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From: rp6@jaguar.ucs.uofs.edu (PAWA RITU)
Newsgroups: sci.bio
Subject: Info. on Infanticidal Behavior
Keywords: neural timing, social cues, hormones (testosterone)
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Date: 19 Apr 91 15:22:39 GMT
Expires: 6 May 91 04:00:00 GMT
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Infanticide includes any form of lethal curtailment of parental investment
in offspring brought about by conspecifics.  Included in this definiton
would be curtailment of parental investment through destruction of gametes
or reabsorbtion of foetus (Charnov, ch.7).

	Why Infanticide occurs?
	Hrdy suggested four hypothesis:
		1) Cannabilism
		2) Competition for resources
		3) sexual selection
		4) parental manipulation

Lot of evidence on sexula selection hypothesis.  This hypothesis suggests
that this form of infanticide appears to be most common among polygynous mating
systems where breeding occurs throughout the year, and where male gets  access
to female for a short time(Hrdy, 1977 ; Chapman and hausfater, 1979).
Ex.  Langurs 
      When the dominant male occupies the territory of another male,
he kills the offsprings of that male.  This happens for many reasons -
Female becomes receptive to the new male faster and secondly the male 
has an increased chance of passing his own genes to the  next generation.

	What mechanism prevent a male from harming his own offspring?
Social cues, fetal and adult hormone, genetic differences , and neural timing
systems are four known mechanism that change the male's behavior towards pups.

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I am doing my term-paper on "Infanticidal behavior."
	Does anyone have any information on this topic?
   Sub-topics
* Fetal and adult hormone (testosterone)
* Genetic differences (differences in strain)
* Neural timing (light:day cycles) 
* social cues

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