scholarly journals Alpine Newts (Ichthyosaura alpestris) Avoid Habitats Previously Used by Parasite-Exposed Conspecifics

2021 ◽  
Vol 9 ◽  
Author(s):  
David R. Daversa ◽  
Andrea Manica ◽  
Héctor Bintanel Cenis ◽  
Pilar Lopez ◽  
Trenton W. J. Garner ◽  
...  

Many organisms avoid habitats posing risks of parasitism. Parasites are not generally conspicuous, however, which raises the question of what cues individuals use to detect parasitism risk. Here, we provide evidence in alpine newts (Ichthyosaura alpestris) that non-visual cues from parasite-exposed conspecifics inform habitat avoidance. Alpine newts breed in aquatic habitats and occasionally move among adjacent terrestrial habitat during breeding seasons. We completed experiments with newts whereby individuals had access to both habitats, and the aquatic habitats varied in prior occupancy by conspecifics with different histories of exposure to the parasitic skin fungus, Batrachochytrium dendrobatidis (Bd). Continuous filming of newt activity for 2 days provided little evidence that prior use of aquatic habitats by conspecifics, regardless of their Bd exposure history, immediately influenced newt habitat use. However, newts that encountered aquatic habitats used specifically by Bd-exposed conspecifics on day 1 spent less time aquatic on day 2, whereas other newts did not alter habitat use. Responses could have been elicited by cues generated by Bd stages on the conspecifics or, perhaps more likely, cues emitted by the conspecifics themselves. In either case, these observations suggest that newts use non-visual cues sourced from exposed conspecifics to detect Bd risk and that those cues cause newts to avoid aquatic habitats. Bd may therefore influence host behavior in early phases of interactions, and possibly before any contact with infectious stages is made, creating potential for non-consumptive effects.

2005 ◽  
Vol 69 (4) ◽  
pp. 1481-1493 ◽  
Author(s):  
JONATHAN V. REGOSIN ◽  
BRYAN S. WINDMILLER ◽  
REBECCA N. HOMAN ◽  
J. MICHAEL REED

2007 ◽  
Vol 274 (1620) ◽  
pp. 1885-1893 ◽  
Author(s):  
Torsten M Scheyer ◽  
P.Martin Sander

The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys quenstedti . Comparison of their shell bone histology with that of extant turtles preferring either aquatic habitats or terrestrial habitats clearly reveals congruence with terrestrial turtle taxa. Similarities in the shell bones of these turtles are a diploe structure with well-developed external and internal cortices, weak vascularization of the compact bone layers and a dense nature of the interior cancellous bone with overall short trabeculae. On the other hand, ‘aquatic’ turtles tend to reduce cortical bone layers, while increasing overall vascularization of the bone tissue. In contrast to the study of limb bone proportions, the present study is independent from the uncommon preservation of appendicular skeletal elements in fossil turtles, enabling the palaeoecological study of a much broader range of incompletely known turtle taxa in the fossil record.


2005 ◽  
Vol 83 (7) ◽  
pp. 983-988 ◽  
Author(s):  
Javier A Rodríguez-Robles ◽  
Manuel Leal ◽  
Jonathan B Losos

Habitat selection can directly affect the fitness of an individual and the evolutionary dynamics of the population to which that organism belongs. We studied habitat use of the Puerto Rican yellow-chinned anole (Anolis gundlachi Peters, 1876) to examine whether this arboreal lizard uses its environment in a nonrandom manner. Males and females preferred woody vegetation substrates over nonwoody plants and sierra palms (Prestoea acuminata var. montana (Graham) A. Henderson and G. Galeano) as perching sites, and they also selected wider vegetation than what was randomly available. Selection for minimizing conspicuousness to potential predators and for increased locomotion capacity may help explain the preference for woody substrates and broader surfaces, respectively. Anolis gundlachi relies almost exclusively on visual cues for foraging and social interactions, and using wider perches also increases an individual's ability to scan a larger proportion of its territory. Our findings thus indicate that the nonrandom habitat use of free-ranging A. gundlachi leads to the selection of perching substrates that may increase performance of ecologically relevant capabilities.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Rasmus Mohr Mortensen ◽  
Stefanie Reinhardt ◽  
Marina Eraker Hjønnevåg ◽  
Rory Paul Wilson ◽  
Frank Rosell

Abstract Background Semi-aquatic mammals exploit resources both on land and in water and may require both to meet their habitat requirements including food- and building resources, refuges, and for social interactions with conspecifics. Within this, the specific availability of both terrestrial and aquatic resources is expected to impact individual fitness. Beavers are highly dependent on water for movement and protection from predators. They are central place foragers and mostly forage on woody vegetation near water although aquatic vegetation may also be an important food resource. However, little is known about their use of aquatic habitats. We aimed to address this knowledge gap by dead-reckoning fine-scale movement tracks and classifying fine-scale diving events, which we then related to the spatial distribution of aquatic vegetation and habitat components within the territory. Results Overall, there was a statistically clear decrease in probability that diving would occur at dawn and with increasing distance from territory borders. In addition, the distance from the lodge at which animals dived decreased through the night and during the spring/early summer. There was strong selection for diving habitats located closer to the riverbank, with stronger selection for these areas being observed in individuals with larger home ranges. We saw a higher selection for diving above clay sediment, and within 150 m from the lodge, presumably because mud and clay sediment tended to be located closer to the lodge than sand and rock sediment. Furthermore, we found a clear selection for diving in the presence of quillwort (Isoetes spp.), shoreweed (Littorella uniflora), and stonewort (Nitella spp.). Selection for these focal species was stronger among subordinate individuals. Individuals with lower body condition dived closer to the beaver lodge, and dives located further from the lodge were associated with high densities of aquatic vegetation. Conclusion We provide new knowledge on the aquatic habitat use in a semi-aquatic mammal and show how energetic constraints may shape how beavers spatially use the aquatic environment, whereby short and shallow dives appear most beneficial. We show how aquatic habitats may have great importance for both foraging, building materials and safety, and discuss to how they may affect the fitness of individuals.


2020 ◽  
Vol 249 ◽  
pp. 108712
Author(s):  
Maldwyn J. Evans ◽  
Benjamin C. Scheele ◽  
Martin J. Westgate ◽  
Marta Yebra ◽  
Jenny S. Newport ◽  
...  

2010 ◽  
Vol 59 (2) ◽  
pp. 122-128
Author(s):  
Laura C. Sanchez ◽  
María Busch ◽  
Nora Madanes

2015 ◽  
Vol 49 (3) ◽  
pp. 437-441 ◽  
Author(s):  
George Zaragoza ◽  
Jonathan P. Rose ◽  
Kathryn Purcell ◽  
Brian D. Todd

Author(s):  
César Ayres

In this work, data are presented about spatial use and behaviour of Iberian brown frog (Rana iberica) during and after the breeding season in Pontevedra (north-western Spain). Field data were collected between November 2008 and February 2010 at a human-altered stream. The results suggest that there was a change in habitat use between the breeding and the non-breeding seasons. Rana iberica individuals concentrated in the upper part of the stream during the breeding season (November-March), moving to lower parts of the stream during late spring and summer. The estimated monthly frog abundance was inversely correlated to the recorded mean daily minimum temperatures.


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