Tourism in protected areas: Disentangling road and traffic effects on intra-guild scavenging processes

The behavior of Broad-tailed hummingbirds is altered by cycles of human activity in a forested area converted into agricultural land

Background

By changing the circumstances in which animals make their behavioral decisions, weekly cycles of human activity might cause changes in wildlife behavior. For example, when there is more human activity in a location, animals may become more vigilant, which can decrease the time they spend foraging, or roam farther from home, leading to increased home range size. Overall, there has been little exploration of how animal species living in locations that have undergone land use change are affected by the temporal dynamics of human activity levels. In this study, we aimed to analyze the effect of the weekend on agricultural activities and hummingbird territorial activity. We examined differences between weekdays and weekends in factors previously shown to follow weekly cyclical patterns, such as pedestrian presence, traffic, and the presence of domestic animals. We hypothesized that territorial hummingbirds would respond to these weekly cycles of human activity by altering their behavior.

Methods

We studied Broad-tailed hummingbird territories in forested areas that had been transformed to agriculture lands in central Mexico. We evaluated whether territorial individuals changed their behaviors (i.e., chases of intruders, foraging within their territory, number of intruders allowed to forage in the territory) in response to variation between weekdays and weekends in the number of pedestrians, cyclists, dogs, farm animals and vehicles.

Results

We found that the level of agriculture-related human activities showed a weekly cycle at our study site. On weekdays there was higher traffic of pedestrians, cyclists, dogs, farm animals and vehicles, compared to the weekends. Hummingbirds responded to these weekday-weekends differences by changing their territorial behavior. Compared to weekends, on weekdays hummingbirds showed a decrease in defense (number of chases) as well as the use of their territory (number of flowers visited), which allowed increased access to intruders (number of visited flowers by intruders).

Conclusions

Our findings suggest that variation in agriculture-related human activities between weekdays and weekends can alter the territorial behavior of hummingbirds. Behavioral shifts seem to be related to these human activity cycles, leading hummingbirds to reduce chases and feeding during weekdays when human activity is highest, but increasing both behaviors during times of minimal disturbance.

Risk effects cascade up to an obligate scavenger

The effects of predation risk on prey populations have been studied extensively; yet, how risk is manifested in a trophically linked guild-scavengers-has been overlooked. Risk could be particularly consequential for obligate scavengers that are vulnerable while foraging and rely on carrion provisioned by, and shared with, apex predators. We investigated whether Andean condors (Vultur gryphus) respond to predation risk in a landscape where the main source of carrion are camelids killed by pumas (Puma concolor). We hypothesized that condors would exhibit different behavioral responses to predation risk while they search, encounter, and exploit carrion. We explored condor habitat selection while flying by tracking nine birds with satellite transmitters and monitored via camera traps 41 natural carcasses and 25 experimental carrion stations. We found that condors searched for carrion in areas with a high probability of occurrence of puma kills. However, condors avoided exploiting carrion in areas featuring tall vegetation and steep slopes-selected by pumas to stalk prey-suggesting that condors manage risk primarily through the identification of safe foraging sites prior to landing. Our finding that condors avoided foraging near stalking cover for pumas highlights the importance of risk effects beyond predator-prey interactions, particularly for obligate scavengers.

Experimental evidence of increased carcass removal along roads by facultative scavengers

Investigating the spatial response of scavenging behaviors to roads may help in understanding the relevance of this overlooked ecosystem service. Roads can provide suitable foraging sites for scavengers, whether they are obligate or facultative. However, only a few studies have investigated the impact of roads on the spatial distribution of scavenging behavior, and most of them focused on areas inhabited by species-rich communities of obligate scavengers. In this study, we investigated this issue in a poorly productive arid environment in southern Tunisia where the main facultative scavengers were stray dogs. Our experimental design was based on the monitoring of carcasses placed at different distances from the road. We found that carcasses were removed faster along roadsides than farther away, showing the important role of road traffic in shaping the spatial distribution of scavenging activity. These results differ from those found by similar experimental studies also conducted on facultative scavengers but in more productive environments. Indeed, given the scarcity of food resources in the arid study area, scavengers seemed to depend largely on road-kills for food, thus concentrating their foraging activity along the roads in accordance with the predictions of the optimal foraging theory. Overall, our findings represent clear evidence that roads and related traffic can alter the spatial distribution of ecosystem services, with potential implications for food webs and ecosystem functioning. They also stress the need for accounting for scavengers when performing road-kill surveys, but also considering road effects when carrying out monitoring of the activity of scavengers.

The role of seasonality in assessments of conflict tendency between tourism development and ecological preservation in protected areas: The case of protected areas in China

Conflict management in PAs (Protected Areas) is becoming increasingly important in the context of the rapid development of nature-based tourism. Literature proposes the Index of Conflict tendency between Tourism development and ecological Protection (ICTP) to analyze the tendency of conflict from a spatial perspective, but this index does not consider the factor of seasonality which is important in tourism. The current study considers seasonality and proposes the CVD (Coverage- Variation- Duration) framework to conduct a spatio-temporal analysis of the ICTP. The applied research based on the case of China's V-PAs (a specific category of PAs) reflects that the CVD framework can describe the spatial distribution of the ICTP from a seasonal perspective. The study finds that, among V-PAs in China, 42.16% of the areas with high ICTP of V-PAs have obvious seasonal variations, which shows that PAs conflict management must incorporate the factor of seasonality. The study also shows that 8.98% of V-PAs have large-scale coverage of areas with high ICTP, revealing priorities for conflict management. 3.96% of V-PAs have large-scale coverage of areas with high ICTP showing seasonal changes. Management in these areas should pay attention to seasonal changes to become more effective. The CVD framework proposed in this paper is operable and extendable and can provide analytical tools for PAs conflict management, and promote ecological protection and more sustainable tourism development in PAs.

Apex scavengers from different European populations converge at threatened savannah landscapes

Over millennia, human intervention has transformed European habitats mainly through extensive livestock grazing. “Dehesas/Montados” are an Iberian savannah-like ecosystem dominated by oak-trees, bushes and grass species that are subject to agricultural and extensive livestock uses. They are a good example of how large-scale, low intensive transformations can maintain high biodiversity levels as well as socio-economic and cultural values. However, the role that these human-modified habitats can play for individuals or species living beyond their borders is unknown. Here, using a dataset of 106 adult GPS-tagged Eurasian griffon vultures (Gyps fulvus) monitored over seven years, we show how individuals breeding in western European populations from Northern, Central, and Southern Spain, and Southern France made long-range forays (LRFs) of up to 800 km to converge in the threatened Iberian “dehesas” to forage. There, extensive livestock and wild ungulates provide large amounts of carcasses, which are available to scavengers from traditional exploitations and rewilding processes. Our results highlight that maintaining Iberian “dehesas” is critical not only for local biodiversity but also for long-term conservation and the ecosystem services provided by avian scavengers across the continent.

Vultures and Livestock: The Where, When, and Why of Visits to Farms

Recent changes in European legislation have legalized the abandonment of carcasses around livestock farms, but our understanding of how vultures exploit these semi-predictable food sources is still very limited. For filling this gap, we determine the individual and ecological drivers influencing vulture visits to farms. We assessed the effects of individual characteristics of both birds and farms on the frequency of vultures' visits to livestock facilities using data collected from 45 GPS-tagged Egyptian Vultures (Neophron percnopterus) and 318 farms (>94% of livestock) on Fuerteventura Island, Spain. Farms were more visited during the vultures' breeding season. Farms located closer to highly predictable feeding places (i.e., vulture restaurants and garbage dumps) or with more available feeding resources were visited by more vultures, whereas those located close to roads and vultures' breeding territories received fewer visits. Younger territorial birds visited a farm more frequently than older territorial ones, whereas older non-territorial individuals concentrated those visits on farms closer to their activity core areas compared with younger ones. Our findings indicate that visits to farms were determined by their spatial distribution in relation to the age-specific birds' activity centers, the availability of carcasses, seasonality, and individual characteristics of vultures. These interacting factors should be considered in vulture conservation, avoiding very general solutions that ignore population structure.

Do Protected Areas Matter? A Systematic Review of the Social and Ecological Impacts of the Establishment of Protected Areas

There is growing interest in evaluating the effects of establishing protected areas (PAs). However, the mechanisms through which the establishment of PAs achieved significant positive effects remain unclear, and how different conservation mechanisms have achieved significant positive social and ecological benefits has also not been sufficiently studied. In this study, we systematically reviewed exemplary cases from Asia, Africa, and South America, using panel data to assess the conservation effectiveness of nature reserves and national parks. By surveying 629 literature samples reported in 31 studies, we found that the establishment of PAs has positive influences on poverty reduction, family incomes, household expenditure, employment, forest cover, biodiversity, carbon sequestration, and a reduction in forest fragmentation. Furthermore, we analyzed the specific aspects that influence the publication of a paper in a high-impact journal. We found that publication is more likely when the research uses panel data, matching methods of data analysis, large samples, and plots or PAs as research units and has significant evaluation results. Our results suggest that future studies should use panel data and matching method analysis to assess the impacts of PAs from multiple perspectives and focus on the effectiveness of specific conservation mechanisms in achieving positive effects.

Response of vertebrate scavengers to power line and road rights-of-way and its implications for bird fatality estimates

Linear infrastructures, such as power lines and roads, are an important source of bird mortality. However, little is known on the potential effect of these infrastructures on local scavenger guilds, their foraging activity and the resulting bird carcass removal patterns. This is an important source of bias in studies aiming to quantify bird fatalities due to linear infrastructures. We used camera-traps to record scavenger identity and persistence patterns of bird carcasses placed close to linear infrastructure and nearby controls in two Mediterranean agricultural regions. We found that linear infrastructure influence on scavenger identity varied depending on the region. Contrary to expectations, linear infrastructure presence had either none or a positive effect on carcass persistence, meaning that carcasses placed within power line or road rights-of-way were not removed faster than the ones placed in controls. We conclude that linear infrastructure effect on vertebrate scavenging patterns is likely to be region-specific, and that reliable correction factors for carcass removal-bias in bird fatality estimates require site-specific experiments to characterize local scavenging processes.