The turtle is in the details: microhabitat choice by Testudo hermanni is based on microscale plant distribution

2011 ◽  
Vol 61 (3) ◽  
pp. 249-261 ◽  
Author(s):  
Silvia Del Vecchio ◽  
Lorenzo Rugiero ◽  
Luca Luiselli ◽  
Massimo Capula ◽  
Russell L. Burke

AbstractAlthough research on habitat use and habitat selection is essential for understanding population ecology and behavior, most such zoological studies have used only general habitat categories describing main habitat features instead of using modern plant ecological approaches. Here, we analyze Testudo hermanni microhabitat use at a coastal Mediterranean site in central Italy by modeling tortoise presence/absence at three spatial scales, using a logistic regression design and quantitative vegetation and plant community analysis to reveal correlates of tortoise habitat use on a fine scale. Our analyses showed that only a few plant species among the many present, and these on a very small spatial scale, are important determinants of tortoise presence and site selection. We also find that tortoises chose a paradoxical combination of high levels of bare soil and high total vegetation cover. This suggests that these tortoises are selecting small patches of habitat in a matrix of less desirable habitat. Our findings also have important implications for habitat management, in that increasing the number of habitat patches containing the few significant plants is likely to be desirable, whereas increasing the size of such patches is probably less relevant.

2020 ◽  
Vol 71 (1) ◽  
pp. 21-35
Author(s):  
Lorenzo Rugiero ◽  
Massimo Capula ◽  
Daniele Dendi ◽  
Fabio Petrozzi ◽  
Massimiliano Di Vittorio ◽  
...  

Abstract Long-term ecological studies are important for understanding wild populations’ dynamics and processes and the actual factors that can determine their decline. Here, we report the results of a 28-years-long (1992–2019) monitoring of three distinct populations of a tortoise, Testudo hermanni, in Central Italy, with an emphasis on their population abundance trends and on the eventual variation in their habitat use across years and among the study areas. Samplings were conducted by Visual Encounter Survey (VES) methodology, and using a suite of statistical analyses including correlations and Generalized Linear Models analyses. Our data showed a statistically significant decline in tortoise sightings through time, and concurrently also a variation in habitat use by tortoises. In all the three study areas, we observed a significant increase of tortoise sighting frequency in the habitat type characterized by high (>taller than 200 cm) shrubby and wooded vegetation. Since our analyses revealed no significant change in the habitat type availability by year in each study area, we suggest that T. hermanni was increasingly selecting closed vegetation spots throughout the years. We hypothesize that this observed trend of shift in habitat selection could be due to lowering their body temperatures to prevent overheating. So, the selection of more covered spots would be a thermal ecology adaptive consequence of the ongoing global warming.


2009 ◽  
Vol 36 (2) ◽  
pp. 134 ◽  
Author(s):  
Guangshun Jiang ◽  
Jianzhang Ma ◽  
Minghai Zhang ◽  
Philip Stott

Potential conflicts between forestry production practices and wildlife habitat requirements are increasing globally with rapid socioeconomic development. Moose (Alces alces cameloides) and roe deer (Capreolus pygargus bedfordi) populations are in decline in north-eastern China, an area managed for forestry production. We obtained detailed information about these species’ use of habitat by following their movement paths in snow and recording behaviours exhibited along their paths. We used fractal analysis, Mann–Whitney U-tests and linear mixed models to analyse the paths and the relationships between tortuousity, habitat, and the expressed behaviours at different spatial scales. This analysis showed a natural break in the fractal dimension of moose movement paths at a scale of ~10 m, suggesting that moose exhibited different responses to their microhabitat and behavioural requirements at scales above and below this threshold. However, we detected no differences in the responses of roe deer over a scale range of 3–20 m. Moose paths tended to pass through areas with higher basal areas of tree stems and those with deeper snow. Roe deer showed positive associations between tortuousity and the number of bedding sites and feeding sites, and a negative association between tortuousity and the total basal area of tree stems. There was a positive relationship between the numbers of bedding and defaecating sites, and a negative association between the number of bedding sites and snow depth. For moose, we found positive associations between tortuousity and the number of defaecating sites, the basal areas of both broadleaf stands and mixed conifer and broadleaf stands, and a negative association between tortuousity and the number of feeding sites. We concluded that roe deer foraged in accordance with patch-use theory, whereas moose foraged in accordance with diet-selection theory. We concluded that modifications to forestry practices to foster the populations of both species of deer will require forestry operations to be conducted on a much finer scale, and that one species can be promoted over the other by selective fine-scale habitat management.


2000 ◽  
Vol 78 (2) ◽  
pp. 219-225 ◽  
Author(s):  
Carl Savignac ◽  
André Desrochers ◽  
Jean Huot

To study the multiple spatial scale pattern of habitat use by Pileated Woodpeckers (Dryocopus pileatus L.), we compared the vegetation characteristics at used sites with those at unused sites at macrohabitat (154 ha radius plots) and microhabitat (ca. 0.04 ha radius plots) scales in the La Mauricie region of Québec. Used macrohabitats were those in which woodpeckers were detected at playback stations. Used microhabitats corresponded to sites showing signs of foraging (i.e., excavated cavities). Pileated Woodpeckers responded to vegetation structure at both scales sampled. Macrohabitats used by woodpeckers had relatively low percentages of mixed shade-intolerant hardwood stands, coniferous stands, and stands of relatively low stem density and tree height, but included high percentages of 51- to 90-year-old stands. Microhabitats used by woodpeckers were characterized most strongly by a high density of large snags but also by a high density of small-diameter snags and a low density of shade-intolerant hardwood trees and coniferous trees [Formula: see text]30 cm diameter at breast height. The concordance between the observed and predicted use of micro- and macro-habitat plots was independent of spatial scale (logistic regression, χ20.05,1 = 1.8, P = 0.18, n = 429), suggesting that habitats use by woodpeckers was influenced to a similar extent by habitat features measured at both spatial scales. Because Pileated Woodpeckers are likely to require specific habitat features at different spatial scales, forest-management guidelines intended to conserve this umbrella species should consider a multiple spatial scales approach.


2016 ◽  
Vol 37 (2) ◽  
pp. 191-198 ◽  
Author(s):  
Dániel Kovács ◽  
István Kiss

Although Ablepharus kitaibelii and its subspecies are wide-spread, being distributed from the Carpathian Basin through the Balkans to Iraq, their habitat and environmental niche is poorly known. Ablepharus kitaibelii fitzingeri is almost entirely limited to the Carpathian Basin, and is amongst the most strictly protected and least known reptiles of Central and Eastern Europe. The main aim of our study was to determine habitat use preferences of different age groups of A. kitaibelii fitzingeri and Lacerta viridis. The occurrence of green lizard was determined by the abundance of refugia rather than by the naturalness of grasslands. The snake-eyed skink prefers semi-natural grasslands with abundant tussock-forming grass or sedge species, avoiding densely shrubby places. For the first time, we show that woodland mosaics lacking shrubs and temporary grasslands next to forest edges are important for the species. Microhabitat use by snake-eyed skink varies with age group; adults preferring shady edge zones rich in leaf litter and shadier grassland spots provided by woodland mosaics, whereas juveniles were found in natural, more open grasslands far from forest edges and in woodland mosaics with dense shrubby understory. Our results contribute to a better understanding of the ecological needs of A. kitaibelii fitzingeri. Our methodology could be adapted to other species and subspecies of Ablepharus. Based on our results, it is important to reconsider habitat management activities, which should not be limited to shrub control: the main goal should be the development of a diverse habitat structure.


2010 ◽  
Vol 9 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Ernesto Filippi ◽  
Lorenzo Rugiero ◽  
Massimo Capula ◽  
Russell L. Burke ◽  
Luca Luiselli

Ecoscience ◽  
2009 ◽  
Vol 16 (2) ◽  
pp. 209-223 ◽  
Author(s):  
Constance L. Browne ◽  
Cynthia A. Paszkowski ◽  
A. Lee Foote ◽  
Alissa Moenting ◽  
Shelly M. Boss

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ariana Strandburg-Peshkin ◽  
Damien R Farine ◽  
Margaret C Crofoot ◽  
Iain D Couzin

For group-living animals traveling through heterogeneous landscapes, collective movement can be influenced by both habitat structure and social interactions. Yet research in collective behavior has largely neglected habitat influences on movement. Here we integrate simultaneous, high-resolution, tracking of wild baboons within a troop with a 3-dimensional reconstruction of their habitat to identify key drivers of baboon movement. A previously unexplored social influence – baboons’ preference for locations that other troop members have recently traversed – is the most important predictor of individual movement decisions. Habitat is shown to influence movement over multiple spatial scales, from long-range attraction and repulsion from the troop’s sleeping site, to relatively local influences including road-following and a short-range avoidance of dense vegetation. Scaling to the collective level reveals a clear association between habitat features and the emergent structure of the group, highlighting the importance of habitat heterogeneity in shaping group coordination.


1999 ◽  
Vol 9 (3) ◽  
pp. 271-281 ◽  
Author(s):  
Gustavo H. Kattan ◽  
J. William Beltran

SummaryGrallaria antpittas are a group of little known birds from the understorey of humid forests of the tropical Andes, with several species having very narrow distributions. At Ucumari Regional Park, which protects the Otún River watershed in the Central Andes of Colombia, five species occur sympatrically at 2,400 m, including the recently rediscovered G. milleri, of which this is the only known population. We studied the patterns of altitudinal distribution, habitat use and abundance of the five species in the park. We found altitudinal segregation at a local scale, with two species, G. ruficapilla and G. squamigera, found at lower elevations (1,800–2,500 m) and two other species, G. nuchalis and G. rufocinerea, at higher elevations (2,400–3,000); G. milleri was recorded only in the 2,400–2,600 m range. The five species overlap in the range 2,400–2,600 m, where they occur in three habitats: early regeneration, overgrown alder plantations and 30-year-old forest. There were no differences in density among habitats for any species; the five species used the three habitats in proportion to their occurrence in the landscape. Grallaria milleri had the highest overall density (1.3 ind/ha) while G. squamigera had the lowest density (0.2 ind/ha), and the other three species were intermediate. We estimated 106 individuals of G. milleri in an area of 63 ha, and only seven individuals of G. squamigera. The Otún River watershed concentrates an unusual number of Grallaria antpittas, including three endemic species, and the information presented here is fundamental to any future habitat management plans to ensure the persistence of these populations.


2021 ◽  
pp. 557-563
Author(s):  
A.A.D. McLaren ◽  
B.R. Patterson

Site fidelity is thought to provide increased fitness through familiarity with the distribution of forage, protective cover, breeding and offspring rearing sites, and predators. For moose (Alces alces (Linnaeus, 1758)), previous research has documented fidelity at varying spatial scales. Our objective was to build on this knowledge and assess fidelity by adult female moose in two areas of central Ontario, Canada (Algonquin Provincial Park (APP) and Wildlife Management Unit 49 (WMU49)). We used global positioning system data to generate mean weekly locations for collared moose, then measured the distance between paired weekly locations among consecutive years to evaluate site fidelity. We tested for effects of study area, biological season, moose age, and reproductive status using generalized linear mixed models. Moose demonstrated stronger site fidelity in WMU49, an area with more anthropogenic disturbance, than the protected area, APP. Fidelity was weakest in the winter, but was similar among other seasons and was independent of maternal age and the presence of a calf. Our study highlights the need to consider the scale of site fidelity relative to habitat management. Actions aimed at supporting moose populations might benefit more by protecting habitat classes selected by moose rather than specific sites used by individuals.


<em>Abstract.—</em> The quality and quantity of habitats determine ecosystem productivity. Hence, they determine the potential fish productivity that sustains the fish harvests extractable from freshwaters and seas. Efforts to conserve and protect fish habitats are frustrated by key unanswered questions: which habitat types and how much must be protected to ensure natural self-sustaining fish stocks? Minns and Bakelaar presented a prototype method for assessing suitable habitat supply for fish stocks in Lake Erie, an analysis that can be used to address conservation issues. Here, the method is refined and extended, taking the assessment of habitat supply for pike <em>Esox lucius </em> in the Long Point region of Lake Erie as a case study. As with the previous study, much emphasis is placed on “learning by doing.” Because available inventories of habitat features are coarse and incomplete, improved guidelines for estimating habitat supply are expected from these prototype studies. The habitat supply method previously presented by Minns and Bakelaar is elaborated in three ways here: (1) the basic physical habitat assessment is derived from a remote-sensing inventory database; (2) methods of quantifying the thermal regime and integrating it with other habitat elements are examined; (3) habitat supply estimates are used in a pike population model, and pike biomass and production are simulated for the Long Point region of Lake Erie and then compared with available records. The roles of error and uncertainty are examined for all elements in the estimation and application of suitable habitat supply values. There is potential for supply measurement and analysis to guide fish habitat management.


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