Data from: Maternal diet influences fecundity in a freshwater turtle undergoing population decline
Data files
Apr 25, 2024 version files 84.08 KB
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Maternal_Diet_Data.xlsx
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README.md
Abstract
Food availability determines the amount of energy animals can acquire and allocate to reproduction and other necessary functions. Female animals that are food-limited thus experience reduced energy available for reproduction. When this occurs, females may reduce frequency of reproductive events or the number or size of offspring per reproductive bout. We assessed how maternal diet affects reproductive output in adult female Murray River short-necked turtles, Emydura macquarii, from four wetlands in Victoria. We previously found that turtle diets differ in the composition of plants and animals between our study wetlands. In this study, we tested whether differences in turtle diet composition (i.e plants and animals) at these wetlands were associated with differences in clutch mass, individual egg mass, bulk egg composition, and hatching success. We found total clutch mass increased with maternal body size at each site. At sites where filamentous green algae were scarce and E. macquarii were carnivorous, females produced smaller clutches relative to body size compared to females from sites where algae were abundant, and turtles were more herbivorous. Individual egg mass, bulk egg composition, and hatching success did not differ across wetlands. Isotopic analysis revealed a significant positive relationships between the carbon and nitrogen isotopes (δ13C, δ15N) of the eggs and those of the mothers, indicating that mothers allocated ratios of carbon and nitrogen isotopes to their eggs similar to those present in their tissues. Our study suggests that at sites where females are more carnivorous due to a relative absence of algae, females produce smaller clutches but other aspects of their reproduction are not significantly impacted. The reduction in clutch size associated with differences in the availability of dietary plants and animals may have long-term consequences for E. macquarii and other freshwater turtle species that are experiencing population declines.
README: Maternal diet influences fecundity in a freshwater turtle undergoing population decline
https://doi.org/10.5061/dryad.05qfttfbg
The attached Excel spreadsheet includes all data related to the associated manuscript. Briefly, gravid female turtles were captured in the wild, induced to lay their eggs with oxytocin, and eggs were collected for either direct analysis or incubation. Eggs (and maternal claw samples) were analysed for isotopic content, and eggs were analysed for total protein, water, fat, and energy content. The incubated eggs were incubated at either 26 or 30 C (clutches split approximately 50-50), and hatching success was measured.
Description of the data and file structure
In the spreadsheet,
Workbook "Egg Collection Data" provides summary data of all eggs collected, including laying date and time, mass, dimensions, and fate
"Hatching Dates" indicates the hatching dates for those incubated eggs which hatched
"Egg and Mother Composition Data" includes all analysed compositional data, including isotopes, dry and wet mass, protein, fat, and energy contents.
"Hatch Success Data" provides the numbers of eggs incubated in each treatment from each mother, and the number of eggs which hatched.
Methods
Please see the published manuscript associated with this data