Nonideal habitat selection by a North American cavity excavator: pecking up the wrong tree?

2010 ◽  
Vol 88 (6) ◽  
pp. 527-535 ◽  
Author(s):  
G. Sadoti ◽  
K. T. Vierling

Nonideal habitat selection occurs when preferred habitat attributes differ from those associated with increased fitness. These mismatches have been widely studied in open cup-nesting birds, but the relationship between habitat-associated preferences and fitness in cavity-nesting birds has received relatively little attention. We studied patterns of preference and fitness during 2006–2007 in an Idaho, USA, population of Red-naped Sapsuckers ( Sphyrapicus nuchalis S.F. Baird, 1858). Using a suite of nonparametric tests, we examined the associations between habitat attributes and both nesting-area preferences and nest productivity (number of fledglings per pair) across four spatial scales. Nest productivity was associated with tree- and cavity-scale attributes, whereas preference was associated with attributes of home ranges. Live trees and southeasterly oriented cavities had higher nest productivity but were not preferred. Microclimates in nests with these attributes may enhance nestling survival, whereas nonpreference for these attributes may be due to energetic constraints in some individuals. Additional studies comparing patterns of nonideal habitat selection between open-cup nesters and cavity nesters should advance our understanding of how life-history characteristics influence selection patterns.

2010 ◽  
Vol 88 (11) ◽  
pp. 1052-1062 ◽  
Author(s):  
M. Pellerin ◽  
C. Calenge ◽  
S. Saïd ◽  
J.- M. Gaillard ◽  
H. Fritz ◽  
...  

In most previous studies of habitat selection, the use of a given habitat type is assumed to be directly proportional to its availability. However, the use and (or) the selection of a given habitat may be conditional on the availability of that habitat. We aim here to (i) identify the environmental variables involved in habitat selection, (ii) identify classes of individuals with similar patterns of habitat selection, and (iii) assess whether habitat use changes with changing availability of habitat types, within monthly home ranges of female western roe deer ( Capreolus capreolus (L., 1758)). We found that some females adjust their habitat use according to the distribution of resources within habitats. Females with similar home ranges in terms of resource quantity and quality showed similar patterns of habitat selection. Differences in habitat use between 2 years with contrasting resource availability showed that temporal changes of environmental conditions influenced the pattern of habitat selection by female roe deer. Habitat selection also differed between periods of the life cycle likely because of contrasted energy requirements. This study shows that the relationship between habitat use by herbivores and habitat availability is nonproportional, and that the availability of resources influences use mostly at intermediate values.


2010 ◽  
Vol 88 (9) ◽  
pp. 846-854 ◽  
Author(s):  
M.-A. Carrière ◽  
G. Blouin-Demers

Understanding habitat use of declining species is essential for their management and successful recovery. We examined habitat selection at multiple spatial scales by Northern Map Turtles ( Graptemys geographica (Le Sueur, 1817)), a species at risk, in the St. Lawrence Islands National Park, Ontario, Canada. At the scale of the home range, Map Turtles generally avoided deep water (>2 m) and selected home ranges in waters <1 m deep. Importantly, turtles used home ranges with significantly more natural than developed shoreline. At the scale of the location, adult females used deep water more often and males preferred areas with surface cover. Management efforts should implement regulations concerning further shoreline development.


2002 ◽  
Vol 80 (9) ◽  
pp. 1602-1609 ◽  
Author(s):  
Adam C Smith ◽  
James A Schaefer

Variation in home-range size can be related to different factors at different spatial scales. This study examined the patterns of home-range size and habitat selection of American marten (Martes americana) in southeastern Labrador, a region of extensive and pristine forests. Over 1.5 years, we monitored 28 radio-collared marten and compared the availability of habitat types with their use. Marten avoided areas with low productivity and low canopy cover (<20%) but showed no selection for tree species composition or cover among more productive forests. Mean home ranges for both sexes (males, 45.0 km2; females, 27.6 km2) were exceptionally large, more than double the largest values previously recorded for the species. We analyzed variation in home-range size at two scales: within our study population and, using data from the literature, among populations across the species range in relation to temperature, snow cover, and body size. Within our population, home-range area was positively related to the proportion of bog and less productive, scrub forests in the home range. Among populations, differences in home-range size were not significantly related to any of the tested factors.


2001 ◽  
Vol 79 (2) ◽  
pp. 319-324 ◽  
Author(s):  
Xin Lu ◽  
Guang Mei Zheng

We investigated habitat selection and use by a recently discovered hybrid of the white eared pheasant (Crossoptilon crossoptilon) and Tibetan eared pheasant (Crossoptilon harmani) in the forests of eastern Tibet (93°39'E, 32°24'N) during the post-incubation period in 1995. The frequency of encountering molted feathers was used as an indicator of the relative abundance of eared pheasants in order to analyze patterns of habitat selection and use. Forests on south-facing slopes, dominated by the hollyleaf-like oak (Quercus aquifolioides) and Tibetan juniper (Sabina tibetica), were the habitats preferred by eared pheasants. North-facing slopes with coniferous forest, which is the most preferred habitat of eared pheasant species in other areas, were completely avoided, probably because moisture-heat conditions there are beyond the birds' physiological tolerance. We conclude that climatic conditions are the main determinant of macrohabitat selection by eared pheasant species. In preferred habitats, oak and juniper woodland accounted for a larger proportion of home ranges of family flocks. Daily movements of a flock might cover a large altitudinal range, from the base of the mountain to the area above tree line, with an apparent preference for sites that can be used for foraging and dusting.


2010 ◽  
Vol 88 (9) ◽  
pp. 875-883 ◽  
Author(s):  
Jodie Martin ◽  
Mathieu Basille ◽  
Bram Van Moorter ◽  
Jonas Kindberg ◽  
Dominique Allainé ◽  
...  

In human-dominated landscapes, species with large spatial requirements, such as large carnivores, have to deal with human infrastructure and activities within their home ranges. This is the case for the brown bear ( Ursus arctos L., 1758) in Scandinavia, which is colonizing more human-dominated landscapes, leading inevitably to an overlap between their home ranges and anthropogenic structures. In this study, we investigated fine-scale habitat selection by brown bears to examine how they deal with this potential disturbance. Using Global Positioning System (GPS) data, we studied (i) habitat selection of female brown bears within their home range and (ii) the influence of diurnal variation in human disturbance on fine-scale habitat use. As expected, females selected habitats within their home range that provided abundant food resources and minimized human-caused disturbance. In addition, our temporal analysis of habitat selection revealed an avoidance of disturbed areas and a selection of slopes by bears during periods of highest human activities, i.e., during daylight hours. We clearly demonstrate the importance of considering the fluctuations in human activity when studying habitat selection, especially at fine spatial scales. Failing to do so may considerably reduce the power to detect important fine-scale habitat-selection behaviors.


2012 ◽  
Vol 90 (2) ◽  
pp. 139-149 ◽  
Author(s):  
J.E. Paterson ◽  
B.D. Steinberg ◽  
J.D. Litzgus

Habitat selection is the disproportionate use of habitat compared with availability. Many studies have focused on specialists, but few have considered habitat selection in populations that are generalists, which can be composed of generalist individuals or individuals that specialize on different habitats. We tested habitat selection and individual specialization in a northern population of a supposed generalist, the Snapping Turtle ( Chelydra serpentina (L., 1758)), during the active season and winter using telemetry. Habitat selection was tested at two spatial scales by comparing random points to home ranges and turtle locations using Euclidean distances. Turtles selected home ranges from the habitats available in the population range. However, at the population level, all aquatic habitats were equally preferred, and the population behaved as a generalist owing to individuals specialized on different habitats. Over half of the individuals showed evidence of individual specialization on different habitat types. Turtles did not select habitat within home ranges during the active season, but overwintering turtles chose locations that were colder than haphazard stations in the same habitats, likely to reduce metabolic costs and the risk of acidosis. These findings have implications for the management of this species at risk and for understanding the evolution of resource generalization.


The environment has always been a central concept for archaeologists and, although it has been conceived in many ways, its role in archaeological explanation has fluctuated from a mere backdrop to human action, to a primary factor in the understanding of society and social change. Archaeology also has a unique position as its base of interest places it temporally between geological and ethnographic timescales, spatially between global and local dimensions, and epistemologically between empirical studies of environmental change and more heuristic studies of cultural practice. Drawing on data from across the globe at a variety of temporal and spatial scales, this volume resituates the way in which archaeologists use and apply the concept of the environment. Each chapter critically explores the potential for archaeological data and practice to contribute to modern environmental issues, including problems of climate change and environmental degradation. Overall the volume covers four basic themes: archaeological approaches to the way in which both scientists and locals conceive of the relationship between humans and their environment, applied environmental archaeology, the archaeology of disaster, and new interdisciplinary directions.The volume will be of interest to students and established archaeologists, as well as practitioners from a range of applied disciplines.


Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 936
Author(s):  
Milan Kojić ◽  
Branka Protić Gava ◽  
Milan Bajin ◽  
Marko Vasiljević ◽  
Jasmina Bašić ◽  
...  

Background: The research objective of the study is to determine the differences in the manifestation of the motor status of normally fed preschool test subjects, classified into groups according to foot status. Methods: This is a simple, comparative observational study. Preschool children included in this study have been subjected to anthropometric measurements in order to determine BMI, tests for motor skills assessment (running at 20 m from a high start, standing broad jump, backwards polygon, rectangular seated forward bend, plate tapping, sit-ups for 60 s, and bent arm hang), and a determination of foot status. The total sample was comprised of 202 test subjects who attended a regular sports program, aged 3.9 to 6.5 years of decimal age (M = 141; Age = 5.3 ± 0.74; Height = 117.3 ± 7.1; Weight = 22 ± 3.7; F = 61; Age = 5.1 ± 0.73; Height = 114.9 ± 7.4; Weight = 21.2 ± 3.8), of which 153 (75.7%) were normally fed, 6 (3%) were undernourished, 30 were overweight (14.9%), and 13 were obese (6.4%). Results: In the total sample, 30 (14.9%) subjects had normal arch feet, 90 (44.6%) high arched feet, and 41 (20.3%) flat feet. We found 41 (20.3%) subjects who had different left and right foot statuses within this sample. The data were processed by means of nonparametric tests (the Kruskal–Wallis and Mann–Whitney U tests) at a significance level p ≤ 0.05. Conclusion: The results show that there is a statistically significant difference between groups of subjects with different foot statuses in the manifestation of motor status in most tests, with a significance level of p ≤ 0.01, and in tests of sit-ups for 60 s and the bent arm hang, there is a statistically significant difference, the level of which is p ≤ 0.05. It is only in the inclination test of rectangular seated forward bend that no statistically significant difference was displayed.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kuang-Yu Chang ◽  
William J. Riley ◽  
Sara H. Knox ◽  
Robert B. Jackson ◽  
Gavin McNicol ◽  
...  

AbstractWetland methane (CH4) emissions ($${F}_{{{CH}}_{4}}$$ F C H 4 ) are important in global carbon budgets and climate change assessments. Currently, $${F}_{{{CH}}_{4}}$$ F C H 4 projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent $${F}_{{{CH}}_{4}}$$ F C H 4 temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that $${F}_{{{CH}}_{4}}$$ F C H 4 are often controlled by factors beyond temperature. Here, we evaluate the relationship between $${F}_{{{CH}}_{4}}$$ F C H 4 and temperature using observations from the FLUXNET-CH4 database. Measurements collected across the globe show substantial seasonal hysteresis between $${F}_{{{CH}}_{4}}$$ F C H 4 and temperature, suggesting larger $${F}_{{{CH}}_{4}}$$ F C H 4 sensitivity to temperature later in the frost-free season (about 77% of site-years). Results derived from a machine-learning model and several regression models highlight the importance of representing the large spatial and temporal variability within site-years and ecosystem types. Mechanistic advancements in biogeochemical model parameterization and detailed measurements in factors modulating CH4 production are thus needed to improve global CH4 budget assessments.


2017 ◽  
Vol 13 (1) ◽  
pp. 20160783 ◽  
Author(s):  
Gabrielle L. Davidson ◽  
Alex Thornton ◽  
Nicola S. Clayton

Strong selection pressures are known to act on animal coloration. Although many animals vary in eye colour, virtually no research has investigated the functional significance of these colour traits. Passeriformes have a range of iris colours, making them an ideal system to investigate how and why iris colour has evolved. Using phylogenetic comparative methods, we tested the hypothesis that conspicuous iris colour in passerine birds evolved in response to (a) coordination of offspring care and (b) cavity nesting, two traits thought to be involved in intra-specific gaze sensitivity. We found that iris colour and cooperative offspring care by two or more individuals evolved independently, suggesting that bright eyes are not important for coordinating parental care through eye gaze. Furthermore, we found that evolution between iris colour and nesting behaviour did occur in a dependent manner, but contrary to predictions, transitions to coloured eyes were not more frequent in cavity nesters than non-cavity nesters. Instead, our results indicate that selection away from having bright eyes was much stronger in non-cavity nesters than cavity nesters, perhaps because conspicuous eye coloration in species not concealed within a cavity would be more visible to predators.


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