Prey Patch Patterns Predict Habitat Use by Top Marine Predators with Diverse Foraging Strategies

Winter movements and habitat use of harbour seals (Phoca vitulina) were investigated in two tidal bays in France, at the southern limit of their species range in the Northeast Atlantic. We fitted 15 seals with Fastloc™GPS/GSMtags in the Baie du Mont-Saint-Michel (BMSM) and the Baie des Veys (BDV). Tags relayed 20.6±7.1 GPS locations per seal-day, 81% of all dives performed by the seals and 87% of haulouts, during an average tracking duration of 108±56 days. One seal travelled 380 km away from the BMSM but the other seals remained stationary, with 95% and 55% of at-sea locations ≤ 5 km from the haulout sites in BMSM and BDV respectively. Home range sizes were 137 and 161 km² in BMSM and BDV, and core areas’ sizes, 35 and 22 km² respectively. The seals remained very coastally in both sites with 93% and 71% of at-sea locations located in the intertidal zone of BMSM and BDV respectively. Accordingly, dives were shallow with 63% and 61% of dive maximum depths <4 m and 94% and 88% <10 m (in BMSM and BDV respectively). Preferred foraging areas were located in tidal channels in BMSM, sometimes in the vicinity of rocks or mussel farms. In BDV one seal made foraging trips 10-15 km offshore but all other seals repeatedly used coastal areas, often foraging around mussel farms, shipwrecks or intertidal rocks in tidal currents. We suggest that the importance of the tides combined with local features of the topography allow seals to predict prey availability, driving their foraging strategies towards a number of specific coastal areas. These results further illustrate the behavioural plasticity of the species according to habitat and environmental conditions. Fastloc™ GPS/GSM telemetry is particularly well adapted for the study of seals’ habitat use at a fine geographical and temporal scale, as long as they occasionally come close to shore within GSM coverage.

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Spatial and temporal patterns of habitat use by three estuarine species of mysid shrimp

Marine and Freshwater Research ◽

10.1071/mf07247 ◽

2008 ◽

Vol 59 (9) ◽

pp. 792 ◽

Cited By ~ 16

Author(s):

Matthew D. Taylor

Keyword(s):

Habitat Use ◽

Full Moon ◽

Foraging Strategies ◽

Habitat Partitioning ◽

Spatial And Temporal Patterns ◽

Benthic Habitats ◽

Trophic Resources ◽

New Moon ◽

Adaptive Foraging ◽

Mysid Shrimp

The mysids Rhopalopthalmus egregius, Haplostylus dakini and Doxomysis australiensis are abundant yet unstudied omnivorous crustaceans in Australian estuaries. Habitat use and population dynamics were investigated for these species over spring and summer in the Tweed River, Australia, to explore their ecological role in estuarine ecosystems. Overall, mysids were concentrated in shallow unvegetated and deep unvegetated estuarine habitats. H. dakini were most abundant in shallow and deep bare habitats at night, whereas R. egregius were most abundant in deep bare habitats during the night. D. australiensis were present across all habitats in the night, but negligible numbers were present during the day. Significantly greater numbers of R. egregius and D. australiensis were sampled during the new moon, compared with the full moon. Significantly larger R. egregius and D. australiensis individuals were present in benthic habitats at night, indicating possible partitioning of habitat for juvenile and adult subpopulations. Adaptive foraging strategies and habitat use facilitates the coexistence of sympatric mysid species, H. dakini and R. egregius, and within-species habitat partitioning allowed juvenile R. egregius to avoid interaction with adult R. egregius. The observed dynamics minimize inter- and intra-specific predation between mysids, and by other predators, while optimizing access to key trophic resources.

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Movement Patterns and Habitat use for Sympatric Species

10.21203/rs.3.rs-827045/v1 ◽

2021 ◽

Author(s):

Elizabeth McAlpine-Bellis ◽

Kaera L Utsumi ◽

Kelly M Diamond ◽

Janine Klein ◽

Sophia Gilbert-Smith ◽

...

Keyword(s):

Habitat Use ◽

Great Basin ◽

Movement Patterns ◽

Step Length ◽

Sympatric Species ◽

Habitat Characteristics ◽

Foraging Strategies ◽

Turn Angle ◽

Visual Predator ◽

Food Movement

Abstract Background: Movement is an important characteristic of an animal’s ecology, reflecting perception of and response to environmental conditions. To effectively search for food, movement patterns likely depend on habitat characteristics and the sensory systems used to find prey. We examined movements associated with foraging for two sympatric species of lizards inhabiting the Alvord Basin in the Great Basin Desert of southeastern Oregon. The two species have largely overlapping diets but find prey via different sensory cues, which link to their differing foraging strategies — the long-nosed leopard lizard, Gambelia wislizenii, is a visually-oriented predator, while the western whiptail, Aspidoscelis tigris, relies heavily on chemosensory cues to find prey.Methods: Using detailed focal observations, we characterized the habitat use and movement paths of each species. We placed markers at the location of focal animals every minute for the duration of each 30-min observation. Afterwards, we recorded whether each location was in the open or in vegetation, as well as the movement metrics of step length, path length, net displacement, straightness index, and turn angle, and then made statistical comparisons between the two species.Results: The visual forager spent more time in open areas, moved less frequently over shorter distances, and differed in patterns of plant use compared to the chemosensory forager. Path characteristics of step length and turn angle differed between species.Conclusions: The visual predator moved in a way that was consistent with the notion that they require a clear visual path to stalk prey whereas the movement of the chemosensory predator increased their chances of detecting prey by venturing further into vegetation. Sympatric species can partition limited resources through differences in search behavior and habitat use.

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

Royal Society Open Science ◽

10.1098/rsos.211052 ◽

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.

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Larger foraging range but similar habitat selection in non-breeding versus breeding sub-Antarctic penguins

Antarctic Science ◽

10.1017/s0954102010000957 ◽

2011 ◽

Vol 23 (2) ◽

pp. 117-126 ◽

Cited By ~ 33

Author(s):

Jean-Baptiste Thiebot ◽

Amélie Lescroël ◽

David Pinaud ◽

Philip N. Trathan ◽

Charles-André Bost

Keyword(s):

Habitat Selection ◽

Foraging Strategies ◽

Breeding Period ◽

Mahalanobis Distances ◽

Juvenile Dispersal ◽

Marine Predators ◽

Eudyptes Chrysolophus ◽

Breeding Grounds ◽

Suitability Maps ◽

Suitable Habitats

AbstractFor land-breeding marine organisms such as seabirds, knowledge about their habitat use has mainly been gained through studies of breeding individuals that are constrained to return frequently to their breeding grounds. In this study we set out to measure whether: a) habitat selection in the non-breeding period predicts habitat selection in the breeding period, and b) whether breeding individuals concentrated their activity on the closest suitable habitats. MacaroniEudyptes chrysolophusand gentooPygoscelis papuapenguins, two marine predators with contrasting foraging strategies, were tracked from the Iles Kerguelen and their habitat selection investigated through Mahalanobis distances factorial analysis. This study presents the first data about gentoo penguins’ juvenile dispersal. For both species, results showed 6.9 times larger maximum ranges and up to 12.2 times greater distances travelled during the non-breeding period. Habitat suitability maps suggested both species made similar environmental selections whatever the period. Macaroni penguins targeted pelagic areas beyond the shelf break while gentoo penguins always remained over the shelf. We consider the ecological significance of larger scale movements made outside the breeding period and suggest that this non-breeding period is of particular interest when attempting to understand an animal's habitat selection.

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Closely related gull species show contrasting foraging strategies in an urban environment

Scientific Reports ◽

10.1038/s41598-021-02821-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

K. A. Lato ◽

D. J. Madigan ◽

R. R. Veit ◽

L. H. Thorne

Keyword(s):

Stable Isotope ◽

Habitat Use ◽

Food Sources ◽

Foraging Strategies ◽

Urban Habitat ◽

Urban Landscapes ◽

Ecosystem Structure ◽

Herring Gulls ◽

Positive Effects ◽

Marine Habitats

AbstractThe expansion of urban landscapes has both negative and positive effects on wildlife. Understanding how different species respond to urbanization is key to assessing how urban landscapes influence regional wildlife behavior and ecosystem structure. Gulls are often described as strong urban adapters, but few studies have explored species-specific differences in habitat use. Here, we use GPS tracking in conjunction with stable isotope analysis (SIA) to quantify the habitat use and trophic ecology of great black-backed gulls (Larus marinus) and herring gulls (L. argentatus) in an urbanized area. Non-Metric Multidimensional Scaling (NMDS) of foraging locations revealed significant differences in the habitat use between species. Great black-backed gulls foraged primarily in marine habitats and herring gulls foraged primarily in specific urban habitats (e.g., landfills, dumpsters) and showed higher site fidelity in terms of the proportion of foraging sites revisited. Further, great black-backed gulls had significantly higher δ15N and δ13C than herring gulls, reflecting the use of marine, rather than urban, food sources. This study highlights the variability in urban habitat utilization among closely related species, assesses stable isotope signatures of urban diets in wild birds, and discusses ecological implications of the relative contribution of urban and marine foraging.

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