Animals lose fear of predators rapidly after they start encountering
humans

Date:
September 22, 2020
Source:
PLOS
Summary:
Most wild animals show a suite of predator avoidance behaviors such
as vigilance, freezing, and fleeing. But these are quickly reduced
after the animals come into contact with humans through captivity,
domestication, or urbanization, according to a new study.



FULL STORY ==========================================================================
Most wild animals show a suite of predator avoidance behaviors such as vigilance, freezing, and fleeing. But these are quickly reduced after the animals come into contact with humans through captivity, domestication,
or urbanization, according to a study led by Benjamin Geffroy from MARBEC (Institute of Marine Biodiversity, Exploitation and Conservation),
publishing September 22nd in the open-access journal PLOS Biology.


==========================================================================
The international team of researchers analyzed the results of 173
peer-reviewed studies investigating antipredator traits (behavioral and physiological) in 102 species of domesticated, captive, and urbanized
mammals, birds, reptiles, fish and molluscs, while taking into account
their position in the Tree of Life.

The scientists found that contact with humans led to a rapid loss of
animals antipredator traits, but simultaneously the variability between individuals initially increases and then gradually decreases over the generations in contact with human. The authors suppose that this two-step process is caused by reduced pressure from natural selection as a result
of living in a safer environment, followed by artificial selection by
humans for docility in the case of domestication.

Animals showed immediate changes in antipredator responses in the first generation after contact with humans, suggesting that the initial response
is a result of behavioral flexibility, which may later be accompanied
by genetic changes if contact continues over many generations. The
researchers also found that domestication altered animal antipredator
responses three times faster than urbanization, while captivity resulted
in the slowest changes. The results also showed that herbivores changed behavior more rapidly than carnivores and that solitary species tended
to change quicker that group-living animals.

The study demonstrates that domestication and urbanization exert similar pressures on animals and can result in rapid behavioral changes. The loss
of anti-predator behaviors can cause problems when those domesticated or urbanized species encounter predators or when captive animals are released
back into the wild. Understanding how animals respond to contact with
humans has important implications for conservation and urban planning,
captive breed programs, and livestock management.

Dr. Geffroy adds "While it is well known that the fact of being protected
by humans decreases antipredator capacities in animals, we did not know
how fast this occurs and to what extent this is comparable between
contexts! We also integrated physiological traits in the study but
they were much less numerous that behavioral traits. We believe they
should be systematically investigated to draw a global pattern of what
is happening at the individual level. We need more data to understand
whether this occurs also with the mere presence of tourists."

========================================================================== Story Source: Materials provided by PLOS. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Benjamin Geffroy, Bastien Sadoul, Breanna J. Putman, Oded
Berger-Tal,
La'szlo' Zsolt Garamszegi, Anders Pape Mo/ller, Daniel T. Blumstein.

Evolutionary dynamics in the Anthropocene: Life history and
intensity of human contact shape antipredator responses. PLOS
Biology, Sept. 22, 2020; DOI: 10.1371/journal.pbio.3000818 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200922144323.htm

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