Download What is the meaning of the term “apex predator”? What is the

What is the meaning of the term “apex predator”?
Apex Predators are predators with no predators of their own, residing at the top of their food
chain. Zoologists define predation as the killing and consumption of another organism
(excluding parasites and bacteria). In this context, "apex predator" is usually defined in terms
of trophic dynamics. Apex predator species occupy the highest trophic level(s) and have a
crucial role in maintaining the health of their ecosystems. The apex predator concept is
commonly applied in wildlife management, conservation, and ecotourism.
Apex predators affect prey species' population dynamics. Where two competing species are in
an ecologically unstable relationship, apex predators tend to create stability if they prey upon
both. Inter-predator relationships are also affected by apex status.
What is the meaning of the term “keystone species”?
A keystone species is a species that has a disproportionately large effect on its environment
relative to its abundance. Such species play a critical role in maintaining the structure of an
ecological community, affecting many other organisms in an ecosystem and helping to
determine the types and numbers of various other species in the community. An ecosystem
may experience a dramatic shift if a keystone species is removed, even if that species was a
small part of the ecosystem by measures of biomass or productivity.
Are prey species in danger of extinction due to hunter species, such as wolves?
Wolves feed on prey species, but in most cases they manage the overall population, keeping
the different species’ numbers stable. In this sense, their contribution to the ecosystem is
positive. Moreover, when comparing the effect of human hunting to that carried out by
wolves, the results are self-explicatory: humans contribute much more heavily to the
elimination of various species than all hunter species combined.
Why do wolves howl?
To express themselves, wolves make use of a wide repertoire of growls, barks, whines, and
squeals to communicate. However, the most famous method of communication is the howl.
Wolves howl for any number of reasons. They may wish to attract a mate, bring the pack
together, express sorrow and mourn, or even inform members of their own pack of their
whereabouts. They may howl before a hunt, after consuming a kill, or when an intruder is
present. Wolf pups may howl in distress or after they have been playing. Experienced
observers note that there are different types of howls used for different occasions and ranging
in duration from one to ten seconds. Across open territory, a wolf howl can be audible for ten
miles. Such communal howls confuse listeners into believing they hear many more wolves
than are actually howling.
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Humans and wolves: friends or foes?
Some thousands of years ago, humans decided to tame wolves in order to use them for
hunting and guarding purposes. Some scientists argue that humans adopted those wolf pups
that were less aggressive and better at begging for food. Thus, succeeding generations
survived thanks to humans and became increasingly tame. Still, at the molecular level not
much changed at all: The DNA of wolves and dogs is almost identical. However, in fables
and fairy tales wolves have traditionally represented the evil. This trend especially escalated
during the Middle Ages, leading wolves very close to extinction. Thus, from friends, humans
and wolves ended up to be foes.
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Vassiliki Markaki ©