Munties in velvet

pete evans

Well-Known Member
Why do muntie bucks come in to velvet at the same time? The other species have a defined rut and the antler growth coincides with the requirement to have hard antler to defend territory or overcome challenge from other stags/bucks. Munties dont have a defined rut so why have a defined antler growth cycle?
 
Pete

Scientific studies suggest that, for muntjac, the threshold level of testosterone required for antler development is higher than that required for mating, i.e. muntjac can breed all year round but their antler development requires a higher peak concentration of testosterone than would be atypical for other species of Cervidae. Another alternative theory is that there may be hormones at work in muntjac other than just testosterone.

Don't forget than muntjac are positively prehistoric by comparison to other deer, having far fewer chromosomes, so that the general rules for deer need not necessarily apply for muntjac.

willie_gunn
 
Muntjac Bucks are fertile whether they are in hard antler, velvet or have just cast their antlers. The blood level of testosterone doesn't drop as low as other deer.The extended pedicles are a conservation of mineral resources so only have to replace the tops.
 
Muntjac Bucks are fertile whether they are in hard antler, velvet or have just cast their antlers. The blood level of testosterone doesn't drop as low as other deer.The extended pedicles are a conservation of mineral resources so only have to replace the tops.

so why do they all come into velvet simultaneously?
 
Testosterone is irrelevant as Morena states. It takes up valuable food resources to grow antlers. Food is plentiful from May onwards until Autumn. It is therefore logical to assume that this is the best time to grow antlers so as not to deplete the bodily resources at a more critical time of year!;)
MS
 
I don't think Morena said anywhere that testosterone is irrelevant?

Studies such as Pei et al (http://zoolstud.sinica.edu.tw/Journals/48.1/120.pdf) have observed that testosterone in muntjac varies throughout the year and that antler casting in muntjac occurs when testosterone is at its lowest, similar to the annual cycle in other deer. Re-growth and antler cleaning is thus also related to testosterone level.

What is apparently unique about muntjac compared to other deer species is that their cycle of antler casting is synchronised across wide geographic areas, and that male muntjac born at any time of the year will then fall in line with that cycle. Thus, immature male muntjac may be observed with their first set of antlers at any time of year, but will subsequently fall into the "normal" antler cycle once that first cast has been completed.

​That same testosterone level, however, doesn't fall below the threshold level at which male muntjac would effectively be infertile, hence why they can continue to breed all year round.

So the level of testosterone in muntjac is relevant to both the annual antler cycle and their reproductive ability.

willie_gunn
 
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I don't think Morena said anywhere that testosterone is irrelevant?

My point may have been misunderstood. Muntjac bucks remain fertile throughout the year regardless of testosterone level was the point I was trying to make. I'm sure it could be a seasonal trigger for antler casting, but it also makes sense that nature has chosen to coincide this with maximum food source for re-growth.
MS
 
My point may have been misunderstood. Muntjac bucks remain fertile throughout the year regardless of testosterone level was the point I was trying to make. I'm sure it could be a seasonal trigger for antler casting, but it also makes sense that nature has chosen to coincide this with maximum food source for re-growth.
MS

No, I understood perfectly what you wrote (Alex, where's that Pedant emoticon) ;)

I would also agree with you 100% that it makes sense for nature to coincide antler growth in muntjac with maximum food source.....except that nature has then gone and chosen winter as the time for roe deer to grow their antlers ;)

Deer, don't you just love them :D

willie_gunn
 
I would also agree with you 100% that it makes sense for nature to coincide antler growth in muntjac with maximum food source.....except that nature has then gone and chosen winter as the time for roe deer to grow their antlers ;)

Deer, don't you just love them :D

willie_gunn

Most things I have an answer for, but I'm afraid I don't for that one!
Why do they rut in July/August when they have no intention of giving birth until May/June? I think Roe just like to be different?
MS:confused:
 
Came across this podcast from the Royal Veterinary College yesterday: http://www.rvc.ac.uk/Review/Podcasts/RVC_Podcast_22.m4a

It's very interesting, though they focus primarily on red deer and so don't talk about the inconsistency of roe. Also, the link between antler size and sexual attraction doesn't explain the success of hummels.

What I do like is the recognition that we still know very little about antler growth and why it only happens in deer.

willie_gunn
 
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