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Bhattacharjee D, Sau S, Das J, Bhadra A. Does novelty influence the foraging decisions of a scavenger? PeerJ 2024; 12:e17121. [PMID: 38525274 PMCID: PMC10961059 DOI: 10.7717/peerj.17121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 02/26/2024] [Indexed: 03/26/2024] Open
Abstract
Acquiring knowledge about the environment is crucial for survival. Animals, often driven by their exploratory tendencies, gather valuable information regarding food resources, shelter, mating partners, etc. However, neophobia, or avoiding novel environmental stimuli, can constrain their exploratory behaviour. While neophobia can reduce potential predation risks, decreased exploratory behaviour resulting from it may limit the ability to discover highly rewarding resources. Dogs (Canis familiaris) living in semi-urban and urban environments as free-ranging populations, although subject to various selection forces, typically have negligible predation pressure. These dogs are scavengers in human-dominated environments; thus, selection against object-neophobia can provide benefits when searching for novel food resources. Although captive pack-living dogs are known to be less neophobic than their closest living ancestors, wolves (Canis lupus), little is known about free-ranging dogs' behavioural responses to novel objects, particularly in foraging contexts. Using an object choice experiment, we tested 259 free-ranging dogs from two age classes, adult and juvenile, to investigate their object-neophobia in a scavenging context. We employed a between-subject study design, providing dogs with a familiar and a potentially novel object, both baited with equal, hidden food items. Adult and juvenile dogs significantly inspected the novel object first compared to the familiar one, even when the hidden food item was partially visible. To validate these findings, we compared novel objects with different strengths of olfactory cues (baited vs. false-baited) and found that they were inspected comparably by adults and juveniles. No significant differences were found in the latencies to inspect the objects, suggesting that free-ranging dogs may still be cautious when exploring their environments. These results indicate that free-ranging dogs, evidently from an early ontogenetic phase, do not show object-neophobia, as demonstrated by their preference for novel over familiar food sources. We conclude that little to no constraint of neophobia on exploratory behaviour in semi-urban and urban-dwelling animals can guide foraging decision-making processes, providing adaptive benefits.
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Affiliation(s)
- Debottam Bhattacharjee
- Centre for Animal Health and Welfare, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, SAR, Hong Kong
- The Dog Lab, Behaviour and Ecology Lab, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, SAR, Hong Kong
| | - Shubhra Sau
- The Dog Lab, Behaviour and Ecology Lab, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
- Department of Botany and Zoology, Masaryk University, Brno, Czech Republic
| | - Jayjit Das
- The Dog Lab, Behaviour and Ecology Lab, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
- Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
| | - Anindita Bhadra
- The Dog Lab, Behaviour and Ecology Lab, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
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Nakagawa-Lagisz T, Lagisz M. Shining a light on duckweed: exploring the effects of artificial light at night (ALAN) on growth and pigmentation. PeerJ 2023; 11:e16371. [PMID: 37927782 PMCID: PMC10625352 DOI: 10.7717/peerj.16371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 10/08/2023] [Indexed: 11/07/2023] Open
Abstract
Background Artificial light at night (ALAN) is a novel environmental stressor of global concern. Various sources of artificial light are now common in urbanized areas and have diverse negative effects on many species of animals and plants. However, ALAN has also been shown to have no effect or a positive effect on some organisms. This study investigates the impact of ALAN on the growth and leaf pigmentation of a common floating freshwater plant species. Methods We exposed wild-derived dotted duckweed (Landoltia punctata) to either darkness during the night (Control group) or to artificial light at night (ALAN group) for 49 days. We set up two large boxes of eighty samples each with 2-3 leaves of duckweed in each sample at the start of the experiment. The ALAN box had an opaque lid with a small lamp that was turned on at night. The Control box was also covered at night with an opaque lid but without a lamp. During the day, plants in both boxes were exposed to natural light. We counted the number of leaves in each sample weekly. We took photos of the samples on day 28 to measure the total leaf surface area per sample. On day 49, we took photos of the underside of the leaves for analyses of the relative levels of dark pigmentation across all samples. Results We found that ALAN-exposed plant samples had, on average, more leaves than control plants after a few weeks of exposure. They also had a more variable number of leaves per sample. The total leaf area per sample on day 28 was larger in the ALAN samples. The underside of the leaves on day 49 was, on average, darker in the ALAN plants than in the control plants. Conclusion There is a significant growth-enhancing effect from exposure to artificial light at night on Landolita punctata. However, higher variability induced by ALAN exposure indicates that ALAN is also a stressful condition for these plants. This is in line with our finding of the presence of larger amounts of dark pigments in the leaves of ALAN-exposed plants. Dark pigmentation in duckweed species could be a defence mechanism protecting tissues from stress-induced oxidative damage. Overall, both positive and negative effects of ALAN can be observed simultaneously in different traits of the same organism. Increased individual variation can facilitate population-level adaptation to stressful conditions. As such, this work contributes to our knowledge of the effects of light pollution in urban environments on common plants.
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Affiliation(s)
- Totoro Nakagawa-Lagisz
- Sydney Boys High School, Sydney, NSW, Australia
- Onna Junior High School, Onna, Okinawa, Japan
| | - Malgorzata Lagisz
- Evolution & Ecology Research Centre and School of Biological, Earth & Environmental Sciences, University of New South Wales Sydney, Sydney, New South Wales, Australia
- Theoretical Sciences Visiting Program, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan
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Martín Y, Paneque P. Moving from adaptation capacities to implementing adaptation to extreme heat events in urban areas of the European Union: Introducing the U-ADAPT! research approach. J Environ Manage 2022; 310:114773. [PMID: 35217442 DOI: 10.1016/j.jenvman.2022.114773] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/18/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
Extreme Heat Events (EHE) are a major concern for many urban areas worldwide and are considered as one of the deadliest natural hazards globally. Climate change and socioeconomic trends (exposure and susceptibility) are expected to exacerbate the risk of urban heat stress. Several urban areas have recently declared a climate emergency and initiated the adaptation process, but progress is still patchy, uncoordinated, and of varied quality. The main constraint is the lack of mechanisms for monitoring and reporting adaptation strategies, not allowing the supervision and evaluation of the adaptation process. The EU-funded project U-ADAPT! (Urban-Adaptation) focuses on the concrete expression of adaptation to evaluate the current implementation and effectiveness of adaptation measures and strategies to reduce Heat Disaster Risk (HDR), moving the emphasis from the study of vulnerability, resilience, and potential adaptation (adaptation capacity) of communities to the actual depth and pace of the past and current adaptation process. In this article, we discuss the theoretical support and design of the project and set the base for next project stages, which ultimately aims to create a unique interdisciplinary framework and a replicable multidimensional indicator on adaptation to EHE that empower European Union citizens to demand a safe and sustainable environment and hold institutions accountable for the adaptation process to current and upcoming risks.
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Affiliation(s)
- Yago Martín
- Departamento de Geografía, Historia y Filosofía, Universidad Pablo de Olavide, Carretera de Utrera Km. 1, 41013, Sevilla, Spain.
| | - Pilar Paneque
- Departamento de Geografía, Historia y Filosofía, Universidad Pablo de Olavide, Carretera de Utrera Km. 1, 41013, Sevilla, Spain.
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