Mulie fawn development questions

[Sagebrush1]

So I posted about fawns with diarrhea last spring and I have a a continuing question:

One of the twins from the “diarrhea question” is still around - we assume his sibling passed. He still has a patchy, scruffy long coat, and is pretty small.

Additionally, there is a set of triplets from last year that we see quite a bit. They were born really late, and were still spotted fawns last fall. They are absolutely tiny little things!

These 4 are constant companions, and are are always alone. We haven’t seen the moms since the winter. Their small size really sets them apart. The triplets are reeeaaally small, and have been the same size since the fall.

Anyway….my questions are related to their development.
- is the lack of “summer coat” transition hormonal or nutritional?
- does the food stress they endured being born late and being momless over winter have a lasting effect in their size?
- is a “second cycle” of the rut a thing here in CO?

Obviously there is a lot of variation in a natural system, so stuff happens, but I’d be interested in any thoughts. The biologist in me loves this stuff!

Here’s a picture of scruffy, and one of the triplets…

 

[Hunting Wife]

I’ll take a stab at it.

Nutritionally deficient individuals will often retain their old coat and not shed out very well. That seems the most likely explanation in this cases.

Yes, there is evidence that nutritional stress of the mother leads to life-long reduction of offspring growth. I’ve linked to the research on this before, but I can try to find it again.

No idea on the specifics to Colorado rut, but second cycles in at least some does are not uncommon.

The “diarrhea” fawns sound suspiciously similar to fawns I’ve observed in EHD years in Montana. Did CO have sn outbreak this year?

 

[Sagebrush1]

Thanks for the info!

I hadn’t heard of EHD here. Those two twins were both struck with it, and the only two deer I saw with it last year.

Can EHD be survivable?

Are there definite time frames to fawns weaning? I understood that mom defines their movements the first couple years? Could the moms have migrated or moved without the fawns or is it more likely they died? (I imagine gestating/nursing 3 late in the year would be very nutritionally very demanding)

I’m pulling for these little ones! It’ll be interesting to see how they develop.

 

[Hunting Wife]

Oh yes. Mule deer seem to survive a little more often than whitetails (though mortality can still be pretty high). In the fall you often see more retained velvet on surviving bucks during EHD years, and you can often see hoof abnormalities-kind of like when you smash your finger and the nail grows back weird.

Fawns of both species also usually survive. I’m not sure why that is, but it’s a known feature. I have seen some with very bad diarrhea during outbreaks- not sure if that is a symptom of EHD or some other fawn malady. When we have outbreaks here, by late summer we are seeing lots of fawns running around with no does. It’s one of the things we look for to identify possible outbreaks. If I had to guess, that would be mine for what you are describing. Very doubtful mom, or two moms in this case, just up and migrated away from fawns.

 

[Sagebrush1]

Thank you! Interesting stuff!
Are you involved with this type of information in a career capacity?

 

[old270hunter]

Looking forward to an update on this. I hunt the area and am interested. I’ve personally never seen what you show and describe. I’ve seen some scrawny looking fawns, but that one in the picture is really on the outside edge of rough. I’ve been hunting that area since 97 or so and do know the rut can start at different times, and I’ve seen it come on early a couple years, and have seen it literally change from nothing to full rut overnight. I’ve never been around late in the rut though.

 

[Hunting Wife]

Thank you! Interesting stuff!
Are you involved with this type of information in a career capacity?

Started my career in wildlife health. Interesting, but nice to go to work now and have more variety than just dealing with dead or dying critters all the time. Felt like the merchant of death some days.

 

[Sagebrush1]

Looking forward to an update on this. I hunt the area and am interested. I’ve personally never seen what you show and describe. I’ve seen some scrawny looking fawns, but that one in the picture is really on the outside edge of rough. I’ve been hunting that area since 97 or so and do know the rut can start at different times, and I’ve seen it come on early a couple years, and have seen it literally change from nothing to full rut overnight. I’ve never been around late in the rut though.

We saw the triplets yesterday, but I bet it’s been two weeks since we saw an adult deer in the neighborhood. That’s really strange.

I’m gonna call a local CPW biologist this week and see if they are seeing it too.