Population spatial structuring on the feeding grounds in North Atlantic humpback whales (Megaptera novaeangliae)

Population spatial structuring among North Atlantic humpback whales Megaptera novaeangliae on the summer feeding grounds was investigated using movement patterns of identified individuals. We analysed the results from an intensive 2-year ocean-basin-scale investigation resulting in 1658 individuals identified by natural markings and 751 individuals by genetic markers supplemented with data from a long-term collaborative study with 3063 individuals identified by natural markings. Re-sighting distances ranged from <1 km to >2200 km. The frequencies ( F ) of re-sighting distances ( D ) observed in consecutive years were best modelled by an inverse allometric function ( F =6631 D ^−1.24, r ²=0.984), reflecting high levels of site fidelity (median re-sighting distance <40 km) with occasional long-distance movement (5% of re-sightings >550 km). The distribution of re-sighting distances differed east and west of 45°W, with more long-distance movement in the east. This difference is consistent with regional patterns of prey distribution and predictability. Four feeding aggregations were identified: the Gulf of Maine, eastern Canada, West Greenland and the eastern North Atlantic. There was an exchange rate of 0.98% between the western feeding aggregations. The prevalence of long-distance movement in the east made delineation of possible additional feeding aggregations less clear. Limited exchange between sites separated by as little as tens of kilometres produced lower-level structuring within all feeding aggregations. Regional and temporal differences in movement patterns reflected similar foraging responses to varying patterns of prey availability and predictability. A negative relationship was shown between relative abundance of herring and sand lance in the Gulf of Maine and humpback whale movement from the Gulf of Maine to eastern Canada.     

Home range and habitat use by the serotine bat, Eptesicus serotinus, in England

Serotine nursery roosts with less than 20 bats were found to have home ranges of at least 24 to 77 km² and core areas of activity from 13 to 33 km². The size of the range may have increased further if more individuals had been tracked, as three of the four colonies studied had not reached their asymptotes. The total home-range area covered by four serotine colonies was 127.36 km². Excluding non-breeding bats, a density of one bat per 120 ha was estimated. However, actual density was likely to be higher if there were additional non-breeding females and immatures that were not in nursery roosts. Colonial home ranges and core areas overlapped, with individuals from different colonies feeding at the same sites. Individual home ranges ( n = 32) varied from 0.16 to 47.58 km², but these were not used exclusively by one individual. Around the colonial core area and breeding roosts, home ranges were used by all individuals from a single colony. It is only further from the core area that ranges appeared to be used by individuals. The distance from roost to feeding areas varied by up to 7.4 km, but the bat usually commuted along lines of trees and hedges and over pastures. This resulted in greater distances being travelled than if they had flown by a direct route. On average, individuals commuted distances of 8 km each night between feeding areas, with a maximum distance of over 41 km. They visited between 0 and 10 feeding sites each night (mean = 2.89).     

Are Flying-Foxes Coming to Town? Urbanisation of the Spectacled Flying-Fox (Pteropus conspicillatus) in Australia

Urbanisation of wildlife populations is a process with significant conservation and management implications. While urban areas can provide habitat for wildlife, some urbanised species eventually come into conflict with humans. Understanding the process and drivers of wildlife urbanisation is fundamental to developing effective management responses to this phenomenon. In Australia, flying-foxes (Pteropodidae) are a common feature of urban environments, sometimes roosting in groups of tens of thousands of individuals. Flying-foxes appear to be becoming increasingly urbanised and are coming into increased contact and conflict with humans. Flying-fox management is now a highly contentious issue. In this study we used monitoring data collected over a 15 year period (1998–2012) to examine the spatial and temporal patterns of association of spectacled flying-fox (Pteropus conspicillatus) roost sites (camps) with urban areas. We asked whether spectacled flying-foxes are becoming more urbanised and test the hypothesis that such changes are associated with anthropogenic changes to landscape structure. Our results indicate that spectacled flying-foxes were more likely to roost near humans than might be expected by chance, that over the period of the study the proportion of the flying-foxes in urban-associated camps increased, as did the number of urban camps. Increased urbanisation of spectacled flying-foxes was not related to changes in landscape structure or to the encroachment of urban areas on camps. Overall, camps tended to be found in areas that were more fragmented, closer to human habitation and with more urban land cover than the surrounding landscape. This suggests that urbanisation is a behavioural response rather than driven by habitat loss.     

What drives long‐distance movements in the nomadic Grey Teal Anas gracilis in Australia?

In contrast to northern temperate environments, where day length and temperature changes are obvious proximate cues for movement to resource-rich breeding habitats, the cues for movement used by birds in an often resource-poor, stochastic environment are less obvious. We recorded long-distance movements of 23 Grey Teal Anas gracilis using satellite telemetry for up to 879 days and examined the relationship between those movements and environmental factors, such as heavy rainfall and flooding, at the destination site. We identified 32 long-distance (> 150 km) movements that met our criterion for minimally interrupted flight between origin and destination. Thirteen of these flights coincided with rainfall and/or flooding events up to 1050 km from the origin. However, some ducks moved without any clear beneficial conditions at the destination onto small wetlands in regions with little surface water. The data suggest that there are two types of long-distance movement – ranging and directed. These flights occurred over distances up to 1200 km across the arid inland. The rates and distances of movement suggest that long-distance movements of Grey Teal entail high energy costs as in waterfowl elsewhere. We conclude that the proximate controls of directed movements need not be very different from those of their temperate counterparts.     

Conservation Values and Risk of Handling Bats: Implications for One Health Communication

Flying-foxes provide critical ecosystem services, but their role as hosts to zoonotic pathogens may undermine conservation support. We surveyed 214 residents of Cairns, Australia, regarding their perceptions about health risks associated with flying-foxes and support for flying-fox conservation. Greater likelihood of handling a flying-fox was associated with lower knowledge about risks, greater conservation support, and environmental organization membership. Respondents less likely to seek medical attention after a minor scratch tended to be younger, unemployed and perceive lower risk. Individuals who support flying-fox conservation should be one group targeted in One Health communication integrating health and conservation messages.     

Movements of Macquaria ambigua, in the Murray River, south‐eastern Australia

A 2 year (2000–2001) radio‐tagging study was undertaken to investigate the movements of 51 golden perch Macquaria ambigua in the Murray River at Nyah in north‐western Victoria, Australia. During the winter of both years, golden perch did not undertake movements >5 km and displayed strong home range fidelity. In the first year of the study there was an increase in the distance of golden perch movement during late spring which coincided with increasing water temperature and river discharge. Nineteen golden perch were tracked during this period, of which 10 travelled downstream between 11 and 290 km. Seven of these fish moved to an area below the junction of the Murray and Wakool Rivers. Five golden perch travelled upstream between 13 and 35 km, four of which travelled to an area around the junction of the Murray River and Speewa Creek. The remaining four golden perch undertook localized movements of <5 km. Many of the long distance movements undertaken in spring 2000 were rapid and 53% of these golden perch returned to within 3 km of their release locations, indicating homing behaviour. Given that the rapid movements of golden perch in spring coincided with the known spawning season of this species, these long distance movements may be associated with reproductive strategy.     

How far away in an hour? Daily movements of juvenile golden eagles ( Aquila chrysaetos ) tracked with satellite telemetry

We tracked the daily movements of three juvenile golden eagles (Aquila chrysaetos) using satellite telemetry. Straight distances covered in an hour and throughout a day were calculated. Daily movements of golden eagles are mostly characterized by short-distance excursions, with 64% of the distances covered in an hour shorter than 1 km and 95% shorter than 9 km. Both the longest movements and the largest proportion of long-distance movements, were concentrated between 1100 and 1800 hours, the peak of daily activities. Average hourly distances during that peak oscillated between 2 and 6 km, with records of more than 20 km. Distances covered in a day ranged between 0.1 and 53.2 km with an average of 14.0 km (SD=13.4). Differences in the distances covered at different times of the day probably reflect a balance between the temporal pattern of preferred prey’s activity and the eagles’ progressive satiation along the day on one hand, and the higher likelihood of thermal and updraughts (which facilitate long-distance movements) occurring at noon and the early afternoon, on the other.     

Bats Without Borders: Long-Distance Movements and Implications for Disease Risk Management

Fruit bats of the genus Pteropus (commonly known as flying-foxes) are the natural hosts of several recently emerged zoonotic viruses of animal and human health significance in Australia and Asia, including Hendra and Nipah viruses. Satellite telemetry was used on nine flying-foxes of three species (Pteropus alecto n = 5, P. vampyrus n = 2, and P. neohibernicus n = 2) to determine the scale and pattern of their long-distance movements and their potential to transfer these viruses between countries in the region. The animals were captured and released from six different locations in Australia, Papua New Guinea, Indonesia, and Timor-Leste. Their movements were recorded for a median of 120 (range, 47–342) days with a median total distance travelled of 393 (range, 76–3011) km per individual. Pteropus alecto individuals were observed to move between Australia and Papua New Guinea (Western Province) on four occasions, between Papua New Guinea (Western Province) and Indonesia (Papua) on ten occasions, and to traverse Torres Strait on two occasions. Pteropus vampyrus was observed to move between Timor-Leste and Indonesia (West Timor) on one occasion. These findings expand upon the current literature on the potential for transfer of zoonotic viruses by flying-foxes between countries and have implications for disease risk management and for the conservation management of flying-fox populations in Australia, New Guinea, and the Lesser Sunda Islands.     

Foraging requirements of the endangered long-fingered bat: the influence of micro-habitat structure, water quality and prey type

Myotis capaccinii is one of the most endangered Mediterranean bats. We radio tracked 21 adult individuals to assess foraging range and analyse micro-habitat selection around a nursery roost in central Italy. Habitats were characterized by development of riparian vegetation, distance between banks, degree of water clutter and levels of water pollution (expressed by macro-benthic bioindicators). Diet was also analysed to see whether prey rarity might account for species decline. Myotis capaccinii proved highly mobile: the maximum straight line distance between roost location and the farthest foraging fix recorded on one night was c . 21 km, whereas this variable averaged 7.5 km for the entire study. In general, the species preferred calm waters bordered by well-developed riparian vegetation and large (>5 m) inter-bank distances. Such factors determined the overall quality of foraging sites. Although diet was dominated by pollution-tolerant insects such as Chironomus midges, bats preferred less polluted waters. Our study also confirmed the occurrence of piscivory in this bat. Of the factors potentially responsible for species endangerment, the most likely are general habitat degradation, that is alteration of riparian vegetation and pollution, and cave roost loss. Given the large ecological niche overlap, increasing Myotis daubentonii may be outcompeting M. capaccinii . The most urgent actions to preserve M. capaccinii are extensive restoration of riparian vegetation and strict roost protection. Our study offers indications about where, and how, restoration of riparian vegetation may translate into best conservation results.     

Ranging behaviour of a large freshwater invertebrate, the white-clawed crayfish Austropotamobius pallipes

• 1 Radio‐telemetry and mark‐recapture methods were used to study the summer movements of adult and juvenile white‐clawed crayfish, Austropotamobius pallipes from a wild population in a small braided stream, Dalton Beck, North Yorkshire, U.K. Radio‐transmitters were attached to the chelae of 18 large (> 35 mm carapace length) crayfish and individuals were subsequently located to within 0.15 m. Additionally a total of 888 crayfish were marked with carapace brands, and 83 were recaptured.
• 2 Radio‐tracked crayfish exhibited significantly greater local activity at dusk (21.00–00.00) than at dawn (03.00–06.00), or during morning (09.00–12.00) and afternoon (15.00–18.00) monitoring periods.
• 3 The greatest movements of radio‐tracked crayfish occurred within 2 days of release. After this time, periods of residence were interspersed by movements to new locations, interpreted as establishment of ephemeral home areas. It is suggested that the initial large movements were the result of a ‘fright response’ following capture.
• 4 Movements varied widely between individuals, some moving more than 300 m in 10 days, while others showed little movement over an equivalent time period. Mean (±SE) daily movements were 4.6 ± 3.0 m for males and 1.5 ± 1.0 m for females. Although crayfish often used specific home sites for in excess of 7 days, displaced animals did not return to home sites.
• 5 The total distances travelled and the mean distance travelled per day by individual radio‐tagged crayfish did not differ significantly between upstream or downstream directions or between males and females. This was also the case for marked crayfish used in mark‐recapture studies.
• 6 Positive correlations between distance moved per day and size (carapace length) were found for downstream movements by male and female crayfish, but not for upstream movements.
• 7 Some preliminary observations of the response of crayfish to flood events suggested that these could be catastrophic with two out of five tracked crayfish found dead after a high stream‐discharge event.

     

Migratory Movements of Pygmy Blue Whales (Balaenoptera musculus brevicauda) between Australia and Indonesia as Revealed by Satellite Telemetry

In Australian waters during the austral summer, pygmy blue whales (Balaenoptera musculus brevicauda) occur predictably in two distinct feeding areas off western and southern Australia. As with other blue whale subspecies, outside the austral summer their distribution and movements are poorly understood. In order to describe the migratory movements of these whales, we present the satellite telemetry derived movements of eleven individuals tagged off western Australia over two years. Whales were tracked from between 8 and 308 days covering an average distance of 3,009±892 km (mean ± se; range: 832 km–14,101 km) at a rate of 21.94±0.74 km per day (0.09 km–455.80 km/day). Whales were tagged during March and April and ultimately migrated northwards post tag deployment with the exception of a single animal which remained in the vicinity of the Perth Canyon/Naturaliste Plateau for its eight day tracking period. The tagged whales travelled relatively near to the Australian coastline (100.0±1.7 km) until reaching a prominent peninsula in the north-west of the state of Western Australia (North West Cape) after which they travelled offshore (238.0±13.9 km). Whales reached the northern terminus of their migration and potential breeding grounds in Indonesian waters by June. One satellite tag relayed intermittent information to describe aspects of the southern migration from Indonesia with the animal departing around September to arrive in the subtropical frontal zone, south of western Australia in December. Throughout their migratory range, these whales are exposed to impacts associated with industry, fishing and vessel traffic. These movements therefore provide a valuable tool to industry when assessing potential interactions with pygmy blue whales and should be considered by conservation managers and regulators when mitigating impacts of development. This is particularly relevant for this species as it continues to recover from past exploitation.     

Movements of satellite-monitored humpback whales on their feeding ground along the Antarctic Peninsula

Humpback whales were instrumented with satellite transmitters off the western Antarctic Peninsula in January of 2004–2006 to examine their movement patterns and habitat use. Whales were tracked from 4 to 80 days (mean = 36.5 days). Distance and travel rate estimates for nine individuals ranged from 223 to 4,356 km and from 17 to 75 km/day, respectively. Considerable individual variation was observed in direction, speed and range of movements. The overall pattern was characterized by short- and long-distance movements between presumed foraging areas with relatively short residency times. Travel rates were lower at these sites, characterized by erratic movements, than during traveling between them. Area usage for six individuals based on the 95% fixed kernel home range with least squares cross-validation ranged from 2,771 to 172,356 km². The management boundary between the feeding grounds associated with Breeding Stocks G and A needs revision, as current available data suggest it should be located to the east of 50°W. This study is the first to present detailed information on the movements of humpback whales in the Southern Ocean.     

Detecting dispersal of Nuphar lutea in river corridors using microsatellite markers

1. River corridors are well-known for their role in plant dispersal. The buoyancy of seeds, the possibility of dispersal by vegetative fragments, and the frequency and efficiency of dispersal among different river catchments determine linear distribution patterns. Little is known about the relative importance of these factors to observed patterns of genetic variation.
2. One hundred and fifty-six Nuphar lutea individuals from forty-four sampling sites in the river catchments of the Cidlina River, the Mrlina River and the Labe River (Czech Republic) were studied using ten microsatellite markers. Interpretation of patterns in genetic variation allowed several conclusions about dispersal mechanisms.
3. Vegetative long-distance dispersal is probably very limited in this species. Only one multilocus genotype was found in more than one sampling site. The distance between the sites was about 75 km.
4. To explain the distribution of Bayesian based clusters of related multilocus genotypes, both along-river and inter-river long-distance dispersals have to be invoked.
5. A marginally significant tendency for higher genetic diversity in the lower part of the river Cidlina was detected. Continuous downstream dispersal of seeds by water currents could be a valid explanation.
6. Significant positive autocorrelation was found among individuals at within-river distances of up to 25 km. Repeated dispersal of seeds over distances in the range of tens of kilometers is common.     

Male post-breeding movements and stopover habitat selection of an endangered short-distance migrant,the Little Bustard Tetrax tetrax

Migratory decisions, such as the selection of stopover sites, are critical for the success of post-breeding migratory movements and subsequent survival. Recent advances in bio-logging have revealed the stopover strategies of many long-distance migrants, but far less attention has been given to short-distance migrants. We investigated the stopover ecology of an endangered grassland bird, the Little Bustard Tetrax tetrax, a short-distance migrant in Iberia. Using high-resolution spatial GPS/GSM data, 27 male Little Bustards breeding in southern Portugal were tracked between 2009 and 2011. We studied post-breeding movements using Dynamic Brownian Bridge models to identify the main stopover sites, and generalized linear mixed models to examine habitat selection in stopovers. During their post-breeding movements, males were essentially nocturnal migrants, making frequent stopovers while maintaining a relatively fast pace to reach more productive agricultural post-breeding areas. Stopovers occurred in most post-breeding movements (83%) regardless of the total distance covered (average 64.3 km), and most stopovers (84%) lasted less than 24 h. Birds used mostly agricultural non-irrigated and irrigated croplands as stopover sites and avoided other land uses and rugged terrain. There was a negative relationship between stopovers and the proximity to roads, but not to power lines. The high frequency of stopovers during post-breeding movements, despite the short distances travelled, together with the nocturnal migratory behaviour of bustards, may impose additional risks to a bird mainly threatened by collision with power lines in non-breeding areas. We also conclude that even for short-distance migrants, habitat connectivity between breeding and post-breeding areas is likely to be a key conservation concern.     

Movement patterns of the round stingray Urobatis halleri(Cooper) near a thermal outfall

Fine‐scale movements and site fidelity of round stingrays Urobatis halleri at Seal Beach California, U.S.A., were examined using acoustic telemetry. Actively tracked fish generally exhibited limited nearshore movement, with greater distances travelled at night when the tide was ebbing than during the day with ebbing tides. Increases in round stingray activity were associated with increases in ambient temperature. Passively tracked fish showed seasonal patterns in their presence at Seal Beach. Males left Seal Beach during the autumn, returned the following spring, and remained in the area until the following autumn. Females spent far less time at Seal Beach, remaining in the area for a few weeks during June and July. Passively tracked round stingrays were recorded more often in the warm waters of the San Gabriel River mouth (the location of a thermal outfall from an electric‐generating station) than adjacent beaches, with fish often returning to Seal Beach after periods of absence. Anthropogenic effects resulting from coastal development may have created environmental conditions ( i.e . warmer water and finer sediments) that influence the movements and site fidelity of round stingrays.     

Seasonal movements of Gyrfalcons Falco rusticolus include extensive periods at sea

Little information exists on the movements of Gyrfalcons Falco rusticolus outside the breeding season, particularly amongst High Arctic populations, with almost all current knowledge based on Low Arctic populations. This study is the first to provide data on summer and winter ranges and migration distances. We highlight a behaviour previously unknown in Gyrfalcons, in which birds winter on sea ice far from land. During 2000–2004, data were collected from 48 Gyrfalcons tagged with satellite transmitters in three parts of Greenland: Thule (northwest), Kangerlussuaq (central‐west) and Scoresbysund (central‐east). Breeding home‐range size for seven adult females varied from 140 to 1197 km² and was 489 and 503 km² for two adult males. Complete outward migrations from breeding to wintering areas were recorded for three individuals: an adult male which travelled 3137 km over a 38‐day period (83 km/day) from northern Ellesmere Island to southern Greenland, an adult female which travelled 4234 km from Thule to southern Greenland (via eastern Canada) over an 83‐day period (51 km/day), and an adult female which travelled 391 km from Kangerlussuaq to southern Greenland over a 13‐day period (30 km/day). Significant differences were found in winter home‐range size between Falcons tagged on the west coast (383–6657 km²) and east coast (26 810–63 647 km²). Several Falcons had no obvious winter home‐ranges and travelled continually during the non‐breeding period, at times spending up to 40 consecutive days at sea, presumably resting on icebergs and feeding on seabirds. During the winter, one juvenile female travelled over 4548 km over an approximately 200‐day period, spending over half that time over the ocean between Greenland and Iceland. These are some of the largest winter home‐ranges ever documented in raptors and provide the first documentation of the long‐term use of pelagic habitats by any falcon. In general, return migrations were faster than outward ones. This study highlights the importance of sea ice and fjord regions in southwest Greenland as winter habitat for Gyrfalcons, and provides the first detailed insights into the complex and highly variable movement patterns of the species.     

Long-distance dispersal in red foxes <Emphasis Type="Italic">Vulpes vulpes</Emphasis> revealed by GPS tracking

Dispersal is a fundamental process that facilitates population and range expansion by providing a mechanism for colonization and metapopulation linkages. Yet quantifying the dispersal process, particularly long-distance dispersal events, has been inherently difficult due to technological and observational limitations. Additionally, dispersal distance calculated as the straight-line distance between initiation and settlement fails to account for the actual movement path of the animal during dispersal. Here, we highlight six long-distance dispersal events, representing some of the longest dispersal distances recorded for red foxes. Cumulative dispersal movements ranged from 132 to 1036 km and occurred within both sexes (1 female, 5 males). With one exception, dispersal events ranged from 7 to 22 days and tended to be directed north-northwest. Importantly, cumulative movements were up to five times longer than straight-line distances, with two foxes traveling an additional 114 and 256 km before returning to, and settling in, areas previously encountered during dispersal. This suggests a role of habitat assessment and homing behavior during dispersal and indicates that the capacity and potential for dispersal are not limiting factors to either sex in a red fox population. Dispersal capacity should thus be considered regarding transboundary management and disease control of red fox populations.     

Variation in home-range size and movements of wintering dabbling ducks

Despite a long historical record of radio-tracking analyses, basic home-range information is still lacking for most common waterfowl species, especially during the winter. We investigated how dabbling duck home ranges and daily foraging movements are influenced by extrinsic (site, temperature, date) and intrinsic factors (species, sex, age). We radio-tagged and monitored 125 individuals of three duck species (mallard Anas platyrhynchos, Eurasian teal A. crecca crecca and northern pintail A. acuta) in three French wetlands over four winters. Home-range sizes for a given species varied greatly among our study sites. Moreover, species differed according to home-range structure and distance traveled to reach their foraging grounds (teal had a more patchy home range and traveled farther distances than mallards). Foraging distances increased with temperature and time (over the winter season), but this effect differed among species, suggesting that they behave differently in response to food depletion and/or cold weather. The commuting behavior (i.e., the decision to leave the roost at night for foraging) differed among species and season. Teals were more risk-prone because they were more likely to leave the roost at night. In our study, ducks foraged at distances of 1–2 km from roosts, whereas distances of 2–48 km have been recorded in North America. We suggest that food supply, hunting pressure or population density may account for these inter-continental differences.     

Testing traditional assumptions about regional migration in bats

While some bats cover long distances during migration, moving thousands of kilometers, most migratory bats are considered regional migrants, thought to move relatively short distances (<?500 km) between hibernacula and maternity sites. However, behavior can vary considerably among species and our understanding of these movements has largely been limited to banding studies or detailed tracking of small numbers of bats by aircraft. Inferring population-wide behavior from small samples is difficult and can introduce bias. We tagged 108 Indiana bats (Myotis sodalis) in the Midwestern US and used a regional network of radiotelemetry receivers to study movement patterns. With this dataset, we tested the following traditional generalizations about regional migrants: (1) bats move away from hibernacula in spring in all directions with known maternity roosts, e.g., in a star-like pattern; (2) bats follow linear landscape features; (3) long-distance movements are uncommon; and (4) autumn migration comprises a single movement from summer maternity site to winter hibernaculum. In spring, bats left the hibernaculum immediately and primarily moved north despite available maternity roosts in all directions. We found no evidence that bats follow rivers, the predominant linear element in the landscape. Only six tagged bats traveled >?100 km, suggesting that longer-distance movements may be outliers. In autumn, only two bats visited multiple known hibernacula, and after swarming, some females moved >?100 km to areas without known hibernacula. Common generalizations about regional migrant movements may not be representative of population behavior and care should be taken with respect to management decisions based on those assumptions.