Comparing elk to chickens: male/female ratio

[PioneerChicks]

Recently I have been looking into elk behavior. I find it fascinating because they are so similar to chickens! There are a couple things I am wondering about though. Maybe somebody can answer them, or maybe these are the kinds of questions no one knows the answers to.

A...er...short comparison between elk and chickens:

Female elk (cows) live in herds year round. The bulls (males) live together in a bachelor herd for winter, spring, and summer but live with the females during fall. Chickens live together year round, though sometimes roosters will live alone.

In fall a bull elk will gather "his" cows together and allow no other bulls near. They will bugle and fight over territory. I don't think there are any exceptions to this. Roosters often allow young roosters into the flock, though If they misbehave one too many times they will quickly be kicked out.

Both roosters and bull elk will mate multiple females.

When an elk calf is born, it is three-four times more likely to be female than male. When a chick hatches, it is a 50/50 ratio. Why is this? Can it be changed? If there was an excessive amount of roosters in a flock, would the hens produce more female offspring?

 

[R2elk]

In fall a bull elk will gather "his" cows together and allow no other bulls near. They will bugle and fight over territory. I don't think there are any exceptions to this.

There are always exceptions to everything. There have been documented cases of a pair of bulls that are such close pals that they share the same herd and protect their cows together. It is not common but it can happen.

When an elk calf is born, it is three-four times more likely to be female than male.

What is your source for this claim?

 

[PioneerChicks]

What is your source for this claim?

A ranger at Yellowstone told me that confidently, but I just barely looked up a few sources online. Turns out that it is all a bunch of theories?

This source is complicated, but using birds as an example it says, "In bird species dominated by females, the males have multiple female mates, and females care for the young. In contrast, male-leaning adult sex ratios are linked with females having multiple male mates, and males raising offspring." https://www.livescience.com/52413-why-some-species-have-more-females.html

This claims that there are more bucks than does (it is about deer), but that is because hunting has altered it. It predicts more males than females at birth. https://www.qdma.com/reality-doebuck-ratios/

And this one says that the deer ratio is 51 percent females to 49 percent males. https://hunt-indiana.com/thread/1275/birth-rate-ratio-male-female

What do you know of this, R2elk?

 

[R2elk]

A ranger at Yellowstone told me that confidently, but I just barely looked up a few sources online. Turns out that it is all a bunch of theories?

This source is complicated, but using birds as an example it says, "In bird species dominated by females, the males have multiple female mates, and females care for the young. In contrast, male-leaning adult sex ratios are linked with females having multiple male mates, and males raising offspring." https://www.livescience.com/52413-why-some-species-have-more-females.html

This claims that there are more bucks than does (it is about deer), but that is because hunting has altered it. It predicts more males than females at birth. https://www.qdma.com/reality-doebuck-ratios/

And this one says that the deer ratio is 51 percent females to 49 percent males. https://hunt-indiana.com/thread/1275/birth-rate-ratio-male-female

What do you know of this, R2elk?

As far as I know, normal male to female ratio at birth in mammals is slightly higher for males than females.

Studies are often done with a preconceived idea. Those studies tend to show a bias to the researcher's favored point of view. It would be impossible to complete a realistic study of elk in the wild to actually confirm the sex of newborn calf elk.

As far as deer go, here at the house I see approximately as many male as female fawns show up here every year. The problem is that deer aren't elk.

Just based on the fact that a normal bull has essentially the same number of male sperm as female sperm, I would expect the elk calf male to female ratio to be close to 1:1 also.

As far as chickens go, it is the female that determines the sex of the offspring.

 

[centrarchid]

Chickens, if not managed would operate in smaller social groups with a more balanced sex ratio. Adult females would be in groups of 1 to 3 individuals with a harem master cock and possibly a satellite male or two that are ready to replace the harem master at a moments notice. The harems under some situations would have outright territories, under other situations they would have overlapping home ranges. Aside from female elk having home ranges that overlap with female kin, to my eyes they have very little in common with chickens. The chickens produce more offspring per reproductive effort and more reproductive efforts per year. The male chicken can also invest in his offspring beyond the act to mating while the male elk does nothing of the sort.

 

[PioneerChicks]

Thank you both for all the knowledge!

As far as chickens go, it is the female that determines the sex of the offspring.

Here is another strange question. If somebody kept a flock with more roosters than hens (say, 3 roosters per 2 hens) would the hens produce more female offspring to try to restore balance?

 

[centrarchid]

Thank you both for all the knowledge!


Here is another strange question. If somebody kept a flock with more roosters than hens (say, 3 roosters per 2 hens) would the hens produce more female offspring to try to restore balance?

They do not adjust sex ratio through birth. Adjustments made through who gets ejected or accepted in a group.

 

[R2elk]

Thank you both for all the knowledge!


Here is another strange question. If somebody kept a flock with more roosters than hens (say, 3 roosters per 2 hens) would the hens produce more female offspring to try to restore balance?

No. What @centrarchid said.

Also you would likely have very stressed hens unless one of the roosters was clearly the dominant one.

 

[PioneerChicks]

Ahh, got it. I probably am not aloud to have that many roos anyways... Thank you both!