We assessed the diversity, functional potential, and temporal dynamics of the gut DNA virome in a trans-hemispheric migratory shorebird, the Hudsonian godwit (Limosa haemastica), during pre-migratory fattening. Adult individuals were maintained under controlled aviary conditions for 15 weeks during the preparation for northbound migration, with faecal samples collected at two distinct physiological time points: at the beginning and the end of pre-migratory fattening. Shotgun metagenomic sequencing revealed 798 high-quality viral operational taxonomic units (vOTUs), the majority of which were bacteriophages (92%). Potential functional annotation identified auxiliary metabolic genes (AMGs) associated with nucleotide metabolism, redox balance, and host adaptation. Although overall gut virome diversity did not differ between stages, significant changes in potential functional profiles of phages were observed, especially during the final stage of fattening.