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Abalaka SE, Idoko IS, Adamu AM, Nafarnda WD, Machunga-Mabunla S, Audu Z, Sani NA, Tenuche OZ, Ejeh SA. Histopathological and health risk assessment of heavy metals in the straw-colored fruit bat, Eidolon helvum, in Nigeria. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:411. [PMID: 36807700 DOI: 10.1007/s10661-023-10990-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
There is heightening concern regarding heavy metals environmental pollution requiring renewed global attention because of their bioaccumulation and toxicity at varying levels. The concern is most important in the highly migratory Eidolon helvum (E. helvum) that is very common and traverses wide geographical areas within the sub-Saharan Africa. The present study aimed to evaluate levels of cadmium (Cd), lead (Pb), and zinc (Zn) bioaccumulation in 24 E. helvum of both sexes from Nigeria to assess their indirect health risks to the human consumers of the bats in addition to their direct bioaccumulation and toxic damages in the bats themselves based on standard procedures. Lead, Zn, and Cd bioaccumulation concentrations were 2.83 ± 0.35, 0.42 ± 0.03, and 0.05 ± 0.01 mg/kg, respectively, with significant (p < 0.05) Pb bioaccumulation compared to either Cd or Zn in the affected bats. However, only Pb (markedly) and Cd (marginally) bioaccumulated above small mammals' critical threshold levels as there are no existing established threshold levels for bats. Sex played no major role in their bioaccumulation levels. The bioaccumulation levels posed no life-long non-carcinogenic nor carcinogenic risks to the human consumers of the bats at detected concentrations. The observed lungs, liver, and kidney histopathological changes suggested the possible direct effects of the metals in the bats. Nevertheless, other anthropogenic factors might be responsible as no significant (p > 0.05) correlation existed between cellular changes and the bioaccumulation levels. The presence of the heavy metals and their bioaccumulations above critical threshold levels suggested some levels of environmental contamination and pollution, which might have direct and indirect health implications to the bats and their human consumers.
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Affiliation(s)
| | | | - Andrew Musa Adamu
- Australian Institute of Tropical Health and Medicine, Townsville, QLD, Australia
- College of Public Health, Medical, and Veterinary Sciences, James Cook University, Bebegu Yumba Campus, 4814, QLD, Townsville, Australia
- Department of Veterinary Public Health and Preventive Medicine, University of Abuja, Abuja, Nigeria
| | - Wesley Daniel Nafarnda
- Department of Veterinary Public Health and Preventive Medicine, University of Abuja, Abuja, Nigeria
| | | | - Zakariya Audu
- Department of Animal Health and Production, University of Abuja, Abuja, Nigeria
| | | | | | - Sunday Augustine Ejeh
- Department of Veterinary Physiology and Biochemistry, University of Abuja, Abuja, Nigeria
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2
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Kaňuch P, Kasanický T, Ružinská R, Zelenka J. The effect of logging on fission-fusion behaviour of tree-dwelling bats explored by an agent-based model. ECOL INFORM 2022. [DOI: 10.1016/j.ecoinf.2022.101884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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3
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Flexible energy-saving strategies in female temperate-zone bats. J Comp Physiol B 2022; 192:805-814. [PMID: 35939092 PMCID: PMC9550788 DOI: 10.1007/s00360-022-01452-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/06/2022] [Accepted: 07/19/2022] [Indexed: 12/02/2022]
Abstract
Torpor is characterized by an extreme reduction in metabolism and a common energy-saving strategy of heterothermic animals. Torpor is often associated with cold temperatures, but in the last decades, more diverse and flexible forms of torpor have been described. For example, tropical bat species maintain a low metabolism and heart rate at high ambient and body temperatures. We investigated whether bats (Nyctalus noctula) from the cooler temperate European regions also show this form of torpor with metabolic inhibition at high body temperatures, and whether this would be as pronounced in reproductive as in non-reproductive bats. We simultaneously measured metabolic rate, heart rate, and skin temperature in non-reproductive and pregnant females at a range of ambient temperatures. We found that they can decouple metabolic rate and heart rate from body temperature: they maintained an extremely low metabolism and heart rate when exposed to ambient temperatures changing from 0 to 32.5 °C, irrespective of reproductive status. When we simulated natural temperature conditions, all non-reproductive bats used torpor throughout the experiment. Pregnant bats used variable strategies from torpor, to maintaining normothermy, or a combination of both. Even a short torpor bout during the day saved up to 33% of the bats' total energy expenditure. Especially at higher temperatures, heart rate was a much better predictor of metabolic rate than skin temperature. We suggest that the capability to flexibly save energy across a range of ambient temperatures within and between reproductive states may be an important ability of these bats and possibly other temperate-zone heterotherms.
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Ružinská R, Lőbbová D, Kaňuch P. Demographic characteristics shape patterns of dawn swarming during roost switching in tree-dwelling Daubenton's bat. Sci Rep 2022; 12:10014. [PMID: 35705697 PMCID: PMC9200770 DOI: 10.1038/s41598-022-14246-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 06/03/2022] [Indexed: 11/19/2022] Open
Abstract
Frequent roost switching in fission–fusion societies of tree-dwelling bats is closely associated with swarming behaviour entailing ritualised night-time displays around the roost tree and/or at the roost entrance to signal its actual location, particularly immediately prior to sunrise. However, effects of demographic characteristics of individuals in this social behaviour remain unanswered. Using passive integrated transponders (PIT) and automatic readers, we recorded swarming activity of members of a Daubenton’s bat (Myotis daubentonii) maternity colony in the vicinity of their roosts. In total, 59,622 activity events of 281 PIT-tagged individuals were recorded on ten monitored roosts during three summer seasons. We found a gradual increase of swarming activity from midnight to sunrise in old adult females, whereas young females and juveniles primarily swarmed later at dawn. We attribute this difference to the learning status of younger bats, which are not yet able to perform a defined pattern of swarming activity, whereas older bats likely take a more active role in signalling the position of the roost. Old males exhibited the least swarming activity at maternity roosts, which mostly occurred between crepuscular periods, presumably due to their solitary lives. A negative correlation between genetic distance and swarming activity suggests an important role of kinship in the formation of the maternity colony as well as group cohesion during roost switching.
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Affiliation(s)
- Romana Ružinská
- Institute of Forest Ecology, Slovak Academy of Sciences, Zvolen, Slovakia.,Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, Zvolen, Slovakia
| | | | - Peter Kaňuch
- Institute of Forest Ecology, Slovak Academy of Sciences, Zvolen, Slovakia.
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Komar E, Fasel NJ, Szafrańska PA, Dechmann DKN, Zegarek M, Ruczyński I. Energy allocation shifts from sperm production to self-maintenance at low temperatures in male bats. Sci Rep 2022; 12:2138. [PMID: 35136106 PMCID: PMC8826387 DOI: 10.1038/s41598-022-05896-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 12/21/2021] [Indexed: 11/17/2022] Open
Abstract
The ability of animals to produce endogenous heat provides a buffer against environmental changes but also incurs high energetic costs. Especially small endothermic mammals have high energy demands. Some temperate-zone species (heterotherms) regularly use torpor, which slows down their entire metabolism but also potentially delays reproduction, to compensate for this. We used a unique experimental approach to test the consequences of extended low and high ambient temperatures on the trade-off in energy allocation to body mass maintenance, thermoregulation effort and seasonal sexual maturation in temperate zone male bats. We showed that long exposure to low ambient temperature shifts energy allocation away from sexual maturation to self-maintenance and results in a delay of sperm maturation by as much as an entire month. This effect was partially buffered by higher body mass. Heavier bats were able to afford more intensive thermoregulation and consequently speed up maturation. Interestingly, bats at constant high temperatures avoided deep torpor and matured faster than those at low temperatures, but sperm production was also slower than under natural conditions. Our results show that not only low, but also constant high ambient temperatures are detrimental during seasonal sexual maturation and the trade-off between investing into self-maintenance and fitness is a finely tuned compromise.
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Affiliation(s)
- Ewa Komar
- Mammal Research Institute, Polish Academy of Sciences, Stoczek 1, Białowieża, Poland. .,Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warszawa, Poland.
| | - Nicolas J Fasel
- Department of Ecology and Evolution, University of Lausanne, 1015, Biophore, Switzerland
| | - Paulina A Szafrańska
- Mammal Research Institute, Polish Academy of Sciences, Stoczek 1, Białowieża, Poland
| | - D K N Dechmann
- Max Planck Institute of Animal Behavior, Am Obstberg 1, 78315, Radolfzell, Germany.,Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany
| | - Marcin Zegarek
- Mammal Research Institute, Polish Academy of Sciences, Stoczek 1, Białowieża, Poland
| | - Ireneusz Ruczyński
- Mammal Research Institute, Polish Academy of Sciences, Stoczek 1, Białowieża, Poland
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