Seasonal and other patterns of degu fighting

[fred]

On DeguForum.de the question of seasonal changes in the frequency of degu fights was raised and discussed recently. A member of the German forum, Mandarine, and I decided to go through all the old posts on our respective forums to count all reports of serious figths (blood drawn and/or separation necessary). Mandarine just posted her results: www.degus-online.de/phpbb/viewtopic.php?f=2&t=36884.

To my surprise, I found that our degus seem too be much more of a peaceful disposition. The numbers are actually so small that I counted the reports for quarters. You will note that in the graphs for DeguForum.de and World Degu Forum, I used different scales to reflect the different size of the forums. We have about a third of members, threads and posts but since there are some differences in content and member demography, I think a fifth may be a good estimate.



There is a clear increase in fighting in male groups over the months November to January. This could be related to an increase in testosterone as mentioned in another thread here (the “mating season”). On DeguForum.de, these fights make up 26% of all cases whereas here it is 50%! In other words, compared to DeguForum.de, there seems considerable less fighting in our males for the rest of the year and for the females throughout the year. Now it would be nice to understand the biology behind these differences....

[NightwishRaven999]

Thank you both for compiling these results and producing charts.
You know, one thing I was always told...even by the more experienced owners, what that males are not more prone to fighting than their female counterparts. The idea of males fighting more often, I was informed, was a myth.

This is clearly not what we see here. I believe this is sufficient evidence to prove that male degus are indeed more boisterous/competitive than the females. This would be in line with the vast majority of species in the animal kingdom.

[winic1]

Nov-January is spring to summer in South America.

However, it seems strange that their biology would still be keyed to a hemisphere that they have not been in for many many years and many many many generations. Daylength and climate cues would not match, either. Unless as our fall and winter come, we actually lengthen our "daylight" by keeping lights in the house on longer than we do in the our summer--artificial lights on from waking until bedtime give brighter light/longer "day" than perhaps in our summer when we rely more on natural light coming in windows and so the brightest lights are on less?

and it makes sense that males fight more than females--males compete for the right to mate, and protect their mates from other males, whereas females do not need to compete for males, and actually benefit from cooperating with each other.

[fred]

@jordan Yes this was just one of these degu myths where one can't understand how they persisted for so long. I think we can now give more specific advice to owners of male groups where aggression breaks out during October/November to January.

winic1 In their natural habitat, mating takes places around June, exactly corresponding to our December where we clearly find the peak in male fight fighting on both forums. One reason that this is more spread out here may be that the time clues are not as strong in our homes.

and it makes sense that males fight more than females--males compete for the right to mate, and protect their mates from other males, whereas females do not need to compete for males, and actually benefit from cooperating with each other.

I very much agree, which is why I find it difficult to understand why females are still (seriously) fighting to the extent we experience. In the wild, all females of a social group mate and there is no competition as far as reproduction is concerned. I also don't see the competition for food as degus are foraging herbivores not a pack of predators scrapping over a carcass. In contrast, cooperation is essential to increase vigilance. I also haven's seen any reports of inter-female aggression in wild degus.

[winic1]

okay, so then it looks like they are following seasonal cues--I have 2 males and no plans for females or babies, so I hadn't paid much attention to the baby section info, but 3 months gestation means mate in winter, have babies in spring, which makes sense. We've had our boys through three winters, now, and I guess are lucky that they get along so well, rarely ever any fighting to the extent that we note it as true agression, and never any harm to either.

We have 2-3 huts/hideaways of different types, so while they usually sleep and hang out together, they can separate and have "privacy" when they want to. And 2 food bowls for pellets on different levels, so if one decides to claim a bowl as his, the other is forced to go away to find food elsewhere. One hay jar, but it seems to be the place for us to put the hay so they can pull it out all over and then sit inside the jar eating. When giving seeds or oats, I scatter all over one or two levels so they can forage, but if one gets possessive, again, the other has to go elsewhere, but still gets a good share, or I think we'd have one huge goo and one very skinny one. Leaves, twigs, greens get handed one to each, and then rest spread through cage or again, Chester would be huge and Chitter rather skinny. Sometimes they eat side by side, other times they squabble, but then the other knows to search elsewhere.

Even foraging females still have some degree of food competition, yes, it helps to have others around watching for predators, and tending to young, but if you want to have strong healthy babies and keep yourself strong and healthy, you need to get plenty of food, and someone else around is taking away stuff that you might need, or your babies might need. So some female fighting is to be expected. And even in a big cage, their foraging range is limited (regardless of their food magically appearing every day), so perhaps some are going to feel this competition more strongly, and act out accordingly?