A feather hydrogen (δ2H) isoscape for Brazil

PLoS One. 2022 Aug 3;17(8):e0271573. doi: 10.1371/journal.pone.0271573. eCollection 2022.

Abstract

Spatial patterns of stable isotopes in animal tissues or "isoscapes" can be used to investigate animal origins in a range of ecological and forensic investigations. Here, we developed a feather hydrogen isotope (δ2Hf) isoscape for Brazil based on 192 samples of feathers from the family Thraupidae from scientific collections. Raw values of δ2Hf ranged from -107.3 to +5.0‰, with higher values at the Caatinga biome (northeast Brazil) and lower values at the Amazon and Pantanal. A Random Forest (RF) method was used to model the spatial surface, using a range of environmental data as auxiliary variables. The RF model indicated a negative relationship between δ2Hf and Mean Annual Precipitation, Precipitation in the Warmest Quarter, and Annual Temperature Range and positive relationships for amount-weighted February-April precipitation δ2H (δ2Hp(Feb-April)) and Mean Annual Solar Radiation. Modelled δ2Hf values ranged from -85.7 to -13.6‰. Ours is the first δ2Hf isoscape for Brazil that can greatly assist our understanding of both ecological and biogeochemical processes controlling spatial variation in δ2H for this region. This isoscape can be used with caution, due to its poor predictive power (as found in other tropical regions) and can benefit from new sample input, new GNIP data, ecological and physiological studies, and keratin standard material better encompassing the range in feather samples from Brazil. So, we encourage new attempts to build more precise feather H isoscapes, as well as isoscapes based on other elements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brazil
  • Ecosystem
  • Feathers* / chemistry
  • Hydrogen* / analysis
  • Isotopes / analysis

Substances

  • Isotopes
  • Hydrogen

Grants and funding

The work was supported by the project number 23038.006832/2014-11- Edital CAPES 25/2014 – Pró-Forenses (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior -https://www.gov.br/capes/pt-br). RDA received a pos-doctoral scholarship from CAPES (process number 88881.357615/2019-1) and KAH received funding from the University of Western Ontario (https://www.uwo.ca/) and the Natural Sciences and Engineering Research Council (NSERC -https://www.nserc-crsng.gc.ca/index_eng.asp) of Canada (2017-04430). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.