Knowledge of blue marlin, Makaira nigricans, movement patterns across a range of spatiotemporal scales is important for understanding the ecology of this epipelagic fish, informing responsible management strategies, and understanding the potential impacts of a changing ocean climate to the species. To gain insight into movement patterns, we analyzed data from 66 blue marlin satellite-tagged between 2001 and 2021 throughout the North Atlantic. We recorded migrations connecting west and east Atlantic tagging locations, as well as long-term residency within small sub-regions. Blue marlin showed a pattern of latitudinal migration, occupying lower latitudes during cooler months and higher latitudes in warmer months. Diving data indicate blue marlin primarily inhabited a shallow vertical habitat with deeper diving associated with higher sea surface temperatures and dissolved oxygen content. Consistent patterns in diel vertical habitat use support the hypothesis that these fish are visual hunters, diving deeper during the day, as well as dawn, dusk, and full moon periods. The wide-ranging movements of blue marlin indicate that traditional spatial management measures, such as static marine reserves, are unlikely to be effective in reducing the fishing mortality of this species. Longer tag deployment durations are required to delineate its annual and multi-annual migratory cycle.

Understanding nest site selection is critical to developing effective conservation management actions. The Superb Lyrebird (Menura novaehollandiae) is one of many endemic species extensively impacted by Australia’s unprecedented 2019–2020 megafires. Over a period of 5 months, an estimated 43% of the entire range of this slow-breeding species was burnt, with the biggest impact on the central subspecies M. n. novaehollandiae (55%). Four months prior to these megafires, we conducted a field study of nest site habitat selection in the Superb Lyrebird within the Greater Blue Mountains World Heritage Area (15,400 km 2): a key stronghold of the central subspecies of the Superb Lyrebird. We found that at the local scale, lyrebird nest sites were more likely to be found in habitats characterized by dense canopy trees and rich in rainforest elements such as vines and treeferns. At the landscape scale, lyrebird nests were most likely to be constructed in rainforest; this fire-sensitive habitat type made up only 1% of the Greater Blue Mountains World Heritage Area. The probability of nest occurrence also increased with slope. We also found that >74% of all nesting habitat within the Greater Blue Mountains World Heritage Area burned in the 2019–2020 megafires, including 80% of areas of high suitability for nesting. These results suggest that the impact of these megafires on Superb Lyrebirds may be greater than currently thought. Given the importance of rainforest as nesting habitat for the superb lyrebird, managers should prioritize its restoration and protect it from future fire events. More broadly, our results illustrate how large-scale catastrophic events—such as megafires—can disproportionately affect habitats critical to specific points within an organism’s life cycle.