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

Abstract

Although 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.

Macro- and microhabitat preferences of eastern Hermann’s tortoise (Testudo hermanni boettgeri)

“…Numerous studies on the western subspecies (T. h. hermanni) revealed its preference toward specific habitats for specific purposes (Longepierre et al, 2001;Corti and Zuffi, 2003;Rugiero and Luiselli, 2006;del Vecchio et al, 2011;Corti et al, 2013;Berardo et al, 2015;Vilardell-Bartino et al, 2015): in some places, tortoises were selected both bushy and woody habitats for hibernation (probably due to a more stable local environmental temperature that enables them to survive the winter -see in Steen et al, 2007 andVilardell-Bartino et al, 2015) while shrubs without spines were the most visited in the hottest parts of the summer days (Vilardell-Bartino et al, 2015); during the feeding period, the tortoises showed preference to spots with herbaceous vegetation, while blackberries were predominantly chosen for hiding, shelter and during the mating season. Studies on the Eastern Hermann's tortoise (T. h. boettgeri) analyzed habitat preferences mostly on the broad scale, indicating meadows, bushes, shrubs and the edges of forests as the most preferable habitats both in Mediterranean parts and in the inland of the Balkans (Cruce and Rȃducan, 1976;Meek and Inskeep, 1981;Meek, 1985Meek, , 1988Wright et al, 1988; Rozylowicz and Dobre, 2010; Rozylowicz and Popescu, 2013; Türkozan et al, 2015;Stojadinović et al, 2017).…”

“…Researchers face three problems when conducting studies for detailed determination of habitat preference and these are: characterization of the available microhabitat types, quantification of the relative abundance of different microhabitats and determination of the habitat spatial scale relevant to the focal organism (Del Vecchio et al, 2011). These authors revealed that western Hermann's tortoises choose small patches of suitable habitat in a matrix of less desirable habitats, while this study attempted to investigate macro-and microhabitat selection in eastern Hermann's tortoise where habitat degradation on a large scale is still lower (Rozylowicz and Popescu, 2013;Stojadinović et al, 2017).…”

Seasonal habitat preference by the flagship species Testudo hermanni: Implications for the conservation of coastal dunes

“…Some of these endangered species could act as flagship species, driving public awareness on conservation issues of the coastal dunes. Among these, the tortoises (family Testudinidae) are the best candidates for coastal dune conservation, as they are charismatic and appealing to the target audience (e.g., EU Life Projects), are often endemic [7], and symbolize the uniqueness of the coastal dunes to foster a sense of local pride [8].…”

“…The habitat preferences of this species have been investigated in a variety of habitats, from coastal dunes [8,20,21] to rural landscapes [22], while habitat preference studies taking into account the seasonal utilization of the different vegetation types are still necessary [23].…”

Adaptive Choice of Reproductive Microhabitat and Its Potential for Sexual Conflict in Túngara Frogs

“…Depending on their life stage or activity, individuals may demand specific (a)biotic conditions and therefore often actively seek out locations that best match their needs (Kerth et al, 2001;Del Vecchio et al, 2011;Wennersten et al, 2012). Many taxa have therefore evolved specific preferences for certain microhabitats across a wide range of contexts, such as foraging, resting, growth, or reproduction (Del Vecchio et al, 2011;Wennersten et al, 2012;Rolshausen et al, 2013;Lapinski and Tschapka, 2014;Marques and Nomura, 2015). Selection of the optimal microhabitat may, however, cause conflicts between individuals of the same species, in particular in the context of reproduction.…”