scholarly journals Convoluted shorelines confound diel-range estimates of radio-tracked fish

2010 ◽  
Vol 61 (12) ◽  
pp. 1360 ◽  
Author(s):  
Brendan C. Ebner ◽  
Mark Lintermans ◽  
Mark Jekabsons ◽  
Mark Dunford
Keyword(s):  
Freshwater Fish ◽  
Spatial Ecology ◽  
One Dimension ◽  
Radio Tracking ◽  
Convex Polygons ◽  
Reservoir Area ◽  
Use Of Space ◽  
Primary Means ◽  
Range Length

Understanding the spatial ecology of animals is an important part of conserving biodiversity. In this context, manual radio‐tracking is a primary means for understanding the movement of freshwater fish. Our aim was to determine the suitability of using linear or area‐based estimates to quantify diel use of space by Macquarie perch, Macquaria australasica (Percichthyidae), in a reservoir. Area‐based estimates were calculated as minimum convex polygons (MCPs). Four‐hourly radio‐tracking of 23 adults within diel periods resulted in 136 pairs of linear and area‐based estimates. We encountered problems with MCPs that were not associated with outlying radio‐fixes. MCPs were more likely to overlap with land as the extent of an individual’s range increased. Corrections were applied to account for land intersecting with MCPs (33.1% of cases); however, underestimates of diel range occurred in most of these cases. MCPs were also small despite substantial movement along one dimension if individuals occupied only straight‐edged sections of the reservoir and did not traverse bays or peninsulas (8.1% of estimates). Mean (±s.e.) diel‐range length was 516 ± 89 m (n = 23) and records varied from 6 to 1972 m. In waterways with convoluted shorelines, linear estimates of diel range are more reliable than area‐based estimates derived from manual radio‐tracking.

Radio-tagging and tracking of translocated trout cod (Maccullochella macquariensis: Percichthyidae) in an upland river

2009 ◽  
Vol 60 (4) ◽  
pp. 346 ◽  
Author(s):  
B. C. Ebner ◽  
L. Johnston ◽  
M. Lintermans
Keyword(s):  
Spatial Ecology ◽  
Effective Means ◽  
Release Site ◽  
Early Morning ◽  
Home Ranges ◽  
Radio Tracking ◽  
Natural Habitats ◽  
Radio Transmitters ◽  
Radio Tagging ◽  
Species Rarity

Radio-tracking provides an effective means of studying the spatial ecology of threatened fishes where almost inaccessible habitats and species rarity render conventional mark–recapture methods impractical. Initially, validation of an effective radio-tagging method is required; in the present study, an aquaria trial based on nine hatchery-reared, adult male Maccullochella maquariensis (Percichthyidae) was conducted. Fish resumed feeding within days of being internally implanted with a radio-tag, and tag rejection was not observed (0%, n = 9) based on a 2-month observational period. Following release into an upland stream, individual-specific movements resulted in upstream (n = 1) and downstream (n = 6) dispersal as well as fidelity to the release site (n = 2) at the completion of the study. Individuals established small home-ranges (mean length of river used by an individual per diel period ranged from 47 to 292 m) and were most active in the early morning and evening (n = 6). Complete survivorship of individuals bearing active radio-transmitters (n = 8) was recorded up until 4 months after release. However, an estimated zero or one individual was alive when the last active radio-tag expired 11 months after release (n = 8). The present study highlights the use of radio-tracking in monitoring the dispersal and survivorship of small numbers of hatchery-reared threatened fish released into natural habitats as part of species re-introduction programs.

Short-term movement patterns and diet of small dasyurid marsupials in semiarid Australia

2012 ◽  
Vol 34 (1) ◽  
pp. 49 ◽  
Author(s):  
Lisa Warnecke ◽  
Gerhard Körtner ◽  
Chris J. Burwell ◽  
James M. Turner ◽  
Fritz Geiser
Keyword(s):  
Spatial Ecology ◽  
Arid Zone ◽  
Activity Patterns ◽  
Movement Patterns ◽  
Small Scale ◽  
Radio Tracking ◽  
Short Term ◽  
Resting Sites ◽  
Sminthopsis Crassicaudata ◽  
Radio Transmitters

Since little information is available on the spatial ecology of small arid-zone marsupials, we used radio-tracking to investigate the small-scale activity patterns of three dasyurid species in semiarid Australia. Sminthopsis crassicaudata, Planigale gilesi and S. macroura were equipped with miniature radio-transmitters to monitor choice of resting sites and daily movements. Resting sites were located within an area of 1.27 ± 0.36 ha, 0.12 ± 0.02 ha and 3.60 ± 0.95 ha, respectively and individuals returned to previously used resting sites regularly. We also analysed scat samples of S. crassicaudata and P. gilesi, and identified Araneae, Hymenoptera and Orthoptera as the major prey taxa for both species. Our study presents the first radio-tracking-based information on movements for these species in semiarid habitat, which indicates that, over a period of several weeks, resting sites are situated within small and defined areas.

scholarly journals A moving target—incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations

2016 ◽  
Vol 188 (4) ◽  
Author(s):  
Steven J. Cooke ◽  
Eduardo G. Martins ◽  
Daniel P. Struthers ◽  
Lee F. G. Gutowsky ◽  
Michael Power ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Spatial Ecology ◽  
Fish Populations ◽  
Moving Target

Zamenis scalaris prefers abandoned citrus orchards in Eastern Spain. Ecological insights from a radio-tracking survey

2019 ◽  
Vol 40 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Fernando Martinez-Freiria ◽  
Marcial Lorenzo ◽  
Miguel Lizana
Keyword(s):  
Spatial Ecology ◽  
Home Range Size ◽  
Home Ranges ◽  
Radio Tracking ◽  
Spatial And Temporal Patterns ◽  
Citrus Orchard ◽  
Subsequent Increase ◽  
Citrus Orchards ◽  
Active Forager ◽  
One Year

Abstract Zamenis scalaris is a generalist active forager Mediterranean snake for which knowledge on spatial ecology is very limited. We report insights into the spatial and temporal patterns, and habitat use of four snakes, obtained through one-year radio-tracking monitoring in a citrus orchard landscape, in Eastern Iberia. Snakes showed a highly secretive behaviour, remaining hidden most of the annual cycle (>96% of records). Annual home ranges and movements were reduced in contrast to the expected energetic requirements of the species. Despite a similar pattern of non-activity during winter and a subsequent increase of movement rate and home range size in spring, each snake adopted a distinct spatial behaviour in summer and autumn. Abandoned citrus orchards and accessory constructions were the most frequent habitats selected by snakes, offering abundant prey and shelter. These resources are likely playing a crucial role in the spatial ecology of Z. scalaris.

Retention of radio tags in golden perch (Macquaria ambigua), silver perch (Bidyanus bidyanus) and carp (Cyprinus carpio)

2009 ◽  
Vol 60 (4) ◽  
pp. 334 ◽  
Author(s):  
J. P. O'Connor ◽  
J. D. Koehn ◽  
S. J. Nicol ◽  
D. J. O'Mahony ◽  
J. A. McKenzie
Keyword(s):  
Success Rate ◽  
Freshwater Fish ◽  
Peritoneal Cavity ◽  
Retention Rates ◽  
Radio Tracking ◽  
Tag Retention ◽  
Limited Success ◽  
Carp Cyprinus Carpio ◽  
Fish Survival ◽  
Rejection Rates

Radio tagging and tracking are widely used to study freshwater fish; however, details of fish survival or tag retention rates are rarely reported. The results from five independent tagging trials associated with different tag attachment methods are reported in the present study. Implanted peritoneal cavity tags were trialled for two native Australia freshwater fish species (golden perch and silver perch) and introduced carp. Oesophageal and external tags were also trialled on silver perch. The results from the peritoneal cavity implantation trials in golden perch, silver perch and carp achieved an overall success rate of 81% (after 315 days), 18% (after 200 days) and 43% (after 323 days) respectively. The external attachment of radio tags to silver perch had limited success with all fish either rejecting their tags or dying before 256 days. Silver perch trialled with oesophageal tags had an overall success rate of 25% after 200 days. The trials indicate that internal tagging is suitable for longer-term radio tracking of golden perch, but further developments are required for longer-term applications to silver perch and carp. Tag rejection rates are unlikely to be constant between species or through time and this variability should be incorporated into the study design to prevent bias.

Home range, habitat use and movements by the little raven (Corvus mellori) in a coastal peri-urban landscape

2015 ◽  
Vol 42 (6) ◽  
pp. 500 ◽  
Author(s):  
Desley A. Whisson ◽  
Michael A. Weston ◽  
Kelly Shannon
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Spatial Ecology ◽  
Coastal Wetland ◽  
Urban Landscape ◽  
Habitat Preferences ◽  
Urban Environments ◽  
Home Ranges ◽  
Convex Polygons ◽  
Natural Habitats

Context In peri-urban environments, high availability of anthropogenic resources may result in relatively high abundances of some species, with potentially negative implications for other native biota. Effective management of such impacts requires understanding of the spatial ecology of problem species. However, home range and habitat use have not been described for the little raven (Corvus mellori), a superabundant native predator that occurs in urban and natural habitats, including those where threatened shorebirds breed. Aims The aim of this study was to provide basic information on little raven home range, habitat use and movements in a coastal peri-urban landscape. Methods Between October 2011 and January 2012 we radio-tracked 20 little ravens captured in a coastal wetland (near Melbourne, Australia). Key results Little ravens were highly mobile, moving up to 9.9 km in an hour (median = 2 km), and had large ranges: Minimum Convex Polygons were 1664–9989 ha (median = 3362 ha). Although most birds used both anthropogenic and natural habitats, some birds strongly selected for coastal wetland habitat. Birds used multiple roosts during the study period, most of which occurred in grassland (58.7%) or urban (22.3%) areas. Movement of up to 8.3 km (median = 2.2 km) between roosts during the night was also detected. Conclusions Ravens were highly mobile and used large home ranges and a variety of habitats, with habitat preferences varying between birds. Implications Considering the large home ranges and inter-individual variation in habitat preferences of little raven populations, localised management to reduce their impacts on breeding shorebirds is unlikely to be successful.

Home ranges and movements of the Chinese stripe-necked turtle (Ocadia sinensis) in the Keelung River, northern Taiwan

2008 ◽  
Vol 29 (3) ◽  
pp. 383-392 ◽  
Author(s):  
Kuang-Yang Lue ◽  
Tien-Hsi Chen
Keyword(s):  
Home Range ◽  
River Management ◽  
Seasonal Patterns ◽  
Home Ranges ◽  
Radio Tracking ◽  
Daily Movement ◽  
Riverine Habitat ◽  
Conservation Concern ◽  
Northern Taiwan ◽  
Range Length

Abstract We investigated home ranges and movements of 13 adult Ocadia sinensis by radio-tracking in a narrow and disturbed riverine habitat of the Keelung River, northern Taiwan from January 2001 to April 2002. Our results indicated that individuals of this turtle were sedentary, with home range length averaging 703 m (range 170-1460 m). Home range length did not differ between the sexes. Movement patterns of radio-tracked turtles were highly variable, with no apparent seasonal patterns. The daily movement distances ranged from 5-245 m, equalling 0.3 to 47.1% of their home range length. Usually, O. sinensis moved into a new pool during flooding or after a longer period of low water level. This turtle was seldom relocated terrestrially, showing its highly aquatic nature. Ocadia sinensis used the riverine habitat unevenly, preferring the deep and slow-current pools and avoiding highly modified river sections. Our results raise conservation concern about loss of deeper, slow-current pools in many river management projects, which was important habitat for O. sinensis in their home ranges.

Reconstruction of Objects from their Projections Using Orthogonal Functions

1973 ◽  
Vol 31 ◽  
pp. 268-269
Author(s):  
Elrnar Zeitler
Keyword(s):  
Unit Area ◽  
Three Dimensional ◽  
One Dimension ◽  
Spatial Density ◽  
Dimensional Representation ◽  
Orthogonal Functions ◽  
Object A ◽  
Plane Normal ◽  
Dimensional Object ◽  
Spatial Density Distribution

Considering any finite three-dimensional object, a “projection” is here defined as a two-dimensional representation of the object's mass per unit area on a plane normal to a given projection axis, here taken as they-axis. Since the object can be seen as being built from parallel, thin slices, the relation between object structure and its projection can be reduced by one dimension. It is assumed that an electron microscope equipped with a tilting stage records the projectionWhere the object has a spatial density distribution p(r,ϕ) within a limiting radius taken to be unity, and the stage is tilted by an angle 9 with respect to the x-axis of the recording plane.

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