Notes � Animal behaviour I, The four problems of ethology

Greg Detre

Thursday, May 03, 2001

Prof. Steve Simpson, Natural History Museum

 

Essay title

Discuss the evolution of �honesty� and �deceit� in animal communication.

Reading

Wiley (1983) in Animal Behaviour ed,. by Halliday and Slater, Vol.2 Communication.

Axelrod & Hamilton (1981) Science 211, 1390-

R. Dawkins & Krebs (1978, 1984) in Behavioural Ecology (two editions have different versions) ed. by Krebs and Davies.

M. Dawkins & Guilford (1991) Anim. Behav. 41, 865-

Blumberg & Alberts (1992) Anim. Behav. 44, 382-

Dugatkin et al. (1992) Trends Ecol. Evol. 7, 202-

Noe (1990) Animal Behaviour 39, 78-90.

Reading � Wiley

Notes

�information� as �decreasing uncertainty�

Notes � Batesian mimicry, Salvato 1997 (web)

http://ufbir.ifas.ufl.edu/chap28.htm

Batesian mimicry involves a palatable, unprotected species (the mimic) that closely resembles an unpalatable or protected species (the model) (Devries 1987). This theory was first presented in 1861 by H. W. Bates in his attempt to explain the similar appearance and behavior of otherwise unrelated Central American butterfly species (Devries 1987). The larvae of these model butterflies eat plants that contain noxious substances which pass, either altered or unaltered, to the adult stage (Sheppard 1962). Such chemicals make the model undesirable to predators. The mimics lack these substances in their bodies making them quite edible. True Batesian mimicry is parasitic in nature with the model deriving no benefit and possible harm (Devries 1987). The mimics don�t share the models nasty taste or painful sting, just its appearance and behavior. Thus, the models may be harmed by being mistaken for palatable mimics and should evolve to rid themselves of these relationships (Devries 1987).

Since its conception, Batesian mimicry has been the subject of great debate and countless papers. Charles Darwin, although accepting Batesian mimicry, viewed it as accidental with the mimic looking similar enough to the unrelated model to allow it slight protection (Clarke and Sheppard 1960a). The theory is often misrepresented and confused with its counterpart, Mullerian mimicry. In this case, the model is not defined and several unpalatable species share warning colors or patterns to evade predation. Batesian relationships are found in many insect orders. This paper identifies the most spectacular example.

The swallowtail butterfly, Papilio dardanus, occurs throughout most of Africa. While the males maintain a typical swallowtail appearance, the females occur in over thirty different mimetic forms that clearly resemble various species of two danaid genera.

Notes � mimicry

http://www.accessexcellence.org/AE/AEPC/WWC/1995/mimicry.html

Mimicry is one of several anti-predatory devices found in nature. Specifically it is a situation in which one species called the mimic resembles in color, form, and/or behavior another species called the model. In so doing, the mimic acquires some survival advantage.

There are 2 basic forms of mimicry:

1. Batesian - the mimic (palatable) resembles the model (unpalatable) and only the mimic benefits.

2. Mullerian - both the mimic and the model are unpalatable and both benefit.

Batesian mimicry is most effective when the mimic is rare and its emergence follows that of the model. In Mullerian mimicry as density increases so does the adaptive value. Since mimicry provides potential survival value, the mimic with an adaptation that increases the likelihood of surviving is selected. Natural selection of these favorable variations has led to the coevolution of many species. The distinction among camouflage (cryptic coloration), warning coloration, and mimicry is not always clear. Mimicry, as opposed to camouflage and warning coloration, is specifically the resemblance between two organisms. The same techniques of deception are sometimes utilized in all three anti-predatory devices. These include variations in color, pattern, and structure.

Vocabulary

Mimicry, evolution, natural selection, adaptation, camouflage, warning coloration

Examples of Mimicry

Visual

1. monarch and viceroy butterflies (see Fig. 48.13 in Curtis, Barnes. 1989. Biology, 5th Ed.)

2. yellow jacket and sand wasp (see Fig. 48.15 in above reference)

3. syrphid fly and honey bee (see Fig. 48.11 in Campbell. 1987. Biology)

4. coral snake and colubrid snake (see plates I and II in Pough. Mimicry of Vertebrates; pp. 67-95)

5. cuckoo and various host birds (an example of egg mimicry)

6. red-backed salamander and red salamander

7. poison-fang blenny and Ecsenius blenny

8. gold-of-pleasure plant and the flax plant

9. mantid (insectivorous) and orchid (see Fig. 8 in Wickler. 1968. Mimicry in Plants and Animals)

10. ophrys (orchids) and female of some species

11. pipe-vine swallowtail butterfly and spice-bush swallowtail

12. caterpillars and catkins (see Geographica section of Oct. 89 National Geographic)

Odor

13. caterpillar and Myrmica ant (see Earth Almanac section of Dec. 91 National Geographic)

14. spider and red ant of Florida

Quotes

Discarded

Considering the evolution of communication is of prime importance: within this context of increased fitness derived from a communication, we have to consider the mechanisms by which the signal is produced (vocal, bodily etc.),

Points

Glossary

conspecific /kQnsp<schwa>"sIfIk/ a. & n.M19. [f. CON- + SPECIFIC.] (An organism or individual) of the same species.

deme /di:m/ n.M19. [Gk demos DEMOS.]1 A township of ancient Attica; an administrative division in modern Greece. M19. 2 Biol. A group of taxonomically similar animals or plants forming a distinct local population. M20.

Batesian mimicry � a kind of mimicry in which one non-poisonous species (the Batesian mimic) mimics another poisonous species

Questions

Ethologists have focused on handicapping signals, such as the male peacock�s tail, which provide a direct demonstration of the sender�s good genes or prowess as necessary to overcome the survival handicap???

what exactly is a Batesian mimic???

any difference between ritualisation and conventional systems???

what are:

Theory of "derived activities" (Tinbergen 1952)

signals derived from actions that previously had a direct function; "freed" from original cause

precursors: intention (sky pointing in gannet), ambivalent (forward threat of gull), protective response (rhesus grimace), autonomic (scent marking) displacement activities (preening in mallard courtship), redirected activities (grass pulling in herring gulls)

precursor/precurser???

exadaptation???