Geoscience Reference
In-Depth Information
tinction of their theropod relatives 65 million years ago, continued to be dinosaurs.
Accordingly, they also made traces that overlapped in size with those of Mesozo-
ic dinosaurs, such as the tracks and nests of theropods and ornithopods. Moreover,
these bird traces reflect myriad behaviors that also may have been shared by their
non-avian predecessors, giving ussearch images fortrace fossils that might beused
tointerpret behaviors currently unknownindinosaurs.Forinstance, imagine thein-
credible coolness of finding a Cretaceous trace fossil consisting of a series of de-
pressions linked by a network of trails and realizing that it might be analogous to a
kakapowooingtrace,perhapsprovidingakeytounderstandingadinosaur'smating
behavior.
Thus, knowing about this evolutionary history of avians helps us observers of
present-day traces better appreciate that every bird track, nest, probe, splatter, or
other mark reflects a rich evolutionary history linked to a dinosaurian past that is
minimally 160 million years old. Yes, birds have certainly changed and diversified
enormously since the Jurassic, as well as spread throughout the world, occupying
land,sea,andair.YetmodernbirdsalsostillholdinsightstotheirMesozoicorigins,
and the behaviors and traces we observe today might help us to better understand
dinosaurs of the Mesozoic.
Tracking Birds, on the Ground and in the Air
As mentioned before, tracking is a longtime practical activity connected to hunting,
and as a science has great applications toward understanding animal presence and
behavior. Despite all of this, tracking is normally applied to mammals, not birds.
Just to put this in perspective, watch the difference in people's reactions if you say
“I'm going to go track a deer!” versus “I'm going to go track a robin!” I predict the
latter will result in arched eyebrows, double-takes, and quizzical laughter. After all,
the conventional wisdom is that most birds are too small to track, they fly so often
that they do not leave many tracks, and their tracks all look alike.
Wrong, wrong, and wrong. Granted, the tiniest of birds—such as the bee hum-
mingbird (
Mellisuga helenae
) of Cuba, which weighs only about 2 grams (0.07
