The Speckled Caiman in Puerto Rico:
Assessing abundances and densities
of an unstudied invasive species.
J. Aaron Hogan
Department of Environmental Science, University of Puerto - Rico
The Speckled Caiman
was introduced to the
coastal ecosystems of
Puerto Rico in the
Figure 1. Distribution of Caiman crocodilus.
Populations in Florida (USA), Puerto Rico and
Cuba are introduced.—by Velasco, A. and
Ayarzagüena, J. (2010).
Are they far away from us?
Caiman was sighted in at least 18 watershed localities of San Juan.
1) Laguna San José;
2) Quebrada Juan Méndez;
3) Canal Blasina;
4) Sector Bechara in Avenida Kennedy;
5) Caño Martín Peña;
6) Islote Juan Pérez in Piñones;
8) Canal Vista Mar;
9) Canal Flamboyanes;
10) Borinquen Towers;
11) Río Bayamón in Bayamón;
12) Vertedero in Carolina;
13) several other localities in Carolina;
14) Urb. Villamar in Isla Verde;
15) Ave. Roosevelt in Puerto Nuevo;
16) Ciudad Deportiva Roberto Clemente;
17) San Francisco in Río Piedras; and
18) Base Muñiz in Carolina
Figure 2. San Juan Bay Estuary.
Why should we care?
• Caimans have been reported to:
– Prey on numerous vertebrates and
– Be aggressive and dangerous to humans.
– Serve as vector of foreign pathogens and
What do we already know about caiman?
• Let us build on J. Bauza R. Joglar
• WHY NOT
• What is more?
Goals & Hypotheses
• Objective 1: The primary objective of this study is to
document the extent of the introduced caiman population
on the main island of Puerto Rico. ( Such as size, age
and sex structure of the caiman population). This data
can be use for further research of caiman in Puerto Rico.
• Hypothesis 1: We hypothesize that areas with closer
proximity to the point of introduction (Laguna Tortugero,
Manati, Puerto Rico) will have higher overall abundance
and densities of specked caimans. In other words, areas
further west in the SJBE will have more caimans.
Goals & Hypotheses
• Objective 2: Find out the
Caiman habitat with
• Hypothesis 2: We predict
that the speckled caiman
will be more abundant in
disturbed areas. We also
hypothesize that sites
with poorer water quality
will support more
Figure 3. Relationship illustration
Goals & Hypotheses
• Objective 3: Collect a
sub sample of caimans
found throughout the
estuary to investigate a
number of parameters.
Phylogenetic barcoding to verify
species, caiman health
• Hypothesis 3: We will
Figure 4. Different species of Caiman
• Population quantity investigate
– Spotlight boat surveys
• Conduct a series of pre-planned nightly spotlight
• WE WANT TO SEE CAIMANS. WE WILL COUNT
THEM AND COLLECT DATA
– Body form observation
• We will approach caimans and estimate their total
length, tail length, header size, gender, etc,. The
size records will be divided into 4 categories and
use to speculate their age
• Species identification
– Census counts
• We will document caimans and identify them to the
best of our ability.
• Population Viability Analysis (PVA)
– Sample collection & Genetic analysis
• We propose to collect a subsample of 50 caimans.
• We will collection some tissue in order to identify
genetic diversity. PHYLOGENTIC
• American crocodiles are speculated to be living in
• Water quality assessment
– We will link water quality data from
estuario.org (SJBE program)
• SJBE program has an extensive of water quality
• Scientific obligation
– Link GIS land cover urbanization data
• Extent of urbanization data are available. We
would like integrate into ULTRA (if possible)
Otherwise community involvement is our focus!
• Many projects and offer an great opportunity for
citizens to integrate into the environment.
– BIG TICKET IN PUERTO RICO
• High population densities
– WHAT IS URBAN ECOLOGY?
• ALONZO RAMIREZ
• Biotic homogenization
– URBAN CAIMAN ECOLOGY
• THIS IS EVERYTHING! Por que no?
– Opportunities for research and resume
• We seek to employ anyone and everyone
who is willing to volunteer.
• Experience la naturaleza at night. Why
not count caimans…
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