Sigh. My gelding, who loves all creatures on the planet, especially loves young calves. When we are helping a friend move cattle from winter to summer pasture, he loves riding in the back of the herd and nuzzling them with just the right pressure to help them keep up.
The first time I took him team penning, at age 3, and took him over to check out the cattle still in the pens, he made eye contact with a heifer, they met at the gate, and...licked each other.
The first time I took him on a bison roundup, and found myself solo with a pair of bulls to nurse along til we met up with others, he really truly couldn't understand why I wouldn't let him just go up and nuzzle one on the butt. When we topped a ridge and found a group of 100+ he did get a little more thoughtful about it.
So I don't know that I would categorize it as maternal or paternal instinct but yeah, they wuv 'em.
My mare, on the other hand, will bite cattle that do not do her bidding. But she bonded with a bunch of mules yesterday.
I'm not sure his big display of intense interest was deep, altruistic, over-the-moon love for the calf. His reaction was so definite and quick that either he wanted to sprout an udder or he was going to kill it. The speed of his opinion made me fear that it was anger. What gelding falls motherly in love that quickly with a baby animal he has never seen before?
He didn't react to adult cattle. He didn't show any "cow" when we are trying to cut the momma out of the herd. I don't know if he had ever been out with cattle before.
I think from what you describe, that was the 'helpless newborn herd member' reaction.
Not all critters have it, but it will be highly developed in, say, old broodmares who have had tons of foals, and nurse cows. Occasionally, it will occur in a gelding- those are the tolerant fellows that get put out with the babies right at weaning. (Granted, weaning ain't newborn, but there is some sort of protective instinct in those geldings toward young 'uns.)
If I've just assisted a cow birth, and am wet with fluids, and I go feed either my TB gelding or my Jersey cow, I'm going to get licked to death.
My Jersey cow somehow knows when a calf is newborn and helpless and its mama isn't around; she'll take a calf like that for her own in a few days. But a ten day old calf that has an attentive mother is a two or three week fostering process if we need to get rid of the mama for some reason.
My QH gelding, my two maiden mares, or my had-one-foal mare...could not care less about birth fluids or newborn calves.
Last spring, we moved cows to their forest pasture after gathering them from a lower pasture- in all, it was about a 6 mile move. One day- or two day-old calf made the first part of the move, but hid in the sagebrush. We looked for that little bugger for several days, and would have let mama backtrack to find it, but she wouldn't leave the water trough in the forest. We found that baby three days later, still alive and kicking. We roped her and tied her up standing so she wasn't struggling, and waited for Mr. Fillabeana to come back with the 4-wheeler so he could whisk her up to the forest. While we waited, we stroked, scratched and loved on baby. My TB gelding participated, nuzzling and giving love with us.
If we separate calves from cows, say to vaccinate or haul them, and my TB gelding is anywhere nearby, the calves will end up either right at his feet, or if he isn't inside the corral, right across the fence where he's tied up. (It is common to leave one mama cow in the pen with the babies, to keep them calm. We just let them go hang out with my horse.)
You do have to be careful in such a situation that your horse is REALLY okay with baby calves running underneath and bumping on horse legs, because most horses will kick a calf, or threaten with a kick to tell them not to get too near. But some horses are baby calf magnets....
And by the way, this same TB gelding will bite 500 pound calves that he's trying to move (well, WE are trying to move, and he's helping me!). He will help keep an upset mama cow from running over Mr. Fillabeana while he tags a newborn calf. He sometimes lives in the horse pasture with a few bulls (1000 pounds and up), and he has a GREAT time bossing the bulls around...makes for bulls that respect a horse, instead of charging your horse.
Anyway, I think your gelding might have that protective instinct, but he's never seen a newborn calf before so there was a bit of fear. I wouldn't have trusted him, either, not to kick or strike at the time. With more exposure to calves, he might be trust-able in the future, but I agree with your careful assessment.
Big Man On Campus is one of those horses who lets you know what he is thinking. He didn't have much of a filter until I started training him-- the SOB was 11 and more or less unbroke. So while he's not feral, he also hasn't had people tell him to STFU while he's being asked to do a job.
I think that's the same with other horses. He either didn't get turned out with them, or they were older and weren't going to challenge him. Once I asked the BO to let me supervise putting him out in company (because he was bored, lonely and frustrated), however, he acquired a nice scrape o' the teeth from an old mare who is cut from the same tough cloth.
When the calf was rather dead-looking curled up on the ground, he didn't do anything. Or I didn't think to notice. I found the calf in the grass, jumped off Big Man to check it out and expected gelding to stand there like any regular old broke horse.
He wasn't involved in bringing the calf back up to the top pen. And momma cow wouldn't come because baby wasn't making noise for her. So baby standing up alone in the pen seemed like a new thing for him and there wasn't a huge heifer to keep he and baby apart.
If he was having a "spiritual moment"-- where some deep instincts kicked in-- it would have been nice to give him more time with the baby to get over the shock and figure out how to be a nice papa or uncle. But, man, he was to "up" that while I was holding his reins from the ground that he wouldn't be quicker to attack than I could stop if that's how it played out.
I'll see if I can arrange another meeting from across a fence that seems safe.
My horse acted like a hormonal fool when he saw his first foal. It took two people to hold him. He has since gotten over it and can also look at a calf without losing his mind. Now when we have a new calf, I let him look in the calving pen. He admires them and gets a real soft look on his face. A far cry from the first time.
My Hanoverian gelding is in love with BO's mamma cow and yearling daughter. They will lick each other if close to the fence. Very cute. But when Mamma had this spring's little bull calf, Figaro lost his mind. Stayed away from their shared fence line, raised his tail and passaged, snorted and generally acted the fool. It's taken him about a month to get used to the little guy and not lose his mind when Junior comes near.
Be CAREFUL! My alpha gelding tried to kill a calf when it got through the fence into his pasture. I ran out side in time to see the gelding pick up the calf by the neck and shake it. It was apparent that the calf had already been kicked or stomped when I got to him. The calf just wanted to stay down and acted like it had just given up, but I got him inside the barn, and he ended up being okay. Two minutes later and I'm sure the gelding (or the other herd-members) would have had the calf finished off. It was an AWFUL and violent thing to see and I never would have expected it from him...
We had a bummer calf once that completely bonded to my gelding Ben. Any time we needed to find him, we knew exactly where to look! He napped under Ben's feet and ate from his hay pile. Ben protected him from the other horses and got very distressed when his little buddy wasn't around! Crazy critters.
A couple years ago, one of my photographer colleagues got the most amazing photos of a wild stallion babysitting with a very young foal, whose mom wasn't around. I don't remember what happened to mom, but she wasn't there, and this herd stallion took charge. VERY atypical behavior - and wonderful, heart-warming photos.