Changes in escape behaviour of black iguanas (Ctenosaura similis) over an anthropogenic disturbance gradient

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.

2018 ◽  
Vol 148 (2) ◽  
Author(s):  
Evelien Deboelpaep ◽  
Pieter-Jan Keleman ◽  
Bram Vanschoenwinkel ◽  
Nico Koedam

While escape responses are shown to differ in areas with varying levels of human disturbance, it is not known to what extent these reactions depend on the composition of local species assemblages. We investigated variation in three flight response metrics for the invasive Canada Goose (Branta canadensis) in Belgium in three locations with different human accessibility. Results indicate that heterospecific birds and flock size affected flight initiation distances of the Canada Goose, but that these effects are location-specific. Escape responses were most pronounced in the nature reserve with the lowest human accessibility, and highly reduced in the recreational park. This study illustrates that, when buffer zones are being developed, generalising escape behaviour of birds may lead to potentially dangerous overestimations of their tolerance to human disturbance.


2015 ◽  
Vol 75 (1) ◽  
pp. 58-68 ◽  
Author(s):  
BC. Barbosa ◽  
R. Fagundes ◽  
LF. Silva ◽  
JFV. Tofoli ◽  
AM. Santos ◽  
...  

Interaction among species, like ants and plants through extrafloral nectaries (EFNs), are important components of ecological communities’ evolution. However, the effect of human disturbance on such specific interactions and its ecological consequences is poorly understood. This study evaluated the outcomes of mutualism between ants and the EFN-bearing plant Stachytarpheta glabra under anthropogenic disturbance. We compared the arthropod fauna composition between two groups of twenty plant individuals, one in an area disturbed by human activities and one in a preserved area. We also check the plant investment in herbivory defense and the consequential leaf damage by herbivore. Our results indicate that such disturbances cause simplification of the associated fauna and lack of proper ant mutualist. This led to four times more herbivory on plants of disturbed areas, despite the equal amount of EFN and ant visitors and low abundance of herbivores. The high pressure of herbivory may difficult the re-establishment of S. glabra, an important pioneer species in ferruginous fields, therefore it may affect resilience of this fragile ecological community.


Animals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 605 ◽  
Author(s):  
Muhammad Zaman ◽  
Bryony A. Tolhurst ◽  
Mengyan Zhu ◽  
Guangshun Jiang

Humans and dogs initiate measurable escape responses in wild animals including flight initiation distance (FID), with potentially negative consequences. Golden marmots are important prey for endangered carnivores and are subject to human persecution including via marmot baiting with dogs. We quantified FID at four marmot colonies (72 individuals) in the Karakoram range, Pakistan in response to approach by a pedestrian with a leashed dog versus approach by a pedestrian alone (i.e., a control). Additionally, we related FID to background variables of human activity, namely proximity to roads, and presence of other pedestrians in the vicinity of study sites during sampling. We also controlled for potential environmental and social covariates (e.g., group size, age and sex, and colony substrate). Dogs initiated greater FID than pedestrians alone, and there was evidence that roads increased FID. However, these effects were weaker than those of marmot age and colony substrate. FID was greater at lower elevations, but this may reflect the clustering in these zones of human settlements and livestock pasture. Further work is needed elucidate the importance of colony substrate (linked to ease of human persecution), the effect of settlements and pasture, and the impact of increased FID on marmot fitness.


Author(s):  
Megan D Bjordal

Human population growth results in destruction of natural habitats, although some animals are adapting to living in areas with human disturbance. North American red squirrels (Tamiasciurus hudsonicus) may be one such species that is successfully adapting to living alongside humans. Flight initiation distance, the distance at which an animal flees from an approaching predator, may act as an indicator of habituation to humans. I predicted that if North American red squirrels were habituating to humans, their flight initiation distance would decrease along a gradient of increasing human disturbance. To examine this, I measured flight initiation distances of 39 North American red squirrels across eight sites, classified as low, medium or high human disturbance areas. No significant difference was found in mean flight initiation distances between disturbance levels, indicating that squirrel flight initiation distance may not be sensitive to small scales of human disturbance gradients.


2016 ◽  
Vol 4 ◽  
pp. 257-261
Author(s):  
Barbora Holienková ◽  
Zuzana Krumpálová

Recently, the number of alien landscape species has dramatically increased, and this could be a serious threat, not only for native species but also in cases of outbreaks for farmers. Our objective was to examine the impact of the urban environment (positive or negative) on the diversity of native species; forecast biotic homogenization or diversification of urban fauna; and determine the extent to which each of the zones are affected by invasive species. To examine the effect of urbanization, we selected 16 areas (across three urban zones and one zone in the protected area for comparison) for this study in 2015 in Nitra. We found that snails in open locations had significantly greater species diversity and abundance of individuals than in closed locations. Slightly degraded areas had the most abundant snail species, but areas heavily disturbed had high species diversity and incidence of individuals. It appears that heavily disturbed areas are suitable as new types of refuge for snails, e.g., for Helix lucorum, which was recorded in Slovakia for the first time (numerically recorded at the railway station) in 2014.


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.


2021 ◽  
pp. 1-10
Author(s):  
Carlos M. Delgado-Martínez ◽  
Fredy Alvarado ◽  
Melanie Kolb ◽  
Eduardo Mendoza

Abstract Great attention has been drawn to the impacts of habitat deforestation and fragmentation on wildlife species richness. In contrast, much less attention has been paid to assessing the impacts of chronic anthropogenic disturbance on wildlife species composition and behaviour. We focused on natural small rock pools (sartenejas), which concentrate vertebrate activity due to habitat’s water limitation, to assess the impact of chronic anthropogenic disturbance on the species richness, diversity, composition, and behaviour of medium and large-sized birds and mammals in the highly biodiverse forests of Calakmul, southern Mexico. Camera trapping records of fauna using sartenejas within and outside the Calakmul Biosphere Reserve (CBR) showed that there were no effects on species richness, but contrasts emerged when comparing species diversity, composition, and behaviour. These effects differed between birds and mammals and between species: (1) bird diversity was greater outside the CBR, but mammal diversity was greater within and (2) the daily activity patterns of birds differed slightly within and outside the CBR but strongly contrasted in mammals. Our study highlights that even in areas supporting extensive forest cover, small-scale chronic anthropogenic disturbances can have pervasive negative effects on wildlife and that these effects contrast between animal groups.


2018 ◽  
Vol 77 (2) ◽  
pp. 277-287 ◽  
Author(s):  
Fanshu Xiao ◽  
Yonghong Bi ◽  
Xinghao Li ◽  
Jie Huang ◽  
Yuhe Yu ◽  
...  

2021 ◽  
Vol 9 ◽  
Author(s):  
Yuval Zukerman ◽  
Zehava Sigal ◽  
Oded Berger-Tal

The increasing pressure of ecotourism on wildlife in their natural habitats leads many wild animals to alter their behaviors. The restrictions issued in many places due to COVID-19 provide a rare opportunity to examine wildlife behavior in nature reserves with reduced human presence, and to reveal the impact of human visitation on the behaviors and fitness of local wildlife species. In 2019 and 2020 we placed trail cameras next to two natural springs in the Israeli Negev Desert, Ein-Avdat and Ein-Shaviv, located 9 km apart. Both sites serve as the main water source for local Nubian ibex (Capra nubiana) populations, but Ein-Avdat is situated within a popular national park into which visitors’ entrance was restricted due to COVID-19 regulations in 2020, while Ein-Shaviv is more remote and thus attracts only few visitors regardless of COVID-19 regulations. Our study revealed that during 2020, ibex in Ein-Avdat arrived to drink earlier in the day and the population’s Female:Kids ratio more than doubled. These changes were not observed in Ein-Shaviv. We found that the daily number of visitors in Ein-Avdat affected the arrival time of ibex to the water pool. We conclude that the reduced number of visitors to Ein-Avdat in 2020 compared to 2019 may have allowed ibex to arrive in preferred hours, and may have contributed to the increased kid-to-females ratio. Our study shows that behavioral adaptions to human visitation in nature reserves might carry a high fitness cost.


2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Nadezhda Poddubnaya ◽  
Tatyana Korotkova ◽  
Polina Vanicheva

The rapid growth of cities causes behaviour changes in birds in response to urban environmental factors. The avian response to human disturbance has recently been studied by a non-invasive research tool as an alert distance (AD) and a flight initiation distance (FID) assessment. The tolerance of hooded crows (n = 395), jackdaws (n = 394) and rooks (n = 169) to humans was assessed by AD and FID. It was shown that the FID of all species is maximal during the summer, when the parents send clear “danger—fly away” signals to the young and the birds fly away. The AD and FID of the three species reliably correlates with the season. Rooks showed FID species-specificity in seven cities of Eastern Europe. Comparison of the attitude of birds to people in cities that have similarities in human culture showed that tolerance increases with increasing latitude in all species and is statistically significant only in the jackdaw. This should be taken into account in environmental protection measures.


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