Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey by stealth or by strategy (typically not conscious), rather than by speed or by strength. Ambush predators sit and wait for prey, often from a concealed position, and then launch a rapid surprise attack.
The ambush may be set by hiding in a burrow, by camouflage, by aggressive mimicry, or by the use of a trap. The predator then uses a combination of senses to assess the prey and to time the strike. Nocturnal ambush predators such as cats and snakes have vertical slit pupils, helping them to judge the distance to prey in dim light. Different ambush predators use a variety of means to capture their prey, from the long sticky tongues of chameleons to the expanding mouths of frogfishes.
Ambush predation is widely distributed in the animal kingdom, spanning some members of numerous groups such as the starfish, cephalopods, crustaceans, spiders, insects such as mantises, and vertebrates such as many snakes and fishes.
Ambush predators usually remain motionless (sometimes hidden) and wait for prey to come within ambush distance before pouncing. Ambush predators are often camouflaged, and may be solitary. Pursuit predation becomes a better strategy than ambush predation when the predator is faster than the prey. Ambush predators use many intermediate strategies. For example, when a pursuit predator is faster than its prey over a short distance, but not in a long chase, then either stalking or ambush becomes necessary as part of the strategy.
Bringing the prey within range
Ambush often relies on concealment, whether by staying out of sight or by means of camouflage.
Ambush predators such as trapdoor spiders on land and mantis shrimps in the sea rely on concealment, constructing and hiding in burrows. These provide effective concealment at the price of a restricted field of vision.
Trapdoor spiders excavate a burrow and seal the entrance with a web trapdoor hinged on one side with silk. The most well-known door is the cork-type, which is thick and beveled to precisely fit the opening. The other is the wafer-type door, a simpler sheet of silk and dirt. The top of the door is usually camouflaged with bits of debris such as twigs and rock, making it very difficult to detect. The spider spins silk fishing lines, or trip wires, that radiate out of the burrow entrance. When the spider is using the trap to capture prey, its chelicerae hold the door shut on the end furthest from the hinge. The vibrations of passing prey are conducted by the silk and alert the spider whereupon it quickly throws open the door, ambushes the prey and returns with it down the tube.
Many ambush predators make use of camouflage so that their prey can come within striking range without detecting their presence. Among fishes, the warteye stargazer (Gillellus uranidea) buries itself nearly completely in the sand and waits for prey. The devil scorpionfish (Inimicus filamentosus) typically lies partially buried on the sea floor or on a coral head during the day, covering itself with sand and other debris to further camouflage itself. The tasselled wobbegong is a shark whose adaptations as an ambush predator include a strongly flattened and camouflaged body with a fringe that breaks up its outline.
Many ambush predators actively attract their prey towards them before ambushing them. These animals are often classified as aggressive mimics. The promise of nourishment as a way of attracting prey. The alligator snapping turtle (Macrochelys temminckii) is a well-camouflaged ambush predator. Its tongue bears a conspicuous pink extension that resembles a worm and can be wriggled around; fish that try to eat the "worm" are themselves eaten by the turtle. Similarly, some snakes employ caudal luring (tail luring) to entice small vertebrates into striking range.
The zone-tailed hawk (Buteo albonotatus), which resembles the turkey vulture (Cathartes aura), flies among flocks of turkey vultures, then suddenly breaks from the formation and ambushes one of them as its prey. There is however some controversy about whether this is a true case of wolf in sheep's clothing mimicry.
Flower mantises are aggressive mimics, resembling flowers convincingly enough to attract prey that come to collect pollen and nectar. The orchid mantis Hymenopus coronatus actually attracts its prey, pollinator insects, more effectively than flowers do. Crab spiders, similarly, are coloured like the flowers they habitually rest on, but again, they can lure their prey even away from flowers.
Some ambush predators build traps to help capture their prey. Lacewings are a flying insect in the order Neuroptera. In some species, their larval form, known as the antlion, is an ambush predator. Eggs are laid in the earth, often in caves or under a rocky ledge. The juvenile creates a small, crater shaped trap. The antlion hides under a light cover of sand or earth. When an ant, beetle or other prey slides into the trap, the antlion grabs the prey with its powerful jaws.
Some but not all web-spinning spiders are sit-and-wait ambush predators. The sheetweb spiders (Linyphiidae) tend to stay with their webs for long periods and so resemble sit-and-wait predators, whereas the orb-weaving spiders (such as the Araneidae) tend to move frequently from one patch to another (and thus resemble active foragers).
Detection and assessment
Ambush predators must time their strike carefully. They need to detect the prey, assess it as worth attacking, and strike when it is in exactly the right place. They have evolved a variety of adaptations that facilitate this assessment. For example, pit vipers prey on small birds, choosing targets of the right size for their mouth gape: larger snakes choose larger prey. They prefer to strike prey that is both warm and moving; their pit organs between the eye and the nostril contain infrared (heat) receptors, enabling them to find and perhaps judge the size of their small, warm-blooded prey.
The deep-sea tripodfish Bathypterois grallator uses tactile and mechanosensory cues to identify food in its low-light environment. The fish faces into the current, waiting for prey to drift by.
Several species of Felidae (cats) and snakes have vertically elongated (slit) pupils, advantageous for nocturnal ambush predators as it helps them to estimate the distance to prey in dim light; diurnal and pursuit predators in contrast have round pupils.
Capturing the prey
Ambush predators often have adaptations for seizing their prey rapidly and securely. The capturing movement has to be rapid to trap the prey, given that the attack is not modifiable once launched. Zebra mantis shrimp (Lysiosquillina maculata) capture agile prey such as fish primarily at night while hidden in burrows, striking very hard and fast (mean peak speed 2.30 m s–1 and mean duration 24.98 ms).
Chameleons (family Chamaeleonidae) are highly adapted as ambush predators. They can change colour to match their surroundings and often climb through trees with a swaying motion, probably to mimic the movement of the leaves and branches they are surrounded by. All chameleons are primarily insectivores and feed by ballistically projecting their tongues, often twice the length of their bodies, to capture prey. The tongue is projected in as little as 0.07 seconds, and is launched at an acceleration of over 41 g. The power with which the tongue is launched, over 3000 W kg−1, is more than muscle can produce, indicating that energy is stored in an elastic tissue for sudden release.
All fishes face a basic problem when trying to swallow prey: opening their mouth may pull food in, but closing it will push the food out again. Frogfishes capture their prey by suddenly opening their jaws, with a mechanism which enlarges the volume of the mouth cavity up to 12-fold and pulls the prey (crustaceans, molluscs and other whole fishes) into the mouth along with water; the jaws close without reducing the volume of the mouth cavity. The attack can be as fast as 6 milliseconds,
Ambush predation is widely distributed across the animal kingdom. It is found in many vertebrates including fishes such as the frogfishes (anglerfishes) of the sea bottom, and the pikes of freshwater; reptiles including crocodiles, snapping turtles, the mulga dragon, and many snakes such as the black mamba; mammals such as the cats; and birds such as the anhinga (darter). The strategy is found in several invertebrate phyla including arthropods such as mantises, purseweb spiders, and some crustaceans; cephalopod molluscs such as the colossal squid; and starfish such as Leptasterias tenera.
- Scharf, I.; Nulman, E.; Ovadia, O.; Bouskila, A. (2006). "Efficiency evaluation of two competing foraging modes under different conditions" (PDF). The American Naturalist. 168 (3): 350–357. doi:10.1086/506921. PMID 16947110.
- deVries, M. S.; Murphy, E. A. K.; Patek S. N. (2012). "Strike mechanics of an ambush predator: the spearing mantis shrimp". Journal of Experimental Biology. 215 (Pt 24): 4374–4384. doi:10.1242/jeb.075317. PMID 23175528.
- "Trapdoor spiders". BBC. Retrieved 12 December 2014.
- "Trapdoor spider". Arizona-Sonora Desert Museum. 2014. Retrieved 12 December 2014.
- Moore, Talia Y.; Biewener, Andrew A. (2015). "Outrun or Outmaneuver: Predator–Prey Interactions as a Model System for Integrating Biomechanical Studies in a Broader Ecological and Evolutionary Context" (PDF). Integrative and Comparative Biology: icv074. doi:10.1093/icb/icv074.
- "Trapdoor spiders". BBC. Retrieved December 12, 2014.
- "Trapdoor spider". Arizona-Sonora Desert Museum. 2014. Retrieved December 12, 2014.
- Froese, Rainer and Pauly, Daniel, eds. (2013). "Gillellus uranidea" in FishBase. April 2013 version.
- William A.; Gosline, W.A. (July 1994). "Function and structure in the paired fins of scorpaeniform fishes". Journal Environmental Biology of Fishes. 40 (3): 219–226. doi:10.1007/BF00002508. Retrieved 2010-03-22.
- World Database of Marine Species: Spiny devil fish Archived 2012-03-04 at the Wayback Machine.. Accessed 03-22-2010.
- Scott Michael (Winter 2001). "Speak of the devil: fish in the genus Inimicus" (PDF). SeaScope. 18. Archived from the original (PDF) on 2011-07-13. Retrieved 2010-03-27.
- WetWebMedia.com: The Ghoulfish/Scorpion/Stonefishes of the Subfamily Choridactylinae (Inimicinae), by Bob Fenner. Accessed 03-27-2010.
- Ceccarelli, D. M.; Williamson, D. H. (2012-02-04). "Sharks that eat sharks: opportunistic predation by wobbegongs". Coral Reefs. 31 (2): 471–471. doi:10.1007/s00338-012-0878-z.
- Spindel, E. L.; Dobie, J. L.; Buxton, D. F. (2005). "Functional mechanisms and histologic composition of the lingual appendage in the alligator snapping turtle, Macroclemys temmincki (Troost) (Testudines: Chelydridae)". Journal of Morphology. 194: 287–301. doi:10.1002/jmor.1051940308.
- Smith, William John (2009). The Behavior of Communicating: an ethological approach. Harvard University Press. p. 381. ISBN 978-0-674-04379-4.
Others rely on the technique adopted by a wolf in sheep's clothing—they mimic a harmless species. ... Other predators even mimic their prey's prey: angler fish (Lophiiformes) and alligator snapping turtles Macroclemys temmincki can wriggle fleshy outgrowths of their fins or tongues and attract small predatory fish close to their mouths.
- Willis, E. O. (1963). "Is the Zone-Tailed Hawk a Mimic of the Turkey Vulture?". The Condor. 65 (4): 313–317. doi:10.2307/1365357.
- Clark, William S. (2004). "Is the zone-tailed hawk a mimic?". Birding. 36 (5): 495–498.
- Cott, Hugh (1940). Adaptive Coloration in Animals. Methuen. pp. 392–393.
- Annandale, Nelson (1900). "Observations on the habits and natural surroundings of insects made during the 'Skeat Expedition' to the Malay Peninsula, 1899–1900". Proceedings of the Zoological Society of London. 69: 862–865.
- O'Hanlon, James C.; Holwell, Gregory I.; Herberstein, Marie E. (2014). "Pollinator deception in the orchid mantis". The American Naturalist. 183 (1): 126–132. doi:10.1086/673858. PMID 24334741.
- Levine, Timothy R. (2014). Encyclopedia of Deception. Sage Publications. p. 675. ISBN 978-1-4833-8898-4.
In aggressive mimicry, the predator is 'a wolf in sheep's clothing'. Mimicry is used to appear harmless or even attractive to lure its prey.
- Vieira, Camila; Ramires, Eduardo N.; Vasconcellos-Neto, João; Poppi, Ronei J.; Romero, Gustavo Q. (2017). "Crab Spider Lures Prey In Flowerless Neighborhoods". Scientific Reports. 7 (1). doi:10.1038/s41598-017-09456-y.
- "Video of antlion larva ambushing an ant". National Geographic. Retrieved November 30, 2014.
- "Antlion ambush". BBC. Retrieved November 30, 2014.
- Janetos, Anthony C. (1982). "Foraging tactics of two guilds of web-spinning spiders". Behavioral Ecology and Sociobiology. 10 (1): 19–27. doi:10.1007/bf00296392.
- Banks, M. S.; Sprague, W. W.; Schmoll, J.; Parnell, J. A. Q.; Love, G. D. (2015-08-07). "Why do animal eyes have pupils of different shapes?". Science Advances. 1 (7): e1500391–e1500391. doi:10.1126/sciadv.1500391. Supplement: List of species by pupil shape.
- Shine, R.; Sun, L.-X. (2003). "Attack strategy of an ambush predator: which attributes of the prey trigger a pit-viper's strike?". Functional Ecology. 17 (3): 340–348. doi:10.1046/j.1365-2435.2003.00738.x.
- Fang, Janet (2010-03-14). "Snake infrared detection unravelled". Nature. doi:10.1038/news.2010.122.
- Hoar, W.S.; Randall, D.J.; Conte, F.P. (1997). Deep-Sea Fishes. Fish Physiology. 16. Academic Press. p. 344. ISBN 0-12-350440-6.
- Hyde, N. (2009). Deep Sea Extremes. Crabtree Publishing Company. p. 16. ISBN 0-7787-4501-5.
- Winner, C. (2006). Life on the Edge. Lerner Publications. p. 18. ISBN 0-8225-2499-6.
- Gage, J.D.; Tyler, P.A. (1992). Deep-sea biology: a natural history of organisms at the deep-sea floor. Cambridge University Press. p. 86. ISBN 0-521-33665-1.
- deVries, M. S.; Murphy, E. A. K. & Patek, S. N. (2012). "Strike mechanics of an ambush predator: the spearing mantis shrimp". Journal of Experimental Biology. 215: 4374–4384. doi:10.1242/jeb.075317. PMID 23175528.
- Tolley, Krystal A.; Herrel, Anthony (2013). The Biology of Chameleons. University of California Press. p. 128. ISBN 978-0-520-95738-1.
Chameleons may also employ a form of movement-based camouflage, ... [they] often rhythmically rock backward and forward as they walk ... [perhaps] imitating a swaying leaf ... moving in the breeze ... The behavior is widespread in highly cryptic, generally slow-moving, ambush predators, notably chameleons and some snakes and mantids
- Anderson, C.V.; Sheridan, T.; Deban, S. M. (2012). "Scaling of the ballistic tongue apparatus in chameleons". Journal of Morphology. 273 (11): 1214–1226. doi:10.1002/jmor.20053. PMID 22730103.
- Anderson, Christopher V. (2009) Rhampholeon spinosus feeding video. chamaeleonidae.com
- de Groot, J.H.; van Leeuwen, J.L. (2004). "Evidence for an elastic projection mechanism in the chameleon tongue". Proceedings of the Royal Society of London B. 271 (1540): 761–770. doi:10.1098/rspb.2003.2637. PMC 1691657.
- Anderson, C.V.; Deban, S.M. (2010). "Ballistic tongue projection in chameleons maintains high performance at low temperature". Proceedings of the National Academy of Sciences of the United States of America. 107 (12): 5495–5499. Bibcode:2010PNAS..107.5495A. doi:10.1073/pnas.0910778107. PMC 2851764. PMID 20212130.
- Bray, Dianne. "Eastern Frogfish, Batrachomoeus dubius". Fishes of Australia. Retrieved 14 September 2014.
- "Nile Crocodile: Photos, Video, E-card, Map – National Geographic Kids". Kids.nationalgeographic.com. 2002. Retrieved 2010-03-16.
- "Common Snapping Turtle". Canadian Museum of Nature. 2013. Retrieved December 2, 2014.
- Browne-Cooper, Robert; Brian Bush; Brad Maryan; David Robinson (2007). Reptiles and Frogs in the Bush: Southwestern Australia. University of Western Australia Press. pp. 145, 146. ISBN 9781920694746.
- Richardson, Adele (2004). Mambas. Mankato, Minnesota: Capstone Press. p. 25. Retrieved 2010-05-19.
- Etnyre, Erica; Lande, Jenna; Mckenna, Alison. "Felidae | Cats". Animal Diversity Web. Retrieved 28 September 2018.
- Ryan, P.G. (2007). "Diving in shallow water: the foraging ecology of darters (Aves: Anhingidae)". Journal of Avian Biology. 38: 507–514. doi:10.1111/j.2007.0908-8857.04070.x.
- "Praying mantis ambushes a grasshopper". National Geographic. Retrieved November 30, 2014.
- "Nature wildlife: Praying mantis". BBC. Retrieved November 30, 2014.
- "How the praying mantis hides". Pawnation. Retrieved November 30, 2014.
- Piper, R. (2007). Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals. Greenwood Press.
- Bourton, J. (2010). "Monster colossal squid is slow not fearsome predator". BBC. Retrieved December 1, 2014.
- Hendler, G.; Franz, D.R. (1982). "The biology of a brooding seastar, Leptasterias tenera, in Block Island Sound". Biological Bulletin. 162 (1): 273–289. doi:10.2307/1540983.
- Predation lecture University of Washington