Biology subjects

Grond, K.

Publications and source records attributed to Grond, K..

4 recordsLinked to original sources

bioRxiv2024

Gut microbiome diversity associates with estimated lifetime and annual reproductive success in male but not female collared flycatchers

The gut microbiome (hereafter, GM) varies across individuals of the same species and this pattern has been observed in multiple wild species. Evidence shows that the GM connects to individual health and survival especially in captive species, but more research is needed to understand how the GM connects to host fitness in wild species. We used long-term monitoring data to investigate whether the GM of collared flycatchers Ficedula albicollis associates with annual and lifetime reproductive success (LRS), and survival to the following breeding season. This is the first study that 1) characterized the collared flycatcher GM, and 2) investigated how variation in the GM related to LRS in wild birds. Our results showed that higher GM diversity was associated with a higher annual and lifetime reproductive success in especially male collared flycatchers. We also found that the compositional variation in collared flycatcher GMs was explained by sex, age, and breeding habitat, but not by annual or lifetime reproductive success. Individuals that died before the next breeding season had higher abundances of ASVs belonging to the pathogenic families Enterobacteriaceae and Parachlamydiaceae, and the genera Corynebacteria and Sphingomonas. Our results show that the GM associates with different aspects of host fitness in a wild bird population. More research is needed to evaluate if there is a causal relationship between the GM and individual fitness. These findings also contribute to our understanding of the GMs role in evolution by elucidating the connection between the GM (trait) and reproductive success.

ecology↗

bioRxiv2023

Seasonal and environmental factors contribute to the variation in the gut microbiome: a large-scale study of a small bird

Environmental variation can shape the gut microbiome, but majority of studies use captive-bred species, while data on large-scale variation in the gut microbiome and the associated environmental factors is lacking. Furthermore, previous studies have limited taxonomical coverage, and for example knowledge about avian gut microbiomes is still scarce. We investigated large-scale environmental variation in the gut microbiome of wild adult great tits across the species European distribution range. Our results show that gut microbiome diversity is higher during winter and that there are compositional differences between winter and summer gut microbiomes. During winter, individuals inhabiting mixed forest habitat show higher gut microbiome diversity, whereas there was no similar association during summer. Also, temperature was found to be a small contributor to compositional differences in the gut microbiome. We did not find significant differences in the gut microbiome among populations, nor any association between latitude, rainfall, and the gut microbiome. The results suggest that there is a seasonal change in wild avian gut microbiomes, but that there are still many unknown factors that shape the gut microbiome of wild bird populations.

ecology↗

bioRxiv2022

Associations between brood size, gut microbiome diversity and survival in great tit (Parus major) nestlings

BackgroundThe gut microbiome forms at an early stage, yet data on the environmental factors influencing the development of wild avian microbiomes is limited. As the gut microbiome is a vital part of organismal health, it is important to understand how it may connect to host performance. The early studies with wild gut microbiome have shown that the rearing environment may be of importance in gut microbiome formation, yet the results vary across taxa, and the effects of specific environmental factors have not been characterized. Here, wild great tit (Parus major) broods were manipulated to either reduce or enlarge the original brood soon after hatching. We investigated if brood size was associated with nestling bacterial gut microbiome, and whether gut microbiome diversity predicted survival. Fecal samples were collected at mid-nestling stage and sequenced with the 16S rRNA gene amplicon sequencing, and nestling growth and survival were measured. ResultsGut microbiome diversity showed high variation between individuals, but this variation was not significantly explained by brood size or body mass. Additionally, we did not find a significant effect of brood size on body mass or gut microbiome composition. We also demonstrated that early handling had no impact on nestling performance or gut microbiome. Furthermore, we found no significant association between gut microbiome diversity and short-term (survival to fledging) or mid-term (apparent juvenile) survival. ConclusionsWe found no clear association between early-life environment, offspring condition and gut microbiome. This suggests that brood size is not a significantly contributing factor to great tit nestling condition, and that other environmental and genetic factors may be more strongly linked to offspring condition and gut microbiome. Future studies should expand into other early-life environmental factors e.g., diet composition and quality, and parental influences.

ecology↗

bioRxiv2022

Functional and compositional changes in the fecal microbiome of a shorebird during pre-migratory weight gain

Shorebirds migrate long distances twice annually, which requires intense physiological and morphological adaptations, including the ability to rapidly gain weight via fat deposition at stopover locations. The role of the microbiome in weight gain in avian hosts is unresolved, but there is substantial evidence to support the hypothesis that the microbiome is involved with host weight from mammalian microbiome literature. Here, we collected 100 fecal samples of Ruddy Turnstones to investigate microbiome composition and function during stopover weight gain in Delaware Bay, USA. Using 16S rRNA sequencing on 90 of these samples and metatranscriptomic sequencing on 22, we show that taxonomic composition of the microbiome shifts during weight gain, as do functional aspects of the metatranscriptome. We identified ten genes that are associated with weight class and polyunsaturated fatty acid biosynthesis in the microbiota is significantly increasing as birds gain weight. Our results support that the microbiome is a dynamic feature of host biology that interacts with both the host and the environment and may be involved in the rapid weight gain of shorebirds.

microbiology↗