Ecological and evolutionary physiology最新文献

{"title":"Urbanization, Metabolic Rate, and Body Size Variation of a Common Urban Lizard.","authors":"Rebecca Rimbach, Öncü Maraci, Avery L Maune, Isabel Damas-Moreira","doi":"10.1086/742607","DOIUrl":"https://doi.org/10.1086/742607","url":null,"abstract":"<p><p>AbstractHuman-induced rapid environmental change is intensifying globally. Urbanization, a major form of human-induced rapid environmental change, alters ecosystems and exposes wildlife to environmental changes, including pollution, altered ambient temperatures, changes in habitat structure, and resource shifts. These alterations can benefit particular species while imposing challenges to others, influencing their behavior, physiology, and morphology. Changes in resource availability and ambient temperature are particularly relevant for ectotherms, which are less independent of environmental conditions than endotherms for thermoregulatory behavior and physical activity. To date, physiological and morphological responses have been less well studied than behavioral responses to urban environments in ectotherms. In this study, we measured standard metabolic rate ([Formula: see text]) of common wall lizards (<i>Podarcis muralis</i>) inhabiting habitats that differ in the degree of urbanization (as measured by impervious surface area). Over a period of 4 yr, we also recorded body size (mass and snout-vent length) of lizards from urban ([Formula: see text]) and nonurban ([Formula: see text]) habitats. Standard metabolic rate did not differ between urban and nonurban habitats or with degree of urbanization. While females showed no habitat-associated differences in any trait, males from urban habitats exhibit a reduced body mass and shorter snout-vent length than their nonurban counterparts. Despite these differences, body condition did not vary between the two habitat types. These findings indicate that although sex-specific patterns in body mass and length occur, standard metabolic rate does not vary with urbanization. This underlines the importance of studying physiological and morphological traits of both sexes to better understand the impact of urbanization on wildlife.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 5","pages":"296-307"},"PeriodicalIF":1.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature Effects on Swimming Performance, Oxygen Consumption, and Skeletal Muscle Metabolic Phenotype in Amargosa River Pupfish, <i>Cyprinodon nevadensis amargosae</i>.","authors":"Teresa E Guerre, Kristin M Hardy, Sean C Lema","doi":"10.1086/742917","DOIUrl":"https://doi.org/10.1086/742917","url":null,"abstract":"<p><p>AbstractClimate change is raising temperatures in aquatic habitats and shifting the frequency and severity of precipitation events. In fishes, metabolic demands increase under warmer conditions, which may limit the ability of fishes to survive the physical and metabolic demands of high-water flow events if extreme rainfall occurs during periods of high temperature. Here, we investigated how temperature affected the swimming performance, aerobic metabolism, and skeletal muscle phenotype of Amargosa River pupfish (<i>Cyprinodon nevadensis amargosae</i>) to explore how warmer temperatures may reduce the ability of pupfish to cope with fast-moving water. Adult pupfish were acclimated to 16°C, 27.5°C, or 35°C for 63-114 d, after which their swimming performance and metabolic rates were assessed using an intermittent swim-tunnel respirometry system. The critical swimming speed of pupfish increased from 7.9 body lengths (BL) s^-1 at 16°C to 9.8 BL s^-1 at 27.5°C but declined to 3.8 BL s^-1 at 35°C. Paralleling those differences in swimming performance, maximum metabolic rate and aerobic scope were both lower at 35°C. Those differences in rates of oxygen consumption and swimming performance were accompanied by a shift in skeletal muscle metabolic phenotype, with muscle from pupfish at 35°C having reduced mitochondrial density, diminished citrate synthase activity, and ∼65%-80% reductions in relative messenger RNA abundances for citrate synthase and mitochondrion genes <i>atpase6/8</i> and <i>cox2</i>. These results indicate that pupfish subjected to elevated temperatures experience reductions in skeletal muscle aerobic capacity and swimming performance, which may make these fish more vulnerable to fast-moving waters such as flash floods if those events occur at times of elevated temperature.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 5","pages":"317-336"},"PeriodicalIF":1.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predator-Induced Changes in Prey Behavior Alters the Lipid and Protein Content in Both Prey and Their Resources.","authors":"Celina Costa, Eleanor R DiNuzzo, Haleigh Nogueira, Ken Oliveira, Sarah C Donelan, Michael J Sheriff","doi":"10.1086/742721","DOIUrl":"https://doi.org/10.1086/742721","url":null,"abstract":"<p><p>AbstractThe general stress paradigm predicts that when prey are exposed to predation risk they will mobilize and divert energy toward risk responses and away from costly somatic growth. However, there is mixed evidence to support this paradigm likely because of the different behavioral strategies prey employ to cope with increased predation risk. Furthermore, this paradigm has rarely been tested in marine systems, where both the prey and their resources can be expected to alter their energetics because of top-down pressure. We performed a laboratory mesocosm experiment using a rocky intertidal system exposing snail prey (<i>Nucella lapillus</i>) to two size classes of two crab predators (<i>Hemigrapsus sanguineus</i>, <i>Carcinus maenas</i>) and recording the number of mussels (<i>Mytilus edulis</i>) eaten. We then measured lipid and protein content of <i>N. lapillus</i> and mussels using proximate composition analysis. We found that, in general, predation risk reduced <i>N. lapillus</i> foraging in all crab treatments but that smaller, more numerous crabs tended to have greater effects than single large ones. We also found that predation risk reduced lipid and protein levels in prey and increased lipid and protein levels within mussels. While crab species or size did not affect prey energetics, we found that smaller crabs had a greater effect than larger ones in driving energy values in mussels-likely due to their greater effects on <i>N. lapillus</i> foraging. Thus, we provide robust evidence in support of the general stress paradigm and add to this framework, showing that predation risk can have cascading effects influencing resource energetics.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 5","pages":"308-316"},"PeriodicalIF":1.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feeding in Flow: Environmental Flow Conditions Alter Prey Capture Kinematics in Fish.","authors":"Erik G Axlid, Seth Shirazi, Timothy E Higham","doi":"10.1086/742474","DOIUrl":"https://doi.org/10.1086/742474","url":null,"abstract":"<p><p>AbstractVirtually all terrestrial, aerial, and aquatic organisms regularly interact with moving fluids. In marine and freshwater habitats, water flow is one of the most significant environmental variables impacting the ecology, behavior, biomechanics, and, ultimately, evolution of fishes. Although predatory fishes must attack prey rapidly and accurately across a range of flow conditions in nature, their feeding is almost always studied in still water. Thus, how fishes alter prey capture in response to ecologically relevant flow conditions remains poorly understood. Here, we determined how largemouth bass modulate prey capture across a range of flow speeds (0-60 cm/s) in a flume using high-speed videography. We tested an existing prediction that fishes should swim faster during prey capture in flow to increase momentum and damp external perturbations. If supported, separate established hypotheses state that fishes feeding in flow should also increase mouth expansion to circumvent decreases in strike accuracy associated with swimming faster. Indeed, largemouth bass swam faster and expanded their mouths more in high-flow conditions, which are kinematic changes consistent with maintaining capture success. Interestingly, they also altered the use of their pectoral fins, which are involved in braking, as flow speed increased. Our results reveal how flow, a widespread environmental variable, impacts the ecologically critical process of prey capture and yield important information about how species with high kinematic flexibility can maintain feeding performance in the face of changing environmental conditions.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 5","pages":"273-284"},"PeriodicalIF":1.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149187403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut Microbiome Composition and Diversity Are Associated with Heat Tolerance Plasticity in a Tropical Lizard.","authors":"Samantha S Fontaine, Kelly Lin Wuthrich, Carrie Alfonso, Karla Alujević, Leah Bakewell, Jaden Keller, Yanileth F López-Tacoaman, Nathaly E Ponce-Chilan, Alejandro Vivas, Claire E Williams, W Owen McMillan, Christian L Cox, Michael L Logan","doi":"10.1086/742402","DOIUrl":"https://doi.org/10.1086/742402","url":null,"abstract":"<p><p>AbstractClimate change is detrimentally affecting species worldwide. Against this backdrop, tropical ectotherms, which have evolved under historically stable conditions, are considered especially vulnerable to changing environmental conditions. Phenotypic plasticity may provide a rapid coping mechanism in response to warming. While plasticity is typically attributed to host mechanisms, vertebrates house diverse gut microbial communities that impact host traits and can change rapidly within the host's lifetime. Thus, it is possible that the microbiome may contribute to the capacity of ectotherms to mount plastic responses to environmental warming. We explored this possibility using the Panamanian slender anole (<i>Anolis apletophallus</i>), a tropical forest-dwelling lizard experiencing population declines induced by climate change. We tested for associations between the composition of the gut microbiome in slender anoles and the capacity for plasticity in their heat tolerance at three time points after exposure to an acute heat stress event. We found that the magnitude of host plasticity at two of three time points was significantly associated with gut microbiome composition before heat stress. Furthermore, up to 94% of the variation in host plasticity was explained by gut microbiome diversity at one time point. Our work suggests a potentially key role for the microbiome in modulating plastic responses to climate change in ectothermic vertebrates, although future manipulative experiments are required to confirm causality.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 5","pages":"285-295"},"PeriodicalIF":1.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149187444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduced Urban Lizards (<i>Podarcis muralis</i>) Exhibit Plastic Activity Patterns and Precise Behavioral Thermoregulation.","authors":"Gabrielle H Plunkett, Logan Fraire, Sierra Spears, Tyler Williard, Emma G Foster, Devon X Haley, Alyssa Head, Maya M Moore, Brittney C Parks, Dellen M Roush, Jasmyn D Zimmerman, Shala J Hankison, Emily E Virgin, Allison R Rickfelder, Bryan H Juarez, Eric J Gangloff","doi":"10.1086/742363","DOIUrl":"https://doi.org/10.1086/742363","url":null,"abstract":"<p><p>AbstractEffective thermoregulation is important for most ectotherms, as body temperature determines the rate of nearly all physiological processes. However, for most organisms, we lack an understanding of which environmental factors affect thermoregulatory behaviors, especially outside of a laboratory setting and over an entire day. Introduced populations of the common wall lizard (<i>Podarcis muralis</i>) in Cincinnati, Ohio, are thriving after an introduction almost 75 years ago. To noninvasively quantify daily thermoregulatory behaviors and thermoregulatory effectiveness, we used infrared thermography (a thermal imaging camera) to conduct repeated standardized sampling every 30 min across the lizard's normal activity period (0800-2000 hours) at multiple urban locations. We also measured air temperature, ultraviolet (UV) radiation, and wind speed, while 3D-printed operative temperature models quantified available temperatures throughout the activity period. Lizard activity varied throughout the day and peaked in the early afternoon. Furthermore, activity patterns were associated with the interaction of temperature and UV radiation intensity, such that predicted activity is greatest at high temperatures when UV is low and at low temperatures when UV is high. Activity was limited by cool environmental temperatures, even on hot days in midsummer. When lizards were active, they thermoregulated precisely and achieved body temperatures closely matching preferred temperatures selected in a laboratory gradient in a previous study. Furthermore, field body temperatures did not vary because of sex, reproductive status, or size. Data on daily activity and thermoregulatory decision-making, especially in an urban habitat, provide valuable insight into how an ectothermic organism integrates multivariate sensory inputs from the environment to make behavioral decisions. The role of environmental conditions in behavioral decision-making is especially relevant in predicting geographical range expansions, particularly in the context of changing urban environments and introduced species.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 4","pages":"237-253"},"PeriodicalIF":1.7,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Cost of Phenotypic Mismatch in Avian Energy Intake: Limited Spare Capacity in Extreme Phenotypes Is Compensated by Energy-Saving Mechanisms.","authors":"François Vézina, Oliver P Love, Lyette Régimbald, Ryan O'Connor, Emily Cornelius Ruhs","doi":"10.1086/741917","DOIUrl":"https://doi.org/10.1086/741917","url":null,"abstract":"<p><p>AbstractDaily energy intake in animals is flexible but takes days to adjust when needs surpass capacity. To buffer mismatches between intake and demand, individuals maintain immediate spare capacity for food consumption. The declining spare capacity model posits that this capacity declines as traits approach maximal values. In contrast, the high midrange capacity model suggests that animals may maintain higher spare capacity at intermediate levels between baseline and maximal capacity when facing challenging environments. We tested these models by examining how captive pine siskins (<i>Spinus pinus</i>) acclimated to -5°C, 5°C, and 20°C responded to a 10°C temperature drop. Within 72 h, food intake increased by 22% in birds acclimated to 20°C, 14% in birds from 5°C, and 6% in birds from -5°C, with a treatment effect persisting for 37 d. Despite their highest spare capacity, 20°C-acclimated birds lost nearly three times more fat than those acclimated to -5°C. However, -5°C birds compensated by increasing lean mass and recovered 53% of their initial fat loss. These results support the reduced spare capacity model but also show that although cold-acclimated birds have limited immediate capacity to increase intake, they can still defend and restore energy reserves during mismatches between intake and demand, likely through physiological trade-offs.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 4","pages":"211-223"},"PeriodicalIF":1.7,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fattening Physiology in a Long-Distance Migrant: Interplay between Baseline Corticosterone, Diet, and the Endocannabinoidome.","authors":"Maëlle M Colin, Ilona P Grentzmann, Gilles Gauthier, Frédéric Angelier, Charline Parenteau, Nicolas Flamand, Elizabeth Dumais, Cristoforo Silvestri, Pierre Legagneux","doi":"10.1086/742374","DOIUrl":"https://doi.org/10.1086/742374","url":null,"abstract":"<p><p>AbstractMigration and subsequent reproduction are the most demanding stages in the life cycle of migratory birds, especially for capital breeders. Fattening rate is a key parameter determining the energy available to meet these high energy demands. For five consecutive years, we measured physiological parameters (body condition, baseline corticosterone, diet, endocannabinoidome lipids) involved in energy regulation in female greater snow geese. Goose body condition increased during spring fattening period until reaching a plateau a few days before migratory departure. Baseline corticosterone followed a similar pattern with an initial increase followed by a slight decrease at the end of spring staging. Individuals with high baseline corticosterone also had a high proportion of corn in their diet. The endocannabinoids <i>N</i>-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), known to play central roles in energy homeostasis, appetite, and fat storage, were detected in plasma but showed no association with diet or body condition. Other endocannabinoidome lipids, like <i>N</i>-oleoylethanolamine (OEA) and <i>N</i>-palmitoylethanolamine (PEA), were negatively associated with dietary corn intake, suggesting a potential role in regulating feeding behavior. The endocannabinoids 2-oleoyl-glycerol (2-OG) and 2-palmitoyl-glycerol (2-PG) were negatively associated with body condition, as was the essential fatty acid linoleic acid (LA); all declined sharply once individuals reached their final body condition. This suggests a downregulation of foraging activity and a shift in lipid metabolism from energy accumulation to maintenance at the end of the premigratory stage. Our results suggest complementary roles of the hormonal and lipidic mediators during the fattening process in preparation for migration. The lipidomic results, though exploratory, provide novel directions for future research.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 4","pages":"254-271"},"PeriodicalIF":1.7,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regionalization of Cutaneous Water Loss in Two European Lizards.","authors":"Nicolas Denize-Proust, Tom J M Van Dooren, Julien Cote, Lucie Di Gesu-Pottier, Jean-François Le Galliard","doi":"10.1086/742154","DOIUrl":"https://doi.org/10.1086/742154","url":null,"abstract":"<p><p>AbstractSkin resistance to evaporative water loss (EWL) is essential for terrestrial organisms to maintain water balance. In squamate reptiles, cutaneous EWL (CEWL) represents a significant fraction of total EWL. Recent studies found differences in CEWL among body regions of the same species, which may be due to region-dependent selection to modulate water loss or indirect selection on other skin functions such as resistance to abrasion. Regionalization might also be linked to scale size or number, as scales are a major component of a reptile's integument. We measured CEWL and scale morphology across four body regions (venter, dorsum, throat, and head) in two lacertid lizard species, <i>Zootoca vivipara</i> and <i>Podarcis muralis</i>, from mesic and semiarid habitats, respectively. We estimated individual repeatabilities with and without experimental covariates to investigate the scope for consistent individual regional CEWL variation. Dorsal surface temperature always had positive effects on CEWL. Body size positively influenced CEWL in <i>P. muralis</i>. Our results further demonstrated differences among body regions in each species. The head and dorsum had the highest CEWL rates, while the venter and throat had the lowest CEWL. Accounting for covariates, we found that <i>P. muralis</i> exhibited lower CEWL than <i>Z. vivipara</i> on the throat and dorsum. We found differences in scale sizes among regions, scale types, and species and significant individual variation and correlations between individual scale sizes of different regions. However, a positive relationship between CEWL and mean scale size occurred only for the throat region. Regions with higher CEWL in <i>Z. vivipara</i> had larger scales than those in <i>P. muralis</i>, but the reverse was not the case. These findings contradict previous observations that less exposed regions (throat and venter) would exhibit higher water loss rates in lizards and reject a single general relationship between scale morphology and regional CEWL.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 4","pages":"224-236"},"PeriodicalIF":1.7,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Songbirds Adjust Oxygen-Carrying Capacity through Modulation of the Number Rather than the Size of Erythrocytes.","authors":"Viktor Kovalov, Jowita Niedojadło, Agata Bury, Amadeusz Bryła, Maciej Dzialo, Kristen J DeMoranville, Katherine M Carbeck, Barbara J Pierce, Lisa Trost, Scott R McWilliams, Joanna Rutkowska, Mariusz Cichoń, Ulf Bauchinger, Edyta T Sadowska","doi":"10.1086/741821","DOIUrl":"https://doi.org/10.1086/741821","url":null,"abstract":"<p><p>AbstractOver a lifetime, birds experience changing energy demands, requiring adjustment of their metabolism. Modulation of oxygen-carrying capacity is one way to adjust metabolism to new energy demands, and such modulation depends on hemoglobin concentration. However, little is known about whether the underlying cellular mechanisms controlling hemoglobin concentration are achieved by varying the number and/or size of erythrocytes. Here, we investigated the relationship between four directly measured hematological variables-hemoglobin concentration, hematocrit, erythrocyte number, and erythrocyte size. We used data on 697 individuals from three avian species, zebra finches (<i>Taeniopygia guttata</i>), great tits (<i>Parus major</i>), and common starlings (<i>Sturnus vulgaris</i>), to test our hypothesis that hemoglobin concentration is controlled by erythrocyte number rather than their size. We found that hemoglobin concentration correlates positively with erythrocyte number and hematocrit but that there is no correlation with erythrocyte size. We also observed a weak negative correlation between erythrocyte number and erythrocyte size. Our results support the hypothesis that songbirds adjust their hemoglobin concentration through changes in erythrocyte number, not their size. This finding suggests that modulation of erythrocyte number may serve as a physiological mechanism songbirds apply to regulate oxygen-carrying capacity when energy demands change due to reproduction, physical training, acclimatization, and other demanding activities.</p>","PeriodicalId":519900,"journal":{"name":"Ecological and evolutionary physiology","volume":"99 4","pages":"199-210"},"PeriodicalIF":1.7,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148804205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}