Exercise 13: Behavior of the House Cricket (Acheta domesticus)

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1 Exercise 13: Behavior of the House Cricket (Acheta domesticus) 1

2 Animal Behavior Why do praying mantises display a unique mating system, called sexual cannibalism, where a member of a male-female pair kills and consumes the other during courtship or copulation? At the end of every summer, why do more than 100 million monarch butterflies sweep across North America to overwinter further south in California and Mexico? 2

3 Communication The ability to communicate effectively with other individuals plays a critical role in the lives of all animals. Moths attract a mate Ground squirrels convey information about nearby predators Chimpanzees maintain positions in a dominance hierarchy 3

4 Senders and Receivers Animal communication is classically defined as occurring when...the action of or cue given by one organism [the sender] is perceived by and thus alters the probability pattern of behavior in another organism [the receiver] in a fashion adaptive to either one both of the participants (Wilson 1975). 4

5 The female Photuris fireflies manipulate smaller, male Photinus fireflies by mimicking the flash signals produced by Photinus females. When males investigate the signal, they are voraciously consumed by the larger firefly (Lloyd 1975) Male tungara frogs(physalaemus pustulosus) produce advertisement calls to attract females to their location; fringe-lipped bats also detect the calls, and use that information to locate and capture frogs (Ryan et al. 1982). Who benefits during these interactions? The sender or the receiver? 5

Greater sage grouse illustrate such true communication ; during the mating season, males produce strutting displays, and females use this information about male quality to

6 Greater sage grouse illustrate such true communication ; during the mating season, males produce strutting displays, and females use this information about male quality to choose which individuals to mate with (Vehrencamp et al. 1989). 9_72xLeF0 Who benefits during these interactions? The sender or the receiver? 6

Why communicate? Sexual advertisement and mate attraction Male satin bowerbirds, Ptilonorhynchus violaceus: https://www.youtube.com/watch?

7 Why communicate? Sexual advertisement and mate attraction Male satin bowerbirds, Ptilonorhynchus violaceus: Lyre Bird Conflict resolution, including territory defense. Red deer, Cervus elaphus, exhibit a complex signaling system. Identify young Brazilian free-tailed bats Convey information about the environment to conspecifics, especially close relatives. Vervet monkeys 7

8 Signal Modalities Animals use a variety of sensory channels, or signal modalities, for communication. 8

9 Visual Signaling Visual signals are very effective for animals that are active during the day. 9

10 Chemical Signaling Travel much more slowly through the environment since they must diffuse from the point source of production. Can be transmitted over long distances and fade slowly once produced. Silkmoths: Pheremones Asian Elephants:Specialized vomeronasal organ that is used exclusively to detect chemical cues. 10

11 Tactile Signaling Physical contact occurs between the sender and the receiver Transmitted over very short distances. Important in building and maintaining relationship among social animals. 11

12 Electrical Signaling For aquatic animals living in murky waters, electrical signaling is an ideal mode of communication. Sharks and rays have the ability to detect electrical signals using specialized electroreceptor cells 1:34-3:04 12

Acoustic Signaling Acoustic communication is abundant in nature- sound can be adapted to a wide variety of environmental conditions and behavioral situations.

13 Acoustic Signaling Acoustic communication is abundant in nature- sound can be adapted to a wide variety of environmental conditions and behavioral situations. Sounds can vary substantially in amplitude, duration, and frequency structure, all of which impact how far the sound will travel in the environment and how easily the receiver can localize the position of the sender. 13

14 Orienting Responses Tropism: turning or bending toward OR away from an external stimulus Kinsesis: Movement in response to a stimulus (but not directly toward or away from the stimulus). Think temperature! Taxis: Movement toward or away from a stimulus Long-distance orientation: toward or a goal they do not yet perceive with their senses. Think compass orientation. 14

15 Acheta domesticus BIO 206L Structure and Function of Organisms 15

16 Only males stridulate (sing)! 16

17 Why Do Crickets Sing? Tinbergen s (1963) Four Questions Causation: How do crickets produce their song? How can they hear it? Development: How do the song system and auditory system arise during ontogeny? Proximate Mechanisms Survival Value (Function): How does singing contribute to survival and fitness? Evolution: How did song production and acoustic communication arise over evolutionary time? Ultimate Mechanisms Niko Tinbergen ( ) and Konrad Z. Lorenz ( ) Nobel Prize in Physiology or Medicine

Cricket songs are produced with forewings (tegmina) On the tegmina is a series of sharp teeth, forming a file. A sharp-edged ridge on the outer edge of the other wing forms a plectrum, or scraper.

18 Cricket songs are produced with forewings (tegmina) On the tegmina is a series of sharp teeth, forming a file. A sharp-edged ridge on the outer edge of the other wing forms a plectrum, or scraper. By moving the scraper across the other file, a vibration is set up which resonates on an area of the wing known as the harp. Is this a proximate or ultimate explanation of cricket song? 18

19 Crickets Wear Their Ears on Their Forelegs Just Below the Knees Spiracle Spiracle Tympanum Spiracle Spiracle Tympanum Tympanum Scanning electron micrograph 19

20 The Function of Cricket Song: It s All About Sex! 20

21 Animal Communication SIGNAL SENDER RECEIVER Cricket phonotaxis: by females The parasitic fly Ormia ochracea depositing eggs on a male cricket 21

22 More Information about Cricket Songs Crickets chirp at different rates depending on their species. Crickets chirp at different rates depending on ambient temperature. Several types of cricket songs are in the repertoire of some species: Calling song attracts females and repels other males. Courting song is used when a female cricket is near and encourages her to mate with the caller. Triumphal song is produced after a successful mating. May reinforce the mating bond to encourage the female to lay some eggs rather than find another male. Aggressive song is triggered by contact chemoreceptors on the antennae that detect the presence of another male cricket. Call frequency is a reliable indicator of male size. Female crickets can tell how big a male is just by listening to the pitch of the song. Predators are known to hunt crickets by their sound include cats, herons and geckos. However, as most humans know, crickets will stop vocalizing when approached. 22

23 Designing an Experiment Your job this week is to generate a hypothesis about the relationship between cricket behavior and cricket song and then design and conduct an experiment to test this hypothesis. You will first demonstrate that female crickets can locate males by phonotaxis. You can then explore a variety of questions using the equipment listed on the next slide. Ideas: response to conspecific vs. heterospecific songs, response to visual vs. acoustic signaling, effects of predators or shelter or food or numbers, etc. on response Measure cricket morphometrics AFTER experiment (e.g., overall size (length, mass), ovipositor length for females, wing length for males, and others -cerci, pronotum width, etc. 23

song Cricket food Materials to make a cricket shelter

24 Equipment and Supplies Arena Female crickets Male crickets Speakers Conspecific cricket song Heterospecific cricket song Cricket food Materials to make a cricket shelter Predator call: 24

25 Experimental Design 1) Confirm phonotaxis first 2) Design your experiment and then check with your TA before beginning your group experiment! 3) Replicates! Same size needs to be >10 for each group (control group and treatment group!) 4) Think about how you are going to measure cricket behavior 5) Measure cricket morphometrics AFTER experiment ( ~4 C or on ice to help sedate cricket to measure). Use calipers or ruler under dissecting microscope. Morphometric aspects correlated with maturity and often behavior: overall size (length, mass), ovipositor length for females, wing length for males, and others -cerci, pronotum width, etc. 25

Signal Costs and Constraints

Signal Costs and Constraints Costs to senders of signaling Costs to receivers Constraints on senders and receivers Transmission constraints Reading: Ch. 17 Peer evaluation of group projects Please evaluate