The Canadian boreal forest biome has been subjected to a long history of management for wood production. Here, we examined the cumulative impacts of logging on older forests in terms of area, distribution and patch configuration in the managed forest zones of the Eastern Canadian provinces of Ontario and Quebec. We also examined the consequences of these cumulative impacts on a once widely distributed and now threatened species, the woodland caribou (Rangifer tarandus caribou). The cumulative area of recently logged forest (since ~1976) was 14,024,619 ha, with 8,210,617 ha in Quebec and 5,814,002 ha in Ontario. The total area of older forests was 21,249,341 ha, with 11,840,474 ha in Quebec and 9,408,867 ha in Ontario. Patch statistics revealed that there were 1,085,822 older forests with core patches < 0.25 ha and an additional 603,052 < 1.0 ha. There were 52 > 10,00–50,000 ha and 8 < 50,000 ha. Older forest patches (critical caribou habitat) in the 21 local population ranges totalled 6,103,534 ha, distributed among ~387,102 patches with 362,933 < 10 ha and 14 > 50,000 ha. The median percentage of local population ranges that was disturbed was 53.5%, with Charlevoix having the maximum (90.3%) and Basse Côte-Nord the least (34.9%). Woodland caribou local population ranges with disturbed suitable habitats >35% are considered unable to support self-sustaining populations. We found that for the 21 caribou local population ranges examined, 3 were at very high risk (>75% area disturbed), 16 at high risk (>45 ≤ 75% area disturbed), and 2 at low risk (≤35% area disturbed). Major changes are needed in boreal forest management in Ontario and Quebec for it to be ecologically sustainable, including a greater emphasis on protection and restoration for older forests, and to lower the risks for caribou populations.

Australia has lost vast areas of its natural vegetation through agriculture and urbanization, resulting in the area of suitable habitat for many Australian bird species being greatly diminished. Given the geographical and ecological biases in anthropogenic land use, the impact of habitat loss now and into the future may be disproportionately high for some species, threatening their long-term persistence. Such changes are occurring rapidly, and habitat loss needs to be monitored dynamically to prevent extinction. To monitor changes in available unmodified species habitat, we use species’ area of feeding habitat (AFH), which represents the area of habitat within a species’ range with vegetation matching their feeding requirements. We analysed the past, current and future threats of habitat modification for 467 Australian bird species by calculating AFH across three time periods: pre-colonization, current (2020), and a projected future scenario (2100). These values were used to identify species subject to substantial habitat loss due to urbanization and agriculture and delineate predictors of such losses. Most species had experienced habitat loss since colonization (n = 442, 95%), and species that had already experienced considerable habitat loss were more likely to lose habitat into the future. Species with particular habitat associations (e.g., Mallee), were also more prone to greater proportions of habitat lost. The results highlight the utility of AFH and emphasize the importance of protecting what habitat remains for the species with highly depleted geographic ranges, noting that those that have experienced the most loss of unmodified habitat are the most likely to lose more unmodified habitat under future conditions.

Drones are increasingly used to conduct wildlife surveys in complex environments as they can be used in inaccessible areas, quickly survey large areas, and surveys can be reviewed post hoc, often leveraging AI technology. Double-observer methods applied to drone surveys, such as post-survey double-observer review of footage, improve inferences from drone-based wildlife surveys by correcting for individual perceptibility biases of observers. However, occlusion still affects the availability of individuals for detection, especially in complex environments. We explore the possibility that the availability of individuals may be increased by conducting a consecutive repeat survey with a parallel or rotated flight path in a double-observer survey design where individuals are largely stationary. We hypothesized that running this secondary flight would increase the availability of individuals for detection, thereby improving count accuracy, with the most prominent improvement in most complex (e.g., highly vegetated) environments. We explored this using (1) an in-field test of object detectability in environments with differing vegetation, and (2) a simulation of drone wildlife surveys in different levels of occlusion. In both trials, we tested a double-observer detectability estimator tool to correct survey counts. In the field, conducting a secondary flight from a different angle resulted in more accurate counts, with a post-count correction further increasing accuracy. The simulation highlighted detectability benefits from the secondary observer in nearly all trials (99%), and these benefits were generally greater in environments with denser canopies, and from flights paths rotated 90° compared to parallel paths.