AnimalDefensevsPredators.pptx

About animals

1. Animal Defense against Predators

2. Animal Defense Against Predators Throughout millions of years of evolution, animals have evolved numerous ways of defending themselves against predators. Obviously, being able to flee a predator is the choice of many prey animals we can consider. However, there are some often overlooked but interesting methods of defense which involve deception and chemistry. These include using toxic chemicals , camouflage , and mimicry .

3. Animal Defense Against Predators Presented here are several descriptions and examples of animal defense.

4. 1. Chemical Defense There are two main ways animals can use chemicals to defend themselves. Animals can synthesize toxin using their own metabolic processes, or they can accumulate toxin from the food they eat.

5. 1. Chemical Defense Animals which synthesize their own toxin are able to convert chemical compounds in their body to a poison. There are many amphibians that produce skin toxins. The skin toxins are produced by special poison glands, usually located on the animal's back or throughout the skin. The poison dart frog has poison glands scattered all over its body. Photo courtesy of Dr. John Daly

6. Malaysian ants internally combust under threat, causing their bodies to explode (they wait until their enemies are close enough to die before detonating). Camponotus saundersi  soldier ants have large glands full of poison inside their bodies. When they sense a threat, they contract their abs, causing the glands on either side of their bodies to explode and spray poison.

7. The Pacific Ocean Hagfish  has a disgusting way of defending itself. When under attack, it oozes a suffocating slime from its many pores that envelops its predator in a fatal mass of fibrous goo. The hagfish, unfortunately, sometimes falls prey to its own defense mechanism, but normally it twists itself into knots to escape the gelatinous goop

8. The bombardier beetle may look innocent enough, but it is famous for being able to spray boiling hot and chemically toxic bodily fluids in the direction of any would-be predator. The bombardier beetle doesn't exactly melt in your mouth (but it will melt you).

9. Chemical Defense In another example, the fire salamander makes a nerve poison, which it can squirt from glands on its back. Photo courtesy of Henk Wallays , Cal. Acad. of Sciences.

10. Chemical Defense Many animals accumulate toxin from their food rather than synthesizing it from scratch. For example, the larvae of Monarch butterflies accumulate toxins from the plants they inhabit.  Birds that eat the Monarchs vomit and learn to avoid them in the future.  Their bright coloration allows birds to remember and avoid them.  Photo courtesy of T. W. Davies, Cal. Acad. of Sciences.

11. Chemical Defense Interestingly, many organisms which are distasteful advertise this fact to predators by having bright body colors or markings, as if to say, “Notice me! I’m dangerous!”

12. Chemical Defense You can see this in the bright colors of the Monarch and the poison dart frog. Photo courtesy of Dr. John Daly Photo courtesy of T. W. Davies, Cal. Acad. of Sciences.

13. Physical Defenses This is called “aposematic coloration ”, and is widely used among the insects and amphibians. The Cream-spot Tiger is aposematically colored . Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature.

14. 2. Camouflage/cryptic coloration Animals that camouflage themselves pretend to be something they are not. Either their coloration , marking patterns , or entire body resembles something else in their environment

15. orchid mantis

16. Gecko

17. Flying lizard

18. 2. Camouflage Here an aptly named walking stick pretends to be a twig, in an attempt to avoid being seen by a bird or other predator. This is an example of cryptic coloration . Photo courtesy of Dr. Lloyd Glenn Ingles, Cal. Acad. of Sciences. Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else.

19. Camouflage In this picture, a four-eyed butterfly fish uses deceptive markings . The large spot near the tail resembles an eye. When predators attack the wrong end, the butterfly fish can swim away in the other direction!

20. Camouflage Some predators also depend on camouflage, but this time it is in order to avoid being seen by their prey. Here, a frogfish resembles a sponge. Small fish swimming nearby will be engulfed in the frogfish’s enormous mouth!

21. 3. Mimicry In mimicry, an organism (the mimic) closely resembles another organism (the model) in order to deceive a third, (the operator). The model and the mimic are not always closely related, but both usually live in the same area. This is similar to camouflage, but in mimicry the model is generally a similar organism rather than a static part of the background environment.

22. 3. Mimicry There are several types of mimicry. The two most common types are Batesian mimicry and Mullerian mimicry .

23. 3. Mimicry Batesian mimicry occurs when an edible mimic resembles an unpalatable or poisonous model. In this type of mimicry, only the mimic benefits. An example of Batesian mimicry is the scarlet king snake, a non-poisonous mimic of the extremely venemous coral snake. Above: scarlet king snake Right: coral snake Photo courtesy of John H. Tashjian, Cal. Acad. of Sciences .

24. Mimicry Another example of Batesian mimicry is the locust borer. This insect not only looks like a bee or wasp, it sounds like one, too!

25. Mimicry By contrast, Mullerian mimicry occurs when two (or more) distasteful or poisonous organisms resemble each other. Both species benefit because a predator who learns to avoid one species will most likely avoid the other, too.

26. Mimicry The two invertebrates on the left are different species of sea slugs, while the one on the right is a marine flatworm. All three secrete noxious substances and are unpalatable. Notice their similar aposematic coloring .

27. Fly Orchid

28. Physical means of Defense The South American Three Banded Armadillo is the only one that can roll into a perfect ball; this is accomplished thanks to its loosely jointed armor which allows for a greater range of movement, and to its armored head and tail which interlock when the animal rolls into a ball, thus making it completely invulnerable to most enemies. This animal has also been known to shut closed at the last moment, making a snapping sound to startle its enemies as a clever additional defensive trick .

29. Found in Africa and southern Europe (mainly in Italy), the Crested Porcupine is among the largest rodents in the world, and also among the best protected mammals. Its quills, which have black and white banding so that predators can spot them from the distance, are actually modified hairs, covered with layers of hard keratin. These quills are longer in the front part of the body, forming an erectile crest that gives the animal its name. However, the most dangerous quills are the short ones in the back of the body. When threatened by a predator, the porcupine usually shakes its tail quills, which are hollow and sound like a rattle; if this doesn’t scare the enemy away, the porcupine charges backwards, trying to stab the predator with its back quills.

30. Physical means of defense The hairy frog or "horror frog" intentionally breaks its own bones to turn out a wicked set of cat-like claws. Like Wolverine, only slimy and a lot more terrifying because  it's a freaking frog . Scientists don't know if the claw is able to retract once it pierces through the skin. According to New Scientist: " Trichobatrachus robustus  actively breaks its own bones to produce claws that puncture their way out of the frog's toe pads, probably when it is threatened." Also, it is apparently hairy.

31. Behavioral Defenses Living in groups – maintain a tight cohesive group that it would be difficult for any predator to obtain a victim.

32. The cute little Opossum has a number of tricks up its defensive sleeve. It can play dead. It can foam at the mouth in an attempt to convince its predators that it is toxic, sick. It can also emit a green anal fluid that smells nearly as bad as a skunk's offensive spray (though mercifully it can easily be washed off). Opossums playing dead actually slip into a semi-comatose state, thus removing any excitement of the kill for a predator.

33. Predators mechanism of hunting tactics Ambush hunting – lying in wait for prey to come along. It has a low frequency of success and it requires minimal energy. Example Frog, alligator, crocodile, lizards   Stalking – form of hunting with a quick attack. The potential predator’s search time may be great but pursuit time is minimal. Example herons, cats   Pursuit hunting – involves minimal search time because the predator usually knows the location of the prey, but pursuit time is usually great. Example Hawks, Lions, wolves

34. Characteristics of Predation If prey population increases, it will support more predators. The number of predators tend to go low than the prey because the predator being large has a slower rate of increase. More prey will escape the predators if there is much cover. When the prey populations falls, it becomes unprofitable for the predator to pursue the prey, it must shift to some other source or suffer decline. Predation maintains the balance of animal production.

35. 6. Predators selectively remove the young, old and diseased individuals from the prey populations. Predation functions as a natural method of quality control by removing individuals which are slow, weak and incapable. 7. The alert, healthy and well adapted animals are less likely to fall as victim to the predator. 8. Method of biological control of pests animals particularly insects and rodents. 9. Occurrence of various adaptations in response to predation.

36. Thank you for listening!