Benjamin Geffroy

How Nature-Based Tourism Might Increase Prey Vulnerability to Predators.

Tourism can be deleterious for wildlife because it triggers behavioral changes in individuals with cascading effects on populations and communities. Among these behavioral changes, animals around humans often reduce their fearfulness and antipredator responses towards humans. A straightforward prediction is that habituation to humans associated with tourism would negatively influence reaction to predators. This could happen indirectly, where human presence decreases the number of natural predators and thus prey become less wary, or directly, where human-habituated individuals become bolder and thus more vulnerable to predation. Building on ideas from the study of traits associated with domestication and urbanization, we develop a framework to understand how behavioral changes associated with nature-based tourism can impact individual fitness, and thus the demographic trajectory of a population.

Behavioural syndrome in juvenile eels and its ecological implications

Behavioural syndrome, which refers to a suite of correlated behaviours across differing situations, has been identified in numerous animals, including fish. The presence and conservation of a behavioural syndrome throughout evolutionary times suggests it confers various advantages at a population level. In eels, such as the European eel (Anguilla anguilla), activity and aggressiveness are important factors in their life history, since both traits influence dispersal and territoriality. In the present study we investigated whether these behavioural traits were consistent at both the nychtemeral scale (24 h) and over a long time period (7 months). In addition, we investigated if aggressiveness and activity were positively correlated. Both activity and aggressiveness were significantly repeatable, indicating that both behavioural traits could be considered as personality traits. Interestingly, nocturnal activity was correlated to diurnal activity, indicating that this personality trait was highly stable at the circadian scale. Both aggressiveness and activity were correlated in the course of the experiment, underlining the presence of a behavioural syndrome. The detection of two behaviourally distinct groups in juvenile eels: aggressive and active individuals versus their counterpart have implications in the understanding of the colonization profile of the watershed. We discuss these findings in relation to the ecology of this species.

Sexually dimorphic gene expressions in eels: useful markers for early sex assessment in a conservation context

Environmental sex determination (ESD) has been detected in a range of vertebrate reptile and fish species. Eels are characterized by an ESD that occurs relatively late, since sex cannot be histologically determined before individuals reach 28 cm. Because several eel species are at risk of extinction, assessing sex at the earliest stage is a crucial management issue. Based on preliminary results of RNA sequencing, we targeted genes susceptible to be differentially expressed between ovaries and testis at different stages of development. Using qPCR, we detected testis-specific expressions of dmrt1, amh, gsdf and pre-miR202 and ovary-specific expressions were obtained for zar1, zp3 and foxn5. We showed that gene expressions in the gonad of intersexual eels were quite similar to those of males, supporting the idea that intersexual eels represent a transitional stage towards testicular differentiation. To assess whether these genes would be effective early molecular markers, we sampled juvenile eels in two locations with highly skewed sex ratios. The combined expression of six of these genes allowed the discrimination of groups according to their potential future sex and thus this appears to be a useful tool to estimate sex ratios of undifferentiated juvenile eels.

Physiological and Behavioral Consequences of Human Visitation

The more people lose contact with nature in their daily lives, the greater the need to compensate for this loss through nature-based recreation and ecotourism. However, these tourist activities are often not without consequences for animals. The mere presence of humans can affect resident wildlife. Short-term changes in physiology and behavior may accumulate and thus affect individuals. The cumulative impacts of these often small changes, combined with other environmental assaults, may have population-level consequences and thus reduce the likelihood of a population of persisting over time. In this chapter, we describe how human visits in natural areas might modulate the physiology and behavior of animals. We find that most animals are particularly sensitive to tourist numbers as well as behavior and noise associated with human presence. Feeding practices often change the behavior of focal animals, leading to some individuals becoming bolder and more aggressive. At the physiological level, a shift from a natural to an artificial diet could also have long-term consequences by affecting animals’ body condition and other traits essential for population survival. We list current and forthcoming challenges that need to be addressed to reduce negative impacts of human visitation on wildlife species in the context of sustainable tourism management.

Nature-Based Tourism and Prey Vulnerability to Predators: A Reply to Fitzgerald and Stronza

In a recent review [1] we developed a framework to identify potential ecological consequences of long-term benign interactions between humans and animals and to highlight potential deleterious effects of non-threatening wildlife viewing by tourists. Fitzgerald and Stronza [2] questioned our hypothesis stating that ‘It sends a countervailing, mixed message to conservation stakeholders about the real importance of tourism for protecting wildlife’ and claimed that we focused on negative points while ecotourism could bring many more benefits than costs to endangered animals.

Enhanced brain expression of genes related to cell proliferation and neural differentiation is associated with cortisol receptor expression in fishes

Stress enhances or inhibits neurogenesis in mammals and some fish species. The link between the two processes is still unclear. Most studies have been performed in very specific stressful or altered environments. Despite the known inter-individual divergence in coping abilities within populations, the relationship between the stress axis and neurogenesis has never been addressed in unstressed individuals. Here we correlate brain expression of the pcna (proliferating cell nuclear antigen) and neurod1 (neurogenic differentiation factor 1) genes, two markers of neurogenesis, with transcripts of cortisol receptors in three fish species living in very distinct environments. Within the three species, individuals with the highest expression of neurogenesis genes were also those that expressed the high levels of cortisol receptors. Based on these correlations and the hypothesis that mRNA levels are proxies of protein levels, we hypothesize that within unstressed animals, individuals sensitive to cortisol perceive a similar environment to be more stimulating, leading to increased neurogenesis. Although it is difficult to determine whether it is sensitivity to cortisol that affects neurogenesis capacities or the opposite, the proposed pathway is a potentially fruitful avenue that warrants further mechanistic experiments.

Endogenous regulation of 11-deoxycorticosterone (DOC) and corticosteroid receptors (CRs) during rainbow trout early development and the effects of corticosteroids on hatching

Clear evidence for a physiological role of the mineralocorticoid-like hormone 11-deoxycorticosterone (DOC) and the mineralocorticoid receptor (MR) in fish is still lacking. Efforts to demonstrate an osmoregulatory role for this hormone has so far not been conclusive, while a few scattered studies have indicated a role for DOC in development and reproduction. In this study, we investigate the onset of de novo DOC synthesis in parallel with endogenous corticosteroid receptor mRNA production from fertilization to the swim-up stage in rainbow trout. Whole egg DOC content decreased from fertilization until hatching followed by an increase to pre-fertilization levels just after hatching. Onset of de novo transcription of corticosteroid receptor mRNAs was observed shortly after the midblastula transition; initially glucocorticoid receptor 2 (GR2) followed by MR and then GR1. Non-invasive introduction of DOC or cortisol at fertilization resulted in altered corticosteroid receptor regulation and accelerated hatching date, suggesting a regulatory role in trout ontogenesis of both hormones through MR signaling pathway. The results presented in this study suggest a possible physiological role of the DOC-MR signaling pathway during fish ontogenesis, at fertilization and just after hatching.

Pets at ecotourism destinations: cute mascot or trojan horse?

ABSTRACT Alien species are threatening native fauna worldwide and cats and dogs have well-documented deleterious impacts on wildlife. Ecotourism operators often live and raise their pets in natural reserves. Here we discuss how pets add to the list of potential negative impacts of ecotourism and provide recommendations to control or attenuate such impacts.

Introduction: Ecotourism’s Promise and Peril

This is a book that desires to improve the positive impacts of ecotourism and nature-based tourism by properly identifying potential biological impacts so as to help develop effective mitigations and management. We focus mostly on impacts on wildlife. We bring a unique animal-behavior centered approach to potential impacts of eco- and nature-based tourism. Changes in behavior are usually the first reaction of animals to environmental challenges, and ecotourism can be viewed as an environmental challenge. This behavioral perspective focuses on mechanisms of how animals respond to threats and challenges. A conflict between what is good for nature and the societal benefits that may emerge from ecotourism is more-or-less expected given the desire to both reduce impacts on nature while benefiting people and promoting conservation. We develop a research agenda that will ultimately create a culture of evidence-based ecotourism. It is through evidence-based ecotourism research that we will make ecotourism more sustainable for both the natural resources that we seek to explore as well as the communities that are charged with their stewardship.

Best Practices Toward Sustainable Ecotourism

The goal of this book is to empower operators, regulators, and tourists to find the critical balance between possibly damaging consequences of wildlife tourism and the potential benefits to the local human communities, ecosystems, and the wildlife themselves. It is essential to realize that ecotourism is frequently more environmentally friendly than other uses of natural resources. Thus, ecotourism can provide great incentives for nature conservation. Nonetheless, as previous chapters have shown, there are many examples of environmentally unfriendly ecotourism practices. It is imperative to mitigate any negative impacts of ecotourism not only for ecological reasons but also to enhance social and economic sustainability. The objective of this chapter is to provide a list of best practices based on the evidence discussed in previous chapters. Greater awareness of such practices will enable tourism operators and managers to make informed decisions for the benefit of both the wildlife that people wish to see and the human communities that are fortunate enough to share these natural resources.