Editing Turtle (section)

== Behavior==

===Diet and feeding===
[[File:Green Sea Turtle grazing seagrass.jpg|thumb|A [[green sea turtle]] grazing on seagrass |alt=Photograph of a green sea turtle on the seabed, feeding]]

Most turtle species are opportunistic omnivores; land-dwelling species are more [[Herbivore|herbivorous]] and aquatic ones more [[Carnivore|carnivorous]].{{sfn|Franklin|2011|p=28}} Generally lacking speed and agility, most turtles feed either on plant material or on animals with limited movements like mollusks, worms, and insect larvae.<ref name=Firefly/> Some species, such as the [[African helmeted turtle]] and snapping turtles, eat fish, amphibians, reptiles (including other turtles), birds, and mammals. They may take them by [[ambush predator|ambush]] but also scavenge.{{sfn|Orenstein|2012|p=231}} The [[alligator snapping turtle]] has a worm-like appendage on its tongue that it [[Aggressive mimicry|uses to lure fish]] into its mouth. Tortoises are the most herbivorous group, consuming grasses, leaves, and fruits.{{sfn|Franklin|2011|pp=29–30}} Many turtle species, including tortoises, supplement their diet with eggshells, animal bones, hair, and droppings for extra nutrients.{{sfn|Orenstein|2012|p=237}}

Turtles generally eat their food in a straightforward way, though some species have special feeding techniques.<ref name=Firefly/> The [[yellow-spotted river turtle]] and the [[painted turtle]] may [[filter feed]] by skimming the water surface with their mouth and throat open to collect particles of food. When the mouth closes, the throat constricts and water is pushed out through the nostrils and the gap in between the jaws.{{sfn|Orenstein|2012|p=235}} Some species employ a "gape-and-suck method" where the turtle opens its jaws and expands its throat widely, sucking the prey in.<ref name=Firefly/><ref name="Van Damme 1997">{{cite journal |last1=Van Damme |first1=Johan |last2=Aerts |first2=Peter |title=Kinematics and Functional Morphology of Aquatic Feeding in Australian Snake-necked Turtles (Pleurodira;Chelodina) |journal=Journal of Morphology |volume=233 |issue=2 |pages=113–125 |year=1997 |doi=10.1002/(SICI)1097-4687(199708)233:2<113::AID-JMOR3>3.0.CO;2-7 |pmid=9218349 |s2cid=32906130 }}</ref>{{sfn|Franklin|2011|p=30}}

The diet of an individual within a species may change with age, sex, and season, and may also differ between populations. In many species, juveniles are generally carnivorous but become more herbivorous as adults.<ref name=Firefly/>{{sfn|Orenstein|2012|p=239}} With [[Barbour's map turtle]], the larger female mainly eats mollusks while the male usually eats [[arthropod]]s.<ref name=Firefly/> [[Blanding's turtle]] may feed mainly on snails or crayfish depending on the population. The [[European pond turtle]] has been recorded as being mostly carnivorous much of the year but switching to [[Nymphaea alba|water lilies]] during the summer.{{sfn|Orenstein|2012|p=229}} Some species have developed [[Generalist and specialist species|specialized]] diets such as the hawksbill, which eats [[sponges]], the leatherback, which feeds on [[jellyfish]], and the [[Mekong snail-eating turtle]].{{sfn|Franklin|2011|p=28}}<ref name=Firefly/>

===Communication and intelligence===
[[File:Chelodina oblonga 1.jpeg|thumb|The [[oblong turtle]] has a sizable vocal repertoire.<ref name="Glies"/>|alt=Photograph of an oblong turtle]]
{{see also|Animal cognition}}

While popularly thought of as mute, turtles make various sounds to communicate.{{sfn|Pryke|2021|p=39}}<ref name="Ferrara"/> One study which recorded 53 species found that all of them vocalized.<ref>{{cite journal|last1=Jorgewich-Cohen|first1=G|display-authors=etal|year=2022|title=Common evolutionary origin of acoustic communication in choanate vertebrates|journal=Nature Communications|volume=13|issue=1|page=6089|doi=10.1038/s41467-022-33741-8|pmid=36284092|pmc=9596459|bibcode=2022NatCo..13.6089J|s2cid=253111242}}</ref> Tortoises may bellow when courting and mating.<ref name="Ferrara"/>{{sfn|Orenstein|2012|p=36}} Various species of both freshwater and sea turtles emit short, low-frequency calls from the time they are in the egg to when they are adults. These vocalizations may serve to create group cohesion when [[Animal migration|migrating]].<ref name="Ferrara">{{cite journal |last1=Ferrara |first1=Camila R. |last2=Vogt |first2=Richard C. |last3=Sousa-Lima |first3=Renata Santoro |year=2012 |title=Turtle Vocalizations as the First Evidence of Posthatching Parental Care in Chelonians |journal=Journal of Comparative Psychology |volume=127 |issue=1 |pages=24–32 |doi=10.1037/a0029656 |pmid=23088649 |url=http://www.seaturtle.org/PDF/FerraraCR_2013_JCompPsychol.pdf |access-date=September 1, 2017 |archive-date=September 2, 2017 |archive-url=https://web.archive.org/web/20170902055618/http://www.seaturtle.org/PDF/FerraraCR_2013_JCompPsychol.pdf |url-status=live }}</ref> The [[oblong turtle]] has a particularly large vocal range; producing sounds described as clacks, clicks, squawks, hoots, various kinds of chirps, wails, ''{{Not a typo|hooos}}'', grunts, growls, blow bursts, howls, and drum rolls.<ref name="Glies">{{cite journal |last1=Giles |first1=Jacqueline C. |last2=Davis |first2=Jenny |last3=McCauley |first3=Robert D. |last4=Kuchling |first4=Gerald |year=2009 |title=Voice of the Turtle: The Underwater Acoustic Repertoire of the Long-necked Freshwater Turtle, ''Chelodina oblonga'' |journal=The Journal of the Acoustical Society of America |volume=126 |issue=1 |pages=434–443 |doi=10.1121/1.3148209 |pmid=19603900 |bibcode=2009ASAJ..126..434G |doi-access=free }}</ref>

Play behavior has been documented in some turtle species.<ref>{{cite journal |last1=Burghardt |first1=Gordon M. |last2=Ward |first2=B. |last3=Rosscoe |first3=Roger |year=1996 |title=Problem of Reptile Play: Environmental Enrichment and Play Behavior in a Captive Nile Softshelled Turtle, ''Trionyx triunguis'' |journal=Zoo Biology |volume=15 |issue=3 |pages=223–238 |doi=10.1002/(SICI)1098-2361(1996)15:3<223::AID-ZOO3>3.0.CO;2-D }}</ref> In the laboratory, [[Florida red-bellied cooter]]s can learn novel tasks and have demonstrated a long-term memory of at least 7.5&nbsp;months.<ref name="Learning">{{cite journal |last1=Davis |first1=K. M. |last2=Burghardt |first2=Gordon M. |year=2007 |title=Training and Long-term Memory of a Novel Food Acquisition Task in a Turtle (''Pseudemys nelsoni'') |journal=Behavioural Processes |volume=75 |issue=2 |pages=225–230 |doi=10.1016/j.beproc.2007.02.021 |pmid=17433570 |s2cid=34130920 }}</ref> Similarly, giant tortoises can learn and remember tasks, and master lessons much faster when trained in groups.<ref>{{cite journal |date=November 29, 2019 |df=dmy-all |author=<!-- no author listed in ''Nature'' article --> |title=Reptiles Known as 'Living Rocks' Show Surprising Cognitive Powers |series=Animal Behaviour |journal=Nature |volume=576 |issue=7785 |page=10 |doi=10.1038/d41586-019-03655-5 |bibcode=2019Natur.576...10.|s2cid=208613023 |doi-access=free }}</ref> Tortoises appear to be able to retain [[operant conditioning]] nine years after their initial training.<ref>{{cite journal |last1=Gutnick |first1=Tamar |last2=Weissenbacher |first2=Anton |last3=Kuba |first3=Michael J. |date=November 13, 2019 |df=dmy-all |title=The Underestimated Giants: Operant Conditioning, Visual Discrimination and Long-term Memory in Giant Tortoises |journal=Animal Cognition |volume=23 |issue=1 |pages=159–167 |doi=10.1007/s10071-019-01326-6 |issn=1435-9456 |pmid=31720927 |s2cid=207962281 |url=http://id.nii.ac.jp/1394/00001487/ }}</ref> Studies have shown that turtles can navigate the environment using landmarks and a map-like system resulting in accurate direct routes towards a goal.<ref name=":1">{{Cite journal |last1=Salas |first1=Cosme |last2=Broglio |first2=Cristina |last3=Rodríguez |first3=Fernando |date=2003 |title=Evolution of Forebrain and Spatial Cognition in Vertebrates: Conservation across Diversity |url=https://www.karger.com/Article/FullText/72438 |journal=Brain, Behavior and Evolution |language=english |volume=62 |issue=2 |pages=72–82 |doi=10.1159/000072438 |issn=0006-8977 |pmid=12937346|s2cid=23055468 |url-access=subscription }}</ref> Navigation in turtles have been correlated to high cognition function in the medial cortex region of the brain.<ref name=":1" /><ref>{{Cite journal |last1=Reiter |first1=Sam |last2=Liaw |first2=Hua-Peng |last3=Yamawaki |first3=Tracy M. |last4=Naumann |first4=Robert K. |last5=Laurent |first5=Gilles |date=2017 |title=On the Value of Reptilian Brains to Map the Evolution of the Hippocampal Formation |url=https://www.karger.com/Article/FullText/478693 |journal=Brain, Behavior and Evolution |language=english |volume=90 |issue=1 |pages=41–52 |doi=10.1159/000478693 |issn=0006-8977 |pmid=28866680|s2cid=13763864 |url-access=subscription }}</ref>
[[File:Crested Caracara eating a turtle (16753759877).jpg|thumb|[[Crested caracara]] eating a turtle|alt=Photo of a large bird eating a turtle]]
===Defense===
{{see also|Anti-predator adaptation}}
When sensing danger, a turtle may flee, freeze or withdraw into its shell. Freshwater turtles flee into the water, though the [[Sonora mud turtle]] may take refuge on land as the shallow temporary ponds they inhabit make them vulnerable.{{sfn|Orenstein|2012|pp=252–253}} When startled, a softshell turtle may dive underwater and bury itself under the sea floor.{{sfn|Franklin|2011|p=40}} If a predator persists, the turtle may bite or discharge from its cloaca. Several species produce foul-smelling chemicals from musk glands. Other tactics include threat displays and [[Bell's hinge-back tortoise]] can [[Apparent death|play dead]]. When attacked, big-headed turtle hatchlings squeal, possibly startling the predator.{{sfn|Orenstein|2012|pp=252–253, 301}}

=== Migration ===
{{further|Sea turtle migration}}
[[File:Turtle golfina escobilla Oaxaca Mexico Claudio Giovenzana 2010.jpg|thumb|right|An olive ridley sea turtle nesting on Escobilla Beach, [[Oaxaca]], [[Mexico]]. Female sea turtles migrate long distances to nest on favored beaches.]]
Turtles are the only reptiles that migrate long distances, more specifically the marine species that can travel up to thousands of kilometers. Some non-marine turtles, such as the species of ''[[Geochelone]]'' (terrestrial), ''[[Chelydra]]'' (freshwater), and ''[[Malaclemys]]'' (estuarine), migrate seasonally over much shorter distances, up to around {{convert|27|km|mi|abbr=on}}, to lay eggs. Such short migrations are comparable to those of some lizards, snakes, and crocodilians.<ref name="Southwood Avens 2009">{{cite journal |last1=Southwood |first1=Amanda |last2=Avens |first2=Larisa |title=Physiological, Behavioral, and Ecological Aspects of Migration in Reptiles |journal=Journal of Comparative Physiology B |volume=180 |issue=1 |year=2009 |pages=1–23 |issn=0174-1578 |doi=10.1007/s00360-009-0415-8 |pmid=19847440 |s2cid=20245401 |url=https://www.researchgate.net/publication/38028266 |access-date=June 6, 2021 |archive-date=July 24, 2021 |archive-url=https://web.archive.org/web/20210724105250/https://www.researchgate.net/publication/38028266_Physiological_behavioral_and_ecological_aspects_of_migration_in_reptiles |url-status=live }}</ref> Sea turtles nest in a specific area, such as a beach, leaving the eggs to hatch unattended. The young turtles leave that area, migrating long distances in the years or decades in which they grow to maturity, and then return seemingly to the same area every few years to mate and lay eggs, though the precision varies between species and populations. This "natal homing" has appeared remarkable to biologists, though there is now plentiful evidence for it, including from genetics.<ref name="Lohmann et al 2013">{{cite book |last1=Lohmann |first1=Kenneth J. |last2=Lohmann |first2=Catherine M. F. |last3=Brothers |first3=J. Roger |last4=Putman |first4=Nathan F. |chapter=Natal Homing and Imprinting in Sea Turtles |editor-last=Wyneken |editor-first=Jeanette |title=The Biology of Sea Turtles |publisher=CRC Press |year=2013 |isbn=978-1-4398-7308-3 |oclc=828509848 |pages=59–78}}</ref>

How sea turtles navigate to their breeding beaches remains unknown. One possibility is [[Imprinting (psychology)|imprinting]] as in [[salmon]], where the young learn the chemical signature, effectively the scent, of their home waters before leaving, and remember that when the time comes for them to return as adults. Another possible cue is the orientation of the [[Earth's magnetic field]] at the natal beach. There is experimental evidence that turtles have an effective magnetic sense, and that they use this in [[Animal navigation|navigation]]. Proof that homing occurs is derived from genetic analysis of populations of loggerheads, hawksbills, leatherbacks, and [[Olive ridley sea turtle|olive ridleys]] by nesting place. For each of these species, the populations in different places have their own [[mitochondrial DNA]] genetic signatures that persist over the years. This shows that the populations are distinct and that homing must be occurring reliably.<ref name="Lohmann et al 2013"/>