scholarly journals Interaction between dietary and habitat niche breadth influences cetacean vulnerability to environmental disturbance

Ecosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
Author(s):  
Carl S. Cloyed ◽  
Brian C. Balmer ◽  
Lori H. Schwacke ◽  
Randall S. Wells ◽  
Elizabeth J. Berens McCabe ◽  
...  
2018 ◽  
Vol 33 (11) ◽  
pp. 1865-1879 ◽  
Author(s):  
Rémi Torrenta ◽  
Florent Lacoste ◽  
Marc-André Villard

2017 ◽  
Vol 7 (19) ◽  
pp. 7838-7847 ◽  
Author(s):  
Itai Granot ◽  
Noa Shenkar ◽  
Jonathan Belmaker
Keyword(s):  

2020 ◽  
Author(s):  
Marco Basile ◽  
Thomas Asbeck ◽  
João M. Cordeiro Pereira ◽  
Grzegorz Mikusiński ◽  
Ilse Storch

AbstractSpecies associations can have profound effects on the realized habitat niche of species, indicating that habitat structure alone cannot fully explain observed abundances. To account for this aspect of community organization in niche modelling, we developed multi-species abundance models, incorporating the local effect of potentially associated species, alongside with environmental ones, targeting mainly forest management intensity. We coupled it with a landscape-scale analysis to further examine the role of management intensity in modifying the habitat niche in connection with the landscape context. Using empirical data from the Black Forest in southern Germany, we focused on the forest bird assemblage and in particular on the cavity nester and canopy forager guilds. We included in the analysis species that co-occur and for which evidences suggest association is likely. Our findings show that the local effect of species associations can moderate the effects of management intensity. We also found that species express a larger habitat niche breadth in intensively managed forests, depending on the landscape context. Species associations may facilitate the utilization of a broader range of environmental conditions under intensive forest management, which benefits some species over others. Such network of associations may be a relevant factor in the effectiveness of conservation-oriented forest management.


2012 ◽  
Vol 28 (4) ◽  
pp. 385-394 ◽  
Author(s):  
Farshid S. Ahrestani ◽  
Ignas M. A. Heitkönig ◽  
Herbert H. T. Prins

Abstract:There is little understanding of how large mammalian herbivores in Asia partition habitat and forage resources, and vary their diet and habitat selection seasonally in order to coexist. We studied an assemblage of four large herbivores, chital (Axis axis), sambar (Cervus unicolor), gaur (Bos gaurus) and Asian elephant (Elephas maximus), in the seasonal tropical forests of Bandipur and Mudumalai, South India, and tested predictions regarding the species’ seasonal diet browse : graze ratios, habitat selection and habitat-niche preference and overlap. Field data collected for the study included the seasonal variation in grass quality, the seasonal variation in δ13C in the species’ faeces and the seasonal variation in the species’ habitat selection and overlap using a grid-based survey. Results of the δ13C analyses showed that the chital was more of a grazer in the wet season (−17.9‰ to −21.6‰), but that it increased the proportion of browse in its diet in the dry season (−25.6‰ to −27.7‰); the gaur was a grazer for most of the year (−15.3‰ to −18.6‰); the sambar preferred to browse throughout the year (−21.1‰ to −30.4‰); and that the elephant was a mixed feeder (−14.2‰ to −21.4‰). Elephant habitat-niche breadth was high (0.53 in wet and 0.54 in dry) and overlapped equally with that of the other species in both seasons (0.39–0.94). The gaur had the most restricted habitat-niche breadth in both seasons (0.25 in wet and 0.28 in dry), and it switched from the moist deciduous habitat in the dry season to the dry deciduous habitat in the wet season. These results offer the first insights into the seasonal variation in browse : graze diet ratios and the habitat-niche overlap amongst the common largest-bodied mammalian herbivore species found in South India.


Author(s):  
G. Shenbrot ◽  
B. Kryštufek

Habitat niche breadth for Palearctic Arvicolinae species was estimated at both local (α- niche) and global (the entire geographic range, γ-niche) scales using occurrence records of species and environmental (climate, topography, and vegetation) data. Niche breadth was estimated in the space of the first two principal components of environmental variables using kernel smoothing of the densities of species occurrence points. The breadth of α-niches was estimated for a set of random points inside the geographic range in a series of buffers of increasing size around these points. Within each buffer, we calculated the overlap between the distribution of environment values for the kernel smoothed densities of species occurrence points and the distribution of environment values in the background environment. The α-niche breadth was calculated as the slope of the linear regression of the niche breadth for buffers of different size by the ln area of these buffers with a zero intercept. The γ-niche breadth was calculated as the overlap between the distributions of environmental values for the kernel smoothed densities of species occurrence points over the whole geographic range and the distribution of environmental values in the background environment and also approximated by linear regression of the species’ average α-niche to the geographic range area of this species. The results demonstrated that the geographic range size was significantly related with the α- and γ-niche breadth. The γ-niche breadth was significantly positively correlated with the α-niche breadth. Finally, the differences between the γ-niche breadth values that were directly estimated and extrapolated from the α-niche breadth (Δ) values were positively correlated with the geographic range size. Thus, we conclude that the species occupy larger geographic ranges because they have broader niches. Our estimations of the γ-niche breadth increase with the geographic range size not due to a parallel increase of the environmental diversity (spatial autocorrelation in the environment).


1984 ◽  
Vol 62 (5) ◽  
pp. 944-950 ◽  
Author(s):  
Steven W. Buskirk ◽  
Stephen O. MacDonald

Studies of the diet of marten (Martes americana) and the abundance and habitat associations of small mammals were conducted in south-central Alaska for 2 years. Marten were found to eat primarily arvicolid (= microtine) rodents. Other important food items were sciurid rodents, fruits, and birds. Strong seasonal variation in the importance of arvicolid rodents was associated with changes in their density as indicated by trapline capture success. Northern red-backed voles (Clethrionomys rutilus) dominated the diet of marten when they and other arvicolids were generally scarce, whereas tundra voles (Microtus oeconomus) and meadow voles (M. pennsylvanicus) were the primary prey when arvicolids were abundant. Arvicolid species exhibited strong differences in habitat associations and habitat niche breadth. Red-backed voles were found in a wide range of habitat types, but tundra voles and meadow voles were limited to herbaceous and low shrub meadow habitats, where they attained high local densities. Similarities in patterns of prey preference by marten among several North American sites are described. The effects of patterns of habitat use by arvicolid rodents on the food habits of marten are discussed.


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