The author suggests they would do this because sons will potentially produce more offspring while an unhealthy mare would invest more in a filly that will very likely produce at least one offspring while the colt may or may not achieve breeding status.
The article was written about observations of wild horses.
After observing the interactions between several of my mares and foals I agree that mares frequently seem to favor the colts, but I think it is for other reasons.
One of my mares had 6 foals – 3 fillies and 3 colts. She was a very protective mom during the first week and then relaxed more over time, but I did notice that her colts seemed to stick by her side a lot more than the fillies.
I referred to her colts as “mama’s boys” because they were frequently hiding behind her and were extremely vocal and frantic if separated from her by even a short distance.
This made bringing them in and out easy because I knew they were going wherever mama went – they would hop into a trailer with her almost before she was completely loaded.
The colts were more reluctant about approaching the other foals and I would see the colts peeking out behind their mom when a bold filly came over to check him out.
And the mare was more likely to discourage the other foals visiting with her colt for a longer period of time than she did with her fillies.
As a result the colt played with his mom a lot.
When humans came to visit the colt would usually hide behind mom who while not usually aggressive with people she knew, would quietly help the colt stay hidden by moving her body when you tried to go around her.
When I started halter training with the colts someone had to hold her up against the wall so that he couldn’t hide.
The colts usually took longer to approach people on their own and tolerated it for very short periods of time before needing to make contact with mama again.
In contrast, her fillies were bold, in your face, and almost never hid behind mama.
They were very friendly and curious but much more difficult to lead because they were not that concerned about where their mom was all the time.
The fillies were very quick to come over and check you out and enjoyed being petted and rubbed foras long as you wanted.
It was frequently difficult to take pictures in the field because the filly was right up in the camera and I would have to get someone to help me keep her back if I wanted a shot of anything more than her nose!
At first the mare spent a lot of time moving between the filly and the other horses or people.
She was trying to tell her baby to stay away, but those fillies never listened and mom soon gave it up.
The mare would be quick to move in if the filly was in trouble, but she let her have more freedom to roam and check out the other foals, mares, and people.
Once the colts and fillies were 3 -4 months old the mare was letting them roam all over and paid little attention unless the foal called out to her.
I noticed that while the fillies were still bolder about checking each other out, the colts were a lot more playful in their interactions.
Colts did a lot of biting and rearing, while the fillies were more likely to kick.
They all liked to run and buck! As they got older the fillies became less playful and started discouraging the playful colts.
Before they were a year old I usually had to separate them as the colts were practicing their breeding behavior and the fillies were finding more and more aggressive ways to say “No!”
So what does this say about mare and foal interactions?
Does the mare favor the colt or is she just reacting to the behavior of the foal?
Is the mare wired to favor the foal that will be more a more successful or prolific procreator or is she just responding to the needs of her foal?
Is it coincidence that my mare’s colts were “mama’s boys” and the fillies were more independent?
How does this relate to their behavior as adult horses? An idea for a new post 🙂 ?
I think it would take a bigger study than my 6 foals, but it is an interesting subject. I would love to hear from other breeders on their observations.
Leave me a comment below if you would like to voice your opinion.