of the Amazon westward as far as northeastern Peru
and Bolivia. The species has suffered serious population
reduction throughout most of its range and is today
probably most numerous in the eastern part of its range.
The other caiman species are the Cuvier’s Dwarf Caiman
(Paleosuchus palpebrosus), and Schneider’s Dwarf
Caiman (P. trigonatus), both of which are found in the
Orinoco and Amazon Basins; the Yacare, or Paraguayan,
Caiman (Caiman yacare; plate 12- 24), common in
southern Amazonia and southward to Argentina and
Uruguay; and the Broad- snouted Caiman (C. latirostris),
found in southeastern South America.Turtles
Turtles are evolutionarily ancient animals; the turtle
body is a unique anatomical assemblage that has
impressively stood the test of deep time. The largest
known fossil turtle, appropriately named Stupendemys,
with a carapace (upper shell) in excess of 2 m (6.5 ft)
long, is known from the Pliocene in Venezuela.
You may not see many turtles when you visit Amazonia.
There are only about 20 species, considerably fewer than
inhabit the Mississippi River and its tributaries. Here are
some examples.
Amazonian turtles belong to a relatively ancient
group, called side- necked turtles (Pelomedusidae),
that dates back to the Cretaceous period. Side- necks
do not pull their heads directly back under their shells
but rather tuck them sideways. Otherwise, side- necked
turtles look similar to other freshwater turtles. The
prehistoric- looking Matamata (Chelus fimbriata) is an
imposing turtle with a highly ridged shell and flattened
head that somewhat resembles a snapping turtle. It isa bottom dweller that is frequently caught in fishing
nets but, because it does not emerge to sun itself, is not
often observed by ecotourists.
Riverbanks, at least in some areas, are often lined with
basking Arran Turtles (Podocnemis expansa). A giant
turtle species that reaches 1 m (3.3 ft) in length and
can weigh in excess of 45 kg (100 lb), it was at one time
vastly abundant. When Henry Walter Bates explored
Amazonia in the late 19th century, he commented
on the abundance of this huge turtle and how good it
tasted: “Roasted in the shell they form a most appetizing
dish.” Bates also said he was “astonished” at the skills of
the Amazonian indigenous people in shooting turtles as
well as collecting eggs. They not only hunted the turtles,
they kept many captured individuals penned for later
use as food. Unfortunately, Arran Turtles have been
seriously reduced by hunting for both their meat and
their eggs. The species is now considered endangered
and is seen in only a few protected reserves. The most
commonly seen turtle along Amazonian rivers today
is the Yellow- spotted River Turtle (Podocnemis unifilis;
plate 12- 27). This species reaches a length of about 68
cm (about 27 in), and is thus far smaller than the giant
Arran.Birding along Rivers and Streams
As rivers cut through rain forests and flow along
marshes, as they intertwine with streams and oxbows,
they provide excellent opportunities and vantage
points for observing bird activity. There are numerous
birding- dedicated trips that are based entirely onPlate 12- 27. This Yellow- spotted River Turtle has a hood ornament of sorts. Photo by Sean Williams.chapter 12 cruising the rivers to the sea 219