----- the absence of predators, birds can be trained to call for help.
In
Wrens didn't flee from unfamiliar sounds. But after training, they usually---------- so.
did
This is a useful skill, given ----- hard it can be to see predators.
how
The sites ---------- from single hamlets to large villages.
covered
lined
ranged
graded
Birds learn life skills in various ways. .....some of what they know is innate, some is acquired.
While
Such a narrow focus can ------ to problems.
cause
trigger
result
lead
Researchers --------- satellite images and identified 81 ancient sites.
scoured
sought
peered
probed
An obsession with achieving goals is a common--------- of life in many parts of the world.
point
feature
matter
character
Deforestation has helped reveal evidence, mainly in the ---------- of earthworks.
Form
Feature
Model
Pattern
Birds can learn unfamiliar calls,----------- the bird that made that call even being visible.
without
People are encouraged to ------- goals and then strive to achieve them.
set
lay
fit
mark
In one recent study in a ---------- remote region of the Amazon,....
virtually
roughly
relatively
practically
It is believed European diseases arrived in the area ,even before Europeans ever ------- foot in the area.
put
stepped
left
set
Individual birds learn from each other --------- than through direct experience.
Rather
These accounts were subsequently --------------- as fantasies.
Denied
Dismissed
Declined
Dispelled
The discoveries have added ---------- to the idea the population of the Amazon were much greater than once thought.
weight
size
force
charge
Birds listen to the alarm calls of other species ,---------- it possible for them to take advantage.
making
The research team also came --------- fragments of ceramics.
over
through
across
about
The first Europeans to travel to the Amazon region ------------ seeing widespread settlements.
reported
notified
informed
announced
There are many eyes looking out ------- danger.
for