Since the publication of Tales of Giant Snakes (Murphy and Henderson, 1997),
much of what we know about the largest snakes in the world has changed. The fossil
record has revealed remains of a truly colossal snake, Titanoboa, that was living in
northeastern Colombia 58 to 60 Ma. Evidence and hypotheses about how snakes
evolved their giant size have become more detailed, and ecological field studies of
giant snakes have become much more common. Giant and near-giant snakes are
more popular than ever in the pet trade; these “designer snakes” are bred in captivity
for their unique colors and patterns. The novelty skin industry is consuming giant
snakes in higher numbers than ever before. Giant snakes have become invasive in
southern Florida. Of lesser importance, the record Murphy and Henderson (1997)
considered as representing the largest known extant snake has proved to be false. This
has happened to many previous records believed to be valid. Extant giant snakes do
not get as long or as massive as most people think based on the liberal acceptance of
old and unreliable records that have been published and republished for many years.
Murphy and Henderson (1997) defined giant snakes as those species that exceed
20 feet (6.1 m). In this book, we will continue with that definition for giant species
and describe the near-giant species as those that approach 6.1 m, but may not reach
it. At this point, the extant giant snakes appear to be the Green Anaconda (Eunectes
murinus) of South America, the Reticulated Python (Malayopython reticulatus) and
Burmese Python (Python bivittatus) of Southeast Asia, the South African Python
(Python natalensis), North African Python (Python sebae) from sub-Saharan Africa,
and Kinghorn’s Scrub Python (Morelia kinghorni) of northern Australia.
Near-giants are the Indian Python (Python molurus), and the Western Olive
Python (Liasis olivaceus barroni) from northern Australia. Other species that obtain
significant size are discussed: the Oenpelli Python (Simalia oenpelliensis) from
Australia, the Papuan Python (Apodora papuana) from New Guinea, and the Cuban
Boa, (Chilabothrus angulifer). A discussion of the Boa Constrictor (Boa constrictor)
is included, not because it’s a giant snake—but because so many people think it is!
On March 6, 2015, the U.S. Fish and Wildlife Service (USFW) finalized the
Constrictor Rule, a controversial policy designed to reduce the probability that
more invasive constricting snakes will find their way into ecosystems in the U.S.
The Constrictor Rule declared the Reticulated Python, DeSchauensee’s Anaconda,
Green Anaconda and Beni Anaconda as “injurious” under the Lacey Act. A fifth
species, the Boa Constrictor, was removed from consideration for listing as an injurious
wildlife species after an outcry from keepers of pet snakes and their lobbying organization, the United States Association of Reptile Keepers (USARK), applied
political pressure for the Boa Constrictor removal from the listing.
The rule sparked considerable controversy because these species are in the pet
trade and the designer snake industry, and some are already established as invasive
species in southern Florida. This book is not intended to be a platform for political
activism. It is about science, natural history, and how humans and exceptionally large
serpents relate to each other. Both authors have kept giant and near-giant snakes in
captivity for decades, and we can sympathize with those who want to maintain and
breed giant snakes in captivity. They are amazing animals, and there is much to be
learned from their lives in captivity as well as in the wild. Keeping them in captivity
is challenging because of their size and food requirements, and we discuss this at
length in one of the chapters. However, in a foreign landscape, they are capable of
devastating the local fauna. The argument for keeping giant snakes in captivity can
be reduced to individual rights versus the common environmental good.
This book is not a reworked Tales of Giant Snakes. It is an updated look at the
scientific and popular literature, as well as personal experiences and those of people
the authors know. It is intended to provide a context for giant snakes and their many
relationships with humans.
If you are a reader unfamiliar with the term clade, it refers to an ancestor and
all of its descendants. Clades by definition are monophyletic; that is, they have one
ancestor. Thus, a group of species that shared a common ancestor forms a clade.
In traditional classification, a genus is a clade. In traditional classification, all the
members of a family, in theory, should share a single ancestor, making it also a clade.
Although this book was written for the general public, we have included a section
targeted to people who keep giant snakes as pets but may not be as familiar with
them as we are. Generating an appreciation of giant snakes, their evolution, and the
science that builds knowledge of the natural world are also on our list of goals for
this book.
Common English and scientific names are provided. The scientific name is
followed by the name of the person(s) who originally described the species. If the
person’s name is in parentheses, it means the species is now placed in a different
genus than it was when it was first described.
The maps were made using ArcView, with localities obtained from VertNet and
the literature. Climatic map data were obtained from GLDAS (Global Land Data
Assimilation System).