Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 February 2024 | 16(2): 24760–24768
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.8755.16.2.24760-24768
#8755 | Received 28 September 2023 | Final received 04 February 2024 |
Finally accepted 15 February 2024
First confirmed reproduction by a
translocated female Siamese Crocodile Crocodylus
siamensis (Crocodylidae:
Crocodilia) with observations of nest attendance and
nest-associated fauna
Steven G. Platt 1, Sounantha Boutxakittilath 2,
Oudomxay Thongsavath 3,
Samuel C. Leslie 4,
Lonnie D. McCaskill 5,
Randeep Singh 6 & Thomas R. Rainwater
7
1,2,3,4 Wildlife Conservation Society–Lao
Program, P.O. Box 6712, Vientiane, Lao PDR.
5 Wildlife Conservation Society,
Prospect Park Zoo, Prospect Park Zoo, 450 Flatbush Avenue, Brooklyn, New York
11225, USA.
6,7 Tom Yawkey
Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest
Science, Clemson University, P.O. Box 596, Georgetown, South Carolina 29442,
USA.
1 sgplatt@gmail.com, 2 sboutxakittlah@wcs.org,
3 oThongsavath@wcs.org, 4 sleslie@wcs.org, 5 lmccaskill@wcs.org,
6 usalligator55@gmail.com, 7 trrainwater@gmail.com
(corresponding author)
Editor: Raju Vyas, Vadodara, Gujarat, India. Date
of publication: 26 February 2024 (online & print)
Citation: Platt,
S.G., S. Boutxakittilath, O. Thongsavath,
S.C. Leslie, L.D. McCaskill, R. Singh & T.R. Rainwater (2024). First
confirmed reproduction by a translocated female Siamese Crocodile Crocodylus siamensis
(Crocodylidae: Crocodilia)
with observations of nest attendance and nest-associated fauna. Journal of Threatened Taxa 16(2): 24760–24768. https://doi.org/10.11609/jott.8755.16.2.24760-24768
Copyright: © Platt et al. 2024. Creative Commons Attribution 4.0 International
License. JoTT
allows unrestricted use, reproduction, and distribution of this article in any
medium by providing adequate credit to the author(s) and the source of
publication.
Funding: Agence Française de Dévelopement, European Union, St. Augustine Alligator Farm, and Wildlife Conservation Society.
Competing interests: The authors declare no competing interests.
Author details: Steven G. Platt is the associate conservation herpetologist with Wildlife Conservation Society (WCS) in Southeast Asia. He is responsible for conservation projects involving endangered turtles and crocodilians in Myanmar, Laos, Cambodia, and Thailand. Sounantha Boutxakittilath is the chief biodiversity conservation officer with the WCS-Lao Program in Savannakhet and responsible for all aspects of the Siamese Crocodile Conservation Project. Oudomxay Thongsavath is the project manager for the WCS Savannakhet Landscape Program and directs efforts to protect and restore wetlands in and around the Xe Champhone Ramsar Site. He is currently enrolled in a graduate program at Cornell University in New York, USA. Samuel C. Leslie worked for over a decade on conservation projects in the Mekong Basin, facilitating participatory management and governance of wetland biodiversity. He served as the technical director for WCS Savannakhet Landscape Program between 2019 and 2023 and is currently pursuing graduate education in the United States. Lonnie D. McCaskill was the assistant director and general curator for the WCS Zoological Programs in New York until his retirement in 2023. He was formerly the AZA Studbook Keeper for Siamese Crocodile, and currently serves as the IUCN Crocodile Specialist Group Co-chair for Southeast and South Asia. He has been involved in translocating Siamese Crocodiles in Cambodia and Laos since 2004. Randeep Singh is a
wildlife biologist with Clemson University’s Baruch Institute of Coastal Ecology and Forest Science in Georgetown, South Carolina, USA. Since 2019, he has conducted research on the nesting ecology of American alligators in coastal landscapes. Thomas R. Rainwater is a
research
scientist with the Tom Yawkey Wildlife Center and Clemson University’s Baruch Institute of Coastal Ecology and Forest Science in Georgetown, South Carolina, USA. Much of
his current research focuses on the biology, ecotoxicology, and conservation of crocodilians.
Author contributions: Steven G. Platt—Conceived and designed the study, conducted fieldwork, analyzed data, wrote the manuscript, and secured funding. Sounantha Boutxakittilath—Conducted fieldwork, analyzed data, and assisted with manuscript preparation. Oudomxay Thongsavath—Conducted fieldwork, assisted with manuscript preparation, and secured funding. Samuel C. Leslie—Conducted
fieldwork and secured funding. Lonnie D. McCaskill—Conducted fieldwork and assisted with manuscript preparation. Randeep Singh—Designed the study, analyzed data, prepared figures, and assisted with manuscript preparation. Thomas R. Rainwater—Conceived and designed the study, analyzed data, prepared figures, and wrote the manuscript. All authors reviewed and approved the final draft of the manuscript.
Acknowledgements: Our Government of Lao
counterparts at the Provincial and District Offices of Agriculture and Forestry
in Savannakhet Province are thanked for facilitating
fieldwork. Cassandra Paul, Kent Vliet, Lewis Medlock, and Ruth Elsey provided
literature, Robert Tizard identified many of the birds photographed by our
camera trap, and insightful comments by Lewis Medlock improved an early draft
of this manuscript. Finally, the many VCT members deserve special mention for
their field assistance, enthusiasm, and continuing dedication to crocodile
conservation in Laos. This paper represents technical contribution number 7221
of the Clemson University Experimental Station.
Abstract: The Siamese Crocodile Crocodylus siamensis
is considered one of the most imperiled and poorly-studied crocodilians in the
world. Translocations (reintroductions) - often in conjunction with
head-starting of juveniles - are a critical component of efforts to restore
viable wild populations of C. siamensis. We
here report the first confirmed nesting by a known-age, head-started, and
translocated female C. siamensis together with
observations of nest attendance and nest-associated fauna based on camera trap
imagery. Our observations occurred in the Greater Xe Champhone Wetland Complex (GXCWC) in Savannakhet
Province, Lao PDR. GXCWC encompasses 45,000 ha of seasonally inundated natural
and anthropogenic wetlands, agricultural ecosystems, scrubland, and forest.
While collecting eggs for incubation in May 2022, we were able to identify a
unique series of notched tail scutes on a female C.
siamensis as she aggressively defended a nest.
From these markings we determined the female was hatched on 11 August 2012 (age
= 9.75 years) and released in March 2014, approximately 3.5 km from the nest
site. A game camera placed at the nest on 11 May 2022 and recovered on 5 July
2022 (34 trap nights) recorded 1724 images. These images indicated the female
remained in attendance at the nest throughout the monitoring period. Camera
trap imagery captured eight nest repair events and two nest defense events;
during the latter the female defended the nest from village dogs. Eleven
species of nest-associated fauna were recorded by the game camera, including
eight and three species of birds and mammals, respectively. Our observations
are the first confirmed nesting by a head-started, translocated female C.
siamensis indicating these are effective
conservation strategies for restoring wild populations. We also unequivocally
established that head-started female C. siamensis
are capable of reproducing when nine-years-old.
Keywords: Behavior, camera trap,
commensal fauna, conservation, head-starting, Lao PDR, nest defense, nest
predation, reintroduction, Xe Champhone.
Translocations (defined as the
human mediated movement of organisms from one area with release into another
area; IUCN 2013) – often undertaken in combination with captive-breeding and
head-starting of juveniles – are playing an increasingly important role in the
conservation of reptiles, including crocodilians (Germano
& Bishop 2008; Ewen et al. 2014; Burke 2015). In many cases, translocation
may be the only remaining option for reestablishing depleted or extirpated
populations (Marsh & Trenham 2001; Stofer 1999). Among crocodilians, translocation of both
head-started juveniles and adults is a strategy being used to successfully
restore ecologically functional and demographically viable populations of
several threatened species (e.g., Munoz & Thorbjarnarson
2000; Daltry & Starr 2010; Xing 2010; Manalo
& Alcala 2015; Sam et al. 2015; Kar 2022).
There is no standardized
definition of success regarding wildlife translocation because of varying time
scales and differences in life history traits among target organisms (Seddon
1999; Germano et al. 2014; Miller et al. 2014; Burke
2015). However, a translocation can ultimately be considered successful only
when a viable, self-sustaining population becomes established in the wild
(Griffith et al. 1989; Dodd & Seigel 1991). As a first step towards
achieving this objective, translocated individuals must demonstrate competency
in the wild, such that they survive, grow, and reproduce (Alberts 2007; Roe et
al. 2015). Common demographic indicators of near-term success include positive
survival rates and reproduction by founder females (Armstrong & Seddon
2008; Ewen et al. 2014; Miller et al. 2014; Elsey et al. 2015; Platt et al.
2022b).
The Siamese Crocodile Crocodylus siamensis
(Schneider, 1801) is a large (total length [TL] to ca. 4.0 m) mound-nesting
crocodilian that occurs or formerly occurred in freshwater habitats of mainland
Southeast Asia (Thailand, Laos, Vietnam, Cambodia) and the Sundaic
Islands of Java and Borneo (Platt et al. 2019). Populations throughout this
geographic range are now greatly diminished as a result of habitat destruction,
commercial hunting for skins, direct persecution because of perceived danger to
humans and livestock, and illegal collection to stock crocodile farms (Platt et
al. 2019). Consequently, C. siamensis is
ranked as Critically Endangered on the IUCN Red List of Threatened Species and
considered one of the most imperiled crocodilians in the world (Platt et al.
2019). Despite this parlous conservation status, very little is known about the
ecology of wild C. siamensis, including many
aspects of reproduction (Platt et al. 2019). This dearth of information is
lamentable because such basic natural history data are a necessary prerequisite
for designing and implementing effective conservation strategies for endangered
species (Dayton 2003).
In Lao PDR (hereafter Laos), the
conservation status of C. siamensis is
particularly tenuous with small, fragmented populations that show little or no
evidence of recruitment, restricted to Attapu, Khammouane, Salavan, and Savannakhet provinces (Platt et al. 2022a). In the early
2000s, surveys conducted by the Wildlife Conservation Society-Lao Program
(WCS), working in collaboration with the Government of Laos, identified several
small populations of C. siamensis in the Xe Champhone wetlands of Savannakhet Province that would likely benefit from
conservation efforts (Bezuijen et al. 2013).
Importantly, most of these populations already received some degree of de
facto protection from the widespread local belief that crocodiles embody
the spirits of dead ancestors and to harass, harm, or kill a crocodile could
bring divine retribution in the form of misfortune, illness, or even death to
the individual and community (Baird 2001; Platt et al. 2018a). Local
proscriptions protecting crocodiles notwithstanding, numbers were low and
population recruitment was lacking because of poor nesting success.
In 2010, we launched a
community-based crocodile conservation project in Savannakhet
Province with the ultimate objective of restoring a demographically viable
population of C. siamensis in the Greater Xe Champhone Wetland Complex
(GXCWC; Platt et al. 2014, 2022a), which encompasses 45,000 ha of seasonally
inundated natural and anthropogenic wetlands, agricultural ecosystems,
scrubland, and forest (for detailed site description see IUCN 2011; Platt et
al. 2018b). As part of our project, local Village Conservation Teams (VCTs)
search for crocodile nests and assist us with egg collection, incubation, and
head-starting of juvenile crocodiles (Platt et al. 2022a). To briefly
summarize, we search for crocodile nests during May-August, collect the eggs,
and transport these to a village facility for incubation. Upon hatching, we permanently
mark each hatchling by notching a unique series of double and single caudal scutes (Rainwater et al. 2007). We then head-start
juveniles for approximately 32 months (TL ca. 70–100 cm) before releasing them
into a densely vegetated reservoir near Tan Soum
Village (Platt et al. 2014, 2022a). In 2014, we were forced to terminate our
efforts after donor funding was unexpectedly cancelled; however, the project
resumed in 2019 (Platt et al. 2022a). To date (September 2023), we have
translocated 143 head-started C. siamensis
into GXCWC, including 65 and 78 crocodiles released in 2013–2014 and 2022–2023,
respectively.
We here report the first
confirmed nesting by a known-aged, head-started, and translocated female C. siamensis together with observations of nest attendance
and nest-associated fauna based on camera trap imagery. We broadly define nest
attendance as a suite of parental behaviors that includes females maintaining
and defending the nest, remaining near the nest, opening the nest when eggs
hatch, and transporting hatchlings to water (Merchant et al. 2018; Murray et
al. 2019). We follow Merchant et al. (2014) and characterize nest-associated
fauna as wild and domestic vertebrates present on or in close proximity to the
nest mound. We then categorize these associations according to Rainwater et al.
(2024) as 1) feeding/foraging – the animal probed the nesting substrate,
pursued prey or actively consumed food items on or near the nest; 2) loafing –
the animal slept, sat, stood, rested, or preened (birds only) on or adjacent to
the nest; 3) traveling – the animal moved across or close to the nest; 4)
predation – an animal removed or attempted to remove crocodile eggs from the
mound for consumption. We classified photorecords of
crocodile behavior and nest-associated fauna as independent detections when the
time interval between sequential photographs was ≥ 30 minutes (e.g., O’Brien et
al. 2003; Ngoprasert et al. 2019).
On 21 May 2022, a VCT found an
active crocodile nest in dense vegetation along the shore of Kout Jek (16.3730°N; 105.2221°E;
elevation = 132 m), an oxbow lake in the Champhone
River floodplain. Accompanied by the VCT, we returned to the nest on 24 May
2022 to collect the clutch. The nest (approximate dimensions = 100 cm wide ×
60–70 cm high) was constructed in a dense thicket (vegetative canopy cover =
100%) at the base of a bamboo clump and on top of a nest mound built during the
previous nesting season (2021), and consisted of leaves, woody debris, and
soil. At the time of our visit the nest was located ca. 5.0 m from the edge of
the lake. We previously visited this nest earlier in the year (15 February
2022) and recovered a clutch of 12 badly decomposed eggs from the 2021 nesting
season. According to the VCT, the nest was inundated by seasonal floodwaters in
July 2021, resulting in the loss of the complete clutch (see Joanen et al. 1977).
When we arrived at the nest (ca.
1500 h; 24 May 2023), the female crocodile (TL ca. 2.1 m) was lying in a
well-defined “form” beneath a tangled mass of vines about 2.0 m away from the
mound. As we drew closer to the nest, she crawled on top of the mound and
exhibited aggressive behavior (loud hissing, forward lunges, and jaw claps)
directed at ourselves (Image 1a–b). When the female ascended the mound, we
could clearly discern the three notched double and single caudal scutes allowing us to determine the identification number
of this individual. A subsequent search of our database indicated the female
crocodile was hatched on 11 August 2012 (age = 9.75 years) and released near
Tan Soum Village in March 2014. The straight-line
distance from the release site to Kout Jek is 3.5 km.
Using long bamboo poles, we were
able to direct the female away from the nest, allowing us to open the mound and
collect the eggs. The clutch consisted of 30 eggs with a mean (± 1SD) length,
width, and mass of 74.1 ± 1.9 mm, 45.3 ± 1.0 mm, and 90.9 ± 4.1 g,
respectively. At the request of the VCT and in accordance with local religious
practices (Platt et al. 2018a), we left three non-viable eggs in the nest to
appease the female crocodile. We transported the remaining eggs to our facility
in Tan Soum Village for processing and incubation.
Based on the presence/absence of opaque bands on the eggshells (Ferguson 1985),
we determined the clutch contained only 2 (6.6%) viable eggs. The extent of
opaque banding on the viable eggs suggested the clutch was deposited between
15–17 May. Prior to departing the nest site, we restored the physical structure
of the mound and mounted a Moultrie Series A game camera on a post
approximately 3.0 m from the nest. This game camera uses motion and passive
infrared sensors to detect wildlife. The Moultrie Series A game camera has a
trigger speed of 0.5 second, a flash and detection range of 21 m, and captures 26 megapixel images. The camera trap was aimed at the nest
and programmed to take three photographs at 1-minute intervals when activated.
In response to rapidly rising seasonal floodwaters that threatened to inundate
the area, we returned and recovered the game camera on 5 July 2022. As during
our initial visit, the female aggressively defended the nest when we
approached. During 34 trap-nights of operation, the game camera recorded 1724
images.
Our camera trap imagery indicated
the female remained in attendance at the nest at least intermittently
throughout the 34-day monitoring period. When present, the female was concealed
beneath the vine tangle where we encountered her on 24 May 2023. Because our
camera was aimed at the nest rather than at the vine thicket, the female
usually escaped detection, but was occasionally photographed when moving. In
some images only the tail or tip of her snout is
visible. Between 28 May and 16 June (1223 to 2113 h), our camera recorded eight
nest repair events during which the female climbed onto the nest and employed
her rear legs to scrape leaf litter, woody debris, and soil onto the flanks of
the mound (Image 2a–c). We assume the nest repair behavior was triggered by our
opening the mound to remove the clutch. Notably, nest repair occurred despite
our careful efforts to restore the physical integrity of the mound after
removing the clutch. We also recorded six instances (1323 to 1826 h; 10 June to
3 July 2023) where the female was atop or beside the mound without effecting
repairs. Finally, our camera recorded two nest defense events (1519 to 1520 h
on 22 June 2023 and 1245 to 1250 h on 4 July 2023) directed towards village
dogs (Canis familiaris
[Linnaeus, 1758]) (Image 3). In both events the dogs approached to within ca. 2
m of the female and nest and then hastily withdrew without attempting to open
the mound. In the second event the female left the nest and pursued the dog for
a short distance (< 2m). Our game camera also recorded eleven species of
nest-associated fauna, including eight and three species of birds and mammals,
respectively (Table 1; Image 4a–h). With the exception of the village dogs, in
no cases was the female observed reacting to the presence of nest-associated
fauna.
To our knowledge, these observations
represent the first confirmed nesting by a head-started C. siamensis released into the wild. Head-starting and
translocation are the cornerstones of C. siamensis
restoration efforts throughout Southeast Asia (Polet
2002; Temsiripong 2007; Daltry
& Starr 2010; Sam et al. 2015), and while reproduction by translocated
females is generally assumed (Platt et al. 2019), confirmation has not been
forthcoming until now. Successful recruitment of captive-reared females into
wild breeding populations has likewise been verified for other species of
translocated crocodilians (Elsey et al. 2000; Larriera
et al. 2006; Elsey 2007; Elsey et al. 2015; Platt et al. 2016; Leiva et al. 2019). Collectively, this growing body of
evidence indicates that captive-reared, head-started crocodilians are not only
able to survive and forage in the wild but also reproduce, suggesting these are
effective conservation strategies for restoring wild populations.
Our observations also
unequivocally establish that head-started and translocated female C. siamensis are capable of reproducing at the age of
nine-years-old. Moreover, if the clutch of decomposing eggs we recovered from
the mound in February 2022 (from the 2021 nesting season) was deposited by the
same female defending the nest in May 2022, she reproduced when only
eight-years-old. Although captive-reared female C. siamensis
on commercial farms in Cambodia and Thailand occasionally begin reproducing in
as little as 6–7 years (Platt et al. 2011; Yosapong Temsiripong, pers. comm.), sexual maturity in the wild is
probably attained between 10–15 years or perhaps later (Youngprapakorn
et al. 1971). Accelerated growth and early reproduction by female crocodilians
has been reported for several species that were reared in captivity before
being translocated (e.g., Alligator mississippiensis
[Daudin, 1801] and Caiman latirostris
[Daudin, 1801]) and is probably commonplace among
head-started crocodilians (Elsey et al. 2000; Larriera
et al. 2006). Decreasing the time required for translocated females to begin
producing offspring has the potential to increase population growth rates,
thereby lessening the likelihood that stochastic demographic events will
negatively impact translocation outcomes (Elsey et al. 2000; Larriera et al. 2006).
The aggressive nest defense
exhibited by the female crocodile is only the second instance of this behavior
(see also Platt et al. 2020) we witnessed during visits to 31 C. siamensis nests to collect eggs for incubation
(2011–13 and 2019–23). Although nest attendance and defense are probably
universal among the Crocodylia (Grigg & Kirschner
2015), these behaviors are poorly documented in C. siamensis.
Similar to our observations, the few previous reports of nest attendance
behaviors involved female C. siamensis
defending nests against researchers; Kanwatanakid-Savini
et al. (2012) found a female concealed in dense grass beside a nest in
Thailand, Bezuijen et al. (2013), stated that a nest
in Laos was “fiercely guarded by a female”, and Platt et al. (2020) described
an aggressive encounter with a large female at another nest in Laos. That said,
aggressive nest defense directed towards humans is probably an unreliable index
of attendance behavior because female crocodilians may selectively avoid
humans, and yet still defend nests against smaller predators (Kushlan & Kushlan 1980; Hunt
& Ogden 1991). Tellingly, in a recent aerial survey conducted in GXCWC
using drones (Platt et al. 2023), we observed female crocodiles at 60% of the
nests, suggesting nest attendance behavior is more commonplace among C. siamensis than hitherto recognized. Although our camera
trap imagery appears to be the first showing a wild female C. siamensis undertaking nest repairs, attending female A.
mississippiensis (Dietz & Hines 1980; Joanen & McNease 1989; Hunt
& Ogden 1991) and Spectacled Caiman (Caiman crocodilus
[Linnaeus, 1758]) (González-Desales et al. 2023) are
reported to reshape and add material to nest mounds opened by predators.
The camera trap imagery we
obtained during a relatively brief monitoring period (34 days) is the first to
document fauna associated with C. siamensis
nests. Our findings are consistent with other reports that describe a diversity
of vertebrates using crocodilian nest mounds as feeding and loafing platforms,
foraging substrates, and nesting sites (Merchant et al. 2014; Eversole &
Henke 2018; Escobedo-Galván et al. 2019; Platt
et al. 2021; González-Desales et al. 2020; Rainwater
et al. 2024). Characterizing the associations of the six species of passerines
we recorded at the nest proved challenging owing to the limited number of
images that we obtained; however, most birds appeared to be loafing or
traveling. In contrast, Red Junglefowl (Gallus gallus
[Linnaeus, 1758]) and White-breasted Waterhen (Amaurornis
phoenicurus [Pennant, 1769]) were foraging on and
around the nest mound. While crocodilian nest mounds harbor an abundance of
potential invertebrate prey for birds (Medem 1971; Staton & Dixon 1977; Merchant et al. 2014; Platt et al.
2021; Rainwater et al. 2024), foraging at the mound also entails some degree of
risk because crocodilians (including C. siamensis;
Sam et al. 2015) frequently prey on birds (Gabrey
& Elsey 2017). An unidentified species of rat(s) was the nest associate
most frequently recorded by our camera. Although some rodents are predators of
crocodile eggs (Webb et al. 1977; Hunt & Ogden 1991; Platt et al. 2021),
our images indicated the rats traveled across the nest and through the area
without attempting to breach the mound and consume eggs. Free-ranging dogs are
known predators of crocodile eggs (Vyas 2010; Somaweera
et al. 2013), and we consider the two instances when village dogs approached
the nest as attempted predation events thwarted by the aggressive response of
the attending female. In contrast, the presence of domestic cattle at the nest
on numerous occasions (in one series of images sleeping cattle remained at the
nest for almost five hours) elicited no response from the female crocodile
suggesting these large mammals were not perceived as a threat to the nest.
Likewise, González-Desales et al. (2023) speculated
that female C. crocodilus attending nests
learned to differentiate between potential egg predators and harmless species.
In closing, we caution that our
camera trap imagery almost certainly represents an incomplete record of events
transpiring at the nest during the monitoring period. The passive infrared
sensors in camera traps detect animals based on a combination of heat and
motion, and the effectiveness of these sensors depends on multiple factors such
as distance from the camera to the target individual, body size (i.e., larger
individuals generate more heat), and ambient temperature. As such, passive
infrared sensors are very effective at detecting large mammals, but less
reliable for detecting small-bodied endotherms and ectotherms (Hobbs & Brehme 2017), including crocodilians (Merchant et al. 2012;
Charruau & Henaut 2012;
Combrink et al. 2016). Given the technical
constraints associated with passive infrared sensors, our camera trap likely
either failed to capture or incompletely captured instances of crocodilian
behavior and nest-associated fauna, especially smaller species of birds and
mammals.
Species |
Number of
detections |
Type of association |
Birds |
|
|
Black-headed Bulbul
Brachypodius melanocephalus |
1 |
Traveling |
Blue-winged Pitta Pitta moluccensis |
2 |
Loafing |
Hill Blue
Flycatcher Cyornis whitei |
1 |
Loafing |
Pied Fantail Rhipidura javaniea |
1 |
Foraging and
Loafing |
Red Junglefowl Gallus
gallus |
5 |
Foraging |
Verditer Flycatcher Eumyias thalassinus |
1 |
Loafing |
White-breasted
Waterhen Amauornis phoenicurus |
8 |
Foraging and
Traveling |
White-rumped Shama Copsychus malabaricus |
1 |
Foraging |
Mammals |
|
|
Unidentified Rat
Rodentia |
9 |
Traveling |
Domestic Dog Canis familiaris |
2 |
Predation
(attempted) |
Domestic Cattle Bos
taurus × indicus |
8 |
Loafing |
For
images - - click here for full PDF
References
Alberts, A.C.
(2007). Behavioral
considerations for headstarting as a conservation
strategy for endangered Caribbean Rock Iguanas.
Applied Animal Behavior Science 102: 380–391.
Armstrong,
D.P. & P.J. Seddon (2008). Directions in reintroduction biology. Trends in
Ecology and Evolution 23: 20–25. https://doi.org/10.1016/j.tree.2007.10.003
Bezuijen, M.R., J.H. Cox, Jr., J.B. Thorbjarnarson, C. Phothitay, M. Hedermark & A. Rasphone
(2013). Status of
Siamese Crocodile (Crocodylus siamensis) Schneider, 1801 (Reptilia:
Crocodylia) in Laos. Journal of Herpetology
47: 41–65.
Baird, I.G.
(2001). The protected
crocodiles, wetlands, and forests at Ban Beung Buoa Thong and Ban Nao Neua, Xaibouli District, Savannakhet
Province, southern Lao PDR. Crocodile Specialist Group Newsletter 20(2):
22–24.
Burke, R.L.
(2015). Head-starting
turtles: learning from experience. Herpetological Conservation and Biology
10: 299–308.
Charruau, P. & Y. Henaut
(2012). Nest
attendance and hatchling care in wild American crocodiles (Crocodylus
acutus) in Quintana Roo,
Mexico. Animal Biology 62: 29–51.
Combrink, X., J.K. Warner & C.T.
Downs (2016). Nest
predation and maternal care in the Nile Crocodile (Crocodylus
niloticus) at Lake St. Lucia, South Africa. Behavioural Processes 133: 31–36. https://
doi.org/10.1016/beproc.2016.10.014
Daltry, J.C. & A. Starr (2010). Development of a re-introduction
and re-enforcement program for Siamese Crocodiles in Cambodia, pp. 118–123. In:
Soorae, P.S. (ed.). Global Re-Introduction
Perspectives: Additional Case Studies from Around the Globe. SSC Re-Introduction
Specialist Group, Abu Dhabi, UAE.
Dayton, P.K.
(2003). The
importance of the natural sciences to conservation. American Naturalist 162:
1–13.
Deitz, D.C. & T.C. Hines (1980). Alligator nesting in
north-central Florida. Copeia 1980: 249–258.
Dodd, C.K.,
Jr. & R. A. Seigel (1991). Relocation, repatriation, and translocation of amphibians and
reptiles: Are they conservation strategies that work? Herpetologica
47: 336–350.
Elsey, R.M.
(2007). Precocious
reproductive development in a farm-raised and released American Alligator, Alligator
mississippiensis. Herpetological Bulletin
102: 11–14.
Elsey, R.M.,
V. Lance & L. McNease (2000). Evidence of accelerated sexual
maturity and nesting in farm-released alligators in Louisiana, pp. 244–255. In:
Grigg, G.C., F. Seebacher & C.E. Franklin (eds.).
Crocodilian Biology and Evolution. Surrey Beatty & Sons, Chipping
Norton, Australia, 446 pp.
Elsey, R.M.,
C. Wall & M. Wall (2015). Alligator mississippiensis (American
Alligator). Nesting by a reintroduced female. Herpetological Review 46:
622–623.
Escobedo-Galván, A.H., R.M. Elsey, F. McCann, F.G. Cupul-Magaña & M.A. López-Luna (2019). Putting eggs in one big basket:
communal egg-laying between long-lived reptiles. North-Western Journal of
Zoology 15: 96–100.
Eversole,
C.B. & S.E. Henke (2018). Effects of red imported fire ants (Solenopsis
invicta) presence on success and depredation of
American alligator (Alligator mississippiensis)
nests: Potential value of a non-native invasive species. Herpetological Review
49: 22–25.
Ewen, J.G.,
P.J. Soorae & S. Canesa
(2014). Reintroduction objectives, decisions, and
outcomes: global perspectives from the herpetofauna. Animal Conservation
17: 74–87. https://doi.org/10.1111/acv.12148
Ferguson,
M.W.J. (1985). The reproductive
biology and embryology of the crocodilians, pp. 330–491. In: Gans, C., F.S. Bilet & P.F.A.
Maderson (eds.). Biology of the Reptilia.
Vol. 14. John Wiley & Sons, New York. 692 pp.
Gabrey, S.W. & R.M. Elsey (2017). Birds in the diet of American
Alligators. Journal of Louisiana Ornithology 10: 1–10.
Germano, J.M. & P.J. Bishop (2008). Suitability of Amphibians and
Reptiles for translocation. Conservation Biology 23: 7–15. https://doi.org/10.1111/j.1523-1739.2008.01123x
Germano, J., J. G. Ewen, H. Mushinsky, E. McCoy & L. Ortiz-Catedral
(2014). Moving
towards greater success in translocations: recent advances from the
herpetofauna. Animal Conservation 17: 1–3. https://doi.org/10.1111/acv.12172
González-Desales, G.A., P. Charruau, M.M. Zarco- González & O. Monroy-Vilchis
(2023). Factors
influencing egg predation of two species of crocodilians in Mexico. Herpetological
Conservation and Biology 18: 404–414.
González-Desales, G.A., L.A. Tello-Sahagún,
C.P. Cadena-Ramírez, M.A. López-Luna, A. Buenrostro-Silva,
J. García-Grajales, M.C. González-Ramón, J.E.
Morales-Mavil, P. Charruau,
L. Sigler, A. Rubio-Delgado, M.M. Zarco- González
& O. Monroy-Vilchis (2020). Egg predation and vertebrates
associated with wild crocodilian nests in Mexico determined using camera traps.
Journal of Natural History 54: 1813–1826. https://doi.org/10.1080/00222933.2020.1829723
Griffith, B.,
J.M. Scott, J.W. Carpenter & C. Reed (1989). Translocation as a
species conservation tool: Status and strategy. Science 245: 477–480.
Grigg, G.
& D. Kirschner (2015). Biology and Evolution of Crocodylians. Cornell University Press,
Ithaca, New York, USA, 649 pp.
Hobbs, M.T.
& C.S. Brehme (2017). An improved camera trap for
amphibians, reptiles, small mammals, and large invertebrates. PLoS ONE 12(10): e0185206. https://doi.org/10.1371/journal.pone.0185026
Hunt, R.H.
& J.J. Ogden (1991). Selected aspects of nesting ecology of American Alligators in the
Okefenokee Swamp. Journal of Herpetology 25: 448–453.
IUCN (2011). Baseline Report: Xe Champhone Wetland, Champhone and Xonbuly Districts, Savannakhet Province, Lao PDR. Mekong Water Dialogues Project.
IUCN Publications, Gland, Switzerland, 58 pp.
IUCN (2013). Guidelines for reintroductions
and other conservation translocations.
Version 1.0. IUCN Species Survival
Commission, Gland, Switzerland, 72 pp.
Joanen, T. & L. McNease
(1989). Ecology and
physiology of nesting and early development of the American alligator. Integrative
and Comparative Biology 29: 987–998.
Joanen, T., L. McNease
& G. Perry (1977). Effects of simulated flooding on alligator eggs. Proceedings Annual
Conference Southeastern Association of Fish & Wildlife Agencies 31:
334–342.
Kar, S.
(2022). Nesting
trend of Esturaine Crocodile, Crocodylus
porosus, in the forest blocks of Bhitarkanika Wildlife Sanctuary/National Park, Odisha,
India. Crocodile Specialist Group Newsletter 41(4): 13–14.
Kanwatanakid-Savini, C., M. Pliosungnoen,
A. Pattanavibool, J.B. Thorbjarnarson,
C. Limlikhitaksorn & S.G. Platt (2012). A survey to determine
the conservation status of Siamese crocodiles in Kaeng
Krachan National Park, Thailand. Herpetological Conservation and Biology
7: 157–168.
Kushlan, J.A. & M.S. Kushlan (1980). Function of nest attendance in American
Alligators. Herpetologica 36: 27–32.
Larriera, A., P. Siroski,
C.L. Pina & A. Imhof (2006). Sexual maturity of
farm-released Caiman latirostris (Crocodylidae: Alligatoridae) in
the wild. Herpetological Review 37: 26–28.
Leiva, P.M.L., M.S. Simoncini, T.C.G. Portelinha, A. Larriera & C.I. Pina (2019). Size of nesting female
Broad-snouted Caiman (Caiman latirostris Daudin 1802). Brazilian Journal of Biology 79:
139–143. https://doi.org10.1590/1519-6984.180892
Manalo, R.J.
& A.C. Alcala (2015). Conservation of the Philippine Crocodiles Crocodylus
mindorensis (Schmidt 1935): in-situ and ex-situ
measures. International Zoo Yearbook 49: 113–124. https://doi.org/10.1111/izy.12080
Marsh, D.M.
& P.C. Trenham (2001). Metapopulation dynamics
and amphibian conservation. Conservation Biology 15: 40–49.
Medem, F. (1971). The reproduction of the Dwarf
Caiman Paleosuchus palpebrosus,
pp. 159–165. In: Crocodiles: Proceedings of the 1st Working
Meeting of the IUCN Crocodile Specialist Group. IUCN Publications, Morges, Switzerland.
Merchant, M.,
C.M. Murray & A. Cooper (2014). American Alligator nests as microhabitat for a
diversity of vertebrates. Herpetological Review 45: 201–208.
Merchant, M.,
D. Savage, A. Cooper, J.M. Slaughter, J.J. Perkins & C.M. Murray (2018). Nest attendance patterns in the
American alligator (Alligator mississippiensis).
Copeia 106: 421–426. https://doi.org/10.1643/CH-17-7-709
Merchant, M.,
D. Savage, A. Cooper, M. Slaughter & C. Murray (2012). Assessment of nest attendance of
the American alligator (Alligator mississippiensis)
using a modified motion-sensitive camera trap, pp. 205. In: Crocodiles:
Proceedings of the 21st Working Meeting of the Crocodile Specialist Group.
IUCN–The World Conservation Union, Gland, Switzerland.
Miller, K.A.,
T. Bell & J.M. Germano (2014). Understanding publication bias
in reintroduction biology by assessing translocations of New Zeeland’s
herpetofauna. Conservation Biology 28: 1045–1056. https://doi.org/10.1111/cobi.12254
Munoz, M. del
C. & J. Thorbjarnarson (2000). Movement of captive-released
Orinoco Crocodiles (Crocodylus intermedius)
in the Capanaparo River, Venezuela. Journal of
Herpetology 34: 397–403.
Murray, C.M.,
B.I. Crother & J.S. Doody (2019). The evolution of crocodilian
nesting ecology and behavior. Ecology and Evolution 10: 131–149. https://doi.org/10.1002/ece3.5859
Ngoprasert, D. & G.A. Gale (2019). Tiger density, dhole occupancy,
and prey occupancy in the human disturbed Dong Phayayen-Khao
Yai Forest Complex, Thailand. Mammalian Biology
95: 51–58. https://doi.org/10.1016/j.mambio.2019.02.003
O’Brien,
T.G., M.F. Kinnard & H.T. Wibisono (2003). Crouching tigers, hidden prey:
Sumatran tiger populations in a tropical forest landscape. Animal
Conservation 6: 131–149.
Platt, S.G.,
S. Boutxakittilath, O. Thongsavath,
S.C. Leslie & L. McCaskill (2022a). Restoring the Critically
Endangered Siamese Crocodile to the Xe Champhone Wetlands in Lao PDR (2019-2022). Crocodile
Specialist Group Newsletter 41(4): 6–13.
Platt, S.G.,
F. Li, Q. He, J. Wang & S. Lu (2016). Reproduction in a reintroduced
population of Chinese Alligators. Crocodile Specialist Group Newsletter
35(3): 11–15.
Platt, S.G.,
L. McCaskill, T.R. Rainwater, Y. Temsiripong, M. As-singkily, B.K. Simpson & M.R. Bezuijen
(2019). Siamese
Crocodile Crocodylus siamensis,
pp. 120–132. In: S.C. Manolis & C. Stevenson
(eds.), Crocodiles: Status Survey and Conservation Action Plan, 4th
Edition. IUCN Crocodile Specialist Group, Darwin, Australia. Available: https://www.iucncsg.org
Platt, S.G.,
V. Monyrath, H. Sovannara,
L. Kheng & T.R. Rainwater (2011). Nesting phenology and clutch
characteristics of captive Siamese Crocodiles (Crocodylus
siamensis) in Cambodia. Zoo Biology 30:
1–12.
Platt, S.G.,
T.R. Rainwater & S.T. McMurry (2021). Fauna associated with the nests
of Crocodylus moreletii
and Crocodylus moreletii
× acutus in Belize. Journal of Natural
History 55: 133–149. https://doi.org/10.1080/00222933.2021.1895350
Platt, S.G.,
S.H.N. Aung, M.M. Soe, T. Lwin, K. Platt, A.D. Walde & T.R. Rainwater (2022b). Reproduction of translocated Geochelone platynota
(Testudines: Testudinidae) at two wildlife
sanctuaries in Myanmar. Salamandra 58: 161–165.
Platt, S.G.,
O. Thongsavath, C.D. Hallam & T.R. Rainwater
(2020). Crocodylus siamensis (Siamese Crocodile). Nesting and
nest attendance. Herpetological Review 51: 588–590.
Platt, S.G.,
O. Thongsavath, P. Outhanekone
& T.R. Rainwater (2018a). Notes on traditional ecological knowledge and ethno
herpetology of Siamese crocodiles in Lao, PDR. Crocodile Specialist Group
Newsletter 37(4): 6–12.
Platt, S.G.,
O. Thongsavath, C. Pothitay,
C. Holmes, L. McCaskill & T.R. Rainwater (2018b). A status assessment and
long-term conservation plan for Siamese Crocodiles in the Xe
Champhone Ramsar Site, Savannakhet Province, Lao PDR, pp. 219–237. In: Crocodiles:
Proceedings of the 25th Working Meeting of the IUCN Crocodile
Specialist Group. IUCN Publications, Gland, Switzerland.
Platt, S.G.,
O. Thongsavath, P. Sisavath,
P. Outhanekone, A. McWilliams & C.D. Hallam
(2014).
Community-based Siamese Crocodile conservation in Lao PDR. Crocodile
Specialist Group Newsletter 33(2): 22–27.
Platt, S.G.,
J.C. White, S. Boutxakittilath, D. Phasavath, O. Thongsavath, L.D.
McCaskill, S.C. Leslie & T.R. Rainwater (2023). Evaluating the use of a
quad-copter drone to detect Siamese Crocodile nests in Lao, PDR, with
incidental observations of female nest attendance. Reptiles & Amphibians
30(1): el9950. https://doi.org/10.17161/randa.v30i1.19950
Polet, G. (2002). Crocodylus
siamensis re-introduced in Cat Tien National
Park. Crocodile Specialist Group Newsletter 21: 9–10.
Rainwater,
T.R., T.H. Wu, A.G. Finger, J.E. Cañas, L. Yu, K.D.
Reynolds, G. Coimbatore, B. Barr, S.G. Platt, G.P. Cobb, T.A. Anderson &
S.T. McMurry (2007). Metals and organochlorine
pesticides in caudal scutes of crocodiles from Belize
and Costa Rica. Science of the Total Environment 373: 146–156.
Rainwater,
T.R., R. Singh, C.A. Tuten, A.M. Given, P.W. Gibbons,
B. Song, S.G. Platt, P.M. Wilkinson & C.M.B. Jachowski
(2024). Fauna
associated with American Alligator (Alligator mississippiensis)
nests in coastal South Carolina, USA. Animals 14(4): 620. https://doi.org/10.3390/ani14040620
Roe, J.H.,
M.R. Frank & B.A. Kingsbury (2015). Experimental evaluation of
captive-rearing practices to improve success of snake reintroductions. Herpetological
Conservation and Biology 10: 711–722.
Sam, H., L. Hor, R. Nhek, P. Sorn, S. Heng, B. Simpson, A.
Starr, S. Brook, J.L. Frechette & J.C. Daltry
(2015). Status,
distribution and ecology of the Siamese Crocodile Crocodylus
siamensis in Cambodia. Cambodian Journal of
Natural History 2015: 153–164.
Seddon, P.J.
(1999). Persistence
without intervention: assessing success in wildlife reintroductions. Trends
in Ecology and Evolution 14: 503.
Somaweera, R., M. Brien & R. Shine
(2013). The role of
predation in shaping crocodilian natural history. Herpetologica
27: 23–51.
Staton, M.A. & J.R. Dixon (1977). Breeding biology of the
Spectacled Caiman, Caiman crocodilus crocodilus, in the Venezuelan Llanos. United States
Fish and Wildlife Service, Research Report No. 5, Washington, D.C., 23 pp.
Stofer, A. (1999). Gene flow and endangered
species translocations: a topic revisited. Biological Conservation 87:
173–190.
Temsiripong, Y. (2007). Re-introduction of captive-raised
Siamese Crocodiles in Thailand. Re-introduction News 28: 55–57.
Vyas, R.
(2010). Mugger (Crocodylus palustris)
population in and around Vadodara City, Gujarat States, India. Russian
Journal of Herpetology 17: 43–50.
Webb, G.J.W.,
H. Messel & W.E. Magnusson (1977). The nesting of Crocodylus porosus
in Arnhem Land, Northern Australia. Copeia
1977: 238–249.
Xing, J.H.
(2010). Chinese
Alligator, Alligator sinensis, pp. 5–9. In:
S.C. Manolis & C. Stevenson (eds.). Crocodiles:
Status Survey and Conservation Action Plan. 3rd Edition.
Crocodile Specialist Group, Darwin, 108 pp.
Youngprapakorn, U., J.A. McNeely & E.W.
Cronin (1971). Captive
breeding of crocodiles in Thailand, pp. 98–101. In: Crocodiles: Proceedings
of the 1st Working Meeting of the IUCN Crocodile Specialist Group.
IUCN Publications, Morges, Switzerland.