Australian parrots and their adaptation to habitat change
their adaption to habitat change
thích nghi của chúng đối với thay đổi về môi trường sống
are found across the trophic
southern hemisphere continents
except Australia
but nowhere do the display such a richness of diversity and form as in Australia
one-sixth
the world's parrot species
are found there
has long been renowned for
the number and variety of its parrots
16th century
cartographer
made a world map that
included a place
somewhere near
present-day Australia
that he named...
the land of...
first European settlers in Australia
often
referred to the country as parrot land
the celebrated British naturalist
wildlife artist
no group of birds
gives Australia so tropical
benign an air as numerous species of...
great family
which it is tenanted
descendant
an ancient line
due to
great diversity
most species
inhabit Africa
it seems almost certain
originated
millions of years ago
ancient southern continent
broke up into
the seperate southern hemisphere continents
we know today
much of Gondwana
comprised
vast rainforests
intersected by
huge
slow-flowing rivers
expansive lakes
but by...
eight millions years ago
great changes
underway
center
continent
had begin to
dry out
rainforests that once...
covered it
gradually contracted to...
the continental margins
to a limited extent
still exist today
creatures
remained in
shrinking rainforests
had to
adapt to
the drier conditions
face extinction
reacting to
desperate circumstances
parrot family
typically found in
jungles
in other parts of the world
has populated
some of the...
harshest's environments
spread from
ancestral forest
through
eucalypt woodlands
conlonies
central deserts
as a consequences
diversified into
a wide range of species
adaptations
reflect
the many changes
animals and plants
had to
make to
survive in
evolutionary pressures
helped
mould keratin
substance
from which
breaks are made into a range of tools
capable of
gathering the new food types
favoured by
various species of parrot
short
blunt beak
length
do curved
upper section
are related to
the type of food
each species
eat
comparatively long beaks
extracting seeds from fruit
broader and stronger beaks
are designed for
cracking hard seeds
differently shaped beaks
the only adaptions
that have been made
during the developing relationship
food plants
like all of australia's many...
honey eating birds
the rainbow coloured lorikeets
the flowers on which
they feed
long coevolved with
features
such as
the shape and the color of flowers
adapted to
particular needs
physical a example
most attractive colour to birds
and thus
depend on birds for...
pollination
are more often red
collect as much pollens as possible
most of...
inhabit woodland and open forest
their numbers decline towards both deserts and wetter areas
the majority are nomadic
to some degree
moving around
take advantage of
feeding and breeding places
two of the...
dry country parrots
pink and grey
galah
corella
have expanded their ranges
in recent years
are among the speicies
have adapted well to
brought about
Eropean settlement forest
telling
thrive
other parrot species did not fare so well
when their environments were altered
the clearing
large areas of rainforest
is probably
responsible for
disappearance
double-eye fig parrot
ground parrots