Daily Home Range Research Articles

Black Woodpeckers Dryocopus martius use stepping stones between woodland units

ABSTRACT Capsule Black Woodpeckers Dryocopus martius used small patches of trees as stepping stones when crossing areas of open land during daily movements within their home range in the non-breeding season. Aims To document that Black Woodpeckers, although an obligate forest species, frequently cross areas of open land within their daily home range, using solitary trees or small patches of trees as stepping stones during these movements. Methods We mounted GPS-loggers on 11 Black Woodpeckers and recorded their position every 5 min for approximately 1 week. Three woodpeckers stayed within continuous forest for the duration of the study, or failed to meet assumptions, and were therefore excluded from the analysis. The remaining eight Black Woodpeckers all moved between discrete woodland units at least once during the study period. Using a habitat use-availability framework, 54 GPS-positions located in gaps of open land between separate forest patches were analysed. Results Black Woodpeckers showed a significant preference for trees at low tree availabilities in the open land. However, we could not rule out that their preference for trees was proportional to availability when tree cover was high (> 82% tree cover). The median distance traversed to a location in open land between forest patches was 731 m. Conclusion Since the preference for trees was especially pronounced at low tree availabilities, we suggest that Black Woodpeckers use solitary trees or small patches of trees as stepping stones when traversing open areas within their daily home range. We hypothesize that this behaviour lessens the costs of living in a fragmented habitat, and that conservation of trees in open land may contribute to conserving Black Woodpecker populations in areas with fragmented forests.

Trabecular bone morphology in big cats reflects the complex diversity of limb use but not home range size or daily travel distance.

A relationship exists between mechanical loading and bone morphology. Although studies show a relationship between trabecular bone morphology and locomotor strategy in mammals, none of them have studied trabecular bone morphology in felid species occupying disparate and overlapping habitats. We investigate trabecular bone volume fraction (BVF) in the femoral and humeral heads, and distal tibia of four felid species (mountain lions, jaguars, cheetahs, and leopards) to identify whether there is a relationship between BVF and locomotor behavior. This study's goals are to identify whether felid species with high daily travel distance or large home range size have greater BVF compared with those with small daily travel distance or home range size, and whether BVF is correlated among the three elements of the fore and hindlimb studied. We quantified BVF in micro- and peripheral computed tomography images and found no significant differences across species in the femoral and humeral head (p > 0.05). However, in the distal tibia, results showed that leopards, mountain lions, and cheetahs have significantly greater (p < 0.05) BVF than jaguars. Despite differences in home range size and daily travel distance, the proximal elements did not reflect differences in BVF; however, the distal-most element did, suggesting decreased loading among jaguars. These findings suggest that the observed pattern of trabecular bone morphology is potentially due to the diversity in locomotor strategy of the forelimb. Additionally, these results imply that neither home range size nor daily travel distance are clear indicators of activity levels. A cautious approach is warranted in studying how loading influences trabecular morphology.

Changes in movement, habitat use, and response to human disturbance accompany parturition events in bighorn sheep (Ovis canadensis)

Parturition and the early neonatal period are critical life history stages in ungulates with considerable implications for population growth and persistence. Understanding the changes in behaviour induced by ungulate parturition is important for supporting effective population management, but reliably identifying birth sites and dates presents a challenge for managers. Rocky Mountain bighorn sheep (Ovis canadensis canadensis) are one such highly valued and ecologically important species in montane and subalpine ecosystems of Western North America. In the face of changing patterns of anthropogenic land use, wildlife managers increasingly require site-specific knowledge of the movement and habitat selection characteristics of periparturient sheep to better inform land use planning initiatives and ensure adequate protections for lambing habitat. We used movement data from GPS collared parturient (n = 13) and non-parturient (n = 8) bighorn sheep in Banff National Park, Canada to (1) identify lambing events based on changes in key movement metrics, and (2) investigate how resource selection and responses to human use change during the periparturient period. We fit a hidden Markov model (HMM) to a multivariate characterization of sheep movement (step length, daily home range area, residence time) to predict realistic lambing dates for the animals in our study system. Leave-one-out cross validation of our model resulted in a 93% success rate for parturient females. Our model, which we parameterized using data from known parturient females, also predicted lambing events in 25% of known non-parturient ewes in a test dataset. Using a latent selection difference function and resource selection functions, we tested for postpartum changes in habitat use, as well as seasonal differences in habitat selection. Immediately following lambing, ewes preferentially selected high-elevation sites on solar aspects that were more rugged, closer to escape terrain, and further from roads. Within-home range habitat selection was similar between individuals in different reproductive states, but parturient ewes had stronger selection for low snow depth, sites closer to barren ground, and sites further from trails. We propose that movement-based approaches such as HMMs are a valuable tool for identifying critical parturition habitat in species with complex movement patterns and may have particular utility in study areas without access to extensive field observations or vaginal implant transmitters. Furthermore, our results suggest that managers should minimize human disturbance in lambing areas to avoid interfering with maternal behaviour and ensure access to a broad range of suitable habitat in the periparturient period.

First Report of Home Range Size of Hainan Partridge Arborophila ardens, a Vulnerable Species Endemic to Hainan Island

We used radio telemetry to provide the first information concerning home range size of Hainan Partridge Arborophila ardens, a vulnerable species endemic to Hainan Island, China, in both a fragmented and a continuous natural rainforest. Both the monthly and daily home range sizes of the population in the fragmented rainforest were significantly larger than those in the continuous rainforest, with no difference between males and females. Fragmentation reduced habitat quality and thus may have forced the partridges to forage over a wider range, which may threaten their survival.

Food Preference of Long-tailed Macaques (Macaca fascicularis Raffles 1821) in IPB Dramaga Campus

Long-tailed macaques (Macaca fascicularis) will expand their daily home range to obtain good and plentiful food sources, thus often causing conflict. Identification of long-tailed macaque feed preferences needs to be done as a form of minimizing conflict. This research aims to identify the type of feed and feed preference, and also to analyze the daily activity of long-tailed macaques. The research was conducted by vegetation analysis and field observation of the daily activities of long-tailed macaques. The results of this research showed that there were 22 types of feed plants and 2 types of non-plant feeds. Long-tailed macaques are kind of fructivore animals but will be opportunistic omnivores if the availability of fruits decreases. Long-tailed macaques are more interested to eat fruit, especially Belimbing Bintang fruit (Averrhoa carambola), Matoa fruit (Pometia pinnata), and Jabon fruit (Neolamarckia cadamba).

The Activity and Ranging Patterns of Gelada Monkeys as Behavioral Responses to the Effects of Livestock Grazing in the Simien Mountains National Park, Ethiopia

Understanding of behavioral ecology of primates in grazed lands is vital to their conservation and monitoring strategies. Here we investigated how livestock grazing within the Simien Mountains National Park affects the activity time budgeting and ranging behavior of the geladas, a monkey endemic to Ethiopian highlands. This study was carried out from February 2019 to July 2019 by stratifying the study area as grazed and nongrazed sites. Activity time pattern data were collected using 5 minutes instantaneous scan sampling within 15 minutes intervals from 7:00 to 18:00 for 10 days per month in the grazed and nongrazed sites. The ranging data were also collected by tracking the study group and recording GPS points every 15 minutes sample. The effects of livestock grazing on activity time budgets were statistically analyzed by multiple analyses of variance (MANOVA). Daily range length and home range size were estimated by employing the Open Jump toolbox (MOVEAN), and statistically tested by Mann–Whitney U test. From 3427 behavioral scans on the various activities, feeding was the most frequent (43.04%) behavioral activity followed by moving, accounting for 38.06% of the time. The study revealed that grazing has a statistically significant effect on moving and social activity time budgets. The geladas dwelling in the grazed areas of the park spent more time in moving than in the nongrazed areas. The effect of grazing on social behavior is the reverse of moving. Similarly, geladas traveled longer daily range length and cover a wider home range size in the grazed areas. Therefore, these findings of the study imply that livestock grazing is adversely affecting the behavior of gelada monkeys in the park. To minimize such effects on gelada monkeys and harmonize grazing with wildlife habitat conservation, the grazing pressure reduction strategy must be closely monitored and supported by animal feed cultivation technology.

Fitness, risk taking, and spatial behavior covary with boldness in experimental vole populations.

Individuals of a population may vary along a pace‐of‐life syndrome from highly fecund, short‐lived, bold, dispersive “fast” types at one end of the spectrum to less fecund, long‐lived, shy, plastic “slow” types at the other end. Risk‐taking behavior might mediate the underlying life history trade‐off, but empirical evidence supporting this hypothesis is still ambiguous. Using experimentally created populations of common voles (Microtus arvalis)—a species with distinct seasonal life history trajectories—we aimed to test whether individual differences in boldness behavior covary with risk taking, space use, and fitness. We quantified risk taking, space use (via automated tracking), survival, and reproductive success (via genetic parentage analysis) in 8 to 14 experimental, mixed‐sex populations of 113 common voles of known boldness type in large grassland enclosures over a significant part of their adult life span and two reproductive events. Populations were assorted to contain extreme boldness types (bold or shy) of both sexes. Bolder individuals took more risks than shyer ones, which did not affect survival. Bolder males but not females produced more offspring than shy conspecifics. Daily home range and core area sizes, based on 95% and 50% Kernel density estimates (20 ± 10 per individual, n = 54 individuals), were highly repeatable over time. Individual space use unfolded differently for sex‐boldness type combinations over the course of the experiment. While day ranges decreased for shy females, they increased for bold females and all males. Space use trajectories may, hence, indicate differences in coping styles when confronted with a novel social and physical environment. Thus, interindividual differences in boldness predict risk taking under near‐natural conditions and have consequences for fitness in males, which have a higher reproductive potential than females. Given extreme inter‐ and intra‐annual fluctuations in population density in the study species and its short life span, density‐dependent fluctuating selection operating differently on the sexes might maintain (co)variation in boldness, risk taking, and pace‐of‐life.

El uso de bloques nutricionales como herramienta para el manejo del pastoreo en sistemas ovinos extensivos

The improvement in grazing spatial distribution is an important goal for the efficient and sustainable management of rangelands. However, extensive livestock systems such as the Patagonian rangelands generally fails due to the large paddock size (up to 6000 ha). The purpose of this study was to evaluate the effectiveness of the strategic use of nutritional blocks as an attractive element in underused areas of the landscape, in a shrub steppe of low cover (less than 50%) under dry climate. The spatial distribution of sheep was evaluated in two extensive paddocks (1900 and 5500 ha) under two sequential treatments (With nutritional blocks and Traditional management without nutritional blocks) in two years. The study was carried out using wethers of the Corriedale breed, with an average stocking rate of 0.17±0.03 sheep/ha. The geotracking of wethers was obtained by means of collars equipped with global positioning system technology, configured with a measuring frequency of 5 minutes within an average period of 15 days. The use of nutritional blocks resulted in a 46.1-57.4% expansion in the daily home range with respect to the traditional management, suggesting a more spatial homogeneous use of the paddocks by sheep. These results would have important practical implications, considering that the use of nutritional blocks would allow the combination of supplementation strategies with the sustainable use of pastoral resources.

Scared as a hare: effects of capture and experimental disturbance on survival and movement behavior of European hares

Capture and handling of wildlife is an important component of wildlife studies, and hunting can be a central tool for wildlife management. However, human-caused disturbance of animals can cause various negative effects on individuals. Thus, an increased understanding of different disturbances on animals will allow improved mitigation of human stressors for wildlife, and provides the basis for data-censoring when using information obtained from captured individuals. Here, we investigated the effects of capture and handling, as well as experimental disturbance, on the movement behavior of GPS-collared European hares Lepus europaeus. Of 28 hares captured in box traps, three died during handling to fit GPS collars, likely due to acute stress. Apart from an 11% decrease in activity in both sexes the first four days after capture compared to later, capture events had no significant effects on subsequent movement behavior. Hares that were disturbed experimentally, i.e. flushed with or without a shotgun shot fired, moved on average (± SD) 422 ± 206 m directly subsequent to the disturbance, leading to a spatial displacement of their short-term home range and an increased daily home range size on the disturbance day. Home range sizes returned to their before disturbance size on the following days, but hares remained further from field edges and spent more time in short vegetation in the days after simulated hunting, though this effect was comparatively small. Overall, our findings indicate that hares only marginally changed their movement behavior in response to short-term disturbances. Therefore, capture and hunting disturbance should not have severe negative effects on the movement behavior of individuals, but future studies should aim to reduce acute capture-related stress to avoid mortalities. We recommend that researchers should censor the first four days after capture from their analyses to avoid using potentially biased data.

Ranging behaviour and habitat use in Montagu\u2019s Harrier Circus pygargus in extensive farmland of Eastern Poland

Agriculture intensification drives changes in bird populations but also in the space use by farmland species. Agriculture in Eastern Europe still follows an extensive farming model, but due to policy shifts aimed at rural restructuring and implementation of government subsidies for farmers, it is being rapidly intensified. Here, we aimed to document the ranging behaviour and habitat use of a declining farmland bird of prey—Montagu’s Harrier—and to compare it to findings from Western Europe. In 2011–2018, 50 individuals were followed with GPS loggers in Eastern Poland to study species spatial ecology. We found home ranges (kernel 90%) to be considerably large: 67.3 (± 42.3) km2 in case of males, but only 4.9 (± 6.1) km2 in females. Home ranges overlapped by 40%, on average, with other males in colonies and by 61%, on average, between consecutive breeding seasons of a particular male. The average daily distance travelled by males and females reached, respectively, 94.5 and 45.3 km, covering a daily home range of 32.3 and 3.1 km2. Individuals foraged up to 35 km from nests (3.5 km on average). Daily distance travelled and daily home ranges varied across the breeding season, in case of females being shortest in July, but sharply increasing in August. Also, individuals with breeding success had higher daily distance travelled but smaller daily home ranges. Average harriers’ distance to nest was generally increasing over the season, but was also changing over time of day: birds were closest to nest during night time, but at the end of the season, males roosted up to 16 km from the nest. While foraging males slightly preferred grasslands, higher elevation and smaller land-use patches, they avoided slopes and proximity of roads. We conclude that the surprisingly large home ranges of breeding harriers may suggest reduced prey availability or high fragmentation of hunting areas, both driving birds to utilise large areas and potentially contributing to population decline.

Daily Movements, Space Use, and Habitat Selection of GPS‐tagged Northern Bobwhite in Texas

ABSTRACTDetailed information on movements, space use, and habitat selection patterns by northern bobwhite (Colinus virginianus; hereafter, bobwhite) is important for understanding population dynamics, gene flow, disease spread, and development of habitat management activities. Advances in Global Positioning System (GPS) technology has allowed researchers to collect spatial and temporal location data with increasing accuracy, which in turn has shifted the resolution at which habitat evaluations and management focus can occur. Only recently have GPS tags been deployable for small ground‐nesting birds. We conducted a preliminary examination of the spatial ecology of 74 bobwhites equipped with GPS tags during breeding and covey season on 3 private properties in north‐central Texas, USA, during 2015–2017. Specifically, we derived daily estimates of core area and range size using dynamic Brownian bridge movement models, daily distance traveled, and distance between consecutive roost sites. Bobwhites tended to move more during breeding than covey season. Consecutive roost sites were, on average, approximately 130 m apart. Daily core area and home range size of bobwhites across the calendar year were 1.99 ± 0.13 and 6.29 ± 0.85 ha, respectively. During the breeding season, bobwhites avoided hardwood communities and showed no selection or avoidance of shrub, grass, and herbaceous communities. During covey season, bobwhites selected for herbaceous, grass, and hardwood communities, and neither selected nor avoided shrub communities. Global Positioning System data on a variety of species has become the primary information used for habitat and conservation management decisions, therefore, future research on bobwhite will include the application of GPS, which our results show can increase the temporal resolution of information and be used for habitat conservation and restoration actions. © 2020 The Wildlife Society.

Scaling of movements with body mass in a small opossum: evidence for an optimal body size in mammals

Abstract Movement by mammals generally increases with body size, described by a positive exponent scaling with either home range area or day range distances. Below ca. 100 g, however, interspecific comparisons suggest a negative scaling, increasing movement with decreasing body size. Such a pattern is expected from the rising costs of thermoregulation below ca. 100 g, implying that it should also be observed in intraspecific comparisons. We tested this hypothesis by investigating the scaling exponent of daily home range with body mass for a small (&amp;lt; 100 g) marsupial, the gray slender mouse opossum, Marmosops incanus. We tracked 85 opossums (56 M, 29 F) with a spool-and-line device between August 1998 and October 2005 in the Serra dos Órgãos National Park, a region of Atlantic Forest in the State of Rio de Janeiro, Brazil. Individual paths were mapped and daily home ranges quantified by the minimum convex polygon encompassing each path. We formulated linear models and compared them using Akaike information criteria. The best-supported model for females had only climatic season as a main determinant of daily home range, whereas the best model for males had body mass and reproductive season as the main effects. As predicted, the scaling exponent of daily home range with body mass of males was negative, in contrast with positive intraspecific exponents for opossums &amp;gt; 100 g estimated in a previous study. The inversion in scaling relationships around 100 g in opossums supports the rising costs of thermoregulation as the main cause of this general pattern in mammals. Effects of body mass are generally weak in intraspecific comparisons, but might still be detected after standardizing other effects, opening new possibilities for testing macroecological models at smaller scales. Espera-se que a quantidade de movimento de mamíferos aumente com o tamanho corporal, descrita por um expoente de escala positivo, tanto para área de vida quanto para distâncias diárias de deslocamento. Abaixo de ca. 100 g, comparações interespecíficas sugerem um expoente negativo, áreas de movimento aumentando com menores tamanhos de corpo. Este padrão é apoiado pelo custo crescente de termorregulação abaixo de ca. 100 g, que implica que também ocorreria em comparações intraespecíficas. Testamos esta hipótese investigando o expoente de escala da área de vida diária com a massa corporal em um pequeno (&amp;lt; 100 g) marsupial, Marmosops incanus. Indivíduos foram rastreados com carretel-de-rastreamento entre agosto de 1998 e outubro de 2005, no Parque Nacional da Serra dos Órgãos, uma região de Mata Atlântica no Estado do Rio de Janeiro, Brasil. Trajetórias individuais foram mapeadas e sua área de vida diária medida pelo polígono convexo mínimo envolvendo cada trajetória. Oitenta e cinco indivíduos foram rastreados, sendo 29 fêmeas e 56 machos. Modelos lineares foram formulados e comparados com o Critério de Informação de Akaike. O modelo com maior suporte para fêmeas teve apenas estação climática como determinante principal da área de vida diária, enquanto o melhor modelo para machos teve massa corporal e estação reprodutiva como efeitos principais. O expoente de escala de área de vida diária com massa corporal de machos foi negativo, contrastando como os expoentes positivos para marsupiais &amp;gt; 100 g estimados em um estudo anterior. A inversão de relações de escala em torno de 100 g nestes marsupiais apoia que custos crescentes de termorregulação sejam a causa principal deste padrão geral em mamíferos. Os efeitos da massa corporal são geralmente fracos em comparações intraespecíficas, mas podem ser detectados após a exclusão de outros efeitos, abrindo novas possibilidades para testar modelos macroecológicos em escalas menores.

Seasonal effects of habitat structure and weather on the habitat selection and home range size of a mammal in agricultural landscapes

Human land use intensified over the last century and simultaneously, extreme weather events have become more frequent. However, little is known about the interplay between habitat structure, direct short-term weather effects and indirect seasonal effects on animal space use and behavior. We used the European hare (Lepus europaeus) as model to investigate how habitat structure and weather conditions affect habitat selection and home range size, predictors for habitat quality and energetic requirements. Using > 100,000 GPS positions of 60 hares in three areas in Denmark and Germany, we analyzed habitat selection and home range size in response to seasonally changing habitat structure, measured as vegetation height and agricultural field size, and weather. We compared daily and monthly home ranges to disentangle between direct short-term weather effects and indirect seasonal effects of climate. Habitat selection and home range size varied seasonally as a response to changing habitat structure, potentially affecting the availability of food and shelter. Overall, habitat structure and seasonality were more important in explaining hare habitat selection and home range size compared to direct weather conditions. Nevertheless, hares adjusted habitat selection and daily home range size in response to temperature, wind speed and humidity, possibly in response to thermal constrains and predation risk. For effective conservation, habitat heterogeneity should be increased, e.g. by reducing agricultural field sizes and the implementation of set-asides that provide both forage and shelter, especially during the colder months of the year.

Trait variation and trait stability in common marmosets (Callithrix jacchus) inhabiting ecologically distinct habitats in northeastern Brazil.

Understanding the set of factors that promote and constrain a species' ability to exploit ecologically distinct habitats is central for addressing questions of intraspecific variability in behavior and morphology. In this study, we compared newly collected data with published data on body measurements, group size and composition, daily path length, home range, and reproductive output in wild common marmosets naturally inhabiting two contrasting environments in northeastern Brazil: the Atlantic Forest (AF), which is characterized by high biodiversity and reduced seasonality in food availability and the Caatinga (CAT), which is characterized by a severe hot and dry season lasting from 5 to 11 months, drought-resistant plant species, and reduced primary productivity. Despite marked differences in ecological conditions, CAT marmosets and AF marmosets differed minimally in daily path length, home range, reproductive output, and infant survivorship. CAT marmosets were found to live in smaller groups containing fewer adult females than AF marmosets, and also were characterized by a greater surface area to body mass ratio, a trait that may represent an adaptation to the hot and dry conditions of the Caatinga. We propose that in conjunction with body mass reduction, minor adjustments in behavior, the exploitation of cacti as a source of water and nutrients, and access to exudates as a dependable year-round food resource, common marmosets successfully used the same adaptive pattern to maintain high reproductive output and infant survivorship in exploiting these two ecologically distinct environments.

Homing and home range of the European spiny lobster, Palinurus elephas (Decapoda, Palinuridae) acoustically tracked

Abstract A specific study has been carried out for the first time to investigate the homing capability and daily home range of the spiny lobster Palinurus elephas by means of ultrasonic telemetry. Nine lobsters collected in the Capo Gallo — Isola delle Femmine marine protected area (northwestern Sicily, central Mediterranean) were tagged with miniaturized transmitters and released at a single site inside the protected area. The lobsters were monitored with the purpose of calculating their horizontal and vertical positions, analysing their movement patterns to assess their homing capability, and calculating their daily home range. Five lobsters moved back close to the capture sites within the first 20 hours after release (‘homed’). The remaining four lobsters ‘relocated’ to a different refuge. Homed lobsters had a larger home range than relocated lobsters. This study provides the first description of a homing pattern with high spatial resolution in the wild European spiny lobster as inferred by ultrasonic telemetry.

Space use patterns of the burrowing echimyid rodent, Clyomys laticeps

AbstractSpace use patterns of a population are a result of the set of movements of its individuals, which are directly influenced by their attributes and environmental conditions. Understanding space use patterns and its determinants may give us insights about a species’ ecology, social and mating systems. Although echimyid rodents display a variety of mating and social systems, movements of burrowing species are poorly studied due to their cryptic habits. Hence, in this study, we evaluated the effects of body mass, sex, and palm fruit availability on space use patterns of the burrowing echimyid Clyomys laticeps, by measuring their daily home range (DHR) and intensity of habitat use. In 9 months of study in a “cerrado campo sujo” site, we tracked 14 adults with the spool‐and‐line in a backpack method. Adult males had larger DHR size than females, probably as a response to greater body mass and reproductive behavior. Furthermore, adult females had greater intensity of habitat use, presenting site fidelity, which can be due to offspring care as a response to non‐seasonal reproduction observed in our study and/or due to nest site defense strategy to avoid energetic costs associated with burrow construction. Differently from expected, food availability (i.e., Allagoptera campestris palm fruits) had no influence on the space use patterns of C. laticeps. As in other herbivorous rodents, shifts in proportion of consumed food items according to their availability may explain the lack of this influence in our study. Our findings suggest that space use patterns of C. laticeps are mainly explained by behavioral and physiological differences between sexes, including body mass and reproductive strategies. Additionally, larger male movements and female site fidelity suggest a solitary behavior and a polygynous mating system, although further studies regarding spatial organization and genetic structure are necessary to support these suggestions.

Effects of Temperature and Day Length on Daily Movements and Home Range ofGlaucomys volans(Southern Flying Squirrel) in the Northeastern United States

To maximize energy gained and minimize energy expended, animals should forage in a manner that gives them the largest benefit at the lowest cost. Species living in seasonal environments in the northeastern US, such as the Glaucomys volans (Southern Flying Squirrel), need to overcome high energetic demands associated with thermoregulation and food availability. In this study, we measured nightly travelled distance and home range of Southern Flying Squirrel to understand how they adapt to changes in temperature and day length. Our results showed that Southern Flying Squirrel travelled longer distances and expanded their home range in warmer temperatures and longer day-lengths. Our study contributes to our understanding of how animals adapt to constantly changing environmental conditions in the northeastern United States.

Habitat utilization by an invasive herbivorous fish (Siganus rivulatus) in its native and invaded range

Movement is essential for understanding the distribution and abundance of animals. While it has been suggested that invasion success can be facilitated by species’ ability to adapt to novel environments, direct comparisons of movement patterns between native and invaded ranges of animals in their natural habitat are rare. The rivulated rabbitfish Siganus rivulatus was introduced from the Red Sea into the Mediterranean, where it is now found in extremely high abundances, and has overgrazed the coastal marine ecosystem in many locations. Through a continuous acoustic tracking system, we found that the movement of S. rivulatus individuals at a Mediterranean site differed substantially from those at a Red Sea site, with individuals in the Mediterranean having larger overall home ranges and lower site fidelity. However, no variation between sites was found in daily home range sizes. Results show that at the Mediterranean site S. rivulatus individuals have a larger spatial footprint, which may contribute to their impact and ability to expand their distribution. This study demonstrates a potential shift in individual movement of a marine invasive species between its native and invaded range, and highlights the role of movement in understanding biological invasions.

Ontogenetic changes in movement patterns and activity levels of American lobsters (Homarus americanus) in Anse-Bleue, southern Gulf of St. Lawrence

In this study, the activity and movements of juvenile, adolescent, and adult American lobsters (Homarus americanus) were simultaneously quantified for the first time, using two complementary ultrasonic telemetry tracking systems. Fourteen lobsters measuring 28 to 80.5 mm in carapace length were first tracked for two blocks of 14 days starting in late summer 2011 on a shallow nursery ground in Anse-Bleue, southern Gulf of St. Lawrence, Canada. Tagged lobsters were simultaneously tracked at a fine scale (≈5000 m2) using a VEMCO VRAP ultrasonic telemetry system, and at a larger scale (≈2.5 km2) using an array of 38 VEMCO VR2 receivers. Subsequent monitoring of individuals continued for an additional 58 days (72 total) within the larger VR2 array. Juvenile, adolescent and adult lobsters displayed diurnal activity rhythms, being significantly more active at night than during the day, and they behaved as “central place foragers”, undergoing excursions from and to a “central” shelter area. These behaviours were not found to be affected by body size. In contrast, average daily home range increased gradually with increasing body size, and study-length displacements showed a dichotomy between juveniles and adolescents/adults. Most (7/8) adolescent and adult lobsters moved to deeper water as water temperature decreased in the fall, whereas the juveniles (6/6) stayed in shallow water near the VRAP triangle for the duration of the study. This study provides rare empirical data concerning the movement and behavioural ecology of American lobsters on shallow nursery grounds, and it reveals ontogenetic changes in daily and seasonal movements over the juvenile, adolescent and adult life stages.

A multiple-species framework for integrating movement processes across life stages into the design of marine protected areas

A major objective of marine protected area (MPA) network design is to ensure the persistence of species with diverse life histories and functional traits. Considering how species differ in their propensity to move within and between MPAs is therefore a key consideration for multi-species MPA network design. Here, we propose a conceptual framework to incorporate ecological processes that affect movement at multiple life stages into the MPA network design process. We illustrate how our framework can be implemented using a set of hypothetical species that represent regional trait diversity in coastal British Columbia, Canada. We focused on two ecological processes: (1) dispersal during the larval phase and (2) daily home range movement during the adult phase. To identify functional connectivity patterns, we used a biophysical model to simulate larval dispersal, and then prioritized highly-connected patches using a reserve selection algorithm. To ensure that individual reserves were commensurate with home ranges, we also imposed reserve size constraints. Candidate areas for protection were identified based on multi-species connectivity patterns and home range size constraints. Collectively, this conceptual framework offers a flexible approach to multi-species, cross-life stage conservation planning, which can be further adapted to address complex life histories. As marine conservation efforts around the globe aim to design ecologically connected networks of protected areas, the integration of movement and connectivity data throughout ontogeny will be a key component of effective multi-species MPA network design.