Animals brought into cities are starting to behave in quite brazen ways all over the world and are shocking humans (they may have the same ‘opinion’ about us).
Os urban monkeys in New Delhi they are so bold that they steal lunch directly from the plate.
If you have already been to new Yorkyou’ve probably already seen squirrels try to do the same.
Os Sydney white ibises They earned the nickname “garbage chickens” for stealing trash and sandwiches.
This brazen behavior is not normal for most species in the field. However, it appears increasingly in urban wildlife.
Several studies have already shown that animals living in urban environments around the world exhibit common sets of behaviors. At the same time, these urban animals are losing characteristics they would need in the wild.
This process of urban animal behavior becoming more similar is known as “behavioral homogenization”and accompanies the loss of species diversity with urbanization.
In a new study, recently in PLOS Biologyanimals were studied in urban contexts to understand how humans can help wildlife thrive in an urbanizing world.
In an article in , researchers detail the causes and long-term consequences of these behavioral changes for urban wildlife.
What makes animals in cities similar?
Cities, despite their local differences, share many of the same characteristics across the world: they are hotter than the surrounding countryside, noisy, light polluted and, most importantly, dominated by people.
New York squirrels, New Delhi monkeys, seagulls in UK coastal cities and other urban wildlife… all learned that people are a source of food.
Because people typically do not harm animals (directly), animals living in cities learn not to be afraid of people.
Cities also drive evolution. Humans and the changes we have brought to cities have led to the survival of bolder animals, and these bolder animals pass on their characteristics to future generations.
In genetics, scientists refer to this as the environment “select” these characteristics.
Cities select intelligent individuals and species because that is what they are necessary to survive.
Animals can behave similarly in cities because they learn from each other how explore new human food sources.
For example, the .
Buildings and bridges in cities become homes to bats, birds and other urban dwellers, at the expense of learn to use nesting sites more natural. Roads and aqueducts change how and where animals move.
While rural animals may forage in various locations and eat a variety of foods, urban animals may concentrate in garbage containers or dumpsters where they know they can find foodbut end up having a potentially unhealthy diet.
Consequences of similar behaviors
The loss of behavioral diversity is happening everywhere humans increase their presence in nature. But this is worrying on several levels.
At the population level, behavioral variation may reflect genetic variation. Genetic variation, in turn, gives species the ability to respond to future environmental changes. For example, for animals that have evolved to reproduce at a specific time of year, urban heat islands may select for earlier reproduction.
Reducing genetic variation leaves populations less capable to respond to future changes.
Furthermore, as animals become more docile, new conflicts between animals and humans.
For example, there may be more car accidents, animal bites, property damage and transmission of zoonotic diseases. Such conflicts have financial costs and can harm both animals and humans.
The loss of behavioral diversity is also worrying for conservation.
When a species loses behavioral diversity, loses resilience in the face of future environmental changes in the wild, making it more difficult to reintroduce urban animals into the wild.
Losing behavioral diversity also risks erase socially learned behaviorspopulation-specific, such as local migratory routes, foraging techniques, tool-use traditions or vocal dialects.
For example, Australian regent honeyeater populations have been declining and are critically endangered. The isolation of having fewer of their own species around has disrupted normal song learning behavior, making it more difficult for males to sing attractive songs that help them find mates and reproduce successfully.
Behavioral homogenization is causing wildlife in cities like Los Angeles, Lima, Lisbon and Lahore to behave in similar ways, despite living in different environments and having distinct evolutionary histories.
Many of these behaviors influence survival and reproduction, so understanding this form of diversity loss is important for effective wildlife conservation as well as future urban planning.
