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Anti-predator adaptations in animals.pptx

Anti-predator adaptations are specialized traits or behaviors that help animals defend against predators, such as camouflage, mimicry, or defensive structures. These adaptations enhance survival chances by avoiding detection, deterring attacks, or protecting against predator threats.

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 ANTI-PREDATOR ADAPTATIONS IN ANIMALS • An adaptation is a characteristic of a species (e.g., Behavioral, physical) that enables it to survive in its natural environment. • Adaptations develop and change over time through the process of evolution. • It is a characteristic of an organism that develops through time, which improves its chance of survival & reproduction. Adaptation
ANTI-PREDATOR ADAPTATIONS Prey animals have evolved characteristics to escape predators that are called anti-predator adaptations. Anti-predator adaptations include ways to prevent being sensed by predators, as well as to prevent being captured, attacked and eaten. Anti-predator adaptations include ways to prevent being sensed by predators, as well as to prevent being captured, attacked and eaten.
CONTI… Throughout the animal kingdom adaptations have evolved for every stage of this struggle namely by: Avoiding detection Warding off attack Escaping Fighting back Safety in numbers
 CONTI… • Finally, some species are able to escape even when caught by sacrificing certain body parts: crabs can shed a claw, while lizards can shed their tails, often distracting predators long enough to permit the prey to escape.
1. AVOIDING DETECTION • Nocturnality • Live in burrows 1.Staying out of sight • Color resemblance • Counter shading • Disruptive coloration 2. Camouflage
a. Staying Out Of Sight  Animals may avoid becoming prey by living out of sight of predators, whether in caves, burrows, or by being nocturnal.
a. Nocturnality •Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. •This is a behavioral form of detection avoidance called crypsis used by animals to either avoid predation or to enhance prey hunting.
 FOR EXAMPLE • Fruit bats forage by night to avoid predators • This predation risk is of prime importance in determining the time of evening emergence in echo locating bats.
b. LIVE IN BURROWS • This adaptation can be seen in kangaroo rats. • They forage in relatively open habitats, and reduce their activity outside their nest burrows in response to moonlight. • During a full moon, they shift their activity towards areas of relatively dense cover to compensate for the extra brightness. Kangaroo rats live in Burrows
2. CAMOUFLAGE • Camouflage is an adaptation in which a species evolves to resemble its background. • It is the technique used by many animals of resembling and blending in with their surroundings. • Prey animals use camouflage to remain undetected by their predators. • predators use camouflage to sneak up, unseen, by their prey.
a. COLOR RESEMBLANCE • An animal’s color resembles its natural environment. • This helps the animal to not be seen while still in plain view • Some animals such as the Snowshoe Hare adapt seasonally. • They come winter, their color changes to white, which helps them blend in with the snow. • In the spring, their color changes back to brown to blend in with the surrounding environment. For example Snowshoe color in winter Snowshoe color in spring
b. COUNTER SHADING Camouflage designed to hide an animal’s three- dimensional form. • For example: • Canada goose mice and the white-tailed deer use counter shading. • lighter on their bellies • darker on their backs. • When seen from a distance, the two colors blend together, making it difficult to pick out the animal’s outline from surrounding patterns. Counter shading in Canada goose mice
c. DISRUPTIVE COLORATION Markings disguise the animal among its surroundings It leads the eye away from its shape and into the background. Animals that have patterns of spots, stripes or uneven patches use this method of camouflage.
FOR EXAMPLE • Zebras use disruptive coloration. • It lives in herds. Lions like to pick out one member of the herd that looks weak. • When the lion attacks the zebras start running in all directions. • With all those stripes mixing together, it’s easy for the lion to lose the zebra it picked out of the herd. Zebras: a disruptively camouflaged predator
2.WARDING OFF ATTACK Starling the predators Pursuit-deterrent signals Playing dead Mimicry Defensive structures
A. Starling The Predators A variety of animals even sport special colors or body parts to help them startle predators. These colors and parts are used in behaviors called startle displays. Many startle displays of this type involve suddenly flashing a vivid color or pattern.
FOR EXAMPLE • A flash of the large red-eye of tree frog’s can surprise predators, and give it time to escape. • sudden splash of color startles the predator and buys the frog time to get away.
B. PURSUIT-DETERRENT SIGNALS • When encountering predators prey animals often expose themselves by loud vocalization, by repeated movements or by revealing conspicuous colors. • Warning calls given by birds such as the Eurasian jay are similarly honest signals, benefiting both predator and prey: • The predator is informed that it has been detected and might as well save time and energy by giving up the chase, while the prey is protected from attack. For example
C. PLAYING DEAD • A number of animals including mammals, insects and reptiles exhibit a type of adaptive behavior known as playing dead or tonic immobility. • When faced with a threatening situation, an animal may appear lifeless and may even emit odors that resemble the smell of decaying flesh. • Also known as thanatosis, playing dead is often used as a defense mechanism, a trick to catch prey, or a means to sexually reproduce.
FOR EXAMPLE • The animal most commonly associated with playing dead is the opossum. • under a threat, opossums can go into shock. • Their heart rate and breathing is reduced as they fall unconscious and become stiff. • By all appearances they seem dead. Opossums even excrete a liquid from their anal gland that mimics odors associated with death.
D. MIMICRY • Mimicry occurs when an organism (the mimic) simulates signal properties of another organism (the model) to confuse a third organism. • His results in the mimic gaining protection, food, and mating advantages.
There Are Two Classical Types Of Defensive Mimicry • In Mullerian mimicry, two or more aposematic forms share the same warning signals, as in viceroy and monarch butterflies. • Gaining protection, food, mate advantages. For example, in monarch and viceroy two species adopt same warning patterns and these are noxious to predator. Monarch & Viceroy butterflies
 BATESIAN MIMICRY • In Batesian mimicry, a palatable, harmless prey species mimics the appearance of another species that is noxious to predators, thus reducing the mimic's risk of attack. • . In this mimicry two species show same color pattern one is dangerous and other is harmless. Batesian mimicry: coral snake & king snake
E. DEFENSIVE STRUCTURES • When an animal is under attack, it will defend itself with all the weapons it has arms, legs, wings, hooves, teeth, claws, antlers, etc. • Some animals have further adapted to defending themselves and have developed other forms of defense.
FOR EXAMPLE • Porcupine and hedgehogs have spines which act as a defensive structure. • If a predator gets too close, the porcupine can release the quills into its predator, making it draw back in pain as the porcupine escapes. Porcupine defensive structure
3. ESCAPING Flight Autotomy
A. FLIGHT • If predator attacks on the prey then the normal reaction of prey is to flee by an available means such as flying, gliding, running and burrowing. • . Escape paths are often erratic, making it difficult for the predator to predict which way the prey will go next
FOR EXAMPLE • Birds such as snipe, and black-headed gulls evade fast raptors such as peregrine falcons with zigzagging flight. • In stickleback fish follow zigzag pattern to avoid its predation from merganser duck. Stickleback fish
B. AUTOTOMY • Some animals are capable of shedding their own appendages in a last attempt to distract the predator and thereby allow escape. For example • Certain sea slugs discard stinging papillae • crabs can sacrifice a claw, which can be regrown over several successive molts. • Many lizards can drop a portion of their tail in response to an attack by a predator and this behavior known as caudal autotomy. Caudal autotomy in lizard
Fighting back Chemical Defense Suicidal altruis m Commun al defense Defensive regurgitation
A. CHEMICAL DEFENSE • Some animals and insects use chemical defense. • When attacked, some may spit, spray, or squirt chemicals which can cause pain or discomfort to the predator. Many snakes have venom, which when injected into the skin, can stun, numb or paralyze the attacker. For example
CONTI… • Skunks use an odor to protect themselves. • They produce a strong liquid called musk. Musk is made and stored in glands near the tail. • When another animal comes too close, the skunk raises its tail and sprays musk from its glands. • While the intruder is reeling from the powerful odor, the skunk runs away.
B. COMMUNAL DEFENSE • In communal defense, prey groups actively defend themselves by grouping together and sometimes by attacking or mobbing a predator rather than allowing themselves to be passive victims of predation. • Mobbing is the harassing of a predator by many prey animals. • Mobbing is usually done to protect the young in social colonies.
For Example • Red colobus monkeys exhibit mobbing when threatened by chimpanzees. • The male red colobus monkeys group together and place themselves between predators and the group's females and juveniles. • The males jump together and actively bite the chimpanzees. Mobbing in red colobus monkey
C. Defensive Regurgitation • Some birds and insects use defensive regurgitation to ward off predators For example • The northern fulmar chick vomits a bright orange, oily substance called stomach oil when threatened. • The stomach oil is made from their aquatic diets. It causes the predator's feathers to mat, leading to the loss of flying ability and the loss of water repellency. • This is especially dangerous for aquatic birds because their water repellent feathers protect them from hypothermia when diving for food. A northern fulmar chick protects itself with a jet of stomach oil.
D. Suicidal Altruism Colony defense is a necessary but dangerous task for some animals. As an extreme form of colony defense is self-sacrificial behaviors that is evolved by kin selection in various social insects. Most self-sacrificial defensive mechanisms occur in response to an acute threat to the colony.
For Example • In Malaysian exploding ant when a worker ant's leg is grasped it suicidally expels the contents of its hypertrophied submandibular glands expelling corrosive irritant compounds and adhesives onto the predator. • These prevent predation and serve as a signal to other enemy ants to stop predation of the rest of the colony.
5. Safety In Numbers • Group living can decrease the risk of predation to the individual in a variety of way as described below: Improved vigilance Selfish herd Alarm calls
A. Improved Vigilance • In the improved vigilance effect groups are able to detect predator’s sooner than solitary individuals. • As the number of predator increase chances of predator is decrease. • If the prey is alerted early in an attack they have an improved chance of escape.
For Example • Wood pigeon flocks are preyed upon by goshawks. • Goshawks are less successful When attacking larger flocks of wood pigeons than they are when attacking smaller flocks. • This is because the larger the flock size, the more likely it is that one bird will notice the hawk sooner and fly away. Improved vigilance in wood pigeon
b. Selfish Herd • The selfish herd theory was proposed by W.D. Hamilton to explain why animals seek central positions in a group. • The theory's central idea is to reduce the individual's domain of danger. A domain of danger is the area within the group in which the individual is more likely to be attacked by a predator. • The center of the group has the lowest domain of danger, so animals are predicted to strive constantly to gain this position.
c. Alarms calls • Animals that live in groups often give alarm calls that give warning of an attack. For example: vervet monkeys give different calls depending on the nature of the attack. Predator Sounds Prey response Eagle disyllabic cough look up and run into cover leopard or cat loud bark run up into the trees Python or snake chutter stand on two legs and look around for snakes . Mob it some times
VERVET MONKEY
REFERENCES • Daly, M., P. R. Behrends, M. Wilson and L. Jacobs. 1992. Behavioral modulation of predation risk: moonlight avoidance and crepuscular compensation in a nocturnal desert rodent, dipodomys merriami. Anim. Behav., 44: 1-9 • Rosalind, K., D. Humphreys and D. Graeme. 2018. A review of thanatosis (death feigning) as an anti-predator behavior. Behavioral ecology and sociobiology, 72: 1-16. • Scott, r. S., E. Ehrhardt and T. Eisner. 1993. Defensive regurgitation by a noctuid moth larva (litoprosopus futilis). A journal of entomology, 100: 209-221.
CONTI… • Endler, J. A. 1981. An overview of the relationships between mimicry and crypsis. Biological journal of the linnean society, 16: 25-31. • Holmgren, h., M. Enquist. 1999. Dynamics of mimicry evolution. Biological journal of the linnean society, 66: 145-158. • Ritland, d. B. 1995. Comparative unpalatability of mimetic viceroy butterflies (limenitis archippus) from four south-eastern united states populations. Oecologia, 103: 327-336. • Leblanc, a. R. H., M. J. Macdougall, Y. Haridy, D. Scott and R. R. Reisz. 2018. Caudal autotomy as anti- predatory behaviour in palaeozoic reptiles. Scientific reports, 8: 963-965.
Conti… • Warham, j. 1977. The incidence, functions and ecological significance of petrel stomach oils. New zealand ecological society, 24: 84-93. • Pulliam, h. R. 1973. On the advantages of flocking. J. Theor. Biol., 38: 419-22. • Hamilton, w. 1971. Geometry for the selfish herd. Journal of theoretical biology, 31: 295-311. • Stanford, b. And B. Craig. 1995. The influence of chimpanzee predation on group size and anti- predator behavior in red colobus monkeys. Anim. Behav., 49: 577-587.
Anti-predator adaptations in animals.pptx
Anti-predator adaptations in animals.pptx