Aim To test six hypotheses that could explain or mediate the positive correlation between human population density (HPD) and bird species richness while controlling for biased sampling effort. These hypotheses were labelled as follows: productivity (net primary productivity, NPP); inherent heterogeneity (diversity of vegetation types); anthropogenic heterogeneity (diversity of land uses); conservation policy (proportion of conservation land); increased productivity (humaninduced productivity increases); and the reduced-slope hypothesis (which predicts that humans have a negative impact on species numbers across the full range of variation in HPD). Location Australia.Methods All data were collected at a spatial resolution of 1°across mainland Australia. Bird species richness was from 2007 atlas data and random subsampling was used to account for biased sampling effort. HPD was from the 2006 census. All other data were from government produced geographic information system layers. The most important biotic or abiotic factors influencing patterns in both species richness and HPD were assessed using simultaneous autoregressive models and an information theoretic approach.Results NPP appeared to be one of the main factors driving spatial congruence between bird species richness and HPD. Inherent habitat heterogeneity was weakly related to richness and HPD, although an interaction between heterogeneity and NPP indicated that the former may be an important determinant of species richness in low-productivity regions. There was little evidence that anthropogenic landscape heterogeneity or human-induced changes in productivity influenced the relationship between species richness and HPD, but conservation policy appeared to act as an important mediating factor and species richness was positively related to the proportion of conservation land only in regions of high HPD. Main conclusionsThe spatial congruence between bird species richness and HPD occurs because both respond positively to productivity and, in certain circumstances, habitat heterogeneity. Our results suggest that conservation policy could mediate this relationship, but further research is required to determine the importance of conservation reserves in supporting species in regions densely populated by humans.

The consequences of the 2019–2020 bushfires in Australia were also devastating for the aquatic biota. Following abnormal rainfall events in burnt areas, widespread mortality events including fish and invertebrates were recorded in estuarine and freshwater systems. Such negative impacts on aquatic resources highlight the need to include these ecosystems in bushfire recovery plans. Management should prioritise catchments at higher risks of further negative impacts and research must be conducted to understand the efficacy of actions post‐fire.

Maintaining a territory and being able to hunt are imperative for the success of African lion Panthera leo prides. We aimed to determine whether captiveorigin prides display similar territorial and hunting behaviour to wild lions. Behaviours and locations of two captive-origin prides and one wild pride were collected through direct observation. All prides established territories, and core areas corresponded to resource requirements. There was no evidence that pride origin affected territorial or hunting behaviour. Captive-origin prides exhibited behaviours that lead us to be optimistic about each pride's ability to establish and defend a territory successfully, and to hunt, following reintroduction.

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Infrastructure-induced fragmentation of riverine ecosystems has prompted the need for more effective aquatic restoration efforts globally. Fragmentation assessments have been extensively undertaken to inform connectivity restoration efforts for fish and other aquatic biota, but they have potentially underestimated the extent of fragmentation by fixating on large dams and overlooking the contribution of other barriers like road crossings and small irrigation structures. The current study addresses this limitation in Mekong region countries (MReCs) of Southeast Asia, by assessing the fragmentation impacts of road crossings and small irrigation structures together with large dams. Our analysis indicates that the basin-scale fragmentation impact of road crossings is similar to that of large dams in MReCs, while small irrigation structures have a far greater impact. These findings raise concerns about the real global extent of aquatic fragmentation, and highlight the need for decision-makers to think beyond dams when attempting to restore connectivity for aquatic biota.

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