scholarly journals Endangered Apes—Can Their Behaviors Be Used to Index Fear and Disturbance in Anthropogenic Landscapes?

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 660
Author(s):  
Melissa A. Reisland ◽  
Nicholas Malone ◽  
Joanna E. Lambert

Behaviors exhibited by prey species towards predators (including humans) can reduce feeding time and increase time spent in vigilance, thereby impacting animal condition and ultimately limit populations, even when actual mortality from predation is low. Here, we test whether behavioral profiles in an endangered ape, Javan gibbons (Hylobates moloch), correspond to varying degrees of human disturbance in a human-impacted sacred forest, Cagar Alam Leuweung Sancang, West Java. Data were collected August 2010–July 2011. Although all groups reacted differently to human presence, overall, gibbons responded by reducing time spent on conspicuous behavior (e.g., vocalizing, feeding, traveling, and social interactions) as the number of humans in the area increased or distance to the nearest human decreased. In addition, gibbon responses to encountering humans were also more like their responses to encountering potential predators than they were to encountering monkeys or other gibbons. These results support the hypothesis that as human presence and encounter rates increase, gibbons alter their behavior in ways consistent with anti-predator behaviors. Assessing how this endangered species responds to human presence is a vital part of their ultimate conservation.

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 290
Author(s):  
Giacomo Cremonesi ◽  
Francesco Bisi ◽  
Lorenzo Gaffi ◽  
Thet Zaw ◽  
Hla Naing ◽  
...  

The effects of human disturbance represent one of the major threats for wildlife conservation. Many studies have shown that wildlife avoids or reduces direct contact with human activities through changes in activity patterns, and by minimizing spatiotemporal overlap. In this study, we investigated the possible effects of human presence on the temporal activity of medium-to-large mammals using two areas in Myanmar that differ in the intensity of human disturbance. We monitored temporal segregation mechanisms using camera trapping data and with two statistical approaches: daily activity overlaps between humans and wildlife and circular statistics. We did not find a significant difference in overlapping activity between areas but, thanks to circular statistics, we found that some species show changes in activity patterns, suggesting temporal avoidance. We observed that the daily activity of five species differed between areas of Myanmar, likely adopting mechanisms to reduce overlap in areas highly frequented by humans. Interestingly, these species are all threatened by hunting or poaching activities, four of which have been described in literature as “cathemeral”, or species that are active through day and night. This study suggests that some species adapt their behavior, at least partially, to avoid human presence in habitats with higher anthropic occurrence and increase our knowledge on the status of medium–large mammals in a poorly studied country as Myanmar.


Behaviour ◽  
2021 ◽  
pp. 1-21
Author(s):  
Pooja Panwar ◽  
Pilar Angélica Gómez-Ruiz ◽  
Matthew N. Zipple ◽  
Luis Sandoval

Abstract Studies on the impact of human activity on animal behaviour are critical for understanding the extent to which humans affect ecological dynamics. Previous studies have found that human presence alters antipredator behaviours, which can be measured by flight initiation distance (FID). We investigated escape behaviour of 96 black iguanas (Ctenosaura similis) across a gradient of human disturbance in six sites inside a protected area in Costa Rica. We used a field experiment to test for effect of human disturbance on FID. We found that individuals from higher disturbance sites had shorter FIDs, meaning that black iguanas from disturbed areas allow closer approaches. This finding is consistent with the prediction that some animals become more habituated to human presence as the degree of human disturbance increases. We propose that black iguanas’ ability to alter their behaviour in response to humans’ presence could make them especially adept at invading new environments.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Kirby L Mills ◽  
Nyeema C Harris

Wildlife respond to human presence by adjusting their temporal niche, possibly modifying encounter rates among species and trophic dynamics that structure communities. We assessed wildlife diel activity responses to human presence and consequential changes in predator-prey overlap using 11,111 detections of 3 large carnivores and 11 ungulates across 21,430 camera trap-nights in West Africa. Over two-thirds of species exhibited diel responses to mainly diurnal human presence, with ungulate nocturnal activity increasing by 7.1%. Rather than traditional pairwise predator-prey diel comparisons, we considered spatiotemporally explicit predator access to several prey resources to evaluate community-level trophic responses to human presence. Although leopard prey access was not affected by humans, lion and spotted hyena access to three prey species significantly increased when prey increased their nocturnal activity to avoid humans. Human presence considerably influenced the composition of available prey, with implications for prey selection, demonstrating how humans perturb ecological processes via behavioral modifications.


2021 ◽  
Author(s):  
Alexandra Rodriguez ◽  
Sebastien Caron ◽  
Jean-Marie Ballouard

Behavioural studies are more an more implicated in species conservation. Determining individuals personality in the case of reintroduction operations may be very useful. Actually, indiviuals temperament may be associated to their dispersal capacities and their habilities to adapt to novel environments. Considered as asociable species, few studies have been conducted on reptiles and this is even worse in the case of endangered species. Hermann tortoise, Testudo hermanni, an endemic species from Mediterranean region is endangered because of the lost and modification of its habitats. Before conducting reintroduction actions it is important to have more information on individuals personality traits. We have tested the reaction of three groups of tortoises (domestic, wild and from the SOPTOM center) when confronted to a novel environment and to human presence. The aim was to discriminate individuals with bold and shy behaviours. Behavioural profiles are different between the three groups of tortoises, the domestic group appeared to be bolder than the wild one. Moreover, for the wild group, bold individuals travel longer distances in the field, sometimes outside the protected areas. Thus, it is important to take into account the personality of individuals choosen for translocation projects.


2016 ◽  
Vol 106 (4) ◽  
pp. 522-529 ◽  
Author(s):  
F.J. Sola ◽  
R. Josens

AbstractLiquid sugar baits are well accepted by the Argentine ant Linepithema humile and are suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10–30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of post-feeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Holzner ◽  
Krishna N. Balasubramaniam ◽  
Brigitte M. Weiß ◽  
Nadine Ruppert ◽  
Anja Widdig

AbstractHuman-induced habitat alterations globally threaten animal populations, often evoking complex behavioural responses in wildlife. This may be particularly dramatic when negatively affecting social behaviour, which fundamentally determines individual fitness and offspring survival in group-living animals. Here, we provide first evidence for significant behavioural modifications in sociality of southern pig-tailed macaques visiting Malaysian oil palm plantations in search of food despite elevated predation risk. Specifically, we found critical reductions of key positive social interactions but higher rates of aggression in the plantation interior compared to the plantation edge (i.e. plantation areas bordering the forest) and the forest. At the plantation edge, affiliation even increased compared to the forest, while central positions in the macaques' social network structure shifted from high-ranking adult females and immatures to low-ranking individuals. Further, plantations also affected mother–infant relationships, with macaque mothers being more protective in the open plantation environment. We suggest that although primates can temporarily persist in human-altered habitats, their ability to permanently adapt requires the presence of close-by forest and comes with a trade-off in sociality, potentially hampering individual fitness and infant survival. Studies like ours remain critical for understanding species’ adaptability to anthropogenic landscapes, which may ultimately contribute to facilitating their coexistence with humans and preserving biodiversity.


2018 ◽  
Vol 29 (2) ◽  
pp. 277-290 ◽  
Author(s):  
REBECCA K. FRENCH ◽  
CHRIS G. MULLER ◽  
B. LOUISE CHILVERS ◽  
PHIL F. BATTLEY

SummaryHuman disturbance can have behavioural, physiological and population-level consequences on wildlife. Unregulated tourism is having a negative effect on the endangered Yellow-eyed Penguin Megadyptes antipodes on mainland New Zealand. Subantarctic Yellow-eyed Penguins are exposed to tourism on Enderby Island in the Auckland Islands group, 450 km south of New Zealand. Restrictions and guidelines for tourism are in place on Enderby Island, but there has been little study on the efficacy of these. We quantified behavioural responses of the Yellow-eyed Penguin on Enderby Island to human presence by documenting movement patterns and behaviour of penguins in the presence and absence of humans, through both controlled approaches and monitoring penguin behaviour in the presence of tourists. We used these data to model the effective approach distances for reducing disturbance. Human presence caused a significant drop in the probability of a successful transit to or from their nest, and significantly increased the time penguins spent alert and decreased the time spent preening. Modelling showed the distance from a human to a penguin is a significant predictor of the likelihood of a bird displaying disturbance behaviour, with the current minimum approach guideline of 5 m not sufficient for preventing disturbance. Our results indicate that the minimum approach guideline needs to be revised if the probability of disturbance is to be reduced. Modelling the appropriateness of minimum approach guidelines by predicting the probability of disturbance is a useful technique that could be applied to other species and systems. Worldwide, management guidelines need to be scientifically evaluated to ensure efficacy and cater for the more sensitive species affected.


2002 ◽  
Vol 2002 ◽  
pp. 69-69
Author(s):  
J. Williams ◽  
F. Baker ◽  
R. Hooper ◽  
A. Stewart

The move towards group housing of gestating sows has highlighted a number of welfare issues associated with social interactions that are directly related to management and pen design. For example feeding method and total space can impact on both behaviour and performance. Individual feeding stalls combined with a straw based lying area and dunging passage have production and behavioural advantages at feeding time by providing safety from aggressive pen mates. Anecdotal observations would suggest that they also provide an alternative lying space. However, in practice many feeders are either kept closed when not being used or are located in areas that do not provide a good thermal environment. This experiment was designed to evaluate environmental and social factors affecting the choice of lying behaviour of sows with and without access to feeding stalls throughout the day.


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