The COVID-19 pandemic and the subsequent shutdowns in many regions around the world offered a new “human-less” environment for urban wildlife in 2020. In their latest research, Benson et al. share their findings from tracking mountain lion movements in greater Los Angeles, USA during spring 2020.
Early on during the global pandemic, ecologists quickly realised that changes in human behaviour and activity brought on by COVID-19 presented a unique opportunity to learn about human-wildlife interactions. We know that animal behaviour is strongly influenced by humans, but we still do not understand the degree to which animals respond to human activity directly or to human infrastructure, such as roads and buildings.
As people sheltered-in-place to reduce the spread of the virus, speculation in the media and among the public fuelled the perception that wildlife were expanding their ranges and “reclaiming” cities. Ecological theory however, predicts that animals should use the smallest areas within which they can acquire the resources they need to survive and reproduce, such as food and cover.
We saw the pandemic park closures during the spring 2020 California stay-at-home order as a rare chance to see how urban wildlife respond when human activity was dramatically reduced by tracking mountain lion activity along the massive human footprint in greater LA.
In our recent study, we show that resident mountain lions used smaller areas and moved shorter distances with fewer humans in LA area parklands, very much in accordance with ecological theory.
Mountain lions are elusive and remarkably good at staying out of sight of humans – even in LA, the second most populated metropolitan area in the United States. With people staying indoors, mountain lions were able to move more efficiently as they were not constantly trying to avoid humans.
Our findings also suggest that mountain lions generally respond more strongly to humans themselves rather than to human infrastructure, as the animals moved closer to trails, development, and other places that were usually occupied by humans prior to the pandemic.
However, consistent with previous findings from the same population, it is important to note that mountain lions still very rarely entered urban areas. In fact, on average, mountain lions were located almost a kilometre from the nearest development.
Large freeways remained a barrier to movement
Other research has shown that mountain lions in the greater LA area are isolated and inbred because freeways and urbanization act as barriers to their movement – and despite substantially reduced traffic during spring 2020, the new study found no evidence that mountain lions crossed roads more frequently.
This was also consistent with previous research in the LA area indicating that mountain lions are highly conditioned to avoid freeways, such that the reduction in traffic appears to have been insufficient to lead to significant changes in road crossing behaviour.
Implications of inefficient movement by top predators
The reduction in area used and shorter distances travelled by mountain lions during spring 2020 imply that “normal” human activity causes them to move inefficiently. Such inefficiency by top predators may have far-reaching implications for wildlife ecology and conservation.
For example, mountain lions studied in this research are threatened with local extinction in the Santa Monica Mountains due to their isolation from nearby populations. Expending additional energy while navigating human disturbance could add additional stress to a population already threatened by both genetic and demographic factors in the human-dominated landscape of LA.
Our findings highlight the importance of considering some of these cryptic, indirect costs associated with reduced movement efficiency when managing conservation efforts for large carnivores in anthropogenic landscapes.
Read the full article: “Mountain lions reduce movement, increase efficiency during the Covid-19 shutdown” in Issue 2:3 of Ecological Solutions and Evidence.