In Aesop's fable, the city mouse visits his country cousin but finds the hospitality humble. When country mouse accepts an invite to the city, though, their sumptuous repast falls victim to repeated interruptions by cats and other intruders. The moral concludes that "a modest life with peace and quiet is better than a richly one with danger and strife"
This theme arises often in conversations about sustainability: what is the ideal we seek? Are we trying to return to a life like the oft-longed-for "olden days" in which people were free to ply their trades on the land without the complexities of the modern world (at least in the revisionist version enabled through the mirror of distant memories)? Or is the answer to be found in urban density, and more and higher technology?
The philosophical discussion often seeks to start from a premise that "natural" is better. To which end, understanding nature seems to be of the essence. But nature continues to throw curve balls.
A recent study sought to determine if the immune systems of city birds would be suppressed by the stresses of urban living, especially by the dedication of evolutionary resources to the improved cognitive abilities that this life of "danger and strife" demand. As you can see in the video, the urban birds proved to be winners in both capabilities:
The scientists studied Barbados bullfinches, documenting improved problem-solving capabilities and boldness among birds from urban environments, as well as being surprised to find that immune system performance in city birds outranked that of their country counterparts. The scientists had hypothesized that the evolutionary cost of acquiring problem solving powers would have competed with immune system evolution, to the disadvantage of the latter.
In the video, lead author Jean-Nicolas Audet, a Ph.D student in the Department of Biology at McGill University, concludes: "It seems that in this case, at least, the urban birds have it all."
The report also indicates that urban birds are less open to new things, which scientists had not predicted. Although it seems that the frequency of exposure to new threats that might be found in the more diverse urban environment would precondition a sort of anxiety about anything unknown.
Understanding the trade-offs which "nature" has programmed into the manner in which natural organisms confront changes in their environments will be essential to ensuring sustainability in the face of humanity's uncertain future. In this case, the better "natural" outcome appears to be the one we might associate with the "unnatural" urban experience.
Read the original study here (behind a pay-wall):
"The town bird and the country bird: problem solving and immunocompetence vary with urbanization" Jean-Nicolas Audet, Simon Ducatez and Louis Lefebvre, Behavioral Ecology, http://doi.org/10.1093/beheco/arv201