Vega/female dispersal

by jwidness moderator

Saw this short clip (in the spreadsheet) of a large juvenile or small adult, I suspect female due to size/build and seeming lack of testicles: ACP0003vdb

enter image description here

Both ears are normal, brows somewhat curvy, a bald spot in the center of the forehead. Skin neither particularly dark nor particularly light and with fairly even color across the face.

My best guess is a match to MF7Juv07.

Posted July 7, 2015 6:42 PM

by jwidness moderator

Petite female, probably March 2014, found in the spreadsheet:

ACP0003zvc and ACP0003zvd

enter image description here

Small size, normal ears, somewhat rounded brows, medium skin tone, balding on the center of the forehead. I think I'm probably imagining things because I was just looking at MF7Juv07, but we don't have too many lone females of this size, so I'll just throw out a three way match with http://talk.chimpandsee.org/#/boards/BCP000000j/discussions/DCP00007ze

Posted July 7, 2015 7:10 PM

by AnLand moderator in response to jwidness's comment.

Looks good on the first glance. Both propositions. Can you not just merge the discussions, so that we have it all together? Would make sense to me. Thanks!

Posted July 7, 2015 7:20 PM

by jwidness moderator

Done! I wasn't really sure enough to make only one thread, but I'm happy to see at least one other person agrees : )

Posted July 7, 2015 7:24 PM

by AnLand moderator

Ok, I looked at the videos a little bit further. The second one here ( ACP0003zvc and ACP0003zvd ) has a considerably bigger sexual swelling than MF7Juv07. I don't know how important that is. Can this happen or is she more grown-up? I also think that her brows are somewhat straigther than MF7Juv07 and the first one mentioned here. @NuriaM: we need IDs, I think.

MF7Juv07 (for first individual above (in the rain): not right perspective to see anything):

enter image description here

Second individual here:

enter image description here

Another possible match for the second individual might be MF7Fem12. But here I am not sure about the right ear.

Posted July 7, 2015 7:48 PM

by MimiA scientist, moderator in response to AnLand's comment.

The sexual swelling change a lot during the estrous cycle so it is not a great cue to go on in this case.

Posted July 7, 2015 9:42 PM

by AnLand moderator in response to MimiA's comment.

As @MimiA pointed out, the argument about the sexual swelling is probably entirely misleading, so well then.

Posted July 8, 2015 12:17 AM

by NuriaM scientist, moderator in response to AnLand's comment.

#MF7Fem30
#MF7Fem31

Posted July 8, 2015 9:46 AM

by Quia moderator

I think these three (first two posts by @jwidness here, and MF7Juv07) look very similar. The only potential difference I can spot between them is the dip in the browline looks stronger to me for MF7Juv07, but the lighting is very different in those videos.

Posted July 8, 2015 9:58 AM

by NuriaM scientist, moderator

I think Fem31 and Juv07 are quite darker than Fem12...or maybe the light?

Posted July 8, 2015 10:07 AM

by jwidness moderator

I agree that I don't see a match to Fem12 -- her back is greyer and I think her brows are straighter.

Posted July 8, 2015 11:20 AM

by AnLand moderator

Yes, I see that, too. It might be the light or not, but MF7Fem12 has also different, more boxy brows. I could see a match of MF7Juv07 to MF7Fem30 - although the latter looks a bit bigger, but perspectives are not comparable. I do not see a match of either of them to MF7Fem31 because her brows are not nearly as round (the dip @Quia mentioned).

Posted July 8, 2015 2:27 PM

by AnLand moderator

I went again over all the videos of the three females discussed here. I cannot see any definite feature to distinquish them. The ears, nostrils, baldness pattern (as well as face expression) are all very similar. Brows look slightly straighter in MF7Fem31, but she is clearly more relaxed, so that might explain that enhanced straigthness. (I assume here that chimp brows are as mobile as human ones, which might not be true.)

I would like to note that I still see MF7Juv07 as a bit smaller. Also @NuriaM ID'ed one as a juvenile and the others as adult females. Might be a Freudian slip 😉 But the perspectives are not comparable and nothing else shows up against the match.

Posted July 9, 2015 7:16 AM

by NuriaM scientist, moderator in response to AnLand's comment.

exactly, chimps have facial expressions which are very similar to humans. I am sure you have heard about chimps laughter...some studies show that chimps, like humans, can flexibly produce facial expressions without making corresponding vocal sounds.

and raising the brows upwards is one of those expressions common to us; you might find this text interesting:

http://www.chimpfacs.com/Chimpanzee Action Unit 1+2.pdf

Posted July 9, 2015 8:48 AM

by AnLand moderator in response to NuriaM's comment.

That is very interesting! Thanks, @NuriaM!

Posted July 9, 2015 9:35 AM

by NuriaM scientist, moderator

😃

Posted July 10, 2015 9:12 AM

by jwidness moderator

I took another look at these three, and again can only find similarities, but no obvious differences. I did notice one more feature that looks the same across all three: they all have small pale spots on both cheeks between the eye and muzzle. Hopefully you can see them in these images, but it's more obvious in the videos.

Juv07:

enter image description here

Fem30:

enter image description here

Fem31:

enter image description here

Posted July 14, 2015 7:55 PM

by NuriaM scientist, moderator in response to jwidness's comment.

I absolutely agree with you...I would say, we have another match here 😃

@jwidness, it´s all yours!!! name?

Posted July 15, 2015 8:39 AM

by jwidness moderator

Yay : )

Since I made the match suggestion on 7/7, I propose the name Vega for this young lady, with reference to Tanabata.

Just out of curiosity, do you think she's more likely to be a natal female, or an immigrant female?

Posted July 15, 2015 7:39 PM

by AnLand moderator in response to jwidness's comment.

I like the name. To your question: I was thinking about the same. I guess, it doesn't really mean anything that we've seen her twice all by herself, but yes, the question came into my mind too. Maybe @NuriaM has an idea.

Posted July 15, 2015 7:47 PM

by NuriaM scientist, moderator

hey guys,

I have noticed that we have had a situation here: some of us happened to hashtag Harriet as Juv07 (now Vega). I can understand it because they both are in some videos seen together at the same place crucking nuts... ACP0003r9q (#MF7Juv07 hashtag already removed).

It´s no problem, but just please be careful with your hashtags, watch the video before hashtagging even if you are sure that it is the chimp that you mean 😃

very nice name, @jwidness!!

Posted July 16, 2015 8:29 AM

by NuriaM scientist, moderator in response to jwidness's comment.

Hi @jwidness , that´s a very interesting question about natal and immigrant females.

to get down to business, let me first introduce this issue a little bit...

chimp communities follow a female-biased dispersal pattern, which means that males almost never leave their natal community, but females, unlike most mammals in which dispersal is male-biased. Females transfer shortly after sexual maturity ( they become sexually mature between the ages of 10 and 13) to permanently join another group.

Authors distinguish between natal females: those born in the community and immigrants: obviously those not born in the community 😄

But then they make another division between the immigrants:

recent immigrants (considered those females from the moment in which they were first observed in the community until the moment in which they first conceive) and

resident mothers (those immigrants that already conceived inside their new community).

Although female-female aggression is rare in chimps, once a new female comes into the community, the residents (natal and resident mothers) direct high rates of aggression towards (recent) immigrants, and males could protect their interests by intervening in these conflicts, protecting immigrants over residents. It is thought that immigrants may associate closely with males as a strategy to integrate themselves into their new group.

Immigrants are low ranking, which is usually associated to higher foraging costs and poorer body condition.

...and now, answering to your question, is Vega shortly leaving (natal) or has she just arrived in the group (immigrant)? it is very difficult to say just by watching some videos (researchers spend years watching communities in situ ) but Vega gives us some clues: she is young and quite thin, which could fit an immigrant´s definition. She is mostly found alone (as you said) and at the moment when Harriet comes ( ACP0003r97 ) she shows respect by going back a bit (low ranking). And all this bore to say that Vega is likely to be an immigrant individual, but cannot tell for sure 😦

I hope I helped you a bit 😃

Posted July 17, 2015 8:42 AM

by jwidness moderator

Thanks 😃

Hope her transition goes/went smoothly, regardless if it's in or out

Posted July 17, 2015 11:24 PM

by AnLand moderator in response to NuriaM's comment.

Hi @NuriaM,

this is very interesting and I have two additional questions concerning the female dispersal in chimps.

Do all females change the community? (I don't think so, but what is the percentage of females leaving? I read somewhere that it depends from the community size, but cannot really estimate what that means.)
If not, what decides who leaves the community and transfers to a new community? Is it possible that rather daugthers of low-ranking resident mothers leave the native community, so there is already a disadvantage (e.g. poorer body condition) in the beginning?

I also observed that Peter is mostly seen with a young, lean female (not necessarily the same one!). So, this male protection factor might be an explanation here. 😉

Posted July 18, 2015 10:03 AM

by MimiA scientist, moderator in response to AnLand's comment.

Hi AnLand, In most chimp communities most (>90%) of females leave their natal community, the main exception is Gombe which only has 3 communities and 30km2 of habitat so it may be an issue of human disturbance that only 50% of those females disperse. Here is a good paper from 2013 summarizing a lot of what is known about female chimpanzee dispersal http://rstb.royalsocietypublishing.org/content/368/1631/20130077

Posted July 18, 2015 4:04 PM

by AnLand moderator in response to MimiA's comment.

Thank you. Over 90% is actually much more than I expected.

Posted July 18, 2015 4:08 PM

by NuriaM scientist, moderator in response to MimiA's comment.

thanks @Mimi for taking charge of it while I was missing... 😃

Posted July 20, 2015 7:41 AM