- depending on the parenteral investment, there are two different reproductive strategies:
- quantitative strategy: make use of all reproductive possibilities
- qualitative strategy: security and quality of the partner are decisive factors
Topics overview:
Mating motivation
Types of advertising strategies
Mating motivation
The two reproductive strategies resulting from parenteral investment have an impact on mating motivation. Remember:
| Quantitative strategy: | I reproduce as often as possible and invest the absolute minimum per single offspring |
| Qualitative strategy: | I produce few offspring and maximize the chances per single offspring |
Mating motivation under the quantitative strategy:
Within a quantitative strategy, the maxim would be to make use of every reproductive opportunity and remove all barriers. Even if fertility is unlikely, it was worth a try. Even if a high-risk mating costs my life, it was a success if I could pass on my genes.
(Note: It should be mentioned here again that we do not speak from an individually meaningful motivation, but from the perspective of evolution).
Mating motivation under the qualitative strategy:
If, on the other hand, I am pursuing a qualitative strategy, it is essential that I survive, since my descendants depend on me. So I need secure conditions. Also my partner has to prove a certain qualification, because I want the right genes to pass on to my offspring and that they shell receive optimal care, so that they are optimally equipped.
Types of advertising strategies
Since males and females usually appear in the same proportion, males compete for the favour of females who have a much smaller capacity of possible offspring. They in turn sort out the males according to quality characteristics and situational conditions. For an opportunity of reproduction males have to watch out for a favourable situation and know how to convince females of their qualities. There are different ways of advertising among species:
- Demonstrate strength and vitality
- Species for whom success is demonstrating their own strength, this is done by…
1a) threatening the female
- the female is supposed to be impressed by being treated like a competitor
- e.g. Galapagos lizards
- very low parental investment of males
1b) attacking outsiders
- show attacks against outsiders
- staging of the victorious return to the courted one
- e.g. wild geese
- higher parenteral investment of males
If the female does not show any interest despite all efforts, the male knows that it has not convinced and withdraws. If the female is willing, she agrees and the mating act takes place.
2. Demonstrate caring
- in case of high male parental investment and participation in rearing, the female looks for solicitousness
- male must show that he would be a strong partner and demonstrate its commitment and willingness to care
Males who gave up after an unpleasant failure missed further chances to reproduce. Therefore, males have always been under strong selection pressure not to be impressed by personal failure and to try again and again, which might be an aspect why men tend to overestimate themselves and would rather try again, even if a situation seems hopeless1.
» next topic:
The 3 types of aggressiveness
Let´s have a look now how advertising strategies influenced the aggressiveness of the sexes »
sources: 1. Bischof-Köhler 2006 S. 108 – 110
