Subject: Orca Pods

Dagmar Fertl (Dagmar_Fertl@mms.gov)
Mon, 2 Feb 1998 09:58:50 -0500 

     Dear Paul, thanks for your interesting questions regarding killer 
     whales and for your continued interest in WhaleNet.  
     
     For those of you who aren't familiar with killer whale social 
     structure, just a brief recap.  A killer whale pod is very different 
     from groupings of other dolphins (remember, the killer whale is the 
     largest member of the dolphin family).  Most dolphins live in a fluid 
     society, where associations between individuals are usually not 
     long-lived, which means that if you should see "Whitecap" with 
     "Scarback" one day together, it doesn't mean that you'll always see 
     them traveling together.  Killer whales live in more of a family type 
     group, which is matriarchially based (a female is in charge of the 
     group, kind of like with elephants).  
     
     1.  Orcas do not mate for life.
     2.  Males in a pod may be both fathers to some of the calves in their 
     pod and fathers to calves in other pods.  I suspect that the latter is 
     more likely the case, thereby reducing some inbreeding.  Animals do 
     not conciously avoid inbreeding like humans do.  
     3.  The strongest bond in any dolphin grouping is between a mother and 
     her young calf.  There is no tie between the mother and father of a 
     calf, because there is no assurance for the male that he is indeed the 
     father of the calf, hence, see the answer to #1 above.  The female 
     stays with the original pod that she was from.
     4.  Some research on killer whale pods has found that there are 
     subgroups within the big pod.  There probably is a "leader" of sorts 
     (again, remember it will be an older female)


Dagmar

______________________________ Reply Separator _________________________________
Subject: Orca Pods & the Father's Role
Author:  Ppatton@cst.com at ~smtp
Date:    2/2/98 12:35 AM


     
     
     
Hi,  I've been reading the ASK archives tonight 
(helping my daughter with research) and now I'm hooked!
     
As I understand it, the offspring in Orca pods tend to stay 
with the mother for life.   That makes me wonder
how they go about resolving the conflict between
staying with the pod vs. selecting mates for reproduction.
     
First, do Orcas mate for life, or choose a new mate each season?
     
Second, do they tend to mate with members from their own pod?
Wouldn't this cause in-breeding problems eventually?
     
If they mate with members from foreign pods, which tie is strongest, the tie to 
mother Orca and home pod, or to the mate and offspring?
     
Lastly, while I understand the pod is maternally led, there would still 
seem to be several senior-most mothers at any one point in time
within the same pod.  Is there competition among them for pecking order 
as there frequently is in male-led animal societies?
     
     
Thanks,
Paul Patton