Wildlife Ecology and Management. Lecture notes by Peter Kabai

communicative signals
honest advertisement (coming)
altruistic behaviour - kin selection
optimal territory size
male-male competition - breeding system
evolution of antlers

Communicative signals

How about a kiss? (intra- or interspecific?)

Kin selection (Hamilton)
Altruistic behaviour
Altruist individual has cost C
Receiver has benefit B
Altruist trait may survive in offspring of relatives
Brothers, parent-offspring: r = 1
B / C > 2
B / C > 1 / r

Optimal territory size

Behaviour ecol. postulate: behaviour is optimal(within constraints)
Understanding behaviour: understanding factors optimizedunderstanding constrains
Any decision has costs and benefits.
(Not all resources are defendable)

Optimization: maximal gain (benefit cost)

Optimal territory size:
Cost increases with size of territory, population density
Benefit increases with size of territory, quality of territory

Territories are expected to be larger in poor habitat (less gain) or at lower population densities (less cost)

Territorial polygyny: roe deer

Male-male competiton

In most mammals:
investment of males is small
males can sire more offspring than females
sex ratio is 1:1
male-male competition, (ritual and direct fight)
low thresholdfor mating

Forms of competion:
dominance within group (wolves)
female-defence polygyny (harem holding by Red deer)
lekking (fallow deer)
territorial polygyny (roe deer, Thomson gazella)

Lamarck: heritability of acquired traits.

In their fits of anger (which are frequent, above all among the males), their inner feeling, in these efforts, very strongly direct the fluids towards this part of their heads and there create a secretion of horny material in some and in others a bony material mixed with horny material. This gives rise to solid protuberances. Hence, the origin of horns and antlers, with which the heads of the majority of these animals are armed.

Darwin: natural selection

Problem: every step of changes should be advantages

What is the use of a small protuberances?

We really do not know. One line of speculation was presented (if I remember correctly) by Geist.

Let us compare fighting styles of extant deer species.

Chinese water deer: no antler, large canines
Muntjak: short antlers + canines
Antlers protect from hits by canines. Longer antler, more protection.

When antler is longer than canines, canines are ineffective.
Remnants of canines in Red deer.

	BIO szerver		BIO server
	Kabai Péter		Peter Kabai


	back to Wildlife Ecology and Management

	Concepts
	in this part I have summarized some of the concepts we met when discussing different species.		communicative signals honest advertisement (coming) altruistic behaviour - kin selection optimal territory size male-male competition - breeding system evolution of antlers

	Communicative signals

	RITUALIZATION a behaviour pattern with direct function becomes exaggerated in form and functions as communication signal (normally signalling the original function). Example: showing the canines by wolves is signal of aggression. It is, however, also a direct a preparation for biting. (The pictures taken from http://www.wolfpark.org/ illustrate signal of threat and dominance.) Many signals are modified intentional movements.

	ANTITHESIS In his book, The Expression of Emotion in Man and Animals, Darwin suggested that signals expressing opposite intentions are opposite in form thus enhancing clarity of the signal. The pic shows a dominant female following a subordinate male. (http://www.wolfpark.org/)

	INFANTILE BEHAVIOUR Many signals expressing subordinance resemble infantile behaviour. Subordinant wolf often lick the muzzle of dominant individuals when greeting. This behaviour is similar in form of puppies asking for food.
	How about a kiss? (intra- or interspecific?)



	ALARM SIGNALS
	Many animals display conspicuous behaviour or emit calls when detecting a predator. Thomson gazellas stott, roe deer bark (www). When escaping from predators gazellas and deer species display their white ramp. Function of alarm signals is not obvious. Traditonally it was thought that signalling, instead of fast escape might be risky for the individual and therefore it should serve conspecifics.

	However, anyone living close to nature (or by a busy road!) knows, that we are surrounded by potential danger all the time. Signalling to car drivers when crossing a busy road instead just run as fast as you can seems a good idea. It might be a good idea for a Thomson gazella to signal a cheetah, that his presence has been detected. Jumping high might also mean, I am fast and strong, do not waste your time attacking me. Alternatively, displaying white rumps might be communication with conspecifics. It may indeed warn realtive, or help running the herd together. There have been a number of proposals as to the function of such displays. One list of proposed functions is on the right.

	Testing hypothesis List all alternative hypothesis Thought experiment: what do you expect to happen? List all predictions. Are prediction patterns unic? Design observation study or experiment. A list of predictions is illustrated bellow



	A series of observations done by Caro et al. revealed, that stotting gazellas are seldom killed by predators. What is your proposal as to the function of stotting?




	Imprinting learning
	Imprinting by mother: Lamb is born fully developed Ewes immediately start licking the lamb Ewes first recognize their lambs by smell, later also by their looks and voices. Excepts any lamb within 30 min. after birth, but rejects any lamb following that critiacal period. Mother gets imprinted to lamb within 30 min after parturition. What is the mechanism? Parturition, or indeed any kind of articial stimulation of the birth canal elevates oxytocin hormon level, which activates the olfactory bulb. The mother is thus primed to learn new odours.



	KIN SELECTION - ALTRUISTIC BEHAVIOUR in wolf packs alfa pair breeds others do not What is the business for subordinates? (1) For the benefit of the species? - no model for species level selection (2) For the benefit of the group? - groups selection might work for closed groups (3) For the benefit of the family? - kin selection works for relatives		Kin selection (Hamilton) Altruistic behaviour Altruist individual has cost C Receiver has benefit B Altruist trait may survive in offspring of relatives Brothers, parent-offspring: r = 1 B / C > 2 B / C > 1 / r


	Optimal territory size
	Behaviour ecol. postulate: behaviour is optimal(within constraints) Understanding behaviour: understanding factors optimizedunderstanding constrains Any decision has costs and benefits. (Not all resources are defendable) Optimization: maximal gain (benefit cost) Optimal territory size: Cost increases with size of territory, population density Benefit increases with size of territory, quality of territory Territories are expected to be larger in poor habitat (less gain) or at lower population densities (less cost) Territorial polygyny: roe deer




	Male-male competiton
	In most mammals: investment of males is small males can sire more offspring than females sex ratio is 1:1 male-male competition, (ritual and direct fight) low thresholdfor mating Forms of competion: dominance within group (wolves) female-defence polygyny (harem holding by Red deer) lekking (fallow deer) territorial polygyny (roe deer, Thomson gazella)

	Would you have a boy, or a girl? In species with polygny variance of reproduction succes of males is higher than that of females. A male might have no, or many offspring during his life. Success depends on condition, and adult condition is not independent of the condition of the mother. According to quite a few studies (Gomendio et al, 1990, Nature, www) females in good condition (high rank) have more sons, than females in poor condtion. Explain that. More fertile males produce more male offspring (Gomendio et al. 2006)		Interesting: A woman's diet around the time of conception may influence the gender of her baby BBC


	Evolution of antler
	Lamarck: heritability of acquired traits. In their fits of anger (which are frequent, above all among the males), their inner feeling, in these efforts, very strongly direct the fluids towards this part of their heads and there create a secretion of horny material in some and in others a bony material mixed with horny material. This gives rise to solid protuberances. Hence, the origin of horns and antlers, with which the heads of the majority of these animals are armed.		Lamarck
	Darwin: natural selection Problem: every step of changes should be advantages What is the use of a small protuberances?		Darwin
	We really do not know. One line of speculation was presented (if I remember correctly) by Geist. Let us compare fighting styles of extant deer species. Chinese water deer: no antler, large canines Muntjak: short antlers + canines Antlers protect from hits by canines. Longer antler, more protection. When antler is longer than canines, canines are ineffective. Remnants of canines in Red deer.