scholarly journals Movement, Behavior, and Habitat Use of a Marine Apex Predator, the Scalloped Hammerhead

2018 ◽  
Vol 5 ◽  
Author(s):  
R. J. David Wells ◽  
Thomas C. TinHan ◽  
Michael A. Dance ◽  
J. Marcus Drymon ◽  
Brett Falterman ◽  
...  
2014 ◽  
Vol 506 ◽  
pp. 231-242 ◽  
Author(s):  
OJD Jewell ◽  
MA Wcisel ◽  
AV Towner ◽  
W Chivell ◽  
L van der Merwe ◽  
...  

2020 ◽  
Vol 42 ◽  
pp. 109-124 ◽  
Author(s):  
BC DeGroot ◽  
G Roskar ◽  
L Brewster ◽  
MJ Ajemian

Despite being crucial to the conservation of batoids (skates and rays), assessments of fine-scale movements and habitat use of these taxa are lacking in the scientific literature. Here we used active acoustic telemetry to characterize habitat use and movement behavior of the state-protected whitespotted eagle ray Aetobatus narinari in the Indian River Lagoon, Florida, USA. Seven mature individuals (6 males and 1 female) were individually tracked for a total of 119.6 h. Brownian bridge movement models of ray distribution showed the importance of habitats with high anthropogenic activity (i.e. boat traffic) such as inlets and channels, as well as clam aquaculture lease sites close to shore. This was supported by the significantly lower rates of movement in these habitats relative to other regions (offshore, open lagoon). Rate of movement significantly increased with temperature, suggesting that rays are more active during warmer periods. No tidal patterns in ray habitat use or distribution were evident. On average, rays used the deeper portions of the lagoon during the day and shallower portions during the night. While more extensive tracking is required to elucidate long-term movement patterns, this study is the first to characterize fine-scale habitat use by the whitespotted eagle ray in Florida while also identifying areas of potential interactions between this species and multiple anthropogenic threats.


Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3460
Author(s):  
Nicole Starik ◽  
Thomas Göttert ◽  
Ulrich Zeller

Movement behavior and habitat use of the long-eared bat species Plecotus auritus and Plecotus austriacus were studied in the Havelland region in Brandenburg (Germany). Data collection included mist-netting, radiotelemetry, reconstruction of prey items, and monitoring of roosting sites. Body measurements confirm a high degree of phenotypic similarity between the two species. Total activity areas (100% Minimum Convex Polygons, MCPS) of Plecotus austriacus (2828.3 ± 1269.43 ha) were up to five-fold larger compared to Plecotus auritus (544.54 ± 295.89 ha). The activity areas of Plecotus austriacus contained up to 11 distinct core areas, and their mean total size (149.7 ± 0.07 ha) was approximately three-fold larger compared to core areas of Plecotus auritus (49.2 ± 25.6 ha). The mean distance between consecutive fixes per night was 12.72 ± 3.7 km for Plecotus austriacus and 4.23 ± 2.8 km for Plecotus auritus. While Plecotus austriacus was located most frequently over pastures (>40%) and meadows (>20%), P. auritus was located mostly within deciduous (>50%) and mixed forests (>30%) in close vicinity to its roosts. Roost site monitoring indicates that the activity of P. austriacus is delayed relative to P. auritus in spring and declined earlier in autumn. These phenological differences are probably related to the species’ respective diets. Levins’ measure of trophic niche breadth suggests that the prey spectrum for P. auritus is more diverse during spring (B = 2.86) and autumn (B = 2.82) compared to P. austriacus (spring: B = 1.7; autumn: B = 2.1). Our results give reason to consider these interspecific ecological variations and species-specific requirements of P. auritus and P. austriacus to develop adapted and improved conservation measures.


2021 ◽  
Author(s):  
◽  
Rachel Selwyn

<p>Borneo’s rainforests are experiencing some of the fastest deforestation rates worldwide and are home to increasingly vulnerable species, most of which remain poorly understood. Bornean rainforests exhibit dramatic fluctuations in fruit and seed availability during mast-fruiting events which can exert considerable influence on frugivore ecology. Comprehensive spatiotemporal assessments of habitat use, resource partitioning, and responses to fruit availability in mast-fruiting rainforests are lacking for most species, including ungulates. The distribution and habitat use of an apex predator, the Sunda clouded leopard (Neofelis diardi), may be largely shaped by the availability of these ungulates. Yet, factors driving the spatial ecology of this elusive felid remain uncertain. I aimed to quantify spatiotemporal habitat use dynamics of these species and consequently inform effective conservation planning. Specifically, I quantified the effects of human activity, forest type, elevation, and mast-induced fluctuations in resources on the habitat use of lesser mousedeer (Tragulus kanchil), greater mousedeer (T. napu), Bornean yellow muntjacs (Muntiacus atherodes), red muntjacs (M. muntjak), and bearded pigs (Sus barbatus) in Gunung Palung National Park, West Kalimantan, Indonesian Borneo. I applied data from an extensive camera trapping study (n = 42,610 trap nights) to a modified single-season occupancy model to evaluate habitat use over space and time. I then applied estimates of occurrence (Ψ) of the five ungulate species to quantify if habitat use of the Sunda clouded leopard was influenced by prey occurrence and thus if this apex predator responded to bottom-up effects of resource variability. The results from the ungulate modelling revealed that forest type was an important predictor of habitat use of all ungulate species, each preferring different forest habitats. Habitat use estimates were highest in peat swamp forests for lesser mousedeer (Ψ = 0.92 ± 0.05), alluvial bench forests for greater mousedeer (Ψ = 0.52 ± 0.08), lowland granite forests for yellow (Ψ = 0.95 ± 0.07) and red muntjacs (Ψ = 0.98 ± 0.09), and freshwater swamp forests for bearded pigs (Ψ = 0.84 ± 0.07). Bearded pigs exhibited a link between variation in fruit availability and habitat use, indicating an ability to respond to resource variability. Occupancy modelling for Sunda clouded leopards revealed forest type, fruit availability, and bearded pig occurrence as the best predictors of habitat use. The highest estimates were associated with lowland granite forests (Ψ = 0.87 ± 0.09). My results reveal a novel pattern of niche partitioning through both food and habitat resources among five sympatric ungulate species and demonstrate that Sunda clouded leopards may use fruiting events as a cue for abundant prey. My research sheds light on important factors influencing habitat use of understudied ungulates and an apex predator and can be used to refine estimates of habitat suitability across a greater landscape to inform conservation practice amidst continually shrinking remnant forests in Indonesian Borneo.</p>


2007 ◽  
Vol 85 (7) ◽  
pp. 802-808 ◽  
Author(s):  
L. Baker

Corridors are a common conservation strategy intended to increase the spatial connectivity among isolated habitat patches. Corridors, however, are not always effective. This study demonstrates that corridors increase movement to new patches for the jumping spider Phidippus princeps (Peckham and Peckham, 1883) (Araneae, Salticidae), a visually oriented predator. I assigned spiders to one of three microlandscape treatments, created in an old field dominated by alsike clover ( Trifolium hybridum L.) and alfalfa ( Medicago sativa L.), in which patches were connected to (i) vegetated corridors and bare pathways, (ii) only vegetated corridors, and (iii) only bare pathways. The movement of P. princeps was effectively directed by corridors. When given a choice of paths, spiders invariably chose vegetated corridors over bare pathways to emigrate from and to immigrate to new patches. Spiders rarely moved between patches when only bare pathways were available. In the absence of corridors, P. princeps did not risk open ground to move to new habitat even though conspecific density was high. The corridors facilitated the interpatch movement of P. princeps, suggesting that P. princeps is restricted in its habitat use. Thus, a higher degree of spatial connectivity is likely to increase the exchange of individuals for species that are restricted in their movements by unsuitable habitat.


2011 ◽  
Vol 68 (12) ◽  
pp. 2029-2045 ◽  
Author(s):  
Nigel E. Hussey ◽  
Sheldon F.J. Dudley ◽  
Ian D. McCarthy ◽  
Geremy Cliff ◽  
Aaron T. Fisk

Understanding the role of predators is challenging but critical for ecosystem management. For community dynamics, predator-specific size-based variation in diet, trophic position, and habitat use are rarely accounted for. Using two applied tools (stable isotopes and stomach content data), we examined inter- and intra-species ontogenetic variability in diet (stomach contents), trophic position (TPSIA for δ15N and TPSCA for stomach contents), and habitat use (δ13C) of two large sharks, the scalloped hammerhead ( Sphyrna lewini ) and the dusky ( Carcharhinus obscurus ). Stomach contents identified size-based and gender-specific shifts in diet indicating resource partitioning for and between species. Calculated TP for the two sharks varied by method, either TPSIA or TPSCA and with species, size, and gender, but were complicated by differing baselines and broad functional prey groups, respectively. TP increased with size for S. lewini, but was low in large C. obscurus compared with small sharks. Size-based δ13C profiles indicated habitat partitioning by sex in S. lewini and a movement to shelf edge foraging in large C. obscurus. These results demonstrate that predators exert proportional size-based effects on multiple components of the marine system that are further complicated by species- and gender-specific strategies.


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