52 NEBRASKAland • JULY 2015
false maps actually dominated their
catch and that the species was not as
threatened as originally believed.
Seeing Patterns
Still, with only two rounds of
sampling, it might be too early to
make any meaningful conclusions on
the Missouri River and the state of its
turtles. But Ruskamp and Mestl are
seeing some interesting things. For
example, segments one (Niobrara) and
four (Brownville) have more snapping
turtles than segments two (Ponca) and
three (Blair). "Those are two of the
most productive fish reaches, one and
four. Is that cause and effect? I don't
know. But those are the two healthiest
reaches from several standpoints mostly
because of the tributaries. The Niobrara
dumps in all that sediment and nutrients
in one, and then the Platte dumps in
sediment into segment four," said
Mestl. However, they are only seeing
this pattern in snapping turtles. The
same does not hold for other species.
"We turn around and look at
false map turtles and there were
almost 1,000 caught in segment two
throughout the six years, compared
to about 460 in segment one," said
Ruskamp. Segment two does not
provide the same nutrients that the
Niobrara supplies in segment one, but
for unknown reasons, it is "false map
heaven," indicating that false maps
may require different habitat conditions
than snapping turtles.
Nebraska's two softshell species
also do not mirror one another.
Spiny softshell turtles do better in
the channelized river than smooth
softshells.
"Softshells fascinate me," said Mestl.
"In the unchannelized river (segments
one and two), we don't have very big
populations, but they're similar. Then
we get into the channelized river, and
we have one species but not the other
– no smooth. So there's something
going on there that we can probably
talk about once we find out more about
both turtles' life histories."
The team is also learning about
turtle movement and other behavior in
ways that few researchers have seen
In one of the traps, biologists found a common snapping turtle, two softshell turtles, a channel catfish and an eaten common carp.
