Project

From global to local: impacts of human disturbance on niche partitioning among carnivores

Goal: Interspecific competition and resource partitioning are strong evolutionary forces, shaping communities. The mechanisms of coexistence and competition among species have been a central topic within community ecology, with a particular focus on mammalian carnivore community research. However, the influence of humans and their activities on those processes is still poorly understood.
This project will first review the existing literature on spatial, temporal, and trophic niche partitioning in carnivore communities to propose a theoretical framework covering the three main outcomes of the impact of humans on resource partitioning, intraguild competition and community structure.
Secondly, we will evaluate the relative influence of a range of human, meteorological and ecological variables on the coefficients of temporal overlap within carnivore communities on a global scale, using data extracted from the existing literature.
Finally, the methodology and reasoning employed by the currently available literature to calculate the coefficient of temporal overlap between pairs of species will be evaluated. Key guidelines and recommendations will be provided to future studies to develop an improved and standardised research practice on the study of animal activity pattern and temporal partitioning.
This project fills an important knowledge gap on the effects of human pressures on carnivore communities, by focusing on the impacts on niche partitioning and coexistence.

Date: 1 October 2017 - 31 December 2021

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Project log

Anthony Sévêque
added 2 research items
• Interspecific competition is an important evolutionary force, influencing interactions between species and shaping the composition of biological communities. In mammalian carnivores, to reduce the risks of negative encounters between competitors, species can employ a strategy of temporal partitioning, adapting activity patterns to limit synchronous activity. This strategy of non-human competitor avoidance, however, may be influenced by the expansion of human activities, which has driven wild mammals towards nocturnality. • We hypothesise that the disruption of temporal niche partitioning by humans and their activities could increase temporal overlap between carnivores, enhancing interspecific competition. • We reviewed the published literature systematically and employed generalised linear models to evaluate quantitatively the relative influence of a range of human, meteorological and ecological variables on coefficients of temporal overlap within mammalian terrestrial carnivore communities (orders Carnivora and Didelphimorphia) on a global scale. • None of the models investigated showed evidence of an impact of humans on temporal partitioning between carnivores on a global scale. This illustrates that temporal avoidance of humans and competitors does not always follow a consistent pattern and that its strength may be context-dependent and relative to other dimensions of niche partitioning (spatial and trophic). • Similarly, the regulation of activity patterns may be strongly site-specific and may be influenced by a combination of biotic and abiotic characteristics. Temporal avoidance of both humans and competitors by carnivores may take the form of short, reactive responses that do not impact activity patterns in the longer term. • Although we did not detect a global disruption of temporal partitioning due to human disturbance, carnivore communities may still experience an increase in interspecific competition in other niche dimensions. Further research would benefit from using controlled experimental designs and investigating multiple dimensions of niche partitioning simultaneously. Finally, we recommend complementing the coefficient of temporal overlap with other metrics of fine-scale spatiotemporal interactions.
Antonio Uzal
added a research item
Among species, coexistence is driven partly by the partitioning of available resources. The mechanisms of coexistence and competition among species have been a central topic within community ecology, with particular focus on mammalian carnivore community research. However, despite growing concern regarding the impact of humans on the behaviour of species, very little is known about the effect of humans on species interactions. The aim of this review is to establish a comprehensive framework for the impacts of human disturbance on three dimensions (spatial, temporal and trophic) of niche partitioning within carnivore communities and subsequent effects on both intraguild competition and community structure. We conducted a systematic review of the literature on carnivore niche partitioning (246 studies) and extracted 46 reported effects of human disturbance. We found evidence that human disturbance impacts resource partitioning, either positively or negatively, in all three niche dimensions. The repercussions of such variations are highly heterogeneous and differ according to both the type of human disturbance and how the landscape and/or availability of resources are affected. We propose a theoretical framework of the three main outcomes for the impacts of human disturbance on intraguild competition and carnivore community structure: (i) human disturbance impedes niche partitioning, increasing intraguild competition and reducing the richness and diversity of the community; (ii) human disturbance unbalances niche partitioning and intraguild competition, affecting community stability; and (iii) human disturbance facilitates niche partitioning, decreasing intraguild competition and enriching the community. We call for better integration of the impact of humans on carnivore communities in future research on interspecific competition.
Anthony Sévêque
added an update
This project aims to investigate the influence of anthropogenic pressure on: 1) the strategy of niche partitioning within carnivore communities; 2) the foraging behaviour of carnivores in human-dominated landscapes; and 3) its subsequent impact on available biomass for scavenging communities.
PART 1 The first section of the project consists of a global systematic review of the human influence on niche partitioning within carnivore communities. This document will provide a synthesis of the effects of human disturbance on the spatial, temporal and trophic niche partitioning strategies within carnivore communities, while critically evaluating existing literature. The manuscript is at its final stage of redaction, and will be submitted shortly.
PART 2 The second section of the project consists of a global meta-analysis on the effects of anthropogenic, biogeographical and ecological factors on temporal niche partitioning within carnivore communities. The manuscript is currently under redaction, and will be submitted early 2020.
PART 3 The third section of the project consists of the monitoring of carcasses resulting from wolf kills in the human-modified landscapes of Northern Spain. The study will evaluate variations in the scavenger assemblage in regard to the spatial distribution of the carcasses and temporal factors. Expected start in the first half of 2020.
PART 4 The final section of the project consists of the experimental disposal and monitoring of carrions in the human-modified landscapes of Northern Spain. The study will evaluate variations in the scavenger assemblage in regard to the spatial distribution of the carrions and temporal factors, while experimentally testing for a range of human disturbance in the landscape. Expected start in the first half of 2020.
 
Antonio Uzal
added an update
A new PhD project starting October 2017. Currently we are looking for partners across Europe to facilitate fieldwork in areas of recent recolonisation by large predators and/or areas in which the species are established but under contrasting human pressure from hunting, extraction or development.
 
Antonio Uzal
added a project goal
Interspecific competition and resource partitioning are strong evolutionary forces, shaping communities. The mechanisms of coexistence and competition among species have been a central topic within community ecology, with a particular focus on mammalian carnivore community research. However, the influence of humans and their activities on those processes is still poorly understood.
This project will first review the existing literature on spatial, temporal, and trophic niche partitioning in carnivore communities to propose a theoretical framework covering the three main outcomes of the impact of humans on resource partitioning, intraguild competition and community structure.
Secondly, we will evaluate the relative influence of a range of human, meteorological and ecological variables on the coefficients of temporal overlap within carnivore communities on a global scale, using data extracted from the existing literature.
Finally, the methodology and reasoning employed by the currently available literature to calculate the coefficient of temporal overlap between pairs of species will be evaluated. Key guidelines and recommendations will be provided to future studies to develop an improved and standardised research practice on the study of animal activity pattern and temporal partitioning.
This project fills an important knowledge gap on the effects of human pressures on carnivore communities, by focusing on the impacts on niche partitioning and coexistence.