In May of 2018, Shawn wrote Professor. Patricia Brennan regarding the hormonal behavior in our very large drake flock (out of 110 ducks in 2021, 62 are drakes!) which we ultimately had to divide into compatible pairs to avoid fighting. Dr. Brennan studies duck genitalia and behavior, and provided invaluable information that has helped us create a relatively stress-free lives for our drakes, after several years of fighting, injury, and constant distress. EDIT: Now, at 5.5 years of age, the drakes are capable of being outside together as one flock (with the exception of 10 drakes that live with the hens) during their low-hormone season (our dream is to reunite the entire flock one day, inside and out!), and they return in their bonded pairs to their individual, 50-90 square-foot pens in the evening. We share this information so that other sanctuaries struggling with drake behavior might learn from our experience.
PB: I am not surprised you are getting a lot of homosexual behaviors in your drakes. [Khaki Campbell] ducks and their cousins are derived from the mallard which is one of the most prone to forced copulations. Drakes are generally pretty violent during breeding season. In fact, there is a paper on one male mallard raping another male that had just crashed against a window and was dead. So yeah. Domestication selects for males that can breed multiple females, and therefore are likely to have higher testosterone levels. We know that they have larger penises than their wild counterparts. So, I am afraid that you are just going to have to put up with the shocking behavior for as long as you keep them penned together. There is no castration equivalent for drakes. I am attaching two papers that may be of interest to you [see below for links to Dr. Brennan’s papers].
SS:The remaining drakes are in pairs of 2 and kept in 23 separate pens to prevent incessant, aggressive, injury- causing behavior. We still struggle with aggression between pairs and at times between pair mates. I randomly see one trying to mate his pen mate and I worry what the effects of this are if there is penetration?
PB: Males likely intromit, and their penises evert with some force, but luckily I think the elasticity of the intestinal wall will be able to withstand the force of penetration. In other words, I don’t think they will hurt their insides by having homosexual sex.
SS: I didn’t know that drakes’ phalluses fell off at the end of mating season and then regrew the following season in proportion to the pressure they felt from other drakes.
PB: They don’t really fall off, but they do shrink dramatically, and then regrow from a smaller base the next year. Domesticated ducks like yours, have much less obvious seasonality.
SS: I’m wondering if the mere existence of so many young drakes kept in close proximity to one another is having an effect on their genitalia never mind their challenging behavior.
PB: Probably. My experimental set up in the attached paper, showed that males grew longer penises in pens with multiple males and fewer females.
SS: I’m wondering if you’ve ever studied this kind of captive duck flock size and have any insights?
PB: I think you are doing the best you can by keeping them in pairs. I would check often to see if you have any particularly violent males that you need to remove. They can kill each other on occasion. Then you will have to decide what to do with those!
SS: We are a vegan agroecological, agroforestry farm on 1300 acres practicing rewilding agriculture and trying to demonstrate how to partner with traditional farm animals in a new context where they are not commoditized as part of the food chain.
PB: I understand.
SS: When does the sex hormone driven behavior end in non wild ducks?
PB: [Wild ducks] have two testosterone peaks, one in the fall (small one), and one in the spring (big one!), but domesticated ones have much longer reproductive seasons, so you are looking at relatively high levels of T for a longer time than wild ducks.
SS: Thank you so much for your insights and the papers - I’ll look forward to studying them.
Couple of follow up questions.
Are the males’ hormones driven by certain, known factors such as
-hearing females
-seeing females
-smelling females
And same with other drakes?
My current theory is that seeing other drake pairs really sets them off. I’m thinking of redoing their pens so that there is zero ability for them to see each other.
The theory is based on our history of observation, experimental past set ups, and current arrangement.
When the flock of 116 ducklings arrived in Aug 2016 they were all together and very happy. They were also about 9 weeks old (they were hatched June 13/14 2016). Life was great.
Females started laying in Nov - we were shocked (we were not encouraging them to lay, quite the opposite). By January 2017 we started observing drake fighting and ever since it’s been chaos.
At first we kept 12 drakes with the females. The remainder is drakes were split into 3 male flocks. Over months we had to break up each male flock 2 drakes at a time to prevent injury and death. After months and months of this we realized the safest set up for them was in pairs.
For awhile they could see each other 100 percent but they would try to fight between the pens and necks were getting twisted, eyes damaged, serious neck feather removal. No deaths, some eye and leg injuries that were all caught early and healed.
We then cardboarded the lower 1/2 of their pens so they couldn’t stick heads through at ground level, where they could assert greatest leverage and do real damage. When this fighting occurred between pens not only did pairs fight but pen mates would get so worked up they’d turn on their pen mate. The cardboard helped but they destroy it in a few days and it’s huge maintenance/time.
The ducks are kept on one floor in our predator proof barn. We have them separated around the first floor due to spatial demands. Each section or grouping of ducks has several pens with 2 ducks per pen, and then a common exercise area where they can roam while we muck their pens. They can see each other because the pen front panels are partially cardboarded. Most pens also have bamboo reed fencing to help prevent flyovers.
All winter it was fine to let pairs roam the common areas for quite awhile, but now the minute a pair leaves their pen all hell breaks out and its incessant fighting.
I’m thinking of replacing all the pen dividers with metal panels so they can’t see or get to one another and when a pair is in the common no one can see them [edit: we did indeed accomplish this using metal roofing panels as pen dividers, and the stress levels in the barn went down DRAMATICALLY and the drakes relaxed, stopped fighting, and started expressing a healthy range of personality traits].
Hearing other males and being able to hear the females is a concern through of verbal communication also insights aggressive behavior/hormone spikes - I’m wondering if you know if that’s the case?
The females are kept in a single large indoor pen and the drakes can him them - is that adding fuel to the hormonal fire!
What a situation we have - never could’ve imagined this.
PB:Yes, hearing females and other males will incite more competition, but seeing them would be the worst, so your conclusion is correct. Making your pens visually isolated will go a long way in reducing aggression. Moving them away from each other fi you have the space, and giving them larger pens will also help. My experimental pens were large, and I kept one male and one female alone, so they were super happy all the time and not aggressive even though they heard other pairs around them. Can you do this? Just pair one male and one female together? This would not be the optimal egg production strategy, but if you are more into rescuing them and giving them a happy life, that may be a good solution. Smell is not a problem. Most birds have a really bad sense of smell.
SS: Thanks so much for all this great science-based information. So helpful. On a theoretical/“actually can do” level - yes, we can pair 1 male with 1 female, and perhaps have 1 micro-flock of 5 residual females.
On a practical, “every day care” level - that would basically require 52 individual pens. We struggle greatly with our current set up of 23 individual pens for the 46 paired drakes, and 1 large pen for all the females and their 6 (lucky) drake mates. It’s a long, 10 hr day to clean and care for that many pens - and that’s without tending to the outdoor yards, injured/sick ducks needing treatment or special attention. So, doubling the number of pens that need daily care is something I can’t see being practical for us
I’ve heard their hormones will calm down at some point, maybe go away altogether — like when they’re 4 or 5 years old (as if that’s “right around the corner”) - we have sort of been holding on to that idea as something to work toward, when they can all be reunited into a single flock again. But perhaps that’s bad information, and a very unlikely outcome.
I’ve tried to find others to adopts some of the males, as you can imagine - no luck (at least no takers who would give them a forever loving home, not use them for experiments or as food).
You’re not too far from us, in case you’re ever interested in visiting and seeing this well-intentioned but chaotic situation I’ve created for us and for these poor little feathered friends of ours. Most people in the duck sanctuary/rescue world tell me they are lucky ducks, and have an amazing set up and I should never feel bad — that they are happy and healthy and living a ducky dream. I guess, but I hate seeing the missing feathers, injured eyes, and mounting. I guess it’s nature…
Patricia L. R. Brennan, PhD
Department of Biological Sciences
Mount Holyoke CollegeSouth Hadley, MA (413)538-3319
www.pattybrennan.com
Check out my research in the XX files at Science: http://www.sciencemag.org/projects/xxfiles/9
Check out press coverage of my latest paper: http://www.nature.com/news/sexual-competition-among-ducks-wreaks-havoc-on-penis-size-1.22648