And says a lot about the advantages of cooperative breeding. My Kunwinjku
relatives have a similar situation. Hence my son Rowan was made Ngaba,
"little daddy" as a toddler, and then expected to help rear his children.
Denise
on 19/5/08 12:43 PM, Merrilyn Serong at wrote:
> Hi Belinda and others,
>
>
> It is obvious that if a male bird mates with lots of females, he is more
> likely to produce a greater number of offspring than if he mates with
> only one bird. If his male offspring inherit the behavioural propensity
> to mate with lots of females, then the proportion of multiple-mating
> males in the population will increase, and so it goes on. Those that
> only mate with one female, will be relatively scarce.
>
> If a female bird mates with several males, she will be more likely to
> produce young with a wide variety of characteristics (sperm competition
> aside). Depending on environmental conditions, this may increase the
> number of offspring that survive to sexual maturity. If the survivors
> inherit the propensity to mate with several partners, then the chances
> of their offspring surviving will also increase, etc.
>
> On the other hand, if a female mates with only one male, even a really
> good quality one, if environmental conditions change, then the offspring
> might not be well suited to the new conditions and may not survive to
> maturity. However, if environmental conditions are unchanging, then
> mating with the best (fittest for the current conditions) available male
> will produce the greatest number of surviving offspring.
>
> Similarly, under certain circumstances, young will be more likely to
> survive if they have more than one carer, i.e. both mother and father
> (and sometimes older siblings as well). These survivors will inherit the
> capacity to care for young in a socially stable partnership along with
> whatever mating system was employed by their parents (single or multiple
> partners).
>
> It's all about inheritance and survival.
>
> Cheers,
> Merrilyn
>
>
> Belinda Cassidy wrote:
>> Hi Kurtis, John, Rosemary, Storm, and everyone,
>>
>> I must apologise for being so curt. I don't know whats got into me today;
>> anyway I didn't mean to put everyone off side. Its been an emotional week
>> for me and I guess I sprung a leak.
>>
>> I think we all agree that the scientific evidence demonstrates that some
>> birds pair for life, and some do not. I don't even know why this is being
>> hotly debated, but like I said, I have my suspicions as to the reasons.
>> You're right though Kurtis, suspicions are not the same as scientific fact.
>>
>> Cheers,
>> Bel
>>
>>
>
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