part 2 個體行為與機制

Part 2 個體行為與機制鄭先祐 (Ayo)

國立臺南大學環境生態研究所教授

part 2 Chap. 2 Sensory systems and behavio行為生態學ur

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Part 2 Mechanisms and Individual behaviour

Chap. 2 Sensory systems and BehaviourChap. 3 The ecology of information useChap. 4 Recognition systems Chap. 5 Managing time and energyChap. 6 Sperm competition and mating systems


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Chap. 2 Sensory systems and Behaviour / R. Wehner

How behaviour is affected by constraints from both the physical environment and the animal’s own body. ( 個體行為如何受到環境與自身的限制 )

How complex behaviour may be the outcome of simple subroutines. ( 複雜行為如何可能是簡單機制之展現 )– Some migratory birds may use a simple sun-compass mech

anism to fly the great-circle route around the globe.


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2.1 IntroductionFunctional ( 功能 ) (why-question) approach

– Aims at an understanding of the fitness consequences of a particular mode of behaviour

Mechanistic ( 機轉 ) (how-question) approach– Tries to understand the physiological machinery

mediating that behaviour.Economic ( 經濟 ) approach

– Cost – benefit analyses ( 本利分析 )– Currency ?

Constraints ( 限制 ) approach


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Constraints approach

By the physical environment (sect. 2.2)By the organism itself (body size) (sect. 2.

3)The fine tuning of behavioural performance

s (sect. 2.4)– Constraints ( 限制 ) set by the animal’s comput

ational capabilities


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2.2 constraints imposed on behaviour by the physical environment

環境限制行為的展現。– 水域 (water) vs. 空域 (air)

• 體型、大小、活動力 ( 魚類 vs. 鳥類 )– 有光 vs. 黑暗

• 海面，深海， 800-1200m 深海• 愈深海的魚類，眼睛的感光能力愈是重要。• 直到黑暗的深海，眼睛才完全退化。


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Molecular constraints ( 分子的限制 )

The rods, dim-light receptors, are tightly clustered around 500nm. – Good adaptation to the spectral light conditions prevailin

g at depths of about 100m. (Fig. 2.1a)– The cones 的吸收光譜，隨著不同的生活環境，不同種的魚類各有不同。 (Fig. 2.1b)

Why does the family of rod pigments exhibit such evolutionary inertia, while that of the cone pigments does not?– Molecular constraints might be as significant as ecologica

l ones.


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Fig 2.1(a) Histogram: absorption maxima of 274 photopigments (rhodopsins) of vertebrate rod photoreceptors. Curves relative sensitivity (relative quantum catch ) of rod rhodopsin as a function of λmax calculated for various depths of water (0 – 1000m).


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Fig. 2.1(b) Absorption maxima (λmax) of the photopigments of rods (dark grey area) and cones (black bars) of 12 species of teleost fish belonging to the genus Lutjanus and inhaviting different marine habitats. 1. outer reef; 2. middle reef; 3. inner reef; 4. estuary.


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聲音的傳導 The propagation of sound pressure waves is almost f

ive times faster in water than in air. The power of sound emission depends on the produ

ct of the velocity of propagation and the density of the medium. 水大約是空氣的 3,500 倍。

因此，水中的聲音可以傳送很遙遠。 Fin whales might hear each other over distances of s

everal hundred kilometers. ( 數百公里的距離 )


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Trade-off between the range and the accuracy of target detection

The higher the frequency of the emitted sound, the better the spatial resolution that can be achieved, but the stronger the attenuation of the signal as distance increases. 頻率高，較精準；但易隨距離耗弱。

The frequency of the echolocating sound is inversely related to the height of the preferred foraging area. ( 覓食區愈高，頻率愈低 ) (Fig. 2.2)

唯一例外， false vampire, which hunts close to the ground, detects its prey (beetles, birds, mice, etc.) not by using its sonar system but by listening to the sounds produced by the moving prey itself.


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Fig. 2.2 Relationship between the best frequencies and the preferred foraging ranges of echolocating bats in southern india.


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Auditory communication in insects

Most insect songs lie in the high sonic or ultrasonic range.

The attenuation and degradation of these high-frequency sounds by vegetation poses intricate( 難理解的 ) questions.

植被愈密，聲音愈大。但不只是要聽到，且也需要辨識，這是個難題。干擾過多。 Body size?


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2.3 constraints due to one of the most fundamental biological characteristics: body size

不同大小的動物，體型不會以等比的方式改變。動物體型加大，其體型就會改變，運動方式也會改變。

– 大人國？小人國？– 大象 vs. 小老鼠


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Fig. 2.3 (a) Frequency- dependent sound attenuation in a bushcricket habitat. The four curves refer to sounds of 5, 10, 20 and 40 kHz.


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2.3.1 Visual acuity ( 敏銳度 )

單眼 (single lens eyes) vs. 複眼 (compound eyes)Compound eyes are rather large and restricted to s

mall animals (Fig. 2.4a)– 每單位 information 的 cost, 複眼較高。– 單眼有較高的 information uptake (Fig. 2.4b)

Why are insects and crustaceans using such an inferior optical instrument?


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Fig. 2.4a Relative size of compound eyes and single-lens eyes in arthropods (A) and vertebrates (V).


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Fig. 2.4 b. the unit cost of the total amount of information acquired.


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Fig. 2.5 (a ) The visual field of a jumping spider. (with single-lens eyes)(b) visual field of a praying mantis. (with compound eyes)


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2.3.2 sound-source detection

身體愈小，發聲的頻率愈高，傳送的距離愈短。 Body lengths below 1cm are restricted generally to u

ltrasound. Ultrasound is a useful means of communication only

in free space or at a short range. 小型昆蟲，要傳聲音到數公尺遠，運用 substrate-

borne vibrations. 或是 air oscillation, caused by wing vibration.


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2.4 Constraints set by the animal’s computational capabilities

Computational software and physiological hardware of animal behaviour

2.4.1 coping with spherical geometry: the egg and the globe

2.4.2 Reading skylight patterns and landmark panoramas( 全景象 ): the insect navigator

2.4.3 Computing interception courses: male pursuits and fly-ball catching


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2.4.1 coping with spherical geometry: the egg and the globe

Ichneumonid wasps lay their eggs into the eggs of other insect species.

The number of eggs which are deposited on the size of the host egg.

In determining the volume of the spherical host, the wasp assumes a particular body posture, in which the angle between the head and the first segment of the antenna is related to the radius of the sphere (Fig. 2.6)


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Fig. 2.6 Parasitoid wasps, Trichogramma minutum, use the surface curvature of their host eggs to determine the number of progeny allocated to the host.


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Migrating birds: Orthodrome vs loxodrome

Fig. 2.7 Orthodrome (great circle) and loxodrome (constant angles) courses drawn on the surface of the globe.

Solid line, orthodrome; dotted line, loxodrome


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Migrating birds Long distance migrants do not travel on either ortho-dr

ome or loxo-drome courses, but seem to employ a number of navigational subroutines rather than an all-purpose system of navigation.

In conclusion, during evolutionary time the migration routes of birds have been shaped by a number of quite different selection pressures, e.g. by synoptic weather patterns, large-scale topography, suitability of celestial or magnetic cues, etc.


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2.4.2 Reading skylight patterns and landmark panoramas( 全景象 ): the insect navigator

While foraging in a circuitous way over distance of more than 200m, Cataglyphis ants of the Sahara desert navigate by path integration.

They continually measure all angles steered and all distances covered, and integrate these angular and linear components of movement into a continually updated vector always pointing home. (Fig. 2.8)


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Fif. 2.8 Outward and homeward paths of an individually foraging desert ant, Cataglyphis fortis.Grid width, 5m.Time marks (small filled circles) are given every 60s.


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Reading skylight patternsThe compass used by Cataglyphis ant to mo

nitor the angular components of its movements.

This compass is a skylight compass based primarily on a peculiar stray-light pattern in the sky, the pattern of polarized light (or E-vector pattern; Fig. 2.9a).


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Fig. 2.9 (a) Two-dimensional representation of the E-vector pattern in the sky shown for two elevations of the sun (black disc): 25 度 (left) and 60 度 (right). The orientation of the E-vectors (the directions of polarized light) are represented by the orientation of the black bars.

The zenith ( 天頂 ) is depicted by an open circle.

0 度 , solar meridian ( 子午線 );

180 度 , anti-solar meridian

The sizes of the black bars mark the degree of polarization.


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Fig. 2.9 (b) The ant’s internal representation of the sky as derived from behavioural experiments. The open bars indicate where in the sky the insect assumes any particular E-vector to occur. This ‘template’ is used invariably for all elevations of the sun (for details see Wehner, 1994)


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In conclusion, evolution has managed to build into the insect navigator a nervous system that includes only some general knowledge about the geometrical characteristics of the celestial world, but this partial knowledge is sufficient if the navigator restricts its field trips to short periods of time.

The insect assumes that the celestial hemisphere does not change during any of its particular foraging excursions.


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The snapshot-matching mechanism

Ants seem to acquire a two-dimensional visual template – or ‘snapshot’ – of the three dimensional landmark array around their nest, and later move so as to match this template as closely as possible with the current retinal image.


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2.4.3 Computing interception courses: male pursuits and fly-ball catching

Male hoverflies pursuing and finally catching passing females.

A male fly is able to foresee the female’s flight path and to compute the proper interception course (Fig. 2.12).


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Fig. 2.12 (a) Film recording of a hoverfly male, pursuing his quarry. Positions of male ( 黑點 ) and quarry ( 白點 ) 。 The broken line indicates the line of sight between male and quarry 20ms before the fly accelerates. (b) Simulation of the male;s behaviour on the assumption that he does not adopt and interception course but tracks his quarry.


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2.5 Outlook

行為生態學者與生理學者的整合。NeuroethologistsAdaptations tailored to particular ecological

needs rather than general-purpose processing devices.

New physiology, evolutionary physiology


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part 2 個體行為與機制

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