Chapter 13: Communication Communication and Honesty Communication and Group Foraging Finding Mates Predators

FIGURE 13. 1a. Vervet alarm calls FIGURE 13.1a. Vervet alarm calls. Vervets give different alarm calls depending on what type of predator has been sighted. (A) Vervets stand up after hearing a “chutter” alarm call indicating that a snake (approaching from the bottom left of the photo) has been spotted. When a leopard (B) is detected, vervets give a “barking” alarm call and (C) climb trees for safety. (Photo credits: Richard Wrangham/Anthrophoto; Ian Jones/Alamy)

FIGURE 13. 1b. Vervet alarm calls FIGURE 13.1b. Vervet alarm calls. Vervets give different alarm calls depending on what type of predator has been sighted. (A) Vervets stand up after hearing a “chutter” alarm call indicating that a snake (approaching from the bottom left of the photo) has been spotted. When a leopard (B) is detected, vervets give a “barking” alarm call and (C) climb trees for safety. (Photo credits: Richard Wrangham/Anthrophoto; Ian Jones/Alamy)

FIGURE 13. 1c. Vervet alarm calls FIGURE 13.1c. Vervet alarm calls. Vervets give different alarm calls depending on what type of predator has been sighted. (A) Vervets stand up after hearing a “chutter” alarm call indicating that a snake (approaching from the bottom left of the photo) has been spotted. When a leopard (B) is detected, vervets give a “barking” alarm call and (C) climb trees for safety. (Photo credits: Richard Wrangham/Anthrophoto; Ian Jones/Alamy)

Honesty in Communication FIGURE 13.3. Toad size and croaks. The relationship between male size (as indicated by his snout-vent length) and the frequency of a male’s call. Call frequency may be an honest indicator of size, and hence of fighting ability. (Based on Davies and Halliday, 1978)

Honesty in Communication: Coordinating Group Foraging FIGURE 13.4. Vocal repertoire and group size. There is a positive correlation between vocal repertoire and group size in the 42 species of primates examined here. The x-axis and y-axis are measured in “contrasts,” which allow a statistical analysis that takes into account the phylogenetic relationship of the species studied (see Chapter 2). (From McComb and Semple, 2005)

TABLE 13.1. Squeak calls attract others.

FIGURE 13.5. Raven yells. Under certain conditions, ravens emit a loud “yell” upon uncovering a new food source. Such yells attract other birds. (Photo credit: Bernd Heinrich)

FIGURE 13. 6. Yellers are hungry FIGURE 13.6. Yellers are hungry. In ravens, “yelling” is often associated with foraging—in particular, calling others to a food bonanza. Immature ravens yell progressively more as a function of hunger. (Based on Heinrich and Marzluff, 1991)

FIGURE 13. 7. Raven recruitment FIGURE 13.7. Raven recruitment. The line denotes when the number of ravens that knew of the prey source equals the number of ravens at the prey source the next day. Points below the line indicate recruitment because they are instances in which more birds arrived at food after roosting than birds that previously knew of the food’s location. (Based on Marzluff et al., 1996, p. 99)

FIGURE 13.8. Bee foraging. Honeybee foraging involves a complex communication system, including waggle dances. This dance, along with other informational cues, gives bees in a hive information about the relative position of newly found food sources. (Photo credit: Leroy Simon/Visuals Unlimited)

FIGURE 13. 9. Honeybee waggle dances FIGURE 13.9. Honeybee waggle dances. (A) Imagine a patch of flowers that is 1,500 meters from a hive, at an angle 40 degrees west of the sun. (B) When a forager returns, the bee dances in a figure-eight pattern. In this case, the angle between a bee’s “straight run” (up and down a comb in the hive) and a vertical line is 40 degrees. (C) The length of the straight run portion of the dance translates into distance from the hive to the food source. (Based on Seeley, 1985)

FIGURE 13. 10. Different honeybee dances. The three honeybee dances FIGURE 13.10. Different honeybee dances. The three honeybee dances. Each bee at its initial starting point is shown in full color, and the same bee is shown in fainter colors as it moves along the path of its dance. (Based on Johnson et al., 2002, p. 171)

FIGURE 13. 11. Number of dance circuits FIGURE 13.11. Number of dance circuits. The number of “figure-eight” circuits in a waggle dance when bees were raised at a temperature of 36˚C or 32˚C. (Based on Tautz et al., 2003, p. 7345)

FIGURE 13. 13. Devastating leafcutters FIGURE 13.13. Devastating leafcutters. Leaf-cutter ants can ravage foliage in their path. The ants don’t attack all the leaves, however, but instead they often strip some leaves to the stalk (for example, those that are most tender or have fewer secondary compounds present), while leaving other leaves untouched. (Photo credit: Carver Mostardi/Alamy)

FIGURE 13. 14. Stridulating communication FIGURE 13.14. Stridulating communication. A schematic of a leafcutter ant cutting a leaf and stridulating its gaster up and down. (Based on Holldobler and Roces, 2001)

Finding Mates FIGURE 13.16a. Communication in cock-of-the-rocks. (A) A male cock-of-the-rock. (B) A group of males displaying and singing to attract females. (Photo credits: Sylvain Cordier/Getty Images; SA Team/Foto Natura/Getty Images)

FIGURE 13. 16b. Communication in cock-of-the-rocks FIGURE 13.16b. Communication in cock-of-the-rocks. (A) A male cock-of-the-rock. (B) A group of males displaying and singing to attract females. (Photo credits: Sylvain Cordier/Getty Images; SA Team/Foto Natura/Getty Images)

FIGURE 13. 17. Same versus different songs FIGURE 13.17. Same versus different songs. Female cowbirds had longer copulation-solicitation displays (CSDs) when they were exposed to three different songs than to the same song played three times. Each point represents the CSDs of one female. (From Hosoi et al., 2005, p. 89)

FIGURE 13. 18. Sex differences and songs FIGURE 13.18. Sex differences and songs. Across seventeen species of blackbirds, the maximum note length of songs increased as the size difference between males and females increased. The x and y axes have been transformed into independent contrasts and can take negative values. (From J. J. Price and Lanyon, 2004a, p. 490)

FIGURE 13. 19. Phylogeny, sexual selection, and song FIGURE 13.19. Phylogeny, sexual selection, and song. A phylogeny of oropendola and cacique birds with changes in song characters mapped on. Above the branches are song characters as they are added or dropped from the song repertoire. SO = song output, SV = song versatility, FR = frequency range, PR = pause rate, NL = maximum note length, and NO = note overlap. Numbers below branches show male/female size ratios. (From Price and Lanyon, 2004a)

TABLE 13.2. The different ways to sing.

FIGURE 13. 20a. Ripple communication by water striders FIGURE 13.20a. Ripple communication by water striders. (A) The concentric circles of these ripples in a pond are part of the communication used by the water strider, R. kraepelini. (B) A close-up of the male water strider (R. kraepelini) and the ripples he is making to communicate with other water striders. (C) An experimental setup to study ripple communication, in which an A. remigis female is making a signal via a magnet glued to her leg. In nature, female water striders don’t emit such signals. (Photo credits: Stim Wilcox)

FIGURE 13. 20b. Ripple communication by water striders FIGURE 13.20b. Ripple communication by water striders. (A) The concentric circles of these ripples in a pond are part of the communication used by the water strider, R. kraepelini. (B) A close-up of the male water strider (R. kraepelini) and the ripples he is making to communicate with other water striders. (C) An experimental setup to study ripple communication, in which an A. remigis female is making a signal via a magnet glued to her leg. In nature, female water striders don’t emit such signals. (Photo credits: Stim Wilcox)

FIGURE 13. 20c. Ripple communication by water striders FIGURE 13.20c. Ripple communication by water striders. (A) The concentric circles of these ripples in a pond are part of the communication used by the water strider, R. kraepelini. (B) A close-up of the male water strider (R. kraepelini) and the ripples he is making to communicate with other water striders. (C) An experimental setup to study ripple communication, in which an A. remigis female is making a signal via a magnet glued to her leg. In nature, female water striders don’t emit such signals. (Photo credits: Stim Wilcox)

Predation FIGURE 13.21. Protecting a mate. While downy woodpeckers don’t give alarm calls when they are paired with same-sex partners, they emit such alarm calls when they are paired with a member of the opposite sex. (Photo credit: Harold R. Stinnette Photo Stock/Alamy)

FIGURE 13. 22. Age differences in reaction to alarm calls FIGURE 13.22. Age differences in reaction to alarm calls. In meerkats, a pup’s response to alarm calls was not as strong as the response seen in adults: (A) time until reaction after hearing playback of alarm call, (B) duration of response to playback of alarm call, and (C) length of time spent “scanning” the environment for predators after hearing alarm call. (Based on Hollen and Manser, 2006, p. 1350)

FIGURE 13. 23. Dishonest alarm calls in swallows FIGURE 13.23. Dishonest alarm calls in swallows? (A) Male barn swallows often give false alarm calls when their fertile mates leave the nest vicinity. (B) These false alarm calls sometimes disrupt extrapair copulations (EPCs). (C) Møller hypothesized that male swallows would give false alarm calls when they were at the greatest risk of EPCs to disrupt the EPCs. To test this hypothesis, Møller removed a female from the nest at different stages in the breeding cycle for both solitary breeding swallows and colonial breeding swallows. Solitary breeding males almost never emitted alarm calls when their mate was temporarily gone. Colonial breeding males emitted false alarm calls during the period in which EPCs were most likely (during egg laying). (Based on Møller, 1990)

FIGURE 13. 23. Dishonest alarm calls in swallows FIGURE 13.23. Dishonest alarm calls in swallows? (A) Male barn swallows often give false alarm calls when their fertile mates leave the nest vicinity. (B) These false alarm calls sometimes disrupt extrapair copulations (EPCs). (C) Møller hypothesized that male swallows would give false alarm calls when they were at the greatest risk of EPCs to disrupt the EPCs. To test this hypothesis, Møller removed a female from the nest at different stages in the breeding cycle for both solitary breeding swallows and colonial breeding swallows. Solitary breeding males almost never emitted alarm calls when their mate was temporarily gone. Colonial breeding males emitted false alarm calls during the period in which EPCs were most likely (during egg laying). (Based on Møller, 1990)

FIGURE 13. 24. Deceptive alarm calling in topi FIGURE 13.24. Deceptive alarm calling in topi. (A) A male topi (in background) has given a false alarm snort close to the boundary of his territory and now stares into the distance, as he does when a stalking predator has been detected. A sexually receptive female in the foreground (darker) looks toward the potential danger. (B) As the female begins to move away, the male looks toward the female (note the change in the orientation of his gaze and the different position of the ears. (C) Soon thereafter, the male mates with the female. (From Bro-Jorgensen and Pangle, 2010)

FIGURE 13. 25. Alarm calls in Richardson’s squirrels FIGURE 13.25. Alarm calls in Richardson’s squirrels. Over time, when predator alarm calls are unreliable, juvenile squirrels begin to ignore such false alarm cues. (Photo credit: John Cancalosi/naturepl.com)

FIGURE 13. 26. Responses to reliable and unreliable alarm calls FIGURE 13.26. Responses to reliable and unreliable alarm calls. Postural change—elevation of the head in the direction of the perceived threat—differed depending on whether the alarm caller was a reliable source. Reliable alarm calls are shown in green; unreliable alarm calls are shown in orange. (From Hare and Atkins, 2001, p. 110)