scholarly journals Spatial distribution, abundance and habitat use of the protected fan mussel Pinna nobilis in Souda Bay, Crete

2009 ◽  
Vol 8 ◽  
pp. 45-54 ◽  
Author(s):  
S Katsanevakis ◽  
M Thessalou-Legaki
Keyword(s):  
Spatial Distribution ◽  
Habitat Use ◽  
Pinna Nobilis

scholarly journals Spatial distribution, abundance and habitat use of the endemic Mediterranean fan mussel Pinna nobilis in Gera Gulf, Lesvos (Greece): comparison of design-based and model-based approaches

2018 ◽  
Vol 19 (3) ◽  
pp. 642 ◽  
Author(s):  
ALEXANDROS TSATIRIS ◽  
VASILEIOS PAPADOPOULOS ◽  
DESPINA MAKRI ◽  
KONSTANSTINOS TOPOUZELIS ◽  
EVA MANOUTSOGLOU ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Population Density ◽  
Habitat Use ◽  
Additive Models ◽  
Mussel Population ◽  
Population Densities ◽  
Model Based ◽  
Pinna Nobilis ◽  
Eastern Aegean ◽  
Muddy Sediments

An important population of the endemic Mediterranean fan mussel Pinna nobilis thrives in the marine protected area of Gera Gulf (Lesvos island, north-eastern Aegean Sea, Greece), and was assessed for the first time. To estimate the abundance, spatial distribution and habitat use of fan mussels in Gera Gulf, a distance sampling underwater survey was conducted. Detectability was modelled to secure unbiased estimates of population density. Two approaches were applied to analyze survey data, a design-based and a model-based approach using generalized additive models. The first approach was based on stratified random sampling on two strata, an assumed ‘preferable’ zone close to the coastline and an assumed unsuitable habitat, with predominantly muddy sediments, in which low sampling effort was applied. For the needs of the model-based approach, a dedicated cruise was conducted to collect bathymetric data with a single-beam echo-sounder and map the bathymetry of the study area. A very high-resolution image from the Worldview-3 satellite was processed, based on an object-based image analysis, for mapping all main habitat types in the study area. The estimated abundance using the design-based approach was low-biased as the stratum of pre-assumed unsuitable habitat proved to include patches of suitable habitats with high population densities that were missed by sampling. The model-based approach provided an abundance estimate of 213300 individuals (95% confidence interval between 97600-466000 individuals), which renders the fan mussel population of Gera Gulf the largest recorded population in Greece. Population density peaked between 1.5-8 m depth and became practically zero at depths >15 m. A bathymetric segregation of fan mussel size classes was noted, with the density of small individuals peaking in shallow waters, while that of large individuals peaked deeper. The highest population densities were observed in Posidonia oceanica meadows, followed by mixed bottoms (with reefs, rocks and sandy patches), while densities were very low on sandy and zero on muddy sediments. The current assessment provides a baseline for future monitoring of the fan mussel population in Gera Gulf. In view of the current (2017-2018) ongoing mass mortality of the species in the western Mediterranean, continuous monitoring of the main fan mussel populations, such as the one in Gera Gulf, is of utmost importance.   

Habitat use of the introduced cane toad (Rhinella marina) and native frog species in tropical Australia

2015 ◽  
Vol 31 (6) ◽  
pp. 531-540 ◽  
Author(s):  
Martin Mayer ◽  
Gregory P. Brown ◽  
Barbara Zimmermann ◽  
Matthew J. Greenlees ◽  
Richard Shine
Keyword(s):  
Spatial Distribution ◽  
Habitat Selection ◽  
Habitat Use ◽  
Ecological Impacts ◽  
Northern Australia ◽  
Cane Toad ◽  
Rhinella Marina ◽  
Frog Species ◽  
Tropical Australia ◽  
Reducing Activity

Abstract:The ecological impacts of introduced species can reveal mechanisms underlying habitat selection and behaviour. We investigated the habitat use of native frog species and the invasive cane toads (Rhinella marina) in tropical northern Australia to measure overlap in habitat use, and to test if the presence of the cane toad influences frog behaviour. Native frog species and the cane toad both preferred habitats close to water and unvegetated holes. However, native frogs were found further from water (on average 19.4 m) than were toads (on average 12.6 m), and preferred areas with higher vegetation (8–50 cm) than did toads, which were more abundant in vegetation lower than 8 cm. For both types of anuran, the next neighbour was more often of the same type (89% in frogs, 52% in toads) than expected by chance (observed ratio: 75% frogs vs 25% toads), reflecting these differences in habitat use. Our counts of frog abundance increased on average 14.5% in areas from which we removed cane toads temporarily. This result suggests that cane toads inhibit the activity of native anurans either by inducing avoidance, or by reducing activity. By modifying the behaviour and spatial distribution of native taxa, invasive cane toads may curtail activities such as feeding and breeding.

scholarly journals Influence of environmental variation on spatial distribution and habitat-use in a benthic foraging marine predator

2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Cassie N. Speakman ◽  
Andrew J. Hoskins ◽  
Mark A. Hindell ◽  
Daniel P. Costa ◽  
Jason R. Hartog ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Habitat Use ◽  
Large Scale ◽  
Environmental Variability ◽  
Southern Oscillation ◽  
Environmental Variation ◽  
Climate Indices ◽  
Marine Systems ◽  
Marine Predators ◽  
Eastern Australia

The highly dynamic nature of the marine environment can have a substantial influence on the foraging behaviour and spatial distribution of marine predators, particularly in pelagic marine systems. However, knowledge of the susceptibility of benthic marine predators to environmental variability is limited. This study investigated the influence of local-scale environmental conditions and large-scale climate indices on the spatial distribution and habitat use in the benthic foraging Australian fur seal ( Arctocephalus pusillus doriferus ; AUFS). Female AUFS provisioning pups were instrumented with GPS or ARGOS platform terminal transmitter tags during the austral winters of 2001–2019 at Kanowna Island, south-eastern Australia. Individuals were most susceptible to changes in the Southern Oscillation Index that measures the strength of the El Niño Southern Oscillation, with larger foraging ranges, greater distances travelled and more dispersed movement associated with 1-yr lagged La Niña-like conditions. Additionally, the total distance travelled was negatively correlated with the current year sea surface temperature and 1-yr lagged Indian Ocean Dipole, and positively correlated with 1-yr lagged chlorophyll- a concentration. These results suggest that environmental variation may influence the spatial distribution and availability of prey, even within benthic marine systems.

Spatial distribution and habitat use of reed warblers Acrocephalus scirpaceus during the autumn migration

Behaviour ◽  
2014 ◽  
Vol 151 (6) ◽  
pp. 799-817 ◽  
Author(s):  
Miren Andueza ◽  
Juan Arizaga ◽  
Emilio Barba ◽  
Ibon Tamayo-Uria
Keyword(s):  
Spatial Distribution ◽  
Habitat Use ◽  
Breeding Site ◽  
Autumn Migration ◽  
First Year ◽  
Home Ranges ◽  
Spatial Behaviour ◽  
Stopover Site ◽  
Stopover Sites ◽  
Acrocephalus Scirpaceus

Spatial behaviour and habitat selection at stopover sites have a strong influence on the foraging and fuelling performance of migrating birds and hence are important aspects of stopover ecology. The aim of this study was to analyse the spatial behaviour and habitat use of reed warblers Acrocephalus scirpaceus during the autumn migration. We used radio tracking data from reed warblers surveyed at a stopover site in northern Iberia and assigned to three different groups: (1) local adult birds which were still at their breeding site, (2) migrating first-year birds (originating from beyond Iberian peninsula) and (3) migrating adult birds. Overall, migrating first-year birds tended to have larger home ranges than both local and migrating adults and to move more widely in the study area. They also showed lower fat deposition rates than adults. The proportion of habitats in home ranges (reed-beds and tidal flats being the most abundant habitats) was similar amongst groups. The spatial distribution and habitat use of organisms have been theorised to follow an ideal-free or ideal-despotic distribution. However, according to our results, other complex underlying mechanisms may play an important role in shaping the spatial behaviour of birds at stopover sites.

scholarly journals Spatial Distribution and Habitat Use of Javan Langur (Presbytis Comata): Case Study in District of Kuningan

2016 ◽  
Vol 33 ◽  
pp. 340-353 ◽  
Author(s):  
Toto Supartono ◽  
Lilik Budi Prasetyo ◽  
Agus Hikmat ◽  
Agus Priyono Kartono
Keyword(s):  
Spatial Distribution ◽  
Habitat Use

Short-term changes in spatial distribution pattern of an herbivore in response to accumulating snow

2017 ◽  
Vol 95 (12) ◽  
pp. 949-954
Author(s):  
Toshinori Kawaguchi ◽  
André Desrochers
Keyword(s):  
Spatial Distribution ◽  
Habitat Use ◽  
Snow Depth ◽  
Spatiotemporal Variation ◽  
Short Term ◽  
Distribution Models ◽  
Dense Vegetation ◽  
Snowshoe Hares ◽  
Canadian Boreal Forest ◽  
Track Counts

Deep snow can reduce accessibility to vegetation and cover by herbivores by blanketing understory cover, yet simultaneously increase access to foliage at higher levels. Thus, snow depth fluctuation should lead to spatiotemporal variation in herbivore habitat use. We measured shifts in habitat use by snowshoe hare (Lepus americanus Erxleben, 1777) as a function of snow depth in an eastern Canadian boreal forest where snow depth often exceeds 1 m. We hypothesized that as snow accumulates, snowshoe hares shift from locations with dense vegetation just above ground to locations with dense vegetation higher above ground. We surveyed 58 km of transects over three winters and found 1954 hare tracks. We analyzed track counts as a response to a density index of low vegetation (0–1.5 m above ground), high vegetation (2–4 m above ground), predator tracks, and snow depth. We found more hare tracks in sites with dense high vegetation when snow was deeper, and more hare tracks in sites with dense low vegetation when snow was shallower. Predator track presence did not influence responses to snow depth. Snow depth dynamics can drive hare distribution, and in turn, introduce uncertainty in spatial distribution models for the species and possibly its interactions with predators.

Spatial Distribution and Habitat Use of Spawning American Shad in the St. Johns River, Florida

2015 ◽  
Vol 32 (7) ◽  
pp. 1493-1504
Author(s):  
A. C. Dutterer ◽  
W. E. Pine ◽  
S. J. Miller ◽  
A. R. Hyle ◽  
M. S. Allen
Keyword(s):  
Spatial Distribution ◽  
Habitat Use ◽  
American Shad

scholarly journals Spatial Distribution Changes and Habitat Use in Red Porgy in Waters off the Southeast U.S. Atlantic Coast

2020 ◽  
Vol 12 (6) ◽  
pp. 381-394
Author(s):  
Tracey I. Smart ◽  
Walter J. Bubley ◽  
Dawn M. Glasgow ◽  
Marcel J. M. Reichert
Keyword(s):  
Spatial Distribution ◽  
Habitat Use ◽  
Atlantic Coast ◽  
Red Porgy
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