confucianus,were mark-recaptured from July to November,2009 and from March to November,2010 on two islands of the Thousand Island Lake region.The maximum movement distances of Chinese white-bellied rats that were recaptured 4 or more times were calculated in spring,summer and autumn by Biotas 2.0.Then we used independent sample T test,one-way ANOVA or Mann-Whitney U test to analyze the effects of age,sex and season on the maximum movement distance.We aim to explore movement and home range of Chinese white-bellied rats in isolated island environment,and to predict its behavioral responses to isolated island environment.The results showed that there was no significant difference in the maximum movement distance between two islands,and the data of the two islands could be pooled.There were highly significant differences in the maximum movement distance among four different age groups.The maximum movement distance of males was significantly longer than females in adults,but did not differ between the sexes in any other age groups.The maximum movement distance differed significantly among spring,summer and autumn in sub-adults,but not in other age groups.The maximum movement distance of both males and females was longest in autumn and shortest in spring.Our results indicate that the maximum movement distance is positively correlated with the age of Chinese white-bellied rats,and is significantly longer in males than females.Our results were inconsistent with some of the previous studies on home range size in rats.This inconsistency likely reflects the restriction of resources in isolated island environment and specificity of behavior in Chinese white-bellied rats.This study preliminarily displays the effects of island isolation on small mammals,and more studies are needed to examine the island effects in the future.

A pilot study of deepwater fish movement with respect to marine reserves

BackgroundThe spatial ecology of deepwater demersal teleosts is poorly understood, and this group of fishes has rarely been studied using conventional or electronic means to discern movement and migration. Likewise, the development of management tools for such species has received less attention as compared to shallow water species, and there are few fishery closed area systems developed for the purpose of managing deepwater demersal fishes. The eteline snappers, which occur in depths of 100 to 400 m, are an important fishery resource throughout the tropical Pacific, and are believed to be vulnerable to over-exploitation.ResultsDeepwater eteline snappers were tagged with acoustic transmitters and detected on a network of listening stations that encompassed a fishery closed area in the Main Hawaiian Islands. Differences were detected in movement between species, with the bentho-pelagic Etelis coruscans moving more frequently and over slightly longer distances (1.4 movements/day detected, interquartile range (IQR) 0.0 – 2.4; maximum distance 4.7 km, interquartile (IQR) 4.7 – 6.4 km) than the demersal Etelis carbunculus (0.0 movements/day detected, interquartile range 0.0 - 0.3; maximum distance 4.7 km, interquartile range 4.6 - 4.7 km). The maximum single movement distance was 8.9 km for E. coruscans and 4.7 km for E. carbunculus. The median length dimension for bottomfish closed areas in the Main Hawaiian Islands is 9.2 km (IQR) range 7.3 – 13.0 km).ConclusionsKnowledge of the spatial ecology of animals is essential to understanding the effects of spatial management measures such as marine reserves. Differences between species indicate that effective reserve size will differ depending on the species. These results suggest that the reserves set up for bottomfish in the Main Hawaiian Islands are likely to have effects in reducing fishing mortality for E. carbunculus due to its low rate of cross border movement.

被动式电子标签用于花鼠种群动态研究的可行性

在野生动物研究过程中经常需要对动物个体进行标记。传统的标记方法存在着标记物易脱落、可能影响被标记动物的生理和行为、难于进行个体识别等缺点。被动式电子标签(passive integrated transponder, PIT)是基于射频识别技术的电子标签,可用于体内标记,具有不易脱落消失且能够进行个体识别的优点。在凉水国家级自然保护区以PIT标签为标记物,采用标志重捕技术开展花鼠(<em>Eutamias sibiricus</em>)的种群动态研究,同时对应用PIT标签的可靠性进行了研究。2011年秋季至2012年春季共标记花鼠个体140只,其中86只被重捕至少1次。2011年秋季标记的72只个体中有38只在2012年春季被重捕。重捕的花鼠个体注射口愈合完好,体重无明显降低。结果表明PIT标签是一种安全可靠、识别迅速、数据准确、不易丢失、可循环使用的体内标记电子标签,适用于基于个体识别的小型哺乳动物生态学研究。;In wildlife studies, individual animals are usually uniquely marked to collect data related to population ecology and behavior such as social structure, migration and dispersion, growth and age identification, seasonal fluctuation of physical features, reproductive patterns, life-history strategy, nesting territory and home range. Wild animals are mainly superficially marked with ear tags, ear-rings, neck collars, cut toes, foot bands, hair shearing, clipped ears, colored hair, brands, and tattoos. Using cut toes, colored hair and ear tags to mark individuals are normal techniques in population ecology studies on small rodents. However, all of these marking methods have various disadvantages. For example, clipped ears and cut toes physically harm animals and may affect their normal behavior as well as physiological condition. Because ear-rings are easily lost and colored hair lasts only a short time, these two methods are not suitable for long-term ecological research. Furthermore, all regular marking methods are difficult to use for marking individuals in a large population. These obvious disadvantages may potentially affect the reliability of results obtained.<BR> A passive integrated transponder (PIT) is part of an electronic marking system based on radio frequency identification allowing each marked animal to bear a unique international code. The PIT tag remains dormant until activated at close-range by a handheld reader, which generates an electromagnetic field. PIT tags are small and light, giving them an advantage over traditional marking methods in that they can be implanted inside animal bodies and have a minimal affect the physiology and behavior of marked animals. PIT tags were first used in measuring fish movement in 1983. Since then, PIT tags have been widely applied in animal research among invertebrates, amphibians, reptiles, birds and mammals and are popular worldwide especially for use in zoos, aquiculture and animal trade. Nevertheless, the application of PIT tags is restricted to a few aquatic animals in China.<BR> We adopted PIT tags and mark-recapture techniques to investigate the population dynamics of Siberian chipmunks (<em>Eutamias sibiricus</em>) during five time periods from October, 2011 to June, 2012 in Liangshui National Nature Reserve in Heilongjiang Province, China. A total of one hundred and forty chipmunks were marked, of which eighty-six were recaptured at least once. Seventy-two chipmunks were marked in autumn, 2011, thirty-eight of which were recaptured in spring, 2012. The injection wounds of all recaptured chipmunks had healed well and they exhibited no significant decrease in body weight. We estimated the dynamics of the chipmunk population based on mark-recapture data. The results showed that the average population density of chipmunks in the Korean pine forests of the Reserve was 8.91±2.76 per hectare in autumn, 2011 and 6.14±1.29 per hectare in spring, 2012. After the analysis of individual recapture records, we found that the maximum movement distance of studied chipmunks was not significantly different in autumn ((65±8) m) and in spring ((67±4) m). Chipmunks exhibited a clumped distribution pattern in autumn and uniform pattern in spring. These results indicated that PIT tags provide an ideal internal safe and reliable electronic marking system because they allow rapid and accurate identification of individuals when collecting data, last a long time when worn inside animal bodies, are less harmful to marked animals than other marking techniques, are rarely lost and are reusable. In summary, PIT tags allow the identification of individual small mammals, are mainly useful in wildlife ecology, and are especially suitable for population ecology.

Movement patterns of giant Pacific octopuses, Enteroctopus dofleini (Wülker, 1910)

We attached sonic transmitters to, and tracked, 40 giant Pacific octopuses (Enteroctopus dofleini) ranging from <1 to 21kg in size in south-central Alaska using near-continuous tracking by fixed-array receivers and intermittent tracking with a mobile receiver. We documented area use, daily activity patterns, spatial scale of movements and whether these differed by octopus size, and whether octopuses actively selected habitats. Near-continuous fixed tracking provided positions about every 4 min over a limited area, while intermittent mobile tracking provided positions every 1–6h but over open and larger areas. Mantle-mounted transmitters on modified Peterson disks had >83% retention to the end of a tracking period (range <1day [before animal left the study area] to at least 88days post-release), an improvement over published studies. Octopuses were found to be stationary or hiding 94% of the time. Otherwise, octopuses were active throughout the day but more so from midnight to 0500. During low tides, movements were restricted for animals in intertidal habitats but not for those deeper. Maximum movement distance from release was 4.8km (by a 16.5kg female). Minimum convex polygon area use averaged 4,300m2 for the smallest animals to an average over 50,000m2 for the largest during 2 to 20days of tracking, substantially larger than previously reported. Larger octopuses moved further and used greater area than smaller animals, but differences between sexes were not significant.Stationary behavior and periods without detection (rest) by fixed near-continuous tracking were bi-modally distributed, with peaks <3h duration and >18–48h. Direct movements (indicating relocation or den switching) were common at night, central-tendency movements (indicating localized area use and return to den) were common at dawn, and stationary behavior was common in daylight, although each pattern occurred at all periods. Central-tendency movements recorded by intermittent tracking were oriented parallel to contours, while movements without central-tendency crossed contours, suggesting that animals navigate by contour following to return to a known den. During a relocation experiment, octopuses released at shallow depths moved deeper and those released deeper moved shallower, both into habitats with greater kelp cover. Although >90% of their time was spent stationary and hiding, Enteroctopus dofleini utilizes information about its environment (contour following), selects habitats (preference for more kelp cover), and occupies large use areas (minimum convex polygons) by making substantial direct movements from previous use areas.

Radiotelemetric Study of Movement Patterns of Lotic Freshwater Turtles during Breeding and Hibernation Seasons

ABSTRACT We conducted a radio tracking study to assess movement patterns and microhabitat use of lotic turtles during their nesting and hibernation seasons. During the nesting season, female turtles moved from the sandbank along the river to the outer-embankment and/or inner-embankment that includes rice fields. The maximum movement distance was over 2.5 km. Turtles frequently utilized terrestrial microhabitats for basking but also for other activities such as feeding and resting. Calm, deep aquatic sites near banks were used for hibernation. These results indicate that large areas that include different microhabitat type (both aquatic and terrestrial) are essential for freshwater turtles inhabiting river environments.

Winter behaviour of juvenile Atlantic salmon Salmo salar L. in experimental stream channels: effect of substratum size and full ice cover on spatial distribution and activity pattern

Activity and choice of areas offering different cover (substratum or surface ice) for juvenile Atlantic salmon Salmo salar were studied in experimental stream channels during winter. Channels were completely ice covered between December and March. During this period, the ice thickness increased from 50 to 300 mm after which 50% of the ice was experimentally removed and followed by c. 2·5‐fold increase in discharge to simulate the effects of spring flood. Large substrata provided preferred habitats but areas with small substratum sizes were also used when full surface ice provided above‐stream cover and the stream discharge was relatively low. The fish remained nocturnal throughout the study but the level of day activity significantly increased as the surface ice became thicker. Maximum movement distance during a 24 h period and homing‐at‐dawn behaviour remained at a constant level throughout the main winter, but significantly changed during the simulated spring flood (mean ±s.e. maximum extent of movements within 24 h increased from 1·1 ± 0·1 to 3·0 ± 0·5 m; homing behaviour decreased from the highest level of 89·3 to 34·6% during spring flood). Overwinter survival was high (92·9%). Relative mass increase during the study ranged from –8·3 to 28·5%, and 84% of the juvenile Atlantic salmon gained mass. The highest rates of mass increase were associated with frequent movements between areas of different substratum size. The results indicate that during winter: (1) Atlantic salmon parr preferred large substratum cover compared with surface ice cover at the fish densities studied here, (2) juvenile Atlantic salmon were predominantly nocturnal but diurnal activity increased as surface ice became thicker and (3) increase in water discharge during spring altered the behaviour of juvenile Atlantic salmon and may have caused additional habitat shifts.

Predicting Spatial Distribution of Foragers over Large Resource Landscapes: A Modeling Analysis of the Ideal Free Distribution

Ideal Free Distributions (IFD) have successfully been used to describe the spatial distributions of animals in heterogeneous or patchy environments over relatively small areas. Ideal Free theory and the logic underlying it have recently been used to describe animal distributions over large landscapes and in doing so, these studies have not precisely met all of the assumptions of the IFD. Here, we use an individual-based simulation model of a population of generalized foragers to test the ability of the IFD to predict the equilibrium distribution of organisms in a large environment. Conditions of the model meet the assumptions of Ideal Free theory. Food abundance follows a fractal distribution spatially through the environment. Model foragers have a type II functional response and a marginal-value theorem type patch departure rule. Foragers may move through the environment without cost, and foraging does not affect food availability. In a simulation experiment, we manipulate the scale of heterogeneity in food distribution, the number of foragers in the population, the distance foragers move, and the scale of IFD predictions to determine the ability of the IFD to predict equilibrium spatial distribution of foragers. The experiment shows that correlations between IFD predictions and the distribution of simulated foragers were lower when food had a fractal distribution than when food resources had a random spatial distribution. IFD predictions best fit simulated forager distributions on fractal food landscapes when the scale at which distributions were measured was similar to the maximum movement distance of the foragers. Large differences between maximum movement distance and scale of measure resulted in low correlations between equilibrium distributions of simulated foragers and IFD predictions. These results indicate that the IFD is likely not a good predictor of animal distributions in large environments and that the extent of the area over which an IFD is used should be similar to the maximum daily movement of the animals under study.