SEASONAL FOCUS
Destruction of nature is creating the perfect conditions for the next pandemic Billy Flynn wonders if urban living is a threat to the wild species around us but also, could they be a threat to us?
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f you live in a city, whatever the size, it is likely that at some stage you’ve taken pleasure – or maybe even delight – in some of the wild species that share this built space with you and the other humans. Finding out what wildlife dwells in the midst of the streets and buildings is one of the things that natural history enthusiasts never seem to tire of. Over years of attending (and occasionally leading) IWT events in Dublin, it was heartening to see the thrill that participants took from finding otter scats near the River Dodder or birds that travel thousands of kilometres to over-winter at a site within the busiest part of the city centre. I have often been asked what it is about certain species that allows them to thrive in these least natural of places when others cannot. A corollary question is: why do they live here? Another question that I have often considered, when looking at our litter, waste and bright street-lighting is, does city living harm the wild species that dwell among us? One question that never occurred to me was whether these new neighbours could be harmful to us. A recent paper in Nature (August, 2020) has examined all these questions with the widest-ranging study of its kind so far and the answers give cause for concern. The study looked at nearly 7,000 ecological assemblages and 376 species and how our 24
urbanisation has affected them. The results showed that the advances of the urban area and farmland into the wilds disproportionately affects larger species. This leaves the smaller and more adaptable species more likely to survive and to be the ones sharing our built-up spaces. Another key finding is that these species are far more likely to be the ones carrying zoonotic pathogens (diseases-causing organisms that can ‘jump’ from animal to human hosts). The degree to which this occurs is highly significant. Known wildlife hosts of human-shared pathogens and parasites overall
were shown to comprise a greater proportion of local species richness (18–72% higher) and total abundance (21–144% higher) in sites under substantial human use (secondary, agricultural and urban ecosystems) compared with nearby undisturbed habitats. How this effect was found in different animal groups varied but was strongest in rodent, bat and passerine (perching) bird host species. These are the ones that we must focus on. An interesting (and disturbing) aspect of the study was that conversion of wild areas to farmland and not just urbanisation is as significant
Irish Wildlife Autumn ‘20
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