Not all urban landscapes are the same: interactions between urban land use and stress in a large herbivorous mammal

Abstract

Urbanization significantly impacts the health and viability of wildlife populations yet it is not well understood how urban landscapes differ from non‐urban landscapes with regard to their effects on wildlife. This study investigated the physiological response of eastern grey kangaroos (Macropus giganteus) to land use at a landscape scale. Using fecal glucocorticoid metabolites (FGM) we compared stress levels of kangaroo populations in urban and non‐urban environments. We modeled FGM concentrations from 24 kangaroo populations against land use (urban or non‐urban) and other anthropogenic and environmental factors, using a linear modeling approach. We found that land use was a significant predictor of FGM concentrations in eastern grey kangaroos with significant differences in concentrations between urban and non‐urban populations. However, the direction of the relationship differed between northern and southern regions of Australia. In the northern study sites, kangaroos in urban areas had significantly higher FGM levels than their non‐urban counterparts. In contrast, in southern sites, where kangaroos occur in high densities in many urban areas, urban kangaroos had lower FGM concentrations than non‐urban kangaroos. Rainfall and temperature were also significant predictors of FGM and the direction of the relationship was consistent across both regions. These results are consistent with the contrasting abundance and persistence of kangaroo populations within the urban matrix between the two study regions. In the northern region many populations have declined over the last two decades and are fragmented, also occurring at lower densities than in southern sites. Our study indicates that it is the characteristics of urban environments, rather than the urban environment per se, which determines the extent of impacts of urbanization on kangaroos. This research provides insights into how the design of urban landscapes can influence large mammal populations.

Kangaroos at maximum capacity: health assessment of free-ranging eastern grey kangaroos on a coastal headland

“…Significantly higher N:L ratios found in kangaroos at the peri-urban sites LAMN, NBGC, and HP, compared to AM (a nature reserve) could indicate populations under stress. Previous research in Queensland established that kangaroos living within the peri-urban space had higher levels of stress hormone metabolites than their rural counterparts ( Brunton et al 2020 ). However, the opposite was true for populations in the Australian Capital Territory ( Brunton et al 2020 ).…”

“…Previous research in Queensland established that kangaroos living within the peri-urban space had higher levels of stress hormone metabolites than their rural counterparts ( Brunton et al 2020 ). However, the opposite was true for populations in the Australian Capital Territory ( Brunton et al 2020 ). In our study, it was not possible to delineate the impacts of anthropogenic stress from other causes such as nutritional stress, high density, and parasitism.…”

Campylobacter in aquatic and terrestrial mammals is driven by life traits: A systematic review and meta-analysis

“…Indeed, urbanization is increasingly identified as a potential driver of infectious disease emergence as it can change host spatial dynamics and pathogen transmission patterns in ways that are unpredictable (Neiderud, 2015;Hassell et al, 2017). For example, urban landscapes may alter host-pathogen dynamics directly by changing the way pathogens move through a system, or indirectly through changes to host immunocompetence or behavior (Brearley et al, 2013;Brunton et al, 2020). Urbanization has been shown to increase individual dispersal between troops in the banded mongoose (Mungos mungo), which may heighten the transmission risk of pathogens that spread through close contact (Verble et al, 2021).…”

Qiviut cortisol is associated with metrics of health and other intrinsic and extrinsic factors in wild muskoxen (Ovibos moschatus)

“…The impact of some of these factors on GC levels has previously been highlighted in other wildlife species [e.g. anthropogenic activities and disturbances ( Ewacha et al, 2017 ; Périquet et al, 2017 ; Santos et al, 2018 ), predation risk ( Brunton et al, 2020 ; Lavergne et al, 2020 ), weather conditions and events ( Cizauskas et al, 2015 ; Fardi et al, 2018 )]. These factors could not be included in our analyses but are likely important drivers of physiological stress in muskoxen, which are crucial to understand in the context of accelerating climate change.…”