Conservation Physiology最新文献

{"title":"Critical review of the phytohemagglutinin assay for assessing amphibian immunity","authors":"Lauren Hawley, Kelly L Smalling, Scott Glaberman","doi":"10.1093/conphys/coad090","DOIUrl":"https://doi.org/10.1093/conphys/coad090","url":null,"abstract":"Infectious diseases are a major driver of the global amphibian decline. In addition, many factors, including genetics, stress, pollution, and climate change can influence the response to pathogens. Therefore, it is important to be able to evaluate amphibian immunity in the laboratory and in the field. The phytohemagglutinin (PHA) assay is an inexpensive and relatively non-invasive tool that has been used extensively to assess immunocompetence, especially in birds, and more recently in amphibians. However, there is substantial variation in experimental methodology among amphibian PHA studies in terms of species and life stages, PHA doses and injection sites, and use of experimental controls. Here, we compile and compare all known PHA studies in amphibians to identify knowledge gaps and develop best practices for future work. We found that research has only been conducted on a limited number of species, which may not reflect the diversity of amphibians. There is also a lack of validation studies in most species, so that doses and timing of PHA injection and subsequent swelling measurements may not effectively evaluate immunocompetence. Based on these and other findings, we put forward a set of recommendations to make future PHA studies more consistent and improve the ability to utilize this assay in wild populations, where immune surveillance is greatly needed.","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138581763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intake and growth histories modulate bone morphology, microarchitecture, and mineralization in juvenile green turtles (Chelonia mydas)","authors":"Morgan C Abell, José A Sánchez Hernández, Robin Bast, Karen A Bjorndal, Alan B Bolten, Alison M Roark","doi":"10.1093/conphys/coad080","DOIUrl":"https://doi.org/10.1093/conphys/coad080","url":null,"abstract":"Compensatory growth (CG) is accelerated growth that occurs when food availability increases after food restriction. This rapid growth may be associated with sublethal consequences. In this study, we investigated the effects of food restriction and subsequent realimentation and CG on bone structure in juvenile green turtles (Chelonia mydas). Turtles were fed ad libitum food for 12 weeks (AL), restricted food for 12 weeks (R), or restricted food for 5 weeks followed by ad libitum food for 7 weeks (R-AL). R-AL turtles demonstrated partial CG via enhanced food conversion efficiency (FCE) upon realimentation. After the 12th week, gross morphology (GM), microarchitecture, and mineralization of the right humerus of each turtle were analyzed. Many GM measurements (including proximal and maximal bone lengths, bone widths, and shaft thickness), most measurements of bone microarchitecture (excluding cortical and trabecular thickness and trabecular separation), and all mineralization measurements were labile in response to intake. We examined the possibility that changes in nutrient allocation to bone structure during realimentation facilitated CG in previously food-restricted turtles. Restoration of bone lengths was prioritized over restoration of bone widths during CG. Furthermore, restoration of trabecular number, connectivity density, and bone volume fraction was prioritized over restoration of cortical bone volume fraction. Finally, diaphyseal bone mineralization was partially restored, whereas no restoration of epiphyseal bone mineralization occurred during CG. Shifts in nutrient allocation away from certain bone attributes during food restriction that were not rectified when food availability increased probably provided an energy surplus that enhanced the conversion of food to growth and thus powered the CG response. Our study revealed how resource allocation to various bone attributes is prioritized as nutritional conditions change during development. These “priority rules” may have detrimental consequences later in life, indicating that conservation of green turtle foraging grounds should be given high priority.","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138556204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential heat shock protein responses in two species of Pacific salmon and their utility in identifying heat stress.","authors":"Vanessa R von Biela, Amy M Regish, Lizabeth Bowen, Ashley E Stanek, Shannon Waters, Michael P Carey, Christian E Zimmerman, Jonathon Gerken, Daniel Rinella, Stephen D McCormick","doi":"10.1093/conphys/coad092","DOIUrl":"https://doi.org/10.1093/conphys/coad092","url":null,"abstract":"<p><p>Rapid and accelerating warming of salmon habitat has the potential to lower productivity of Pacific salmon (<i>Oncorhynchus</i> species) populations. Heat stress biomarkers can indicate where warming is most likely affecting fish populations; however, we often lack clear classifications that separate individuals with and without heat stress needed to make these tools operational. We conducted a heat exposure experiment with trials lasting 12 or 36 h using juvenile Chinook salmon (<i>Oncorhynchus tshawytscha</i>) and coho salmon (<i>Oncorhynchus kisutch</i>) to validate heat stress biomarkers in white muscle. Following habituation to 13°C, individuals were exposed to water temperatures that increased to 15°C, 17°C, 19°C, 21°C or 23°C. Heat shock protein 70 abundance (HSP70 measured by ELISA) and transcription of 13 genes (mRNA measured by qPCR) including three heat shock protein genes (<i>hsp70, hsp90, hsp27</i>) were measured. A distinct heat stress response was apparent by 21°C in juvenile Chinook salmon and 23°C in juvenile coho salmon using HSP70. A threshold for heat stress classification in Chinook salmon of > 2 ng HSP70 mg^.1 total protein identified heat stress in 100% of 21 and 23°C treated individuals compared to 4% in cooler treatments. For coho salmon, > 3 ng HSP70 mg^.1 total protein identified heat stress in 100% of 23°C treated individuals compared to 4% in cooler treatments. Transcription from a panel of genes separated individuals between cooler and stressful temperature experiences (≥21°C for Chinook salmon and ≥23°C for coho salmon) with ~ 85% correct classification. Our findings indicate that juvenile Chinook salmon were more temperature-sensitive than juvenile coho salmon and support the use of a HSP70 threshold sampled from muscle for assessing heat stress in individual wild Pacific salmon with an option for non-lethal biopsies for spawning adults.</p>","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10709668/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138809678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal temperatures in South Eleuthera, The Bahamas, have considerable impacts on the cardiorespiratory function and swimming performance of Nassau grouper (Epinephelus striatus)","authors":"E S Porter, A K Gamperl","doi":"10.1093/conphys/coad086","DOIUrl":"https://doi.org/10.1093/conphys/coad086","url":null,"abstract":"Surprisingly, the impacts of environmental changes on the physiology of tropical/subtropical marine fishes have received limited attention. Given that (i) temperature is considered to be a key factor controlling the biology of fishes; (ii) no published data are available on the swimming performance, metabolic capacity or cardiac function of any of the ~165 grouper species worldwide; and (iii) the Nassau grouper is an endangered species of great ecological and socioeconomic significance in The Bahamas, we investigated how current summer/early fall (30°C) and winter (22°C) temperatures in South Eleuthera affected the aerobic metabolism and heart function of wild Nassau grouper when swum to exhaustion (i.e. to their critical swimming speed, Ucrit). The Nassau grouper had a very low Ucrit at 30°C (i.e. &amp;lt;1 body lengths s−1), and a 30% lower swimming performance during the winter (at 22°C), and this was that was indicative of a reduced absolute aerobic scope (~185 vs. 290 mg O2 kg−1 h−1) and values of maximum heart rate ($f$HMax) and scope for $f$H that were only one-half of that achieved at 30°C (~60 vs. 120 and 29 vs. 61 beats min−1, respectively). Overall, these data reveal that the Nassau grouper’s aerobic and swimming capacity are well below values reported for other tropical/subtropical fishes and suggest that, despite a compensatory (~30–40%) increase in stroke volume, constraints on $f$H near this species’ lower thermal limit negatively affect its cardiac output and swimming performance. These findings have considerable ecological implications as Bahamian grouper populations migrate over long distances to spawn during the winter months, and given the predicted increase in temperature variability with climate change.","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138556698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of total dissolved gas supersaturation and flow velocity on survival and swimming ability of juvenile Schizothorax prenanti","authors":"Quan Yuan, Jun Du, Ke-feng Li, Yuanming Wang, R. Liang","doi":"10.1093/conphys/coad091","DOIUrl":"https://doi.org/10.1093/conphys/coad091","url":null,"abstract":"Abstract Although developing large-scale hydropower cascades in the upper Yangtze River effectively improves the hydropower resource utilization, it produces total dissolved gas (TDG) supersaturation. In the flood season, the high level of TDG supersaturation (TDGS) frequently occurs in the downstream of dams, causing migratory fish to suffer from gas bubble trauma (GBT) and reducing their survival and swimming ability. Currently, there is a deficiency in particular approaches to evaluate the ecological hazard posed by TDGS on migratory fish as they traverse different flow velocities within their migratory routes. This study assessed the vulnerability of juvenile Schizothorax prenanti (S. prenanti) to GBT from the static setting to 9.0 BL/s during exposure to nominal levels of 100%, 110%, 120% and 130% TDG. The mortality occurs when the flow velocity surpasses 6.0 and 7.5 BL/s in 100% and 110% TDG levels, respectively. For fish exposed to 120% and 130% TDG levels, the relationship between survival time and flow velocity is an approximately inverse bell-shaped curve with increasing velocity. The optimal velocity of maximal survival time of juvenile S. prenanti is 3.0 and 4.5 BL/s in 120% and 130% TDG-supersaturated water. Both TDG level and flow velocity significantly affect burst swimming speed (Uburst) and critical swimming speed (Ucrit). The cases involving GBT showed substantial declines in Uburst and Ucrit, exceeding 6.0 BL/s and TDG levels greater than 120%. The results may contribute to formulating a specific management strategy for hydropower operation during the migratory period and conserving vulnerable species in the Yangtze River.","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138591890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of tourist visitation on the heterophyl to lymphocyte ratios and trophic values of Magellanic penguins (<i>Spheniscus magellanicus</i>) at Martillo Island, Argentina.","authors":"Sabrina Harris, Gabriela Scioscia, Andrea Raya Rey","doi":"10.1093/conphys/coad063","DOIUrl":"10.1093/conphys/coad063","url":null,"abstract":"<p><p>Wildlife tourism is increasing worldwide and monitoring the impact of tourism on wild populations is of the utmost importance for species conservation. The Magellanic penguin <i>Spheniscus magellanicus</i> colony at Martillo Island, Argentina, was studied in the 2016-2020 breeding seasons. In all seasons, adults and chicks belonged to: (i) an area close to or within the tourist trail or (ii) an area far from the tourist trail and out of sight of the tourists. Blood samples were taken for carbon and nitrogen stable isotope composition, in order to estimate trophic niches, and for smears that were made <i>in situ</i> and were then stained in the laboratory where leucocyte counts and differentiation were made under optical microscope. Heterophil to lymphocyte ratios were used as proxies of stress. Repeated sampling showed individual stress levels reduced while wintering. In 2017, stress levels and trophic values were lower than 2018 for the same individuals. Trophic levels did not differ between tourism and no tourism areas within each season, and differed between 2017 and the remaining seasons, indicating a possible diet shift that year. Stress levels were higher for the tourism area than the no tourism area for adults and chicks in all years except for 2020, when stress levels in the tourism area were lower and similar to the no tourism area that year and previous years. Vessel transit within the Beagle Channel and tourist visitation to the penguin colony was greatly reduced in 2020 due to the Covid-19 pandemic. A combination of internal characteristics and external factors may be affecting the stress physiology of individuals. Therefore, future research should include sampling of multiple aspects of penguin physiology, behaviour and environmental context in order to evaluate each effect on Magellanic penguin stress and, ultimately, inform the conservation of this iconic species in time.</p>","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10694407/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138489106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological plasticity in elephants: highly dynamic glucocorticoids in African and Asian elephants","authors":"Sanjeeta Sharma Pokharel, Janine L Brown","doi":"10.1093/conphys/coad088","DOIUrl":"https://doi.org/10.1093/conphys/coad088","url":null,"abstract":"Slowly reproducing and long-lived terrestrial mammals are often more at risk from challenges that influence fitness and survival. It is, therefore, important to understand how animals cope with such challenges and how coping mechanisms translate over generations and affect phenotypic plasticity. Rapidly escalating anthropogenic challenges may further diminish an animal’s ability to reinstate homeostasis. Research to advance insights on elephant stress physiology has predominantly focused on relative or comparative analyses of a major stress response marker, glucocorticoids (GCs), across different ecological, anthropogenic, and reproductive contexts. This paper presents an extensive review of published findings on Asian and African elephants from 1980 to 2023 (May) and reveals that stress responses, as measured by alterations in GCs in different sample matrices, often are highly dynamic and vary within and across individuals exposed to similar stimuli, and not always in a predictable fashion. Such dynamicity in physiological reactivity may be mediated by individual differences in personality traits or coping styles, ecological conditions, and technical factors that often are not considered in study designs. We describe probable causations under the ‘Physiological Dynamicity Model’, which considers context–experience–individuality effects. Highly variable adrenal responses may affect physiological plasticity with potential fitness and survival consequences. This review also addresses the significance of cautious interpretations of GCs data in the context of normal adaptive stress versus distress. We emphasize the need for long-term assessments of GCs that incorporate multiple markers of ‘stress’ and ‘well-being’ to decipher the probable fitness consequences of highly dynamic physiological adrenal responses in elephants. Ultimately, we propose that assessing GC responses to current and future challenges is one of the most valuable and informative conservation tools we have for guiding conservation strategies.","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138537572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Capture and transport of white rhinoceroses (<i>Ceratotherium simum</i>) cause shifts in their fecal microbiota composition towards dysbiosis.","authors":"Friederike Pohlin, Carolin Frei, Leith C R Meyer, Franz-Ferdinand Roch, Narciso M Quijada, Beate Conrady, Viktoria Neubauer, Markus Hofmeyr, Dave Cooper, Gabrielle Stalder, Stefanie U Wetzels","doi":"10.1093/conphys/coad089","DOIUrl":"10.1093/conphys/coad089","url":null,"abstract":"<p><p>Translocations of <i>Rhinocerotidae</i> are commonly performed for conservation purposes but expose the animals to a variety of stressors (e.g. prolonged fasting, confinement, novel environment, etc.). Stress may change the composition of gut microbiota, which can impact animal health and welfare. White rhinoceroses in particular can develop anorexia, diarrhea and enterocolitis after translocation. The aim of this study was to investigate the associations of age, sex and translocation on the rhinoceros' fecal bacterial microbiota composition. fecal samples were collected from rhinoceroses at capture (<i>n</i> = 16) and after a >30-hour road transport (<i>n</i> = 7). DNA was isolated from these samples and submitted for 16S rRNA V3-V4 phylotyping. Alpha diversity indices of the rhinoceros' fecal microbiota composition of different age, sex and before and after transport were compared using non-parametric statistical tests and beta diversity indices using Permutational Multivariate Analysis Of Variance (PERMANOVA). Resulting <i>P</i>-values were alpha-corrected (<i>P</i>adj<i>.</i>). Alpha and beta diversity did not differ between rhinoceroses of different age and sex. However, there was a significant difference in beta diversity between fecal samples collected from adult animals at capture and after transport. The most abundant bacterial phyla in samples collected at capture were <i>Firmicutes</i> and <i>Bacteroidetes</i> (85.76%), represented by <i>Lachnospiraceae</i>, <i>Ruminococcaceae</i> and <i>Prevotellaceae</i> families. The phyla <i>Proteobacteria</i> (<i>P</i>adj<i>.</i> = 0.009) and <i>Actinobacteria</i> (<i>P</i>adj<i>.</i> = 0.012), amongst others, increased in relative abundance from capture to after transport encompassing potentially pathogenic bacterial families such as <i>Enterobacteriaceae</i> (<i>P</i>adj<i>.</i> = 0.018) and <i>Pseudomonadaceae</i> (<i>P</i>adj<i>.</i> = 0.022). Important commensals such as <i>Spirochaetes</i> (<i>P</i>adj. = 0.009), <i>Fibrobacteres</i> (<i>P</i>adj. = 0.018) and <i>Lachnospiraceae</i> (<i>P</i>adj. = 0.021) decreased in relative abundance. These results indicate that the stressors associated with capture and transport cause an imbalanced fecal microbiota composition in white rhinoceroses that may lead to potentially infectious intestinal disorders. This imbalance may result from recrudescence of normally innocuous pathogens, increased shedding of pathogens or increased vulnerability to new pathogens.</p>","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10673814/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138464301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fasting durations of Steller sea lion pups vary among subpopulations-evidence from two plasma metabolites.","authors":"Stephanie G Crawford, Robert H Coker, Todd M O'Hara, Greg A Breed, Tom Gelatt, Brian Fadely, Vladimir Burkanov, Patricia M Rivera, Lorrie D Rea","doi":"10.1093/conphys/coad084","DOIUrl":"10.1093/conphys/coad084","url":null,"abstract":"<p><p>Geographic differences in population growth trends are well-documented in Steller sea lions (<i>Eumetopias jubatus</i>), a species of North Pacific pinniped listed under the U.S. Endangered Species Act in 1990 following a marked decline in population abundance that began during the 1970s. As population growth is intrinsically linked to pup production and survival, examining factors related to pup physiological condition provides useful information to management authorities regarding potential drivers of regional differences. During dam foraging trips, pups predictably transition among three fasting phases, distinguished by the changes in the predominant metabolic byproduct. We used standardized ranges of two plasma metabolites (blood urea nitrogen and β-hydroxybutyrate) to assign pups to fasting categories (n = 1528, 1990-2016, 12 subpopulations): <i>Recently Fed-Phase I</i> (digestion/assimilation-expected hepatic/muscle glycogen usage), <i>Phase II</i> (expected lipid utilization), transitioning between <i>Phases II-III</i> (expected lipid utilization with increased protein reliance), or <i>Phase III</i> (expected protein catabolism). As anticipated, the majority of pups were classified as <i>Recently Fed-Phase I</i> (overall mean proportion = 0.72) and few pups as <i>Phase III</i> (overall mean proportion = 0.04). By further comparing pups in <i>Short</i> (<i>Recently Fed-Phase II</i>) and <i>Long</i> (all other pups) duration fasts, we identified three subpopulations with significantly (<i>P</i> < 0.03) greater proportions of pups dependent upon endogenous sources of energy for extended periods, during a life stage of somatic growth and development: the 1) central (0.27 ± 0.09) and 2) western (0.36 ± 0.13) Aleutian Island (declining population trend) and 3) southern Southeast Alaska (0.32 ± 0.06; increasing population trend) subpopulations had greater <i>Long</i> fast proportions than the eastern Aleutian Islands (0.10 ± 0.05; stabilized population). Due to contrasting population growth trends among these highlighted subpopulations over the past 50+ years, both density-independent and density-dependent factors likely influence the dam foraging trip duration, contributing to longer fasting durations for pups at some rookeries.</p>","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10673819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138464379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of stored lipids in fall migratory monarch butterflies (<i>Danaus plexippus</i>): Nectaring in northern Mexico allows recovery from droughts at higher latitudes.","authors":"Keith A Hobson, Orley Taylor, M Isabel Ramírez, Rogelio Carrera-Treviño, John Pleasants, Royce Bitzer, Kristen A Baum, Blanca X Mora Alvarez, Jude Kastens, Jeremy N McNeil","doi":"10.1093/conphys/coad087","DOIUrl":"https://doi.org/10.1093/conphys/coad087","url":null,"abstract":"<p><p>The eastern population of the North American monarch butterfly (<i>Danaus plexippus</i>) overwinters from November through March in the high-altitude (3000 m+) forests of central Mexico during which time they rely largely on stored lipids. These are acquired during larval development and the conversion of sugars from floral nectar by adults. We sampled fall migrant monarchs from southern Canada through the migratory route to two overwintering sites in 2019 (n = 10 locations), 2020 (n = 8 locations) and 2021 (n = 7 locations). Moderate to extreme droughts along the migratory route were expected to result in low lipid levels in overwintering monarchs but our analysis of lipid levels of monarchs collected at overwintering sites indicated that in all years most had high levels of lipids prior to winter. Clearly, a significant proportion of lipids were consistently acquired in Mexico during the last portion of the migration. Drought conditions in Oklahoma, Texas and northern Mexico in 2019 resulted in the lowest levels of lipid mass and wing loading observed in that year but with higher levels at locations southward in Mexico to the overwintering sites. Compared with 2019, lipid levels increased during the 2020 and 2021 fall migrations but were again higher during the Mexican portion of the migration than for Oklahoma and Texas samples, emphasizing a recovery of lipids as monarchs advanced toward the overwintering locations. In all 3 years, body water was highest during the Canada-USA phase of migration but then declined during the nectar foraging phase in Mexico before recovering again at the overwintering sites. The increase in mass and lipids from those in Texas to the overwintering sites in Mexico indicates that nectar availability in Mexico can compensate for poor conditions experienced further north. Our work emphasizes the need to maintain the floral and therefore nectar resources that fuel both the migration and storage of lipids throughout the entire migratory route.</p>","PeriodicalId":54331,"journal":{"name":"Conservation Physiology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10673816/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138464302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}