Animal Behavior

1. 25 Animal Behavior 0

2. 25.1 How Do Innate先天性行为and Learned Behaviors 学习行为 Differ? 25.2 How Do Animals Communicate? 25.3 How Do Animals Compete for Resources? 25.4 How Do Animals Find Mates? 25.5 Why Do Animals Play? 25.6 What Kinds of Societies Do Animals Form? 25.7 Can Biology Explain Human Behavior? Chapter 25 At a Glance

3. Behavior is any observable activity of a living animal Some examples of behavior include Moths 飞蛾 fly to a light Honeybees fly to a cup of sugar-water Bluebirds sing Wolves howl 嚎叫 Frogs croak 呱呱地叫 Humans dance, play sports, and wage wars 进行战斗 25.1 How Do Innate and Learned Behaviors Differ?

4. Innate behavior 先天行为 can be performed without prior 之前 experience Innate behaviors are performed in reasonably 相当地complete form the first time an animal of the right age and motivational 动机的 state encounters a particular stimulus The behavior appears even if the animal is deprived of 被剥夺 the opportunity to learn it For example, a red squirrel 红松鼠 will attempt to bury a nut when presented with it for the first time 25.1 How Do Innate and Learned Behaviors Differ?

5. Innate behavior can be performed without prior experience (continued) Some innate behaviors can be recognized by their occurrence 出现 immediately after birth, before any opportunity for learning presents itself The female cuckoo birds 杜鹃鸟 lay their eggs in the nests of other bird species to be raised by the unwitting 未觉察的 adoptive parents After a cuckoo egg hatches 孵出, the cuckoo chick will display the innate behavior of shoving 推开 the nest owner’s eggs out of the nest to eliminate 消除 competition for food 25.1 How Do Innate and Learned Behaviors Differ?

6. Figure 25-1 Innate behavior A foster parent feeds a cuckoo A cuckoo chick ejects an egg

7. Learned behaviors 学习行为 require experience Natural selection 自然选择 may favor innate behaviors in many circumstances 在许多情况下 A gull chick pecks at 啄食 its parent’s bill 鸟嘴 after hatching The capacity to make changes in behavior on the basis of experience is called learning An example of learning is the process by which a human learns language Another example is a sparrow’s 麻雀 use of stars for navigation 导航 25.1 How Do Innate and Learned Behaviors Differ?

8. Learned behaviors require experience (continued) Habituation is a decline 下降 in response to a repeated stimulus A common form of learning is habituation 习惯, defined as a decline in response to a repeated stimulus The ability to habituate prevents an animal from wasting its energy and attention on irrelevant 不相干的stimuli For example, a sea anemone 海葵 will retract its tentacles 触角 when touched, but will stop retracting if the touch is repeated frequently 25.1 How Do Innate and Learned Behaviors Differ?

9. Figure 25-2 Habituation in a sea anemone After many touches, theanemone habituates andno longer responds Touched for the first time,the anemone withdraws

10. Learned behaviors require experience (continued) Habituation is a decline in response to a repeated stimulus (continued) The ability to habituate is generally adaptive 适应的 Humans habituate to nighttime traffic sounds, as country dwellers 居住者 do to choruses 齐声 of crickets 蟋蟀 and tree frogs Each may initially find the other’s habitat 栖息地unbearably noisy at first, but eventually stops responding to the novel sounds 25.1 How Do Innate and Learned Behaviors Differ?

11. Learned behaviors require experience (continued) Conditioning 条件反射 is a learned association between a stimulus and a response A more complex form of learning is called trial-and-error learning 尝试-错误学习in which new and appropriate responses to stimuli are acquired through experience 25.1 How Do Innate and Learned Behaviors Differ?

12. Learned behaviors require experience (continued) Conditioning is a learned association between a stimulus and a response (continued) Animals are faced with naturally occurring rewards and punishments and can learn to modify their behavior in response to them A hungry toad 蟾蜍 that captures a bee quickly learns to avoid future encounters with bees 25.1 How Do Innate and Learned Behaviors Differ?

13. Figure 25-3 Trial-and-error learning in a toad A naive toad is presentedwith a bee. Presented with a harm-less robber fly 食虫虻, which resembles a bee, thetoad cringes 畏缩. While trying to eat thebee, the toad is stung 螫伤painfully on the tongue. The toad is presentedwith a dragonfly 蜻蜓. The toad immediately eats thedragonfly, demonstrating that thelearned aversion 厌恶 is specific to bees.

14. Learned behaviors require experience (continued) Conditioning is a learned association between a stimulus and a response (continued) Trial-and-error learning 尝试-错误学习is an important factor in the behavioral development of many animal species This type of learning plays a key role in human behavior For example, a child learns which foods taste good or bad, that a stove 火炉 can be hot, and not to pull a cat’s tail 25.1 How Do Innate and Learned Behaviors Differ?

15. Learned behaviors require experience (continued) Conditioning is a learned association between a stimulus and a response (continued) Operant conditioning 操作性条件反射 allows animals to learn behaviors to receive a reward or to avoid punishment Operant conditioning has been used to train animals to perform tasks far more complex than pressing a lever 压杆 Rats have learned to avoid foods that make them sick 25.1 How Do Innate and Learned Behaviors Differ?

16. Learned behaviors require experience (continued) Insight 直觉 is problem solving without trial and error In certain situations, animals seem to solve problems suddenly, without prior experience This kind of sudden problem solving is called insight learning 顿悟学习, because it is superficially similar to 表面上的相似 how humans mentally manipulate concepts to arrive at a solution 25.1 How Do Innate and Learned Behaviors Differ?

17. Learned behaviors require experience (continued) Insight is problem solving without trial and error (continued) In certain situations, animals seem to solve problems suddenly, without prior experience (continued) In 1917, Kohler showed that a hungry chimpanzee, without any previous training, could stack boxes to reach a banana suspended from the ceiling Epstein and colleagues performed an experiment showing that pigeons may be capable of insight learning 25.1 How Do Innate and Learned Behaviors Differ?

18. There is no sharp distinction between innate and learned behaviors No behavior is totally innate or learned All behaviors are a mixture of the two 25.1 How Do Innate and Learned Behaviors Differ?

19. There is no sharp distinction between innate and learned behaviors (continued) Seemingly innate behavior can be modified by experience Behaviors that seem to be performed correctly on the first attempt without prior experience can later be modified by experience For example, a newly hatched gull chick is able to peck at a red spot on its parent’s beak 喙, an innate behavior that causes the parent to regurgitate 反刍 food for the chick to eat 25.1 How Do Innate and Learned Behaviors Differ?

20. Figure 25-4 Innate behaviors can be modified by experience

21. There is no sharp distinction between innate and learned behaviors (continued) Seemingly innate behavior can be modified by experience (continued) Habituation can also fine-tune 微调 an organism’s 生物体 innate responses to environmental stimuli For example, young birds crouch down 蹲下身 when a hawk flies over but ignore harmless birds such as geese Early scientists hypothesized that only the very specific shape of predatory birds provoked crouching 25.1 How Do Innate and Learned Behaviors Differ?

22. There is no sharp distinction between innate and learned behaviors (continued) Seemingly innate behavior can be modified by experience (continued) Using an ingenious 设计独特的 model, Tinbergen and Lorenz, two of the founding fathers of ethology 动物行动学, tested and confirmed the hypothesis 25.1 How Do Innate and Learned Behaviors Differ?

23. There is no sharp distinction between innate and learned behaviors (continued) Learning may be governed by innate constraints Learning always occurs within boundaries that help increase the chances that only the appropriate behavior is acquired Example of this concept includes a robin 知更鸟, whose ability to learn songs is limited to those of its own species; the songs of other species are excluded 25.1 How Do Innate and Learned Behaviors Differ?

24. There is no sharp distinction between innate and learned behaviors (continued) Learning may be governed by innate constraints (continued) The innate constraints on learning are perhaps most strikingly illustrated by imprinting 印痕 Imprinting is a form of learning in which an animal’s nervous system is rigidly 严格地 programmed to learn a certain thing only during a certain period (sensitive period) of development 25.1 How Do Innate and Learned Behaviors Differ?

25. There is no sharp distinction between innate and learned behaviors (continued) Learning may be governed by innate constraints (continued) Imprinting is best known in geese, ducks, and chickens These birds learn to follow the animal or object that they most frequently encounter during an early sensitive period In the laboratory, these birds may imprint on a toy train or other moving object 25.1 How Do Innate and Learned Behaviors Differ?

26. Figure 25-5 Konrad Lorenz and imprinting

27. There is no sharp distinction between innate and learned behaviors (continued) All behavior arises out of interaction between genes and the environment Ethologists realize that no behavior can be caused strictly by genes or strictly by the environment The relative contributions of heredity 遗传性 and learning vary among animal species and among behaviors within an individual 25.1 How Do Innate and Learned Behaviors Differ?

28. There is no sharp distinction between innate and learned behaviors (continued) All behavior arises out of interaction between genes and the environment (continued) The nature of the link between genetics and environmental components is not well understood, but some evidence exists Bird migration is learned by experience through navigation with celestial 天空的 cues 25.1 How Do Innate and Learned Behaviors Differ?

29. There is no sharp distinction between innate and learned behaviors (continued) All behavior arises out of interaction between genes and the environment (continued) Naive migrating birds, hatched only months earlier, travel properly from one location to another without any previous experience The birds, thus, appear to be born with the ability to migrate; it must be in their genes 25.1 How Do Innate and Learned Behaviors Differ?

30. There is no sharp distinction between innate and learned behaviors (continued) All behavior arises out of interaction between genes and the environment (continued) Genetically controlled ability to migrate is supported by hybridization experiments with blackcap warblers 林莺 This species breeds in Europe and migrates to Africa Birds from western Europe travel in a southwesterly direction to reach Africa Birds from eastern Europe travel to the southeast 25.1 How Do Innate and Learned Behaviors Differ?

31. There is no sharp distinction between innate and learned behaviors (continued) All behavior arises out of interaction between genes and the environment (continued) If birds from the two populations are crossbred in captivity 笼养, however, the hybrid offspring migrate due south向正南方 —the intermediate 中间的 between the orientations of the two parents This suggests that parental genes—of which offspring inherit a mixture—influence migratory direction 25.1 How Do Innate and Learned Behaviors Differ?

32. Figure 25-6 Genes influence migratory behavior breeding range winter range

33. Animals frequently broadcast information Sounds uttered Movements made Chemicals emitted Level of aggression 攻击 Readiness to mate If this information evokes a response from other individuals, and if that response tends to benefit the sender and the receiver, then a communication channel can form 25.2 How Do Animals Communicate?

34. Communication 交流 is the production of a signal by one organism that causes another organism to change its behavior in a way beneficial to both Although animals of different species may communicate, most animals primarily communicate with members of their own species The ways in which animals communicate are astonishingly diverse Visual displays, sound, chemicals, and touch 25.2 How Do Animals Communicate?

35. Visual communication is most effective over short distances Animals with well-developed eyes use visual signals to communicate Visual signals can be active, in which a specific movement or posture conveys 表达 a message Visual signals may be passive 被动的, in which the size, shape, or color of the animal conveys important information, commonly about its sex and reproductive state 25.2 How Do Animals Communicate?

36. Figure 25-7 Active visual signals

37. Figure 25-8 A passive visual signal

38. Visual communication is most effective over short distances (continued) Active and passive signals can be combined Like all forms of communication, visual signals have both advantages and disadvantages On the plus side, visual signals are instantaneous 即刻的 and can convey a variety of messages in a short period, and they are quiet and unlikely to alert distant predators 25.2 How Do Animals Communicate?

39. Visual communication is most effective over short distances (continued) Like all forms of communication, visual signals have both advantages and disadvantages (continued) On the negative side, visual signals are generally ineffective in dense vegetation 浓密的植被 or in darkness, and they are limited to close-range communication 25.2 How Do Animals Communicate?

40. Figure 25-9 Active and passive visual signals combined 变色龙蜥蜴

41. Communication by sound is effective over longer distances As with visual signals, sound signals are almost instantaneous But unlike visual signals, sound can be transmitted through darkness, dense forests, and murky water 混水 Acoustic 声学的 signals can also be effective over longer distances than visual signals The low, rumbling 隆隆声calls of an African elephant can be heard by elephants several miles away 25.2 How Do Animals Communicate?

42. Communication by sound is effective over longer distances (continued) Different messages can be conveyed by variations in sound pattern, volume, and pitch For example, ethologist Thomas Struhsaker, studying vervet monkeys 长尾猴 in Kenya, found that they produced different calls in response to threats from each of their major predators 捕食者: snakes, leopards 美洲豹, and eagles 25.2 How Do Animals Communicate?

43. Communication by sound is effective over longer distances than visual signals (continued) The use of sound is not limited to birds and mammals Male crickets 蟋蟀 produce species-specific songs that attract female crickets of the same species The high-pitched whine 哼哼唧唧 of a female mosquito 蚊子, as she prepares to bite, alerts nearby males that she may soon have the blood meal necessary for laying eggs 产卵 25.2 How Do Animals Communicate?

44. Communication by sound is effective over longer distances than visual signals (continued) The use of sound is not limited to birds and mammals (continued) Male water striders 水黾 vibrate their legs, sending species-specific patterns of vibrations through the water, attracting mates and repelling other males Many species of fish produce croaks呱呱, grunts呼噜声, or other sounds 25.2 How Do Animals Communicate?

45. Figure 25-10 Communication by vibration

46. Chemical messages persist longer but are hard to vary Chemicals produced by individuals that influence the behavior of other members of the same species are called pheromones信息素 Pheromones can carry messages over long distances and take little energy to produce They are typically not detectable by other species, and so do not attract predators 25.2 How Do Animals Communicate?

47. Chemical messages persist longer but are hard to vary (continued) Chemicals produced by individuals and that influence the behavior of other members of the same species are called pheromones(continued) They can act as a signpost 标志杆, persisting over time and marking an animal’s boundaries 界限 While chemicals convey critical information, fewer and simpler messages can be conveyed than with sight- or sound-based systems 25.2 How Do Animals Communicate?

48. Chemical messages persist longer but are hard to vary (continued) Pheromones can cause immediate changes in the behavior of the detecting animal For example, foraging termites 觅食白蚁 that discover food lay a trail of 一路 pheromones from the food to the nest, and other termites follow the trail 25.2 How Do Animals Communicate?

49. Figure 25-11 Communication by chemical messages

50. Chemical messages persist longer but are hard to vary (continued) Pheromones can also cause physiological 生理的changes in the detecting animal For example, the queen honeybee produces a pheromone, queen substance 蜂王浆信息素, which prevents other females in the hive 蜂巢 from becoming sexually mature 25.2 How Do Animals Communicate?