Biology subjects

Cerri, J.

Publications and source records attributed to Cerri, J..

5 recordsLinked to original sources

bioRxiv2020

Artificial feeding of invasive grey squirrels (Sciurus carolinensis) at urban parks: a social norms approach to understand its drivers and to guide behavioral interventions

Artificial wildlife feeding might contribute to the successful establishment of some invasive alien species, like the Eastern grey squirrel (Sciurus carolinensis) in Europe and the UK. Reducing squirrel feeding at urban parks can be important to reduce squirrel populations while avoiding social conflicts. From April to October 2018, we conducted interviews and administered factorial surveys to two samples of visitors at the Valentino urban park in Torino (Italy). We established whether squirrel feeding can be regarded as an independent or an interdependent behavior, by eliciting visitors moral beliefs, and their empirical and normative expectations. Most respondents did not regard artificial feeding as something neither intrinsically positive nor negative. Satisfaction, the need for a connection with nature and the presence of children were its main causes. On the other hand, feeding squirrels was deemed to be potentially dangerous for squirrel health, and leading to high squirrel densities and to confident squirrels. Factorial surveys indicated that empirical expectations about the behavior of other visitors, altogether with their past behavior, lead visitors to feed squirrels, while the availability of suboptimal food types (e.g. sweets), was deemed to made people less prone to forage squirrels. Our findings indicate that supplementary feeding is an interdependent behavior, governed by descriptive norms. It might be reduced by means of informative panels containing descriptive information about the fact that most visitors indeed do not feed squirrels, as well as by panels emphasizing the potential damage that squirrels could suffer from eating suboptimal food provided by humans.

ecology↗

bioRxiv2019

Graphical factorial surveys reveal the acceptability of wildlife observation at protected areas.

Approaching large ungulates at protected areas is dangerous both for visitors and the animals. Nudging interventions can mitigate this issue, but conservationists need to be sure about which factors influence the acceptability of human-wildlife encounters, to design them.\n\nIn summer 2018, we recruited a sample of visitors (n = 205) at the Gran Paradiso National Park (Italy). They evaluated the acceptability of 9 digitally modified pictures, depicting a group of visitors observing an alpine ibex (Capra ibex) close to a trail. Pictures were characterized in terms of group size and distance from the ibex.\n\nObserving ibexes was deemed to be acceptable if visitors were further than 25 meters from animals and when groups included less than 3 people. Approaching ibexes at 5 meters was always deemed to be unacceptable. Potential for Conflict Index (PCI) was constant across distance classes and it was generally low.\n\nOur findings indicate that visitors share normative beliefs about the optimal distance and group size, that should characterize encounters with large ungulates, when visiting the park. These normative beliefs are crystallized, because previous encounters with ibexes did not affect the evaluation of each scenario and because the PCI was constant and low. We believe that behavioral interventions aimed at promoting respectful and safe human-ibex interactions can be enforced in areas where this interaction is critical, mostly in form of panels on hiking trails introducing normative pressures on visitors and motivating them to comply with rules.

ecology↗

bioRxiv2019

Invasive Siberian chipmunks Eutamias sibiricus in Italy: a socio-ecological analysis indicates that they could, and should, be removed

BACKGROUNDEradication of invasive alien species is a form of pest control linked to biodiversity conservation that usually involves killing animals. Squirrels are prominent among invasive alien species in Italy with four species introduced. Three of them are included within the list of alien species of European concern and their eradication and control is recommended. However, their local control is not an easy task, being highly appreciated by the general public. We propose a socio-ecological approach to evaluate the feasibility of eradicating Siberian chipmunks (Eutamias sibiricus) populations. We performed a structured questionnaire to assess the social perception of invasive Siberian chipmunks in urban parks where they occur and to identify groups of visitors who might oppose eradication. We also carried out geographic profiling to test for the spatial expansion of chipmunk populations. RESULTSOverall, park visitors regarded chipmunks positively and appreciated to see them, but human-chipmunk interactions were still rare. We did not identify any group of visitors with a strong attachment to chipmunks, who might oppose future control programs. Geographic profiling showed that chipmunks in Valeggio sul Mincio are starting to expand outside of their introduction site. CONCLUSIONSData from questionnaires show that chipmunks eradication, coupled with adequate communication initiatives, might be feasible. Moreover, geographic profiling indicates that time for a rapid removal is running out. Socio-ecological approaches, combining the analysis of structured questionnaires administered to stakeholders and statistical modeling of pest observations, could be a valuable tool to decide the feasibility and the urgency of invasive pest control.

ecology↗

bioRxiv2018

Characterizing noncompliance in conservation: a multidimensional Randomized Response Technique for multinomial responses.

Rule violation is critical for biological conservation worldwide. Conventional questionnaires are not suitable to survey these violations and specialized questioning techniques that preserve respondents privacy, like the forced-response RRT, have been increasingly adopted by conservationists. However, most of these approaches do not measure multinomial answers and conservationists need a specialized questioning technique for real-world settings where non-compliance could occur in different forms. We developed a multidimensional, statistically-efficient, RRT which is suitable for multinomial answers (mRRT) and which allows researchers to test for respondents noncompliance during completion. Then, we applied it to measure the frequency of the various forms of illegal restocking of European catfish from specialized anglers in Italy, developing an operational code for the statistical software R. A total of 75 questionnaires were administered at a large fishing fair in Northern Italy, in winter 2018. Our questionnaires were easily compiled and the multinomial model revealed that around 6% of respondents had moved catfish across public freshwater bodies and private ponds. Future studies should better address their characteristics, and the mRRT could allow for modeling the effect of co-variates over restocking behavior. The multinomial mRRT could be adopted to measure many forms of rule violation in conservation that could take different forms, like various forms of fish restocking or different modes of wildlife persecution.

ecology↗

bioRxiv2018

A fish rots from the head down: how to use the leading digits of ecological data to detect their falsification.

Managing wildlife populations requires good data. Researchers and policy makers need reliable population estimates and, in case of commercial or recreational harvesting, also trustworthy information about the number of removed individuals. However, auditing schemes are often weak and political or economic pressure could lead to data fabrication or falsification. Time-series data and population models are crucial to detect anomalies, but they are not always available nor feasible. Therefore, researchers need other tools to identify suspicious patterns in ecological and environmental data, to prioritize their controls. We showed how the Benfords law might be used to identify anomalies and potential manipulation in ecological data, by testing for the goodness-of-fit of the leading digits with the Benfords distribution. For this task, we inspected two datasets that were found to be falsified, containing data about estimated large carnivore populations in Romania and Soviet commercial whale catches in the Pacific Ocean. In both the two datasets, the first and second digits numerical series deviated from the expected Benfords distribution. In data about large carnivores, the first too digits, taken together, also deviated from the expected Benfords distribution and were characterized by a high Mean Absolute Deviation. In Soviet whale catches, while the single digits deviated from the Benfords distribution and the Mean Absolute Deviation was high, the first two digits were not anomalous. This controversy invites researchers to combine multiple measures of nonconformity and to be cautious in analyzing mixtures of data. Testing the distribution of the leading digits might be a very useful tool to inspect ecological datasets and to detect potential falsifications, with great implications for policymakers and researchers as well. For example, if policymakers revealed anomalies in harvesting data or population estimates, commercial or recreational harvesting could be suspended and controls strengthened. On the other hand, revealing falsification in ecological research would be crucial for evidence-based conservation, as well as for research evaluation.

ecology↗