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Play behavior in crocodilians is not uncommon, but it remains virtually undescribed in scientific literature. I present the first overview of play behavior of three types (locomotor play, object play and social play) in crocodilians based on original observations, published reports and anecdotal evidence. Object play is the type most often reported; social play can include interactions with conspecifics and mammals. Apparently, play behavior is not particularly rare in crocodilians, but is underreported due to the difficulties of observing it and interpreting the observations.
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Sciknow Publications Ltd. ABC 2015, 2(1):49-55
Animal Behavior and Cognition DOI: 10.12966/abc.02.04.2015
©Attribution 3.0 Unported (CC BY 3.0)
Animal Behavior and Cognition 2015, 2(1):49-55
Play Behavior in Crocodilians
Vladimir Dinets1*
1University of Tennessee, Knoxville
*Corresponding author (Email:
Citation Dinets, V. (2015). Play behavior in crocodilians. Animal Behavior and Cognition, 2(1), 49-55. doi:
Abstract - Play behavior in crocodilians is not uncommon, but it remains virtually undescribed in scientific
literature. I present the first overview of play behavior of three types (locomotor play, object play and social play) in
crocodilians based on original observations, published reports and anecdotal evidence. Object play is the type most
often reported; social play can include interactions with conspecifics and mammals. Apparently, play behavior is not
particularly rare in crocodilians, but is underreported due to the difficulties of observing it and interpreting the
Keywords - Alligator, Behavior, Caiman, Crocodile, Object, Play, Sociality
In the most comprehensive overview of play behavior in various animal taxa to date, Burghardt
(2005) listed two published and three unpublished observations of apparent play in crocodilians, and
suggested that such behavior would be reported more commonly if the animals were regularly observed
under right conditions. So far, this prediction has been only partially correct in terms of published reports.
As the number of crocodilians kept in captivity increased, and their behavior became the focus of much
attention due to its previously underestimated complexity (Dinets, 2014a; Doody, Burghardt, & Dinets,
2012), observations of play became more frequent, and its occurrence is now common knowledge among
zoo keepers and crocodile farm personnel (A. Britton, personal communication, 2013; J. Brueggen,
personal communication, 2014; S. Mukerjee, personal communication, 2013). However, despite
numerous unpublished personal observations, no new reports of such behavior have appeared in scientific
literature. Many aspects of crocodilian behavior remain poorly known due to their rare occurrence and to
the difficulty of observing predominantly nocturnal predators (Dinets, 2014b), but in the case of play, an
additional problem appears to be that people witnessing such behavior consider their observations
unworthy of publishing or unlikely to be taken seriously.
Here I provide an overview of play behavior in crocodilians, compiled from my own observations
and a variety of published and unpublished sources. I use the three-way classification of play (locomotor
play, object play, and social play) as typically used in animal play research (Fagen, 1981).
Materials and Methods
The original observations were conducted opportunistically during over 3,000 hr of observing
wild and captive crocodilians in the course of a study of crocodilian communication during the mating
season (Dinets, 2013). Due to the aim of the study, focal animals were always adults. This might partially
explain the small number (N = 7) of observed play occurrences, since in most other animals known to
play, juveniles play more often than adults (Burghardt, 2005).
To supplement the small number of personal observations, an informal survey of people working
with crocodilians was conducted in 2013-2014 at various conferences and through social networks
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Twitter and Facebook (particularly Facebook groups Crocodile Conservation, Crocodiles in Captivity,
and also Crocodile Specialist Group Facebook page). Conference audiences and social network users
were asked to report their observations of behaviors that they thought or suspected could be play. Any
explanation of what play might look like was avoided to prevent respondents from subconsciously
adjusting their original evaluation of behaviors to better match the request. The respondents provided
three reports mentioned below; additionally, 8 people stated that they had had such observations, but
failed to provide any details. Due to the small number of records, data on all species are presented jointly;
the species-by-species breakdown is provided in the Discussion.
Locomotor Play
Locomotor play was characterized by Burghardt (2005, p. 84) as performing “intense or sustained
locomotor movements... often without any apparent immediate reason or stimulus. Being ambush
predators with low metabolism level, crocodilians seldom engage in intense or sustained movements of
any kind, so it is not surprising that this type of play is rarely observed. Burghardt (2005) quotes
unpublished observations by Harry Green and Paul Weldon of captive young American alligators
(Alligator mississippiensis) repeatedly sliding down slopes into water. A hatchling broad-snouted caiman
(Caiman latirostris) kept in a concrete pool in Santa Cruz Zoo, Bolivia, would repeatedly approach a
water bulge formed on the pool surface by an upward stream from an inflow pipe opening on the bottom
and allow the outward current to carry it across the pool (J. Herrera, personal communication, 2007).
Sunday Mail newspaper published (on November 3, 1996) observations and photos by Phil Cook of a
~2.5 m long estuarine crocodile (Crocodylus porosus) repeatedly “surfing the waves” off a beach near
Port Douglas, Australia.
Object Play
Object play appears to be the most frequently observed type of crocodilian play; it is so common
that many zoo caretakers now provide various objects as toys for crocodilians as part of habitat
enrichment programs.
Streams of water seem to be particularly popular play targets. Lazell and Spitzer (1977) reported
an American alligator playing with water dripping from a pipe for at least 45 min. The young alligator
would swim around the dripping pipe, then turn to face the pipe. After watching for a few moments, the
alligator would slowly pass towards, then veer away from the drip. It then began snapping at the drip as it
cruised past it, sometimes allowing it to drip onto his head before biting at it. This behavior continued
until the drip stopped. Heinbuch and Wiegmann (2000) observed juvenile Cuvier’s dwarf caimans
(Paleosuchus palpebrosus) repeatedly standing on their hind legs under a warm shower. The authors tried
to elicit similar behavior from crocodilians of other species, but, although those animals seemed to enjoy
the shower, they never assumed an upright position. It is possible that the dwarf caimans were playing
with the water stream, although it could also be an instinctive attempt to orient oneself facing the current,
as to be expected in a species adapted to life in relatively fast streams (Ross, 1992). I observed a young
adult American alligator in Saint Augustine Alligator Farm Zoo Park (Florida, USA) moving its head
horizontally back and forth across a stream of water falling from a pipe and making snapping movements
as if trying to bite the stream. This behavior continued for over half an hour, sometimes interrupted with a
few minutes of rest under the stream (Figure 1).
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Animal Behavior and Cognition 2015, 2(1):49-55
Figure 1. An American alligator (Alligator mississippiensis) resting after a bout of play with a stream of water, Saint Augustine
Alligator Farm Zoo Park, Florida, USA.
Another category of object play is interacting with various floating objects, often provisioned toys
or commercial enrichment items. Burghardt (2005, p. 283) quotes Andrew Odum at the Toledo Zoo, who
observed a male Cuban crocodile (Crocodylus rhombifer) “attacking and pushing around a large ball and
approaching it while blowing bubbles used in courtship. There is no reason to think that the male was
actually trying to court the ball, since attack behavior was also involved. A video of a large male estuarine
crocodile playing with a ball, filmed by John Brueggen at Saint Augustine Crocodile Farm Zoo, can be
seen at The video might look like feeding response, but the crocodile has
been playing with that particular ball for years (J. Brueggen, personal communication, 2015). Adult
crocodilians of many species can often be seen pushing twigs, grass and other floating vegetation while
swimming (personal observations). In many cases this behavior appears to be accidental, but on two
occasions I have seen crocodilians doing this in a manner strongly suggesting play. In both cases, the
objects were pink Bougainvillea flowers that were floating in the pools where the animals were kept
captive. Adult male Cuban crocodile in Zoo Miami (Florida, USA) manipulated such flowers repeatedly
over seven days of observation, picking them up, pushing around, and carrying in the teeth or on the tip of
the snout (Figure 2A). An adult West African dwarf crocodile (Osteolaemus cf. tetraspis) in Madras
Crocodile Bank (Tamil Nadu, India) behaved in exactly the same way (Figure 2B). In both cases, there
was a variety of other small objects floating in the pools (small green and yellow dry leaves and white
flower petals in Zoo Miami; yellow dry leaves and white egret feathers of varying size in Madras
Crocodile Bank), but these objects were completely ignored. Anecdotal observations suggest that
crocodilians are generally attracted to small pink objects, and prefer them over similar objects of other
colors for biting and manipulating (J. Harding, personal communication, 2014). However, a floating or
submerged object of any color, if left in an enclosure with captive crocodilians, is likely to be repeatedly
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Animal Behavior and Cognition 2015, 2(1):49-55
bitten and severely damaged sooner or later (John Brueggen, personal communication, 2008; Patty
Register, personal communication, 2009).
Figure 2. Crocodiles playing with Bougainvillea flowers. A) Cuban crocodile (Crocodylus rhombifer) in Zoo Miami, Florida,
USA. B) West African dwarf crocodile (Osteolaemus cf. tetraspis), Madras Crocodile Bank, Tamil Nadu, India.
Not all object play takes place in the water. Lani Lyman-Henley (personal communication, 2014)
reported observing the following behavior in human-raised, very tame juvenile American alligators kept
in a residential house (her interpretations of observations are quoted verbatim):
When cleaning their tank, I'd put them in the bathtub. When they'd gotten pretty big,
they'd splash around for a bit, then climb out of the tub and I'd find them hanging out on
the tiled floor. One time I heard clattering noises in that bathroom, but when I opened the
door to look, they froze, and were just sitting still on the floor looking at me. I left,
listening at the door. The clattering started again after a few minutes, and I swept in to
try to catch them in the act. Again, froze. But I watched as one of them, staring right at
me, slowly dropped a ceramic dome from the corner of his mouth...and I realized what it
was. They had knocked the ceramic caps off the screws of the toilet base, and I can only
guess that they were knocking them around the room. And one of them had one in his
mouth... I never could catch them at it again. I mean, they were really making noise, had
to be knocking that thing against the walls and tub! But the "I wasn't doing anything"
expression was just priceless.
Crocodilians also play with prey items. Divyabhanusinh (1986) observed and photographed a
mugger crocodile (Crocodylus palustris) apparently playing with a dead and partially eaten sambar deer
(Cervus unicolor). The crocodile grabbed the carcass by the neck and spinned five or six times as if trying
to dismember the carcass. It stopped with its feet in the air, then slowly rolled over onto its feet, released
the carcass and walked away without eating any of it. The Telegraph newspaper published (on August 9,
2014) the observations and photographs by Roland Ross of a large Nile crocodile (Crocodylus niloticus)
playing with a dead hippopotamus (Hippopotamus amphibius) calf. The crocodile spent 25 min
repeatedly throwing the carcass in the air, “spinning and jumping and splashing.” It is unknown if the calf
had been killed by the crocodile or died from other causes.
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Animal Behavior and Cognition 2015, 2(1):49-55
Social Play
Social play by crocodilians is almost never reported, but this doesn’t mean that it is particularly
rare. There is a “short sequence of film of two sibling Nile crocodiles tussling with one another in what
looked like play behaviour” (D. Naish, personal communication, 2013). I have observed two juvenile
black caimans (Melanosuchus niger) about 30 cm long in Mamiraua Reserve (Brazil) as they swam in a
tight circle as if chasing each other; this behavior occurred in three bouts of ~1 min each during one night
of observation. Similar behavior is often displayed by adult crocodilians during courtship (Dinets, 2010);
indeed, in other vertebrate species it is quite common for elements of courtship behavior to be
incorporated into play by juveniles as well as adults (Burghardt, 2005). Conversely, courtship might
involve elements of play that are often difficult to recognize as such. I observed and photographed a pair
of adult Cuban crocodiles at Zoo Miami performing a particularly unusual behavior at the time of
courtship: the female would get on the back of the larger male, and he would give her a few rides around
the pool (Dinets, 2011). At the time of observation I interpreted this behavior as part of regular courtship,
but apparently it has never been seen in other courting pairs of Cuban crocodiles in the wild or in
captivity, so it could be a form of play developed by this pair during many years of living together. In
Fakahatchee Strand Preserve (Florida, USA) I observed a somewhat similar behavior in a mixed crèche of
hatchling American alligators from two broods of different age: on three occasions in one morning of
observation, a younger alligator took a short ride on the back of an older one (Figure 3).
Figure 3. A hatchling American alligator (Alligator mississippiensis) riding on the back of an older individual in a multi-brood
crèche, Fakahatchee Strand Perserve, Florida, USA.
An American crocodile (Crocodylus acutus), rescued and named Pocho by Gilberto 'Chito'
Shedden, became a celebrity in Costa Rica for being absolutely tame and very playful with its rescuer.
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Animal Behavior and Cognition 2015, 2(1):49-55
Their unique relationship continued for 20 yrs, until the crocodile died apparently of old age. Play
behavior included swimming together, rushing at Shedden with an open mouth in mock charges, sneaking
on him from behind as if to startle him, and accepting being caressed, hugged, rotated in the water and
kissed on the snout (G. Shedden, personal communication, 2004; also personal observations). Pocho’s
behavior was seen by thousands of tourists, filmed countless times (including a full-length documentary
The Man Who Swims With Crocodiles by Roger Horix), and featured by most Central American
newspapers, but it has never been mentioned in scientific literature; the only published source of detailed
information is a Wikipedia article.
I observed apparent interspecific play between an American alligator and a river otter (Lontra
canadensis) in Big Cypress National Preserve (Florida, USA), in a bayou inhabited by 8-12 subadult
alligators and regularly visited by a group of 4-6 otters. The otters would often harass the alligators by
approaching them closely, nipping on their tail tips, and splashing water onto their heads. Most alligators
responded to harassment by submerging, but one individual ~1.5 m long responded by lunging at the
otters every time they got close. By the third day of observation the otters focused most of their attention
on that individual. On one occasion an otter slipped on a steep bank of the bayou and was grabbed across
the chest by the alligator. The alligator retreated from the bank and pulled the wriggling otter underwater
as if attempting to drown it, but after about 5 s raised its head and released the otter, apparently unharmed.
The interactions between this alligator and the otters then continued for two more days, at which point the
bayou dried out and all otters and alligators moved elsewhere.
Burghardt (2005, pp. 70-78) proposed five criteria for recognizing a behavior as play, and noted
that a behavior can be recognized as play even if it doesn’t match all five. The criteria are as follows:
1. The performance of the behavior is not fully functional in the form or context in
which it is expressed; that is, it includes elements, or is directed towards stimuli, that
do not contribute to current survival.
2. The behavior is spontaneous, voluntary, intentional, pleasurable, rewarding,
reinforcing, or autotelic (done for its own sake).
3. It differs from the “serious” performance of ethotypic behavior structurally or
temporally in at least one respect: it is incomplete (generally through inhibited or
dropped final element), exaggerated, awkward, or precocious; or it involves behavior
patterns with modified form, sequencing, or targeting.
4. The behavior is performed repeatedly in a similar, but not rigidly stereotyped, form
during at least a portion of the animal’s ontogeny.
5. The behavior is initiated when the animal is adequately fed, healthy, relaxed, and
free from stress (e. g. predator threat, harsh microclimate, social instability) or
intense competing systems (e. g. feeding, mating, predator avoidance).
Many observations described above match most of Burghardt’s five criteria. For example, trying
to “catch” a stream of water is not a functional predatory behavior (criterion 1); sliding down steep slopes
appears to be “spontaneous, voluntary, intentional, pleasurable, rewarding, reinforcing, or autotelic”
(criterion 2); releasing a captured otter seems to be a good example of incomplete behavior (criterion 3);
most observations were of repeated behaviors (criterion 4) performed by animals in comfortable, relaxed
situations (criterion 5). Even though these observations of apparent play behavior are mostly singular and,
if taken separately, allow for alternative explanations (some of which are mentioned in Results section),
combined they present strong evidence that play might be a more regular part of crocodilian behavioral
repertoire than currently recognized. As Burghardt (2005) points out, this is to be expected in animals
with complex, flexible behavior. However, he also makes the important point that energetic constraints
reduce the probability of observing sustained vigorous behavior typical of endothermic mammals and
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Animal Behavior and Cognition 2015, 2(1):49-55
birds in ectothermic vertebrates. On the other hand, aquatic environment reduces the cost of locomotion,
possibly facilitating the performance of play in crocodilians (Burghardt, Ward, & Rosscoe, 1996). Indeed,
the most vigorous of the behaviors listed above (“surfing,” mock charges) took place in the water.
The 17 records of possible play behavior listed above involve 10 species of crocodilians (6
records for the American alligator, 3 records for the Cuban crocodile and 1 record for every other species).
It is possible that alligators are involved in play more often than crocodiles because they are more social
(Ross, 1992), but it is far more likely that these numbers reflect nothing more than observational coverage
bias and the randomness of rare observation events.
So, how often do crocodilians play? To answer this question, we need a much better
understanding of crocodilian social interactions and behavioral repertoire in general; that would allow us
to better recognize play when we see it.
I thank Adam Britton, John Brueggen, Joan Harding, Jesus Herrera, Lani Lyman-Henley,
Sokham Mukerjee, Patty Register, and Gilberto Shedden for sharing their observations; IUCN Crocodile
Specialist Group and Darren Naish for help with collecting information; and Gordon Burghardt and the
anonymous reviewers for editorial advice.
Burghardt, G. M. (2005). The Genesis of Animal Play: Testing the Limits. London: The MIT Press.
Burghardt, G. M., Ward, B., & Rosscoe, R. (1996). Problem of reptile play: Environmental enrichment and play
behavior in a captive Nile soft-shelled turtle (Trionyx triunguis). Zoo Biology, 15, 223-228.
Dinets, V. (2010). Nocturnal behavior of the American alligator (Alligator mississippiensis) in the wild during the
mating season. Herpetological Bulletin, 111, 4-11.
Dinets, V. (2011). Crocodylus rhombifer (Cuban crocodile) mating behavior. Herpetological Review, 42, 232.
Dinets, V. (2013). Long-distance signaling in extant crocodilians. Copeia, 517-526.
Dinets, V. (2014a). Apparent coordination and collaboration in cooperatively hunting crocodilians. Ethology
Ecology & Evolution, doi: 10.1080/03949370.2014.915432.
Dinets, V. (2014b). Dragon songs. Love and adventure among crocodiles, alligators and other dinosaur relations.
New York: Arcade.
Divyabhanusinh. (1986). Note on the strange behavior of a marsh crocodile (Crocodylus palustris). Journal of the
Bombay Natural History Society, 83 (Supplement), 220-221.
Doody, J. S., Burghardt, G. M., & Dinets, V. (2012). Breaking the socialnon-social dichotomy: A role for reptiles
in vertebrate social behavior research? Ethology, 119, 1-9.
Fagen, R. (1981). Animal play behavior. New York: Oxford University Press.
Heinbuch, B., & Wiegman, T. (2000). Unusual behavior of dwarf caiman. Crocodile Specialist Group Newsletter,
19, 14-15.
Lazell, J. D. Jr., & Spitzer, N. C. (1977). Apparent play behavior in an American alligator. Copeia, 188.
Ross, C. A. (1992). Crocodiles and alligators. Melbourne: Blitz.
... Despite the skepticism, some researchers, such as Gordon Burghardt (Chapter 21, this volume), thankfully followed a different path and explored play in reptiles and other taxa with a fresh viewpoint. The old scientific approaches that placed severe limits on what "cold-blooded" vertebrates can do or experience are dropping out of vogue, while fresh and innovative perspectives are being embraced and studied, such as social behaviors, personality/temperament, and play (Burghardt, Dinets, & Murphy, 2014;Dinets, 2015;Doody, Bur- ghardt, & Dinets, 2013;Schuett et al., 2016;Waters, Bowers, & Bur- ghardt, 2017). Today, with the inclusion of a greater diversity of vertebrate (and invertebrate) taxa -fishes, amphibians, reptiles, spiders, and octopuses -research on play behavior is undergoing a paradigm shift in the broader disciplines of cognition and comparative behavior (Burghardt, 2005(Burghardt, , 2015Burghardt et al., 2014;Hopper, 2017;Pruitt, Burghardt, & Riechert, 2012;Zylinski, 2015). ...
... Play behavior carried out by nonhuman animals can be classified into three main categories, which are not necessarily mutually exclusive (see Burghardt, 1999Burghardt, , 2011Dinets, 2015;sensu Fagan, 1981). In fact, ...
... Until recently, the topic of play in reptiles was not only vastly understudied (actually, it was essentially absent from the literature; Beach, 1945), but anyone who investigated it was almost certainly shunned by colleagues and treated as a charlatan of real science (Burghardt, 2005). Today, it is a viable and legitimate topic in the study of vertebrate behavior and cognition (Bateson & Martin, 2013;Burghardt et al., 2002;Dinets, 2015;Doody et al., 2013;Graham & Burghardt, 2010;Waters, Bowers, & Burghardt, 2017). ...
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Scientific Foundations of Zoos and Aquariums: : Their Role in Conservation and Research - edited by Allison B. Kaufman, M J Bashaw, and T L Maple. February 2019.
... In particular, the St. Augustine Alligator Farm Zoological Park, which was originally founded in 1893 as a small roadside display of native Floridian reptiles (Burger 2018), has grown, transitioned, and matured into a world-class institution and leader in crocodilian science, conservation, and captive management. By granting outside researchers access to their living collection, the park has facilitated dozens of collaborative studies in crocodilian biology and related subjects (e.g., Dinets 2015;Drumheller and Brochu 2014;Drumheller et al. 2016;Drumheller-Horton et al. 2019;Erickson et al. 2014;Merchant et al. 2018;O'Brien et al. 2019), and fundraising efforts spearheaded and hosted by the park have contributed significant funding to crocodilian conservation and research efforts throughout the world. The expertise of its staff has also been instrumental in advancing industry standards and practices in crocodilian management and in training new generations of herpetologists and other professionals on crocodilian management through the AZA's Crocodilian Biology and Professional Management course which the park hosts each year. ...
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This article highlights two questionable zoo reptile keeping practices and spectacles of the early 20th Century - tortoise rides and alligator slides, and reflects on the evolution and progression of the zoo field over the past century.
... In immature rats (Poole and Fish, 1976;Smith, 1982) and ground squirrels Spermophilus beldingi (Nunes et al., 2004), social play is a rearranged set of elements taken from the agonistic behavior observed in adult males. The arctic whale Balaena mysticetus during games with logs demonstrates elements of precopulative and maternal behaviors; when playing with living fish, the bottle-nosed dolphin Tursiops truncates demonstrates elements of hunting behavior but do not catch prey (Paulos et al., 2010 (Dinets, 2015). When playing with various objects, Octopus vulgaris octopuses demonstrate elements of hunting and hoarding behaviors, making attempts to take toys they like in their den (Kuba et al., 2003(Kuba et al., , 2006. ...
... Initially, play was thought to be limited to mammals and birds, but efforts to define it more objectively have led to the identification of play in a variety of other taxa as diverse as octopodes (Kuba et al., 2006), fish (Burghardt et al., 2015), and reptiles including monitor lizards (e.g. Hill, 1946), turtles (Burghardt et al., 1996;Kramer & Burghardt, 1998) and crocodilians (Lazell & Spitzer, 1977;Dinets, 2015). The widely accepted definition of play is 'repeated, seemingly non-functional behaviour differing from more adaptive versions structurally, contextually, or developmentally, and initiated when the animal is in a relaxed, unstimulating, or low stress setting' (Burghardt, 2014). ...
... Very few studies have looked into reptile enrichment, and fewer still have focused on the crocodilians. Dinets (2015) summarises several instances of play and enrichment use in several species of crocodilian, however, much of this information is anecdotal, with little objective evidence to back it up. Due to this lack of information, enrichment for crocodilians is new terrain upon which to tread. ...
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To date, there has been relatively little research conducted pertaining to behaviour in Reptilia, particularly in the area of enrichment. This is especially true for crocodilians, which are somewhat neglected in the literature in favour of more charismatic animals such as birds and mammals. The primary aim of this study was to test three forms of environmental enrichment to see whether they could influence the behaviours of crocodilians at Paignton Zoo, England and whether individual differences or time would also be factors in these differences. Binary logistic modelling found that all three factors, enrichment (Wald Chi-Square=54.003, d.f.=3, p<0.001), individual (Wald Chi-Square=558.697, d.f.=5, p<0.001) and time class (Wald ChiSquare=119.177, d.f.=5, p<0.001), had a significant effect on the crocodilians use of the pools incorporated within their enclosures. All three enrichment types had significantly different effects from one another. Watermelon (x̄=1.528, S.E.=0.143) was the most effective at encouraging crocodiles to use the water portion of their enclosure, compared against the control condition (x̄=2.287, S.E.=0.149). The boomer ball containing meat (x̄=2.416) had no significant effect compared to the control, however cork bark (x̄=3.062, S.E.=0.178) had significantly reduced water use. A following binary logistic test revealed that enrichment (Wald ChiSquare=4.039, d.f.=3 p=0.257) had no effect on promoting locomotive activity in the crocodiles. The variety in effectiveness of enrichment reinforces the idea that objective testing is required to understand whether enrichments provided are having the effect intended, or whether they are instead having no, or the opposite effect, with a representative from all three scenarios being shown in this study. Further studies should also look to examine why certain enrichments are more effective than others to help identify potential future enrichment with the highest chance of success.
... Predatory behavior is also complex; crocodylians have been reported to use sticks as lures to attract nesting birds within reach, and to engage in collaborative and cooperative hunting (Dinets, 2015a,b). Play and social behaviors involving large numbers of individuals have also been reported (Dinets, 2013b(Dinets, , 2015c. Grigg and Kirshner (2015) provide an overview of the biology of extant crocodylians. ...
Most of the 9300 extant species of non-avian reptiles are squamates (lizards and snakes); there are only 315 extant species of turtles, 23 crocodilians, and one rhynchocephalian. Although the diversity of reptiles is greatest in the tropics, many species occur in the temperate regions and a few have geographic ranges that extend north of the Arctic Circle. Antarctica is the only continent with no extant reptiles. Ectothermy, an ancestral character, is central to the biology of reptiles, and is responsible for their low metabolic rates and their high efficiency of secondary production. Temperature-dependent sex-determination is universal in crocodilians, widespread among turtles, and present in some lineages of squamates. Among lizards, the mode of predation – sit-and-wait, cruising forager, or widely foraging – has a strong phylogenetic component and correlates with many elements of their ecology, morphology, physiology, and behavior. Lizards typically eat daily and consume many small prey items, whereas snakes eat less frequently and consume larger prey items relative to their body size. Most species of reptiles are small, inconspicuous, and have little obvious economic value, and as a consequence we lack information about the viability of their populations. Climate change, habitat loss, and pollution (including the feminizing effects of estrogen analogs) affect many species, and nearly three million lizards, snakes, turtles, and crocodilians are consumed by trade in hides and pets annually. The life histories of most large species of turtles, lizards, snakes, and crocodilians depend on prolonged adult survival and reproduction, and it is unlikely that these species will long withstand the current rate of commercial exploitation.
... Due to the small sample size (N = 4), statistical analyses were not conducted for this study. However, following the procedure of other small-N studies in behavioral science, visual analyses were used to examine the change in the response variables between the no-sound trials and sound trials of TS1 and TS2 (e.g., Dinets, 2015; Graham, Karmarkar, & Ottenbacher, 2012; Osvath, Osvath, & Bååth, 2014; Whitley & Kite, 2012). Since there were four elephants, multiple baselines for each response variable were established; this increases the accuracy of examining changes (patterns/trends) in visual analyses (Graham et al., 2012). ...
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Habituation is a major concern for the development of effective, long-term human-wildlife conflict mitigation and zoo enrichment programs. Elephants are cognitive species that exhibit many types of learning, such as associative, social, and insight learning. However, no study has examined the habituation process in elephants. Elephants possess a well-developed sensory system and may habituate to stimuli that could be used for enrichment and/or management. The aim of this study was to examine their habituation process in response to repeated presentations of two auditory stimuli: buzzing by a disturbed beehive and the sound created by banging on pots and pans, and in comparison to no sound trials. The selected sounds often invoke alert behaviors and movements in wild elephants as part of human-elephant conflict mitigation. We predicted that elephants would initially exhibit strong reactions to both sounds, but these responses would diminish over repeated trials. This study was conducted with four female African elephants (Loxodonta africana) at the Nashville Zoo in Tennessee. During the first sound presentation, the elephants reacted by showing distress, avoidance, and vigilance behaviors. Over repeated presentations, their reactions to the sounds diminished to levels observed during the no-sound trials, suggesting habituation had occurred. The elephants also reduced their response to the second sound more rapidly than to the first sound, suggesting that generalization of their habituation had occurred. The results support our hypothesis that elephants use habituation to learn which stimuli are non-threatening and subsequently stop responding to them. Habituation is an important learning process that should be considered during the implementation of captive and wildlife management, especially for highly intelligent species, such as elephants.
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How far back can we trace behaviour associated with pain? Behaviour is not preserved in the palaeontological record, so, for dinosaurs, we are restricted to what we can deduce from fossilized bones and tracks. This review is a thought experiment using circumstantial evidence from dinosaur fossils and from the behaviour of their extant relatives to describe probable responses of dinosaurs to serious injuries. Searches yielded 196 papers and chapters with: reports of healed serious injuries, and limping gait and injured feet in trackways; information about physiology and behaviour relevant to healing; evidence of evolutionary connections with birds and crocodilians, and their behaviour; and information about relevant aspects of evolution. Clearly, many dinosaurs survived injuries that would have seriously hampered mobility, impairing hunting or escape from predators, and affecting social interactions. Recovery from severe injuries implies pain-mediated responses. Rates of healing seem faster than for other reptiles, possibily aided by warm-bloodedness. Nesting was often communal, raising the possibility of parental and group protection for injured young. The existence of family groups, packs or herds raises the possibility of protection or feeding from pack kills. This is the first study, to our knowledge, of possible pain behaviour and responses to injury in dinosaurs. This article is part of the Theo Murphy meeting issue ‘Evolution of mechanisms and behaviour important for pain’.
Historically, play behavior has been difficult to define. This likely stems from the number of different species, types of play, and context under which it occurs. In 2016, the Chicago Zoological Society – Brookfield Zoo hosted the Psychonomic Society leading edge workshop on the evolutionary and psychological significance of play. Sixteen experts attended from the diverse fields of African ethnology, animal behavior, animal science, animal welfare, cognitive psychology, cognitive zoology, comparative psychology, cultural anthropology, developmental psychology, educational psychology, ethology, neuroscience, primatology, and zoology. Approximately half of the participants studied human play and the other half studied non-human play. Before the workshop, participants were asked to send in either their personal definition of play or the one that they cite in peer-reviewed literature. Definitions were then reviewed to determine characteristics of play inclusive of all disciplines. The goal of the current study was not to do a literature review on play behavior, but to come up with a list of characteristics across all forms of play that could be used as a common terminology moving forward. Hopefully the results of this workshop and the current article will help to increase cross-disciplinary research in the field of play.
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In the course of 380 hours of nighttime observations of American alligators in the wild in 2006-2009, two previously undescribed forms of social behavior were observed. The first behavior, provisionally called "courtship gatherings", involves groups of up to 100 adult alligators in Florida, but less than 10 at various locations in the northern part of the species' range. Alligators gather in those groups on most (but not all) nights during the mating season, at locations slightly changing from night to night. They spend 4-8 hours (but not all night) swimming in pairs, courting, chasing each other, and occasionally fighting. Individual animals were observed to attend such gatherings for many nights, arriving and leaving by themselves or in pairs, and sometimes swimming to the sites of gatherings from 2 miles away. Copulations were observed near the gathering sites or after the gatherings, but never directly within. Bellowing choruses were twice as likely to occur on the mornings following nights with gatherings as on the mornings following nights without gatherings. The second type of behavior is cooperative feeding - or, more precisely, gathering for fishing. Unlike courtship gatherings, cooperative feeding can occur at any time of the day, involves constant feeding activity, and usually has subadults and juveniles present; repertoire and frequencies of observed behaviors differ markedly between these two types of gatherings. Cooperative feeding has been reported for many species of crocodilians, although never before described in detail. Courtship gatherings are present in both alligator species, at least some caimans, and possibly in the Indian gharial, but not in crocodiles, probably because crocodile males are more territorial during the mating season. The reason this common and conspicuous behavior has never been described in literature is most likely that no studies of nighttime alligator behavior in the wild during the mating season have ever been conducted before.
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Long-distance signals such as bellows, roars, headslaps, and infrasound pulses are important components of crocodilian behavioral repertoire, yet there is little or no published information on signaling for many species. Here, original data augmented with a compilation of published and unpublished sources are presented for 24 species of crocodilians. Their analysis shows that crocodilians adapt their signal composition to habitat structure by choosing physically different components. Flexible multi-component composition might partially explain the extraordinary evolutionary longevity of crocodilian signaling. Comparative analysis provides novel evidence for solving the long-standing debate about the phylogeny of the genus Tomistoma, supporting its affinities with crocodiles rather than true gharials. It also suggests that the absence of species with adult male length of less than 120 cm among extant crocodilians might be caused by the necessity of producing infrasound as an honest signal of status.
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Although social behavior in vertebrates spans a continuum from solitary to highly social, taxa are often dichotomized as either ‘social’ or ‘non-social’. We argue that this social dichotomy is overly simplistic, neglects the diversity of vertebrate social systems, impedes our understanding of the evolution of social behavior, and perpetuates the erroneous belief that one group—the reptiles—is primarily ‘non-social’. This perspective essay highlights the diversity and complexity of reptile social systems, briefly reviews reasons for their historical neglect in research, and indicates how reptiles can contribute to our understanding of the evolution of vertebrate social behavior. Although a robust review of social behavior across vertebrates is lacking, the repeated evolution of social systems in multiple independent lineages enables investigation of the factors that promote shifts in vertebrate social behavior and the paraphyly of reptiles reinforces the need to understand reptile social behavior.
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Giving captive animals the opportunity to interact with objects in a “playful” manner is often considered a method of environmental enrichment. However, the occurrence of play in nonavian reptiles is controversial and poorly documented. Similarly, the role of environmental enrichment in fostering psychological well-being in reptiles has been little studied. For several years, an adult, long-term captive, Nile soft-shelled turtle, Trionyx triunguis, at the National Zoo (Washington, D.C.), was provided objects such as balls, sticks, and hoses in an attempt to reduce self-mutilation behavior. The turtle spent considerable time with the objects, and the level of self-mutilation behavior decreased greatly over many months. Video recordings made in various contexts were analyzed in detail, and an ethogram of this turtle's behavior was developed. The turtle interacted with the objects (e.g., basketball, hose, stick) for 20.7% of the time it was observed and was active for 67.7% of the time. Both figures are unusually high for any animal, especially a turtle. The relative lack of play in ectothermic reptiles is supported by the surplus resource theory of play, which considers the joint effects of parental care, metabolism, endothermy, and arousal in providing the context in which playfulness could be manifested and promoted in vertebrate evolution. The existence of vigorous playlike behavior in a member of an ancient reptilian lineage indicates that, in the right circumstances, object play can be performed by reptiles and that having the opportunity to do so may be beneficial in captivity. © 1996 Wiley-Liss, Inc.
Crocodylus rhombifer (Cuban crocodile) mating behavior
  • V Dinets
Dinets, V. (2011). Crocodylus rhombifer (Cuban crocodile) mating behavior. Herpetological Review, 42, 232. Dinets, V. (2013). Long-distance signaling in extant crocodilians. Copeia, 517-526.
Dragon songs. Love and adventure among crocodiles, alligators and other dinosaur relations
  • V Dinets
Dinets, V. (2014b). Dragon songs. Love and adventure among crocodiles, alligators and other dinosaur relations. New York: Arcade.