Mycophagy of White-Tailed Deer (Odocoileus virginianus Zimmermann) in the Boreal Forest

Myriam Cadotte,Steeve D Côté,Julien H Richard,Jean A Bérubé

doi:10.3390/f12091247

Abstract

Mushrooms are a little known source of food for large herbivores, but are of high quality because of their high protein content and digestibility. Approximately 50 epigeous and hypogeous mushroom and lichen species have been identified in the diet of cervids so far using macro remains. Our main objective was to determine which mushroom species are consumed by white-tailed deer (Odocoileus virginianus Zimmermann) using a molecular approach. We collected 114 fecal samples from deer harvested in 2014 and 2015 on Anticosti Island (Québec, Canada), extracted total DNA from feces, and amplified fungal DNA specifically via polymerase chain reaction. Amplified fungi DNA was then sequenced with the Illumina method to identify mushroom species consumed by deer. Our results revealed that deer harvested consumed up to 4979 fungal species, including 580 species that appeared to be consumed directly. Adults tended to consume a higher mushroom diversity than juveniles, and mushroom diversity consumed by deer was much higher in 2015 than 2014. Adult females consumed a higher mushroom diversity than males, especially lactating females. Our results contribute to the understanding of the role of mushrooms and their large diversity in white-tailed deer diet.

Highlights

We obtained >26 million mushroom DNA sequence reads which clustered in 4979 Molecular Operational Taxonomic Units (MOTU), our proxy for mushroom species
Our finding of the probable consumption of 580 mushroom species by white-tailed deer suggest that mycophagy is an overlooked component of the ecology of white-tailed deer in the boreal forest
We showed that white-tailed deer mycophagy is highly variable, even within two successive years, suggesting that mycophagy is probably partly opportunistic and largely dependent on mushroom availability

Summary

Introduction

The higher digestibility of mushrooms is partly related to the absence of cellulose and lignin, two components of plant cells that are difficult to digest [4] This higher digestibility means that for the same value of crude protein and gross energy, herbivores can obtain more proteins and energy from mushrooms than from plants. Mushrooms are a good source of water (80–90% of fresh weight), nutrients such as potassium, phosphorus, iron and selenium, as well as vitamins including thiamine and riboflavin [3,4,8]. All these elements suggest that mushrooms are a high quality resource for herbivores. These percentages can vary from trace (~0%) to a majority (~80%) of the diet depending on individual, habitat and season [4,11,12]

Methods

Results

Discussion

Conclusion