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We present the history of research activities at the Bylot Island Field Station of the Centre d’études nordiques, a hotspot of biodiversity in the Canadian Arctic. Intensive wildlife studies started at the station in the late 1980s, initially focussing on greater snow goose ecology and its impacts on the tundra vegetation. Since then, studies have expanded to encompass the whole vertebrate food web and have become one of the most comprehensive ecological monitoring programs in the Canadian Arctic. The main vertebrate species monitored include snow geese, lemmings, shorebirds, avian predators, buntings, and Arctic foxes. Over time, we recorded 66 bird and 10 mammal species, including 51 confirmed breeders. Contributions of the program to the field of ecology are numerous, but our demonstration of the dominant role played by predator–prey interactions in the Arctic food web is especially significant for the understanding of direct and indirect trophic interactions. Our studies provided essential information for management decisions taken to control the overabundant greater snow goose population and supported international efforts to assess the state of Arctic biodiversity. Future directions will reflect the need to deepen our understanding of trophic interactions and the effects of climate change using innovative advanced technologies.

Within the terrestrial Arctic ecosystem at Karrak Lake, Nunavut, Bartonella bacteria (B. vinsonii subsp. berkhoffii and B. henselae) have been detected in avian nest fleas (Ceratophyllus vagabundus vagabundus) and the blood of Arctic foxes (Vulpes lagopus (Linnaeus, 1758)). We further investigate the transmission dynamics at Karrak Lake by identifying Bartonella present in rodents, migratory geese upon arrival to nesting grounds, and rodent and avian fleas. Conventional PCR targeting the 16S–23S rRNA intergenic transcribed spacer region revealed DNA of B. vinsonii subsp. berkhoffii and B. rochalimae in 42% of 24 nest flea pools, B. rochalimae and B. grahamii in 70% of 10 rodent flea pools (Amalaraeus dissimilis), B. grahamii, B. vinsonii subsp. berkhoffii, and Bartonella sp. BvS12 in 20% of 20 red-backed voles (Myodes rutilus (Pallas, 1779)), and B. vinsonii subsp. berkhoffii in 2% of 42 Ross's geese (Anser rossii Cassin, 1861). These findings suggest that geese and their associated fleas serve as migratory hosts and vectors. Detection of the same or similar species of Bartonella in rodent fleas, nest fleas, and foxes proposes that transmission may occur during predation, and detection of B. rochalimae (a Bartonella species commonly detected in rodents) in nest fleas may suggest that these fleas have generalist feeding tendencies, acquiring Bartonella from rodents or foxes as they visit nests.