Diogo S M Samia

• PhD in Ecology and Evolution
• PostDoc Position at University of São Paulo

When approached by a predator, prey make economic decisions between remaining where they are and obtaining benefits from their current activity or leaving and enhancing their safety. The "flush early and avoid the rush" hypothesis suggests that animals that flee to escape approaching threats flee soon after they become alert to an approaching preda...

Optimal escape theory predicts that animals should balance the costs and benefits of flight. One cost of not fleeing is the ongoing cost of monitoring an approaching predator. We used a phylogenetic meta-analysis to test the general hypothesis that animals should initiate flight soon after they detect a predator-the 'flush early and avoid the rush'...

In many species, sexual dimorphism increases with body size when males are the larger sex but decreases when females are the larger sex, a macro-evolutionary pattern known as Rensch's rule (RR). Although empirical studies usually focus exclusively on body size, Rensch's original proposal included sexual differences in other traits, such as ornament...

In an increasingly anthropic world, humans have profound impacts on the distribution and behaviour of marine fishes. The increased human presence has modified fishes’ antipredator behavioural responses, and consequently flight decisions, as a function of their changed perceptions of risk. Understanding how fish react to human presence can help iden...

Camouflage is widespread throughout the animal kingdom allowing individuals to avoid detection and hence save time and energy rather than escape from an approaching predator. Thus, camouflage is likely to have co-evolved with antipredator behavior. Here we propose that camouflage results in dichotomous escape behavior within and among species with...

Behavioral adjustment is a key factor that facilitates species’ coexistence with humans in a rapidly urbanizing world. Because urban animals often experience reduced predation risk compared to their rural counterparts, and because escape behavior is energetically costly, we expect that urban environments will select for increased tolerance to human...

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.

Many prey flee to refuges to escape from approaching predators, but little is known about how they select one among many refuges available. The problem of choice among alternative refuges has not been modeled previously, but a recent model that predicts flight initiation distance (FID = predator–prey distance when escape starts) for a prey fleeing...

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 tha...

Intended as a guide for wildlife managers and ecotourism operators, as well as interested ecotourists, this book addresses the biological principles governing how ecotourism affects wildlife. The introductory chapters focus on four key responses to human visitation—behavioral, physiological, ecological, and evolutionary. Readers will discover ecoto...

Behavioral adjustment is a key factor that facilitates species' coexistence with humans in a rapidly urbanizing world. Because urban animals often experience reduced predation risk compared to their rural counterparts, and because escape behavior is energetically costly, we expect that urban environments will select for increased tolerance to human...

Reducing ecotourism’s impacts on wildlife requires an evidence-based research agenda that recognizes both the magnitude and effect of anthropogenic stressors on wildlife while also recognizing the value of ecotourism to local communities. We suggest that operators and ecotourists themselves can play a vital role in collecting evidence that can be u...

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...

Human disturbance drives the decline of many species, both directly and indirectly. Nonetheless , some species do particularly well around humans. One mechanism that may explain coexistence is the degree to which a species tolerates human disturbance. Here we provide a comprehensive meta-analysis of birds, mammals and lizards to investigate species...

Supplementary Figures 1-9, Supplementary Tables 1-5, Supplementary Methods and Supplementary References

Model selection of all birds: phylogenetic effect not controlled

Complete data set

Model selection of all birds: phylogenetic effect controlled

Model selection of rural-urban birds: phylogenetic effect not controlled

Model selection of rural-urban birds: phylogenetic effect controlled

Predators exert strong selection pressures on their prey. Prey would therefore benefit by adjusting their behaviour to the risk of predation, while predators conversely would benefit from adjusting their behaviour to that of their prey. Extravagant ornamentation has evolved to attract mates and/or successfully compete with conspecifics of the same...

Ecological investigations are increasingly using functional diversity in order to understand different patterns, such as species occurrence, species competitive abilities, and the influence of biological communities on ecosystem functioning. Here we provide an overview of the history and applicability of functional diversity in ecological studies....

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...

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 wit...

Escape decisions have been studied in a remarkably Tinbergian way that has included examination of both proximate and ultimate questions, including questions about the evolution of escape behavior. Evolutionary studies have been made possible by developing large comparative data sets. Methodological differences, however, may impede our ability to c...

After detecting an approaching predator, animals make a decision when to flee. Prey will initiate flight soon after detecting a predator so as to minimize attentional costs related to on-going monitoring of the whereabouts of the predator. Such costs may compete with foraging and other maintenance activities and hence be larger than the costs of im...

Economic escape theory refers to the escape decisions prey make based on their assessment of the costs and benefits of fleeing. In 1986, Ydenberg and Dill published a seminal paper in Advances in the Study of Behavior that developed the first cost-benefit models of escape. Here, we focus on flight initiation distance (FID), the predator-prey distan...

Prey typically respond to potential predators by taking flight. This results in an optimal flight initiation distance (FID) at which the risk of remaining and the cost of flight are equal. Thus, FID is strongly negatively correlated with susceptibility to predation by the sparrowhawk Accipiter nisus across species of small European birds. However,...

Sexual selection is a powerful evolutionary mechanism that has shaped the physiology, behaviour and morphology of the sexes to the extent that it can reduce viability while promoting traits that enhance reproductive success. Predation is one of the underlying mechanisms accounting for viability costs of sexual displays. Therefore, we should expect...

Since 1986, studies about the escape decisions made by prey are grounded in optimal escape theory (OET) which states that prey will initiate escape when the risk of remaining and the costs of leaving are equal. However, a recent hypothesis, Flush Early and Avoid the Rush (FEAR), acknowledged that the cost of monitoring approaching predators might b...

Systematic reviews and meta-analyses often examine data from diverse taxa to identify general patterns of effect sizes. Meta-analyses that focus on identifying generalisations in a single taxon are also valuable because species in a taxon are more likely to share similar unique constraints. We conducted a comprehensive phylogenetic meta-analysis of...

Current color metrics commonly used to study the animal-substrate contrast, require researchers perform the analyses under controlled conditions of light. We argue that sometimes this approach can be suboptimal because it does not use the same light source as natural habitats, ignores the proportion of the different colors of the pattern, and ignor...

Current color metrics commonly used to study the animal-substrate contrast, require researchers perform the analyses under controlled conditions of light. We argue that sometimes this approach can be suboptimal because it does not use the same light source as natural habitats, ignores the proportion of the different colors of the pattern, and ignor...

Optimal escape theory states that animals should counterbalance the costs and benefits of flight when escaping from a potential predator. However, in apparent contradiction with this well-established optimality model, birds and mammals generally initiate escape soon after beginning to monitor an approaching threat, a phenomena codified as the "Flus...

Background All organisms may be affected by humans' increasing impact on Earth, but there are many potential drivers of population trends and the relative importance of each remains largely unknown. The causes of spatial patterns in population trends and their relationship with animal responses to human proximity are even less known. Methodology/P...

Current color metrics commonly used to study animal-substrate contrast require researchers perform the analyses under controlled light conditions. These are away from the natural conditions in which animal signaling occurs. In addition to practical drawbacks, we argue that it can represent a suboptimal approach due three main reasons: (1) does not...