DOI: 10.5061/dryad.5x69p8dc5
title: Short-term dietary changes are reflected in the cerebral content of adult Ring-billed Gulls

description: Long-chain omega-3s (n3-LCPUFAs) are produced primarily in aquatic
 ecosystems and are essential for the structural integrity of vertebrates’
 brains. Carnivorous mammals must consume n3-LCPUFAs throughout their
 lifespan to maintain optimal cerebral functions; it is unknown whether
 other taxa are under similar nutritional pressures. This is concerning
 because many avian predators now rely on anthropogenic foods lacking
 n3-LCPUFAs. Here, we tested whether a recent or longer-term diet explains
 the encephalic fatty acid composition of a seabird, the Ring-billed Gull,
 that now thrives in cities. During the breeding season, rural gulls
 exploiting marine organisms had significantly higher encephalic levels of
 n3-LCPUFAs (mean±SD: 32±1%) than city-nesting gulls exploiting garbage
 (27±1%). Stable isotope analysis of blood and feathers grown during
 different seasons showed that urban and rural nesters consumed similar
 fall and winter diets, suggesting that the difference in cerebral
 n3-LCPUFA of breeding adults was due to concomitant and transient dietary
 differences. We also experimentally manipulated gulls’ diets throughout
 incubation with a n3-LCPUFA supplement, a n3-LCPUFA-free caloric
 equivalent, or nothing, and found evidence that supplemental n3-LCPUFA
 increased urban nesters’ cerebral levels of n3-LCPUFAs. These
 complementary analyses provide strong evidence that the brain of a seabird
 remains plastic during adulthood and responsive to short-term dietary
 changes.
description: # Short-term dietary changes are reflected in the cerebral content of
 adult Ring-billed Gulls
 [https://doi.org/10.5061/dryad.5x69p8dc5](https://doi.org/10.5061/dryad.5x69p8dc5) ## Description of the data and file structure ### Dataset 1: Lamarre\_Wilson\_2024\_main\_data Contains data regarding ring-billed gulls' breeding colonies, treatment groups, and biomarkers (stable isotopes and fatty acids). Used to establish whether short-term dietary supplementation and long-term diet were reflected in the composition of the brains of adults. **VERSION CHANGES:** Changes between version 1 and version 2 of the dataset: The name of the file has been updated from Lamarre_Wilson_2024_RSOS_rawdata.csv to Lamarre_Wilson_2024_main_data.csv ### Dataset 2: siber\_isotope Stable isotope data used specifically to work with the SIBER package in R | Spreadsheet 1: Lamarre\_Wilson\_2024\_main\_data | | | :----------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Variables** | **Descriptions** | | Capture\_date | Date at which tissues were collected | | Colony | Ring-billed Gull colonies investigated; Long Pond or Salmonier | | Colony\_location | Long Pond = urban, Salmonier = rural | | Bird\_ID | Unique identification | | Treatment\_group | Supplementation treatment group; at Long Pond = 1\_negative\_control, 3\_coconut (oil), 4\_fish\_oil; at Salmonier = 1\_negative\_control, 2\_coconut (oil) | | Treatment\_group2 | Supplementation treatment group 2 by positive control, negative control, or experimental group; at Long Pond = 1\_control (negative control), 2\_positive\_control (coconut oil), 3\_experimental (fish oil); at Salmonier = 1\_control (negative control), 3\_experimental (coconut oil) | | Head\_d15N | Stable isotope nitrogen signature of head feathers (‰) | | Head\_d13C | Stable isotope carbon signature of head feathers (‰) | | P1\_d15N | Stable isotope nitrogen signature of primary P1 feathers (‰) | | P1\_d13C | Stable isotope carbon signature of primary P1 feathers (‰) | | P10\_d15N | Stable isotope nitrogen signature of primary P10 feathers (‰) | | P10\_d13C | Stable isotope carbon signature of primary P10 feathers (‰) | | RBC\_d15N | Stable isotope nitrogen signature of red blood cells (‰) | | RBC\_d13C | Stable isotope carbon signature of red blood cells (‰) | | RBC\_lcn3 | Sum of omega-3 long-chain polyunsaturated fatty acids in the red blood cells (%) | | RBC\_C14:0 \[...] RBC\_DHA | Percentage of the relative concentration of each identified fatty acid in the red blood cells (%) | | RBC\_n3 | Sum of omega-3 polyunsaturated fatty acids in the red blood cells (%) | | RBC\_n6 | Sum of omega-6 polyunsaturated fatty acids in the red blood cells (%) | | RBC\_n6\_n3 | Ratio of omega-6 to omega-3 in the red blood cells (%) | | CH\_C10:0 \[...] CH\_C24:1 | Percentage of the relative concentration of each identified fatty acid in the cerebral hemispheres (%) | | CH\_lcn3 | Sum of omega-3 long-chain polyunsaturated fatty acids in the cerebral hemispheres (%) | | CH\_n3 | Sum of omega-3 polyunsaturated fatty acids in the cerebral hemispheres (%) | | CH\_n6 | Sum of omega-6 polyunsaturated fatty acids in the cerebral hemispheres (%) | | CH\_n6\_n3 | Ratio of omega-6 to omega-3 in the cerebral hemispheres (%) | | | | | **Spreadsheet 2: siber\_isotope** | | | **Variables** | **Descriptions** | | iso1 | Stable isotope carbon signature (‰) | | iso2 | Stable isotope nitrogen signature (‰) | | group | Tissue | | community | Colony | NAs or empty cells in the CSV files indicate missing data that were not or could not be obtained during fieldwork or lab analyses ## Code/Software R script used for this article: Lamarre_Wilson_RSOS_2024.R **VERSION CHANGES:** R Script version two include the omega-6:omega-3 analyses R script runs exclusively with the datasets name Lamarre_Wilson_2024_main_data.csv & siber_isotope.csv R script was written and run on R version 4.1.0 (R Core Team, 2023)