ArticleProceedings of the National Academy of Sciences of the United States of America2007
The digestive adaptation of flying vertebrates: high intestinal paracellular absorption compensates for smaller guts.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 73 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
73 citing papers in PubMed, 182 citations in OpenAlex.
- Effects of temperature acclimation on body mass and energy budget in the Chinese bulbul Pycnonotus sinensis.Dong wu xue yan jiu = Zoological research · 2014Trial
- Microbiota shows major difference in case of two shorebird species with different feeding strategy.Veterinary and animal science · 2026Article
- Bat-Inspired Longevity: Immune Damage Management and Nutritional Modulation for Healthy Aging.International journal of molecular sciences · 2026Review
- Seasonal Variation in the Mutagenic and Oxidative Properties of Gut Microbiota in Active and Hibernating Common Noctules (Nyctalus noctula).Current microbiology · 2026Article
- Do insect food-derived ecdysteroids appear in the blood of waterfowl, predatory birds, carnivorous mammals and primates?PloS one · 2026Article
- Migration-driven microbial adaptation and ecological spillover in birds.ISME communications · 2026Review
- Nutrient transporters in broiler chickens: intestinal gene expression profiles, functional roles, and influencing factors.Journal of animal science and biotechnology · 2025Review
- Host Diet Preference Drives Diversity and Composition of Gut Microbiota in Captive Birds.Ecology and evolution · 2025Article
- Linking digestive efficiency and climate to basal metabolic rate in bats of the family vespertilionidae.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2025Article
- Molecular epidemiology ofMicrobial genomics · 2025Article
- Delayed feeding disrupts diurnal oscillations in the gut microbiome of a neotropical bat in captivity.FEMS microbiology ecology · 2025Article
- Metagenomic analyses of gut microbiome composition and function with age in a wild bird; little change, except increased transposase gene abundance.ISME communications · 2025Article
- Glycation resistance and life-history traits: lessons from non-conventional animal models.Biology letters · 2024Review
- The role of host traits and geography in shaping the gut microbiome of insectivorous bats.mSphere · 2024Article
- Migratory Shorebird Gut Microbes are not Associated with Bivalve Prey in Monsoon Tropical Australia.Current microbiology · 2024Article
- Sex differences and individual variability in the captive Jamaican fruit bat (Artibeus jamaicensis) intestinal microbiome and metabolome.Scientific reports · 2024Article
- Gut Microbiota Composition of Insectivorous Synanthropic and Fructivorous Zoo Bats: A Direct Metagenomic Comparison.International journal of molecular sciences · 2023Article
- Cultivable Gut Microbiota in Synanthropic Bats: Shifts of Its Composition and Diversity Associated with Hibernation.Animals : an open access journal from MDPI · 2023Article
- Gut microbiota enhance energy accumulation of black-necked crane to cope with impending migration.Applied microbiology and biotechnology · 2023Article
- Quantitative investigation of pengornithid enantiornithine diet reveals macrocarnivorous ecology evolved in birds by Early Cretaceous.iScience · 2023Article
13 more citing papers are in PubMed but not listed here.
Corrections and comments
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Authors and funding
6 authors at 2 institutions in 4 countries.
Funding
Abstract
Anecdotal evidence suggests that birds have smaller intestines than mammals. In the present analysis, we show that small birds and bats have significantly shorter small intestines and less small intestine nominal (smooth bore tube) surface area than similarly sized nonflying mammals. The corresponding >50% reduction in intestinal volume and hence mass of digesta carried is advantageous because the energetic costs of flight increase with load carried. But, a central dilemma is how birds and bats satisfy relatively high energy needs with less absorptive surface area. Here, we further show that an enhanced paracellular pathway for intestinal absorption of water-soluble nutrients such as glucose and amino acids may compensate for reduced small intestines in volant vertebrates. The evidence is that l-rhamnose and other similarly sized, metabolically inert, nonactively transported monosaccharides are absorbed significantly more in small birds and bats than in nonflying mammals. To broaden our comparison and test the veracity of our finding we surveyed the literature for other similar studies of paracellular absorption. The patterns found in our focal species held up when we included other species surveyed in our analysis. Significantly greater amplification of digestive surface area by villi in small birds, also uncovered by our analysis, may provide one mechanistic explanation for the observation of higher paracellular absorption relative to nonflying mammals. It appears that reduced intestinal size and relatively enhanced intestinal paracellular absorption can be added to the suite of adaptations that have evolved in actively flying vertebrates.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.