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Carrilho M, Monarca RI, Aparício G, Mathias MDL, Tapisso JT, von Merten S. Physiological and behavioural adjustment of a wild rodent to laboratory conditions. Physiol Behav 2024; 273:114385. [PMID: 37866641 DOI: 10.1016/j.physbeh.2023.114385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/17/2023] [Accepted: 10/20/2023] [Indexed: 10/24/2023]
Abstract
Wild animals are brought to captivity for different reasons, for example to be kept in zoos and rehabilitation centres, but also for basic research. Such animals usually undergo a process of adjustment to captive conditions. While this adjustment occurs on the behavioural and the physiological level, those are usually studied separately. The aim of this study was to assess both the physiological and behavioural responses of wild wood mice, Apodemus sylvaticus, while adjusting to laboratory conditions. Over the course of four weeks, we measured in wild-caught mice brought to the laboratory faecal corticosterone metabolites and body mass as physiological parameters, stereotypic behaviour and nest-quality, as welfare-linked behavioural parameters, and four personality measures as additional behavioural parameters. The results of our study indicate that mice exhibited an adjustment in both behaviour and physiology over time in the laboratory. While the hormonal stress response decreased significantly, body mass and the proportion of stereotypic behaviours showed a tendency to increase over time. The slight increase of stereotypic behaviours, although not statistically significant, suggests the development of repetitive and non-functional behaviours as a response to laboratory conditions. However, we suggest that those behaviours might have been used by animals as a coping strategy to decrease the physiological stress response. Other behavioural parameters measured, such as boldness and nestbuilding behaviour were stable over time. The information obtained in the present study hints at a complex interplay between behavioural and physiological adjustments of wild animals to laboratory conditions, which should be considered when intending to use wild animals in experimental research.
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Affiliation(s)
- Maílis Carrilho
- CESAM - Centre for Environmental and Marine Studies and Department of Animal Biology, Faculty of Sciences of the University of Lisbon, Lisbon 1749-016, Portugal.
| | - Rita I Monarca
- CESAM - Centre for Environmental and Marine Studies and Department of Animal Biology, Faculty of Sciences of the University of Lisbon, Lisbon 1749-016, Portugal
| | - Guilherme Aparício
- CESAM - Centre for Environmental and Marine Studies and Department of Animal Biology, Faculty of Sciences of the University of Lisbon, Lisbon 1749-016, Portugal
| | - Maria da Luz Mathias
- CESAM - Centre for Environmental and Marine Studies and Department of Animal Biology, Faculty of Sciences of the University of Lisbon, Lisbon 1749-016, Portugal
| | - Joaquim T Tapisso
- CESAM - Centre for Environmental and Marine Studies and Department of Animal Biology, Faculty of Sciences of the University of Lisbon, Lisbon 1749-016, Portugal
| | - Sophie von Merten
- CESAM - Centre for Environmental and Marine Studies and Department of Animal Biology, Faculty of Sciences of the University of Lisbon, Lisbon 1749-016, Portugal; Department of Environment and Biodiversity, University of Salzburg, Hellbrunner Straße 34, 5020, Salzburg, Austria
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Devalloir Q, Fritsch C, Alchammas Y, Raoul F, Driget V, Amiot C, Ozaki S, van den Brink N, Scheifler R. Environmental pollution and nutritional quality modulate immune response of the wood mouse (Apodemus sylvaticus) through hormonal disturbances. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 337:122100. [PMID: 37392867 DOI: 10.1016/j.envpol.2023.122100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/16/2023] [Accepted: 06/22/2023] [Indexed: 07/03/2023]
Abstract
Cadmium (Cd) and lead (Pb) are known to enhance immune cell damages and to decrease cellular immunity, promoting higher susceptibility to infectious diseases. Selenium (Se) is an essential element involved in immunity and reactive oxygen species scavenging. This study aimed at evaluating how Cd and Pb and low nutritional (Se) quality modulate immune response to a bacterial lipopolysaccharide (LPS) challenge in wood mice (Apodemus sylvaticus). Mice were trapped near a former smelter in northern France in sites of High or Low contamination. Individuals were challenged immediately after capture or after five days of captivity, fed a standard or a Se-deficient diet. Immune response was measured with leukocyte count and plasma concentration of TNF-α, a pro-inflammatory cytokine. Faecal and plasma corticosterone (CORT), a stress-hormone involved in anti-inflammatory processes, was measured to assess potential endocrine mechanisms. Higher hepatic Se and lower faecal CORT were measured in free-ranging wood mice from High site. LPS-challenged individuals from High site showed steeper decrease of circulating leukocytes of all types, higher TNF-α concentrations, and a significant increase of CORT, compared to individuals from Low site. Challenged captive animals fed standard food exhibited similar patterns (decrease of leukocytes, increase of CORT, and detectable levels of TNF-α), with individuals from lowly contaminated site having higher immune responses than their counterparts from highly polluted site. Animals fed Se-deficient food exhibited lymphocytes decrease, no CORT variation, and average levels of TNF-α. These results suggest (i) a higher inflammatory response to immune challenge in free-ranging animals highly exposed to Cd and Pb, (ii) a faster recovery of inflammatory response in animals lowly exposed to pollution when fed standard food than more exposed individuals, and (iii) a functional role of Se in the inflammatory response. The role of Se and mechanisms underlying the relationship between glucocorticoid and cytokine remain to be elucidated.
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Affiliation(s)
- Quentin Devalloir
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France.
| | - Clémentine Fritsch
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France
| | - Yara Alchammas
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France
| | - Francis Raoul
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France
| | - Vincent Driget
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France
| | - Caroline Amiot
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France
| | - Shinji Ozaki
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France; UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK
| | - Nico van den Brink
- Division of Toxicology, Wageningen University, 6700 EA, Wageningen, the Netherlands
| | - Renaud Scheifler
- UMR 6249 Chrono-environnement, CNRS / Université Bourgogne Franche-Comté, Université de Franche-Comté, 16 Route de Gray, 25030, Besançon Cedex, France
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High Frequency of Apodemus Mice Boosts Inverse Activity Pattern of Bank Voles, Clethrionomys glareolus, through Non-Aggressive Intraguild Competition. Animals (Basel) 2023; 13:ani13060981. [PMID: 36978522 PMCID: PMC10044290 DOI: 10.3390/ani13060981] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 02/26/2023] [Accepted: 03/07/2023] [Indexed: 03/11/2023] Open
Abstract
Sympatric animals with similar requirements can separate their ecological niches along the microhabitat, food and time axes. There may be alternative reasons for an interspecific different activity pattern, such as intraspecific social constraints, predator avoidance or physical conditions such as temperature, precipitation and illumination. We investigated the importance of intraguild competition in a 2-year study in an inner-alpine mixed forest, using small forest rodents as our model species. Apodemus mice were the physically superior, and bank voles, Clethrionomys glareolus, the inferior competitor. We predicted that bank voles would exhibit increased diurnal activity when frequencies of the almost exclusively nocturnal Apodemus mice were high during a seed mast year. To investigate this, we recorded 19,138 1 min videos. Controlling for confounding variables, bank vole diurnal activity was significantly related to the frequency of Apodemus mice. We assume that at high densities of Apodemus mice, a purely nocturnal separation in the niche dimensions of time, habitat and microhabitat is no longer sufficient, and therefore an inverse activity pattern by the bank voles is reinforced. Our videos showed, however, that this does not require persistent aggressive meetings and we explain this by the long co-evolution of the taxa under study.
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Indirect Human Influences in Fear Landscapes: Varying Effects of Moonlight on Small Mammal Activity along Man-Made Gradients of Vegetation Structure. Life (Basel) 2023; 13:life13030681. [PMID: 36983836 PMCID: PMC10053441 DOI: 10.3390/life13030681] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
Risk of predation is one of the main constraints of small mammal distribution and foraging activity. Aside from numerical effects on population size due to the presence and abundance of predators, indirect cues, such as vegetation structure and moonlight, determine patterns of activity and microhabitat use by small mammals. Indirect cues are expected to interact, as shading provided by vegetation can suppress the effects of changing moonlight. We analyzed the effects of moonlight levels on the activity patterns of three common small mammal species in Mediterranean habitats, and tested whether moonlight effects were modulated by shadowing associated with the development of tall vegetation due to spontaneous afforestation following land abandonment. A. sylvaticus, a strictly nocturnal species, decreased activity under moonlight with no interactive effects of vegetation cover. C. russula showed no activity change with moonlight levels and M. spretus increased activity, although activity in both species was mostly determined by vegetation cover, that favored it. The effects of moonlight on small mammal activity were not homogeneous among species, nor were the interactive effects of man-made gradients of habitat structure, a fact that will produce community changes along vegetation gradients mediated by varying fear landscapes.
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Morán-López T, Sánchez-Dávila J, Torre I, Navarro-Castilla A, Barja I, Díaz M. Ungulate presence and predation risks reduce acorn predation by mice in dehesas. PLoS One 2022; 17:e0260419. [PMID: 35969588 PMCID: PMC9377575 DOI: 10.1371/journal.pone.0260419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 07/08/2022] [Indexed: 11/19/2022] Open
Abstract
Foraging decisions by rodents are key for the long-term maintenance of oak populations in which avian seed dispersers are absent or inefficient. Decisions are determined by the environmental setting in which acorn-rodent encounters occur. In particular, seed value, competition and predation risks have been found to modify rodent foraging decisions in forest and human-modified habitats. Nonetheless, there is little information about their joint effects on rodent behavior, and hence, local acorn dispersal (or predation). In this work, we manipulate and model the mouse-oak interaction in a Spanish dehesa, an anthropogenic savanna system in which nearby areas can show contrasting levels of ungulate densities and antipredatory cover. First, we conducted a large-scale cafeteria field experiment, where we modified ungulate presence and predation risk, and followed mouse foraging decisions under contrasting levels of moonlight and acorn availability. Then, we estimated the net effects of competition and risk by means of a transition probability model that simulated mouse foraging decisions. Our results show that mice are able to adapt their foraging decisions to the environmental context, affecting initial fates of handled acorns. Under high predation risks mice foraged opportunistically carrying away large and small seeds, whereas under safe conditions large acorns tended to be predated in situ. In addition, in the presence of ungulates lack of antipredatory cover around trees reduced mice activity outside tree canopies, and hence, large acorns had a higher probability of survival. Overall, our results point out that inter-specific interactions preventing efficient foraging by scatter-hoarders can reduce acorn predation. This suggests that the maintenance of the full set of seed consumers as well as top predators in dehesas may be key for promoting local dispersal.
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Affiliation(s)
- Teresa Morán-López
- Laboratorio Ecotono, INIBIOMA-CONICET, Universidad Nacional del Comahue, Black River, Argentina
| | - Jesús Sánchez-Dávila
- Department of Biogeography and Global Change (BGC-MNCN-CSIC), National Museum of Natural Sciences, CSIC, Madrid, Spain
| | - Ignasi Torre
- Museu de Ciències Naturals de Granollers (MCNG), Granollers, Barcelona, Spain
| | - Alvaro Navarro-Castilla
- Departament of Biology, Unit of Zoology, Faculty of Sciences, Universidad Autónoma de Madrid, Madrid, Spain
| | - Isabel Barja
- Departament of Biology, Unit of Zoology, Faculty of Sciences, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM) Universidad Autónoma de Madrid, Madrid, Spain
| | - Mario Díaz
- Department of Biogeography and Global Change (BGC-MNCN-CSIC), National Museum of Natural Sciences, CSIC, Madrid, Spain
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Mesocarnivore Distribution along Gradients of Anthropogenic Disturbance in Mediterranean Landscapes. DIVERSITY 2022. [DOI: 10.3390/d14020133] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Wildfires are important sources of landscape change in Mediterranean environments, creating large patches of low-growth natural habitats (i.e., scrublands) inside protected areas, whereas woodland patches remain mostly near well protected human settlements. Landscape patterns resulting from these gradients influence habitat suitability for mesocarnivores regarding food and shelter. In winter and summer 2019, we sampled 16 independent line-transects with four camera traps each (64 cameras overall), covering the main habitats of the study area (woodlands, scrublands, and crops). Cameras were baited to compensate for the low detectability of target species, and mesocarnivore contacts were analysed by means of GLMMs and occupancy models. Our results showed a positive and stronger association of wild species with woodland habitats, despite the low proportion of habitat available, higher presence of competitors (other mesocarnivores), and potential predators (human pets, i.e., dogs), and low natural prey availability than in scrubland (i.e., small mammals). However, mesocarnivores will find protection against predators and resting sites in forests as well as other food opportunities in crops and urban areas, despite the possible interference with humans and their pets. Potential cascading effects linked to ecological roles of Mediterranean mesocarnivores on the succession of Mediterranean landscapes would imply longer-term effects of human disturbance on landscape trends.
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Long-Tailed Pygmy Rice Rats Modify Their Behavioural Response and Faecal Corticosterone Metabolites in Response to Culpeo Fox but Not to Lesser Grison. Animals (Basel) 2021; 11:ani11113036. [PMID: 34827769 PMCID: PMC8614544 DOI: 10.3390/ani11113036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 11/24/2022] Open
Abstract
Simple Summary Prey species must fine-tune their antipredator responses to survive, but also to achieve a positive net energy balance which will enhance biological fitness. Given this, we investigated if Oligoryzomys longicaudatus would adapt their behavioural and physiological antipredator responses depending on their relative presence in the predator’s diet. By exposing this rodent species to culpeo fox and lesser grison faeces, we found that O. longicaudatus behavioural and physiological strategies were modulated depending on the predator’s diet. Specifically, rodents would trigger their antipredator responses in the presence of the most dangerous predator, the culpeo, which consumes a higher proportion of O. longicaudatus compared to the lesser grison. Our findings could be of importance for the development of more humane and efficient strategies to control rodent populations. Abstract Even though behavioural and physiological reactions to predation risk exhibited by prey species have received considerable attention in scientific journals, there are still many questions still unsolved. Our aim was to broaden the knowledge on one specific question: do long-tailed pygmy rice rats adapt their behavioural and physiological antipredator strategies depending on the predator species? For this question, we live-trapped in a temperate forest in Southern Chile long-tailed pygmy rice rats (Oligoryzomys longicaudatus), which were exposed to three predator odour phases (Phase 0: preliminary, no predator cues; Phase 1: one plot with culpeo fox faeces (Lycalopex culpaeus), one plot with lesser grison (Galictis cuja) faeces and one plot acting as a control with no odour; Phase 2: post treatment, no predator cues). We measured the behavioural response by the capture ratio. To assess the physiological stress response, we collected fresh faecal samples to quantify faecal corticosterone metabolites (FCM). Our results showed that O. longicaudatus increased both the capture ratio and FCM levels in the presence of culpeo cues. Culpeo foxes have higher densities in the study area than G. cuja and exhibit a higher activity pattern overlap with O. longicaudatus. Moreover, it has been also been reported in other regions that L. culpaeus consumption of O. longicaudatus is more frequent compared to G. cuja diet. The increase in capturability could be because traps can be regarded as a shelter in high-risk settings, but it can also be explained by the predator inspection behaviour. The increase in FCM concentrations during culpeo treatment can be linked to the adaptive mobilisation of energy to execute antipredator responses to increase survival chances.
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Morales JO, Walker N, Warne RW, Boyles JG. Heterothermy as a mechanism to offset energetic costs of environmental and homeostatic perturbations. Sci Rep 2021; 11:19038. [PMID: 34561468 PMCID: PMC8463709 DOI: 10.1038/s41598-021-96828-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/05/2021] [Indexed: 11/30/2022] Open
Abstract
Environmental and biotic pressures impose homeostatic costs on all organisms. The energetic costs of maintaining high body temperatures (Tb) render endotherms sensitive to pressures that increase foraging costs. In response, some mammals become more heterothermic to conserve energy. We measured Tb in banner-tailed kangaroo rats (Dipodomys spectabilis) to test and disentangle the effects of air temperature and moonlight (a proxy for predation risk) on thermoregulatory homeostasis. We further perturbed homeostasis in some animals with chronic corticosterone (CORT) via silastic implants. Heterothermy increased across summer, consistent with the predicted effect of lunar illumination (and predation), and in the direction opposite to the predicted effect of environmental temperatures. The effect of lunar illumination was also evident within nights as animals maintained low Tb when the moon was above the horizon. The pattern was accentuated in CORT-treated animals, suggesting they adopted an even further heightened risk-avoidance strategy that might impose reduced foraging and energy intake. Still, CORT-treatment did not affect body condition over the entire study, indicating kangaroo rats offset decreases in energy intake through energy savings associated with heterothermy. Environmental conditions receive the most attention in studies of thermoregulatory homeostasis, but we demonstrated here that biotic factors can be more important and should be considered in future studies.
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Affiliation(s)
- Javier Omar Morales
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA.
- Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, Illinois, 62901, USA.
| | - Nikki Walker
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
- Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, Illinois, 62901, USA
| | - Robin W Warne
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Justin G Boyles
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
- Cooperative Wildlife Research Laboratory, Southern Illinois University, Carbondale, Illinois, 62901, USA
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Ortiz-Jiménez L, Barja I. Surrounded by challenges: The simulated presence of competitors and predators modulates perianal secretion marking behaviour in the European mink (Mustela lutreola). Behav Processes 2021; 193:104508. [PMID: 34551363 DOI: 10.1016/j.beproc.2021.104508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 11/18/2022]
Abstract
Animals face a variety of daily challenges to their reproduction and survival that can detect in time through to the environment cues. By using an individual focal sampling, we evaluated the variations in the time devoted to the perianal secretion marking behaviour (PSMB) of European mink when they were exposed to the simulated presence of conspecifics and two potential predators. Model results indicated that males and adult individuals dedicated more time to PSMB than females and subadults. The presence of conspecifics increased PSMB time only in adult and males, probably as an intrasexual territorial competence response. The heightened decrease in PSMB time in presence of a dog suggests an innate response due to the detection of volatile substances from faeces of carnivorous. In addition, simulated conspecific presence increased PSMB in absence of odours (control) and with owl faeces. However, when facing dog faeces, the simulated conspecific presence had no effects on PSMB. Thus, minks seem to prioritize the imminent risk of predation to avoid being detected. The stimulation of PSMB in captivity by simulated cues from conspecifics and potential predators could be useful to facilitate the reintroduction of individuals into nature, as well as their adaptation and survival.
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Affiliation(s)
| | - Isabel Barja
- Department of Biology, Universidad Autónoma de Madrid, 28049 Madrid, Spain; Biodiversity and Global Change Research Center (CIBC-UAM), Universidad Autónoma de Madrid, Spain
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Mair RG, Francoeur MJ, Gibson BM. Central Thalamic-Medial Prefrontal Control of Adaptive Responding in the Rat: Many Players in the Chamber. Front Behav Neurosci 2021; 15:642204. [PMID: 33897387 PMCID: PMC8060444 DOI: 10.3389/fnbeh.2021.642204] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/08/2021] [Indexed: 11/13/2022] Open
Abstract
The medial prefrontal cortex (mPFC) has robust afferent and efferent connections with multiple nuclei clustered in the central thalamus. These nuclei are elements in large-scale networks linking mPFC with the hippocampus, basal ganglia, amygdala, other cortical areas, and visceral and arousal systems in the brainstem that give rise to adaptive goal-directed behavior. Lesions of the mediodorsal nucleus (MD), the main source of thalamic input to middle layers of PFC, have limited effects on delayed conditional discriminations, like DMTP and DNMTP, that depend on mPFC. Recent evidence suggests that MD sustains and amplifies neuronal responses in mPFC that represent salient task-related information and is important for detecting and encoding contingencies between actions and their consequences. Lesions of rostral intralaminar (rIL) and ventromedial (VM) nuclei produce delay-independent impairments of egocentric DMTP and DNMTP that resemble effects of mPFC lesions on response speed and accuracy: results consistent with projections of rIL to striatum and VM to motor cortices. The ventral midline and anterior thalamic nuclei affect allocentric spatial cognition and memory consistent with their connections to mPFC and hippocampus. The dorsal midline nuclei spare DMTP and DNMTP. They have been implicated in behavioral-state control and response to salient stimuli in associative learning. mPFC functions are served during DNMTP by discrete populations of neurons with responses related to motor preparation, movements, lever press responses, reinforcement anticipation, reinforcement delivery, and memory delay. Population analyses show that different responses are timed so that they effectively tile the temporal interval from when DNMTP trials are initiated until the end. Event-related responses of MD neurons during DNMTP are predominantly related to movement and reinforcement, information important for DNMTP choice. These responses closely mirror the activity of mPFC neurons with similar responses. Pharmacological inactivation of MD and adjacent rIL affects the expression of diverse action- and outcome-related responses of mPFC neurons. Lesions of MD before training are associated with a shift away from movement-related responses in mPFC important for DNMTP choice. These results suggest that MD has short-term effects on the expression of event-related activity in mPFC and long-term effects that tune mPFC neurons to respond to task-specific information.
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Affiliation(s)
- Robert G Mair
- Department of Psychology, University of New Hampshire, Durham, NH, United States
| | - Miranda J Francoeur
- Department of Psychology, University of New Hampshire, Durham, NH, United States.,Neural Engineering and Translation Lab, University of California, San Diego, San Diego, CA, United States
| | - Brett M Gibson
- Department of Psychology, University of New Hampshire, Durham, NH, United States
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Boughter JD, Fletcher M. Rethinking the role of taste processing in insular cortex and forebrain circuits. CURRENT OPINION IN PHYSIOLOGY 2021; 20:52-56. [PMID: 33681544 PMCID: PMC7932132 DOI: 10.1016/j.cophys.2020.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Over the years, many approaches towards studying the taste-responsive area of insular cortex have focused on how basic taste information is represented, and how lesions or silencing of this area impact taste-focused behaviors. Here, we review and highlight recent studies that imply that insular cortex does not contain a "primary" taste cortex in the traditional sense. Rather, taste is employed in concert with other internal and external sensory modalities by highly interconnected regions of insular cortex to guide ingestive decision-making, especially in context of estimating risk and reward. In rodent models, this may best be seen in context of foraging behaviors, which require flexibility and are dependent on learning and memory processes.
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Affiliation(s)
- John D. Boughter
- Department of Anatomy & Neurobiology, University of Tennessee Health Science Center, 855 Monroe Ave., Memphis TN 38163 USA
| | - Max Fletcher
- Department of Anatomy & Neurobiology, University of Tennessee Health Science Center, 855 Monroe Ave., Memphis TN 38163 USA
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Behavioral Responses of Wild Rodents to Owl Calls in an Austral Temperate Forest. Animals (Basel) 2021; 11:ani11020428. [PMID: 33562286 PMCID: PMC7916001 DOI: 10.3390/ani11020428] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/28/2021] [Accepted: 02/04/2021] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Growing human populations are challenging scientists to find effective ways to control and mitigate human–wildlife conflict while preserving biodiversity. It has been reported that predator odor and calls can drive away rodents, but little is known about species-specific responses of prey. For these reasons, we compared the behavioral changes of common rodent species inhabiting the Chilean temperate forest (Abrothrix spp., the long-tailed pygmy rice rat Oligoryzomyslongicaudatus and the black rat Rattus rattus) when exposed to two different native predator calls (the austral pygmy owl Glaucidium nana and the rufous-legged owl Strix rufipes) and a control (no predator calls). Our results showed that all rodent species modified their behavior in the presence of predator calls, but the effects were species dependent. These findings point to the need to carefully study target rodent species instead of applying a general control plan for all rodent species. Abstract Ecologically based rodent management strategies are arising as a sustainable approach to rodent control, allowing us to preserve biodiversity while safeguarding human economic activities. Despite predator signals being known to generally repel rodents, few field-based studies have compared the behavioral effects of several predators on different prey species, especially in Neotropical ecosystems. Here, we used camera traps to study the behavior of rodent species native to the Chilean temperate forest (Abrothrix spp., long-tailed pygmy rice rat Oligoryzomys longicaudatus) and an introduced rodent (black rat Rattus rattus). Using playbacks of raptor calls, we experimentally exposed rodents to three predation risk treatments: austral pygmy owl calls (Glaucidium nana), rufous-legged owl calls (Strix rufipes) and a control treatment (absence of owl calls). We evaluated the effects of the treatments on the time allocated to three behaviors: feeding time, locomotor activity and vigilance. Moonlight and vegetation cover were also considered in the analyses, as they can modify perceived predation risk. Results showed that predator calls and environmental factors modified prey behavior depending not only on the predator species, but also on the rodent species. Consequently, owl playbacks could be regarded as a promising rodent control tool, knowing that future studies would be critical to deeply understand differences between species in order to select the most effective predator cues.
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Navarro-Castilla Á, Garrido M, Hawlena H, Barja I. Non-Invasive Monitoring of Adrenocortical Activity in Three Sympatric Desert Gerbil Species. Animals (Basel) 2021; 11:ani11010075. [PMID: 33406630 PMCID: PMC7824156 DOI: 10.3390/ani11010075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 02/06/2023] Open
Abstract
Simple Summary In this era, characterized by remarkable anthropogenic impacts on wildlife, it is crucial to monitor the health of wild animal populations while minimizing the interference to them. To this end, for a better understanding of the eco-physiology of wild animals, the adrenocortical activity can be non-invasively evaluated by measuring glucocorticoid metabolites excreted in feces. However, to ensure that the endocrine information is reliable, the experimental assays should be first validated and the causes for the major variability among individuals should be considered. Here we validated an enzyme immunoassay for measuring fecal corticosterone metabolites (FCM) in three wild gerbil species and emphasized the differences among them. These are endangered species, which play a key role in psammophilic communities, and provide a model system for various aspects in ecology. Thus, this work constitutes the first step toward using the FCMs of these species as indicators for individual and community stress. Abstract The study of the endocrine status can be useful to understand wildlife responses to the changing environment. Here, we validated an enzyme immunoassay (EIA) to non-invasively monitor adrenocortical activity by measuring fecal corticosterone metabolites (FCM) in three sympatric gerbil species (Gerbillus andersoni, G. gerbillus and G. pyramidum) from the Northwestern Negev Desert’s sands (Israel). Animals included into treatment groups were injected with adrenocorticotropic hormone (ACTH) to stimulate adrenocortical activity, while control groups received a saline solution. Feces were collected at different intervals and FCM were quantified by an EIA. Basal FCM levels were similar in the three species. The ACTH effect was evidenced, but the time of FCM peak concentrations appearance differed between the species (6–24 h post-injection). Furthermore, FCM peak values were observed sooner in G. andersoni females than in males (6 h and 18 h post-injection, respectively). G. andersoni and G. gerbillus males in control groups also increased FCM levels (18 h and 48 h post-injection, respectively). Despite the small sample sizes, our results confirmed the EIA suitability for analyzing FCM in these species as a reliable indicator of the adrenocortical activity. This study also revealed that close species, and individuals within a species, can respond differently to the same stressor.
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Affiliation(s)
- Álvaro Navarro-Castilla
- Etho-Physiology Group, Unit of Zoology, Department of Biology, Faculty of Sciences, Autonomous University of Madrid, 28049 Madrid, Spain;
- Correspondence:
| | - Mario Garrido
- Jacob Blaustein Center for Scientific Cooperation, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 849900, Israel;
| | - Hadas Hawlena
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 849900, Israel;
| | - Isabel Barja
- Etho-Physiology Group, Unit of Zoology, Department of Biology, Faculty of Sciences, Autonomous University of Madrid, 28049 Madrid, Spain;
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Autonomous University of Madrid, C/Darwin 2, 28049 Madrid, Spain
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Tédonzong LRD, Willie J, Makengveu ST, Lens L, Tagg N. Variation in behavioral traits of two frugivorous mammals may lead to differential responses to human disturbance. Ecol Evol 2020; 10:3798-3813. [PMID: 32313637 PMCID: PMC7160177 DOI: 10.1002/ece3.6178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 11/28/2022] Open
Abstract
Human activities can lead to a shift in wildlife species' spatial distribution. Understanding the specific effects of human activities on ranging behavior can improve conservation management of wildlife populations in human-dominated landscapes. This study evaluated the effects of forest use by humans on the spatial distribution of mammal species with different behavioral adaptations, using sympatric western lowland gorilla and central chimpanzee as focal species. We collected data on great ape nest locations, ecological and physical variables (habitat distribution, permanent rivers, and topographic data), and anthropogenic variables (distance to trails, villages, and a permanent research site). Here, we show that anthropogenic variables are important predictors of the distribution of wild animals. In the resource model, the distribution of gorilla nests was predicted by nesting habitat distribution, while chimpanzee nests were predicted first by elevation followed by nesting habitat distribution. In the anthropogenic model, the major predictors of gorilla nesting changed to human features, while the major predictors of chimpanzee nesting remained elevation and the availability of their preferred nesting habitats. Animal behavioral traits (body size, terrestrial/arboreal, level of specialization/generalization, and competitive inferiority/superiority) may influence the response of mammals to human activities. Our results suggest that chimpanzees may survive in human-encroached areas whenever the availability of their nesting habitat and preferred fruits can support their population, while a certain level of human activities may threaten gorillas. Consequently, the survival of gorillas in human-dominated landscapes is more at risk than that of chimpanzees. Replicating our research in other sites should permit a systematic evaluation of the influence of human activity on the distribution of mammal populations. As wild animals are increasingly exposed to human disturbance, understanding the resulting consequences of shifting species distributions due to human disturbance on animal population abundance and their long-term survival will be of growing conservation importance.
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Affiliation(s)
- Luc Roscelin Dongmo Tédonzong
- Projet Grands Singes (PGS), CameroonCentre for Research and Conservation (CRC)Royal Zoological Society of Antwerp (RZSA)AntwerpenBelgium
- Terrestrial Ecology Unit (TEREC)Department of BiologyGhent University (UGent)GhentBelgium
- Present address:
Wild Chimpanzee Foundation (WCF)MonroviaLiberia
| | - Jacob Willie
- Projet Grands Singes (PGS), CameroonCentre for Research and Conservation (CRC)Royal Zoological Society of Antwerp (RZSA)AntwerpenBelgium
- Terrestrial Ecology Unit (TEREC)Department of BiologyGhent University (UGent)GhentBelgium
| | - Sandra Tewamba Makengveu
- Projet Grands Singes (PGS), CameroonCentre for Research and Conservation (CRC)Royal Zoological Society of Antwerp (RZSA)AntwerpenBelgium
- Department of ForestryFaculty of Agronomy and Agricultural Sciences (FASA)University of DschangDschangCameroon
| | - Luc Lens
- Terrestrial Ecology Unit (TEREC)Department of BiologyGhent University (UGent)GhentBelgium
| | - Nikki Tagg
- Projet Grands Singes (PGS), CameroonCentre for Research and Conservation (CRC)Royal Zoological Society of Antwerp (RZSA)AntwerpenBelgium
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When food access is challenging: evidence of wood mice ability to balance energy budget under predation risk and physiological stress reactions. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2756-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Yadok BG, Pech R, Chapman H. Perception of predation risk by African giant pouched rats (Cricetomys sp. nov) is higher in forest-edge microhabitats. Behav Processes 2019; 168:103953. [PMID: 31493493 DOI: 10.1016/j.beproc.2019.103953] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 08/28/2019] [Accepted: 09/02/2019] [Indexed: 11/30/2022]
Abstract
How rodents perceive predation risk may alter their seed foraging behaviour and therefore potentially influence the recruitment of tree species. In this study we used two methods to investigate the effect of predation risk on habitat use by the African giant pouched rat (Cricetomys sp. nov) in Ngel Nyaki forest reserve, Nigeria. The first method was 'giving up density' (GUD), an index of perceived risk of predation at an artificial food patch, and the second was the 'spool-and-line' approach, whereby unravelling spools attached to rodent bodies are used to trace their tracks. For our GUD experiment, we chose four major sites in the forest; two representative of core habitat and two at the forest edge. Additionally, three characteristic microsites were used in the GUD experiment: dense understory, open understory and near-burrows. We hypothesised that GUDs would be lower on every succeeding observation day as rats learn to use the food patches, higher GUDs would be observed in the forest edges and open microsites, and rats would show preference for the microhabitats with least exposure to potential predators. In support of our first hypothesis, we found that GUDs were highest on the first experimental nights of every session. We also found that GUDs in the forest edges were higher than GUDs in the forest core. Lower GUDs were observed close to the rat burrows and in dense understory microsites, even though these differences were not statistically significant. Tracking of rat movements using the spool-and-line method overall revealed an even use across microhabitats, with a weak preference for those with logs, dense understory or exposed ground. Overall, our results suggest that vegetation density on a microhabitat scale has little or no effect on the perception of predation risk by African giant pouched rats.
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Affiliation(s)
- Biplang G Yadok
- School of Biological Sciences, University of Canterbury, PB 4800, Christchurch, New Zealand; Nigerian Montane Forest Project, Yelwa village, Taraba State, Nigeria.
| | - Roger Pech
- Landcare Research, Lincoln, P. O. Box 69040, Christchurch, New Zealand
| | - Hazel Chapman
- School of Biological Sciences, University of Canterbury, PB 4800, Christchurch, New Zealand; Nigerian Montane Forest Project, Yelwa village, Taraba State, Nigeria
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Eidelman A, Cohen C, Navarro-Castilla Á, Filler S, Gutiérrez R, Bar-Shira E, Shahar N, Garrido M, Halle S, Romach Y, Barja I, Tasker S, Harrus S, Friedman A, Hawlena H. The dynamics between limited-term and lifelong coinfecting bacterial parasites in wild rodent hosts. ACTA ACUST UNITED AC 2019; 222:jeb.203562. [PMID: 31285244 DOI: 10.1242/jeb.203562] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/03/2019] [Indexed: 12/13/2022]
Abstract
Interactions between coinfecting parasites may take various forms, either direct or indirect, facilitative or competitive, and may be mediated by either bottom-up or top-down mechanisms. Although each form of interaction leads to different evolutionary and ecological outcomes, it is challenging to tease them apart throughout the infection period. To establish the first step towards a mechanistic understanding of the interactions between coinfecting limited-term bacterial parasites and lifelong bacterial parasites, we studied the coinfection of Bartonella sp. (limited-term) and Mycoplasma sp. (lifelong), which commonly co-occur in wild rodents. We infected Bartonella- and Mycoplasma-free rodents with each species, and simultaneously with both, and quantified the infection dynamics and host responses. Bartonella benefited from the interaction; its infection load decreased more slowly in coinfected rodents than in rodents infected with Bartonella alone. There were no indications for bottom-up effects, but coinfected rodents experienced various changes, depending on the infection stage, in their body mass, stress levels and activity pattern, which may further affect bacterial replication and transmission. Interestingly, the infection dynamics and changes in the average coinfected rodent traits were more similar to the chronic effects of Mycoplasma infection, whereas coinfection uniquely impaired the host's physiological and behavioral stability. These results suggest that parasites with distinct life history strategies may interact, and their interaction may be asymmetric, non-additive, multifaceted and dynamic through time. Because multiple, sometimes contrasting, forms of interactions are simultaneously at play and their relative importance alternates throughout the course of infection, the overall outcome may change under different ecological conditions.
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Affiliation(s)
- Anat Eidelman
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
| | - Carmit Cohen
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel.,Infection Prevention & Control Unit, Sheba Medical Center, Tel Hashomer, Ramat Gan 52621, Israel
| | - Álvaro Navarro-Castilla
- Department of Biology, Faculty of Sciences, University Autonomous of Madrid, Madrid 28049, Spain
| | - Serina Filler
- School of Veterinary Sciences, University of Bristol, Langford BS40 5DU, UK
| | - Ricardo Gutiérrez
- Koret School of Veterinary Medicine, Faculty of Agricultural, Nutritional and Environmental Sciences, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Enav Bar-Shira
- Section of Immunology, Department of Animal Sciences, Faculty of Agricultural, Nutritional and Environmental Sciences, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Naama Shahar
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
| | - Mario Garrido
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
| | - Snir Halle
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
| | - Yoav Romach
- The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Isabel Barja
- Department of Biology, Faculty of Sciences, University Autonomous of Madrid, Madrid 28049, Spain.,Center for Research on Biodiversity and Global Change (CIBC-UAM), University Autonomous of Madrid, Madrid 28049, Spain
| | - Séverine Tasker
- School of Veterinary Sciences, University of Bristol, Langford BS40 5DU, UK
| | - Shimon Harrus
- Koret School of Veterinary Medicine, Faculty of Agricultural, Nutritional and Environmental Sciences, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Aharon Friedman
- Section of Immunology, Department of Animal Sciences, Faculty of Agricultural, Nutritional and Environmental Sciences, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Hadas Hawlena
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 8499000, Israel
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Hernández MC, Navarro-Castilla Á, Barja I. Wood mouse feeding effort and decision-making when encountering a restricted unknown food source. PLoS One 2019; 14:e0212716. [PMID: 31216280 PMCID: PMC6583954 DOI: 10.1371/journal.pone.0212716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/04/2019] [Indexed: 11/18/2022] Open
Abstract
Animals making foraging decisions must balance the energy gained, the time invested, and the influence of key environmental factors. In our work, we examined the effect of predation risk cues and experience on feeding efforts when a novel food resource was made available. To achieve this, we live-trapped wood mouse Apodemus sylvaticus in Monte de Valdelatas (Madrid), where 80 Sherman traps were set in four plots. Traps were subjected to two food-access difficulties in treatments consisting of three consecutive nights: open plastic bottles (easy) and closed bottles (difficult), both using corn as bait. To simulate predation risk, we set fox faeces in half of the traps in each plot. We also considered moonlight (medium/low) as an indirect predation risk cue. We analysed whether bottles had been bitten by mice and the gnawed area of each bottle was measured. Our results indicated that food access difficulty, experience, and predation risk determined mice feeding decisions and efforts. The ability of mice to adapt feeding effort when a new food source is available was demonstrated because a higher proportion of closed bottles exhibited bite marks and the gnawed area was bigger. Moreover, mouse experience was determinant in the use of this new resource since recaptured mice gnawed broader orifices in the bottles and the gnawed area increased each time an individual was recaptured. Additionally, direct predation risk cues prompted mice to bite the bottles whereas the effect of different moon phases varied among the food access treatments. This study provides direct evidence of formidable efficacy of wild mice to exploit a new nutrient resource while considering crucial environmental factors that shape the decision-making procedure.
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Affiliation(s)
- Mª Carmen Hernández
- Departamento de Biología, Universidad Autónoma de Madrid, Campus Universitario de Cantoblanco, Madrid, Spain
| | - Álvaro Navarro-Castilla
- Departamento de Biología, Universidad Autónoma de Madrid, Campus Universitario de Cantoblanco, Madrid, Spain
| | - Isabel Barja
- Departamento de Biología, Universidad Autónoma de Madrid, Campus Universitario de Cantoblanco, Madrid, Spain
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19
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The role of steroid hormones and individual traits in food intake in the wood mouse (Apodemus sylvaticus). Naturwissenschaften 2019; 106:36. [PMID: 31203436 DOI: 10.1007/s00114-019-1628-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 05/21/2019] [Accepted: 05/24/2019] [Indexed: 10/26/2022]
Abstract
Availability of food resources affects animal survival and reproduction. Thus, coping with changes in food availability is one of the most crucial behavioural and physiological processes in wildlife. Food intake is a key concept in animal ecology that is directly conditioned by food quality and abundance or diet choice, but may also vary according to individual-related factors (e.g. foraging behaviours, social rank or energy-demanding periods) and the influence of the endocrine system on energy metabolism. Here, we studied food intake in relation to individual characteristics (sex, breeding condition and age) and whether steroid hormones (testosterone and corticosterone metabolites) mediate food intake in wild wood mouse (Apodemus sylvaticus). Field work was carried out in February-March 2014 in Monte de Valdelatas (Madrid, Spain). Wood mice were live-trapped for 10 consecutive days in four independent plots. Traps were baited with 4 g of toasted corn and food intake was calculated by subtracting the remaining bait found inside traps. Fresh faecal samples from 130 different wood mice were collected and faecal testosterone and corticosterone metabolites (FTM and FCM, respectively) were analysed by enzyme immunoassays. Food intake was higher in females than males, probably due to greater energy requirements. Non-breeders and young individuals also showed a higher food intake. These individuals usually hold a lower social rank which is associated to limited food resources because of dominants; thus, increased food intake may be a result of freely exploit food bait inside traps while avoiding risky competition. In addition, food intake negatively correlated with FTM levels and positively with FCM levels indicating that both hormones have an active role mediating food intake in the wood mouse. Our data suggest that food intake is a function of both individual traits and the endocrine system that accordingly respond throughout different energy-demanding periods.
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Navarro-Castilla Á, Barja I. Stressful living in lower-quality habitats? Body mass, feeding behavior and physiological stress levels in wild wood mouse populations. Integr Zool 2019; 14:114-126. [PMID: 30019837 DOI: 10.1111/1749-4877.12351] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Wild populations are continuously subjected to changes in environmental factors that pose different challenges. Body condition and hormones have been commonly used as health indicators due to their potential correlation with fitness. In the present study, we analyzed whether habitats of different quality influenced body mass, food intake and physiological stress levels in wild wood mice (Apodemus sylvaticus). Field work was seasonally carried out in Holm oak woods and pine forests in central Spain. A total of 93 wood mice from 4 different populations (2 per habitat type) were live-trapped. From each captured individual we noted body mass and food intake, measured as the amount of bait remaining in each trap. The physiological stress levels were measured non-invasively in collected fresh feces by quantifying fecal corticosterone metabolites (FCM) with a 5a-pregnane-3ß,11ß, 21-triol-20-one enzyme immunoassay. Wood mice abundances decreased from spring to summer, were higher in Holm oak woods than in pine forests and also resulted in different age-class distribution between both habitats. Individuals inhabiting pine forests showed a lower body mass and increased food intake, probably because of the comparatively lower food quality and availability in this habitat. Furthermore, these individuals showed increased physiological stress levels, likely due to the lower quality habitat in relation to both food and vegetation cover availability. Overall, besides affecting local wood mouse abundance, our study underscores the effect of habitat quality on body mass, food intake and the endocrine stress response. Considering the wood mouse's pivotal position in ecosystems, these results could help in the understanding of environmental traits hampering the viability of wild populations.
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Affiliation(s)
- Álvaro Navarro-Castilla
- Department of Biology, Unit of Zoology, Faculty of Sciences, Autonomous University of Madrid, Spain
| | - Isabel Barja
- Department of Biology, Unit of Zoology, Faculty of Sciences, Autonomous University of Madrid, Spain
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21
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Gender difference in unconditioned and conditioned predator fear responses in Smith's zokors (Eospalax smithii). Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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22
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Hernández MC, Navarro-Castilla Á, Planillo A, Sánchez-González B, Barja I. The landscape of fear: Why some free-ranging rodents choose repeated live-trapping over predation risk and how it is associated with the physiological stress response. Behav Processes 2018; 157:125-132. [PMID: 30266620 DOI: 10.1016/j.beproc.2018.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 09/17/2018] [Accepted: 09/21/2018] [Indexed: 12/27/2022]
Abstract
Live trapping is an essential element of field ecological studies. However, the act of trapping provides two types of conditional benefits (food from the bait when hungry, and refuge from a predator when threatened) against one type of drawback (confinement). Our understanding of how animals assess the two benefits against the lone risk determines how we interpret classic field studies in chemical ecology and wildlife management. Here, we studied wood mice responses to these risks and rewards of field trapping by examining experience through recapture and faecal corticosterone metabolites (FCM) as a physiological response indicator. Wood mice were live-trapped in two different plots subjected to two distinct phases: phase 1, absence of predator cues, and phase 2, in which traps were treated with red fox faeces. During phase 1, the recapture percentage was lower indicating that mice avoided traps while FCM levels in recaptured mice were higher. On the contrary, during phase 2, despite the total number of captures was lower we found an increase in the recapture percentage and FCM levels did not increase in recaptured mice. Our results suggest that under increased risk perception traps could be likely considered as a suitable shelter and thus, for some individuals the benefits of traps may outweigh their risks. In addition, we discovered that the effects of combining two stressors do not result in the addition of the response originated by each factor separately.
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Affiliation(s)
- M C Hernández
- Department of Biology, Universidad Autónoma de Madrid, C/ Darwin 2, Campus Universitario de Cantoblanco, 28049, Madrid, Spain.
| | - Á Navarro-Castilla
- Department of Biology, Universidad Autónoma de Madrid, C/ Darwin 2, Campus Universitario de Cantoblanco, 28049, Madrid, Spain
| | - A Planillo
- Terrestrial Ecology Group (TEG), Department of Ecology, Universidad Autónoma de Madrid, C. Darwin 2, 28049, Cantoblanco, Madrid, Spain; Department of Ecological Dynamics, Leibniz Institute for Zoo and Wildlife Research (IZW), Alfred-Kowalke-Straße 17, 10315, Berlin, Germany
| | - B Sánchez-González
- Department of Biology, Universidad Autónoma de Madrid, C/ Darwin 2, Campus Universitario de Cantoblanco, 28049, Madrid, Spain
| | - I Barja
- Department of Biology, Universidad Autónoma de Madrid, C/ Darwin 2, Campus Universitario de Cantoblanco, 28049, Madrid, Spain
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Hernández M, Navarro-Castilla Á, Piñeiro A, Barja I. Wood mice aggressiveness and flight response to human handling: Effect of individual and environmental factors. Ethology 2018. [DOI: 10.1111/eth.12760] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
| | | | - Ana Piñeiro
- Escuela de Medicina Veterinaria; Facultad de Ciencias de la Vida; Universidad Andres Bello; Santiago de Chile Chile
| | - Isabel Barja
- Departamento de Biología; Universidad Autónoma de Madrid; Madrid Spain
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Sánchez-González B, Planillo A, Navarro-Castilla Á, Barja I. The concentration of fear: mice’s behavioural and physiological stress responses to different degrees of predation risk. Naturwissenschaften 2018; 105:16. [DOI: 10.1007/s00114-018-1540-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 01/10/2018] [Accepted: 01/12/2018] [Indexed: 11/29/2022]
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