Genetics vs. Habitat for Big Bucks?

[onpoint]

Which do you think is most important for producing big bucks, genetics or habitat?
If you #1 could transplant a herd with non trophy genetics (defined as being from county that has never produced a B&C entry) into a prime area like central Arizona or New Mexico (assume no mixture with animals native to the prime area)
or #2 transplant a herd with trophy genetics (Assume from an area in central AZ or NM that has produced many B&C entries) into an area that has proven unable to produce big bucks (Assume a county in Utah or Idaho that has never produced a B&C entry) (Again assume no mixture with resident herds)

Which one do you think would produce bigger bucks?

I believe your scenario(s) suffer from extreme over simplification.

....a herd with non trophy genetics (defined as being from county that has never produced a B&C entry)

A variety of factors could contribute to the above: security, hunting access, hunting regs specific to the area, climate, etc., etc.
The same (inversely) could apply to the second scenario.

Seems an attempt to simply answer what could be, and likely is, a complex question.

And this sciency thing - Alot of "good genetics" with critters, IMO, is a result of the habitat over long periods of time.

 

[EliAGrimmett]

It would appear that a bucks lot in life is largely a function of the body condition of its mother when it was born.

This would jive with my theory from 2011 - that a bucks future horn growth is directly related to that bucks health during the year it's born. Stands to reason that the healthier the doe, the healthier the fawn.

 

[El Serio]

After mulling it over for most of a day, the South Dakota whitetail study seems to show that most local perceptions of "trophy genetics" may be more a function of environmental factors (and hence the health of the mother) rather than genetics. In this case the study animals came from the same state however. Do you suppose that such a study would hold true with animals from widely different latitudes? It is widely known that animals of the same species tend to have larger bodies at more northern latitudes, while those at southern latitudes have smaller bodies (Bergmann's rule). If the SD whitetail study were repeated with animals from completely disparate latitudes, such as one group from Saskatchewan and the other group being Coues deer from southern Arizona, would we see similar results, or would we find that by bringing the same location at a central latitude, with uniform environmental/weather conditions, there would still be a large size difference between the two due to genetic differences inherited over thousands of years?

 

[antlerradar]

Antlers form three different mature bucks form the same bachelor group. The largest set is over 200. I haven't measured the smallest buck but he is less than 140. There was also an big bodied older buck with small with small three point antlers in the herd. Hard to say what the conditions of the mothers was when they were born but is safe to say that the habitat was close to the same.

A few miles away I found several antlers from another very large buck a few years later that are very similar in size and shape. I think that the two bucks are likely related. Likely half brothers with the same mother or maybe even full brothers.

 

[jimss]

The highest scoring buck I have ever harvested in Wyo was a year with historic drought. My 2nd highest scoring buck was around 10 years earlier in a different unit with historic drought. Both areas were decent counties known for producing B&C bucks.

I burned a pile of pref pts a couple years after the back to back droughty years in a Red Desert unit that is reknown for producing B&C bucks. It was a wet spring and mild winter with hardly any winterkill for years prior to that hunt. I spent more time scouting that unit than any I have ever drawn. I probably looked over 700+ bucks and ended up shooting the biggest buck I saw that was over 80". Most of the bucks I saw had thin horns and barely 12" long! I was depressed!

Ever since that time I've tried to rationalize what was going on. Shooting bucks in historic drought years....not seeing ANY decent bucks in a unit with incredibile genetics in a year with great moisture that had 4 or 5 mild winters. I came to the conclusion that bucks born in wet years have better horns from the year they are born onward. Bucks born in years of drought would have regressed horn pedicles for their entire life. The more I thought about it, it made sense that horn pedicle wouldn't change a whole lot after they are born. Obviously buck fawns come directly from does so if does are healthy they will likely give birth to fawns with good pedicles. I heard through the grapevine that Eli possibly agrees with this senerio. I've kept pretty tight tabs on weather patterns, moisture, fawn recruitment, etc for quite a few years now and the pattern has been holding true in Wyo.

Some counties in Wyo will all of a sudden produce a round of B&C bucks for a year or 2. I have a feeling all the stars align when that happens. Something is definitely missing when there are 20 years with 0 B&C entries and all of a sudden in 1 year there are 5 entries! I guess if I had the choice I would rather have great genetics rather than great habitat...because there will likely be good years of moisture and other conditions in those poor habitat areas that may produce whopper bucks.

There are a lot of factors that still need to align to produce whopper bucks...even if they have great genetics. It may be possible to import AZ B&C does and bucks to Colorado but if the AZ antelope have trouble adapting and surviving winters and have trouble adjusting to a different diet of plants the does and bucks may not be too terribly healthy...and thus not produce horns like they did in AZ. Obviously it's nice having everything (genetics, feed, cover, age, reduced hunting pressure, predators, moisture) but that often isn't possible.

 

[walking buffalo]

There little to no evidence of Genetic factors alone effecting potential horn size.

Phenotype expression is another matter. This is where the combination of genetics and habitat, individual vitality all combine to produce the final "product".

A perfect storm of variables must collide to realize the potential to produce bigger than average animals.
One variable alone will not do it, well, except for hormonal gigantism.


As Buzz and Eli have noted, health of the mother is probably the leading factor in offering the offspring the ability to be above average in health and future size.
This is likely the most critical driver to allowing a phenotype expression becoming "wired" for the individual to grow larger.

With Pronghorns, dependant on location, a series of mild winters or rains at the right time can be the trigger for exceptionally healthy does, leading to bug bucks.

Other animals seem to thrive size wise better when population levels are low, allowing less completion for resources. This is particularly true for wild sheep.

Mule deer seem to also grow bigger when populations are young and are well below carrying capacity.

Valeries Geist observed and wrote about this. Individual and herd vitality through Young adults with unlimited easy food.

And let's not forget, gay bucks. They don't bother with the rut, just focus on being safe, lazy and getting fat. :lol:

 

[jimss]

Walking Buffalo, would you agree that buck antelope fawns born in wet years will have larger pedicles from the day they are born until they die? A buck born in a year with great moisture will likely still grow above par massive horns in droughty years? I would be curious what you and others think?

Colo has pretty much re-written the B&C moose record books with their introduction to Colo not too terribly long ago (in human years). The B&C magazine had an interesting article about shiras moose in Colo a while back. There has been pretty much an unlimited supply of groceries for them. There obviously was good genetics in the mix but having an incredible food source meant super fat and healthy cows/calves...and great antler growth on bulls. Many of the things Walking Buffalo mentions in his post above holds true for moose as well.

 

[walking buffalo]

Walking Buffalo, would you agree that buck antelope fawns born in wet years will have larger pedicles from the day they are born until they die? A buck born in a year with great moisture will likely still grow above par massive horns in droughty years? I would be curious what you and others think?

Colo has pretty much re-written the B&C moose record books with their introduction to Colo not too terribly long ago (in human years). The B&C magazine had an interesting article about shiras moose in Colo a while back. There has been pretty much an unlimited supply of groceries for them. There obviously was good genetics in the mix but having an incredible food source meant super fat and healthy cows/calves...and great antler growth on bulls. Many of the things Walking Buffalo mentions in his post above holds true for moose as well.

Your focus on "wet" years is likely seasonally and geographically specific. Where are you referencing and do you mean "wet" summers or winters?


I'm not aware of any research specifically analyzing Pronghorn fawn pedicle size with seasonal weather. But lets consider how would we get horn core (not pedicles) measurements from fawns.. maybe not a study anyone wants to do.
I have read some research into adult Pronghorn horn size related to seasonal weather during their gestation period. There does indeed appear to be a direct positive relation to what is suspected to be health of the dam during pregnancy and the production of larger bucks.

Just speculating, but I would expect fawns born from mothers at peak health during pregnancy are not only bigger in overall body size, but in horn core size as well, which just may be the factor that leads to larger than average horn sheath size. There is some pretty detailed research in Bighorn Sheep regarding ewe and offspring health/size and future horn sheath growth rates.... Horn sheath MASS increased along with birth weight. Now note that horn core size was not measured. Is there a correlation between horn sheath volume and vitality? Yet another mystery we can spend some time and money on....

I am from Alberta where the greatest strain on Pronghorn health is the extreme weather during winter, particularly heavy snow and a late spring. Many of our Pronghorns are migratory, so not only do they have to survive winter, the more extreme winters tend to see an increase in migration distance travelled. Kind of a double hit. For our population, a series of mild winters after a severe winter mortality event seems to lead to a year class or two of bucks with exceptional horn growth. The occurrence of "wet" summers just doesn't seen to do a lot for horn growth.

For intrest and this is just anecdotal. In Alberta we recently had a couple of hard winters in a row that hit Pronghorns really hard. A few years later and after a couple of mild winters, the bucks were still typically below average in horn size. I had been expecting to see a year class of Big horned bucks, having seen this phenomenon happen before. A few more years past and suddenly this last year the horn size exploded! BIG bucks everywhere. I wonder why there was this delay in vitality.... perhaps the does that survived the hard years were simply too old to produce exceptionally vigorous offspring? But their offspring could! The timing fits. Just a theory within the theory.



Your observations for Co moose fits right into this concept. Low density populations in great habitats with low stress (winter and predation) are a potion for producing big racks.

 

[jimss]

My observations are in Wyoming. Winterkill and drought tend to be the 2 key weather factors that affect doe health/horn growth in bucks. Good health of does and new born fawns would likely be a result of relatively mild winters with lush vegetation through the growing season. Optimal horn growth of bucks in any given year is a result of being born in a year when does are "healthy" (fawn bucks born with bigger horn sheaths) plus good moisture during the previous growing season and late winter/spring. In Wyo's case it appears that drought conditions in any given year may not be as important as fawn bucks being born in a year when does are healthy. I've harvested my highest scoring bucks in Wyo during drought years....which mirrors this. Obviously there may be lag times after drought and winterkill years before bucks have the chance to age.

It sounds like in Alberta does are stressed the most in years with tough winters. If my assumption is true; Alberta fawn bucks born in years with tough winters (does are stressed) may have smaller horn sheaths from that year until they die? I would expect the lag-delay in great horn growth after tough winters would be partly due to smaller buck horn sheaths born in tough winters and fewer mature bucks with good horns surviving those winters. In Wyo and Western US I've heard it takes 3+ years to produce B&C horns. It likely takes several years before the smaller horn sheath bucks are gone and larger horned sheath bucks age? If you look at the B&C books there is a lag in B&C entries from Wyo in the years after drought and severe winterkill. This may only be in isolated locations in Wyoming depending upon the weather.

I would be curious if that makes sense in Alberta?

 

[Hunting Wife]

Interesting thread. Looks like another factor to consider might be age classes of the population, though it doesn’t follow the typical thinking about buck age and horn growth. More B&C size bucks came from the 2 and 3 year old age cohorts than any other, and horn size declined linearly for every year of age after that in these two studies. Interestingly the finding was the same in populations in both Montana and Arizona.

https://www.google.com/amp/s/www.researchgate.net/publication/261825706_Are_Horn_Characteristics_Related_to_Age_in_Male_Pronghorns/amp

http://www.azantelope.org/Facts___Research/Horn_Growth_Study/horn_growth_study.html

So here’s a hypothetical scenario given those findings....after a period of harsh conditions, you would likely have reduced populations, resulting in reduced competition and more available forage for remaining animals. Throw in a period of mild weather and conditions would be optimal for gestating does, likely resulting in higher fawn recruitment and maybe increased potential for horn growth among bucks in that cohort. These favorable conditions may persist for a couple of years, coinciding with the highest horn growth years for those cohorts of 2-3 year old bucks, resulting in a flush of exceptional growth until population densities begin to rise again, age structure of the population shifts, another significant mortality event occurs, or something completely unaccounted for happens that sets everything back again.

Might this actually be happening? I have no idea...just a stream of consciousness thought on my part. Seems as plausible as other hypotheses, but any way you slice it I think these questions of horn/antler growth illustrate just how complex biological processes can be, and how little we really know about all the factors that influence them. Would be really interesting to have demographic data for those years folks perceive as having better than average horn growth, just to see.

 

[walking buffalo]

My observations are in Wyoming. Winterkill and drought tend to be the 2 key weather factors that affect doe health/horn growth in bucks. Good health of does and new born fawns would likely be a result of relatively mild winters with lush vegetation through the growing season. Optimal horn growth of bucks in any given year is a result of being born in a year when does are "healthy" (fawn bucks born with bigger horn sheaths) plus good moisture during the previous growing season and late winter/spring. In Wyo's case it appears that drought conditions in any given year may not be as important as fawn bucks being born in a year when does are healthy. I've harvested my highest scoring bucks in Wyo during drought years....which mirrors this. Obviously there may be lag times after drought and winterkill years before bucks have the chance to age.

It sounds like in Alberta does are stressed the most in years with tough winters. If my assumption is true; Alberta fawn bucks born in years with tough winters (does are stressed) may have smaller horn sheaths from that year until they die? I would expect the lag-delay in great horn growth after tough winters would be partly due to smaller buck horn sheaths born in tough winters and fewer mature bucks with good horns surviving those winters. In Wyo and Western US I've heard it takes 3+ years to produce B&C horns. It likely takes several years before the smaller horn sheath bucks are gone and larger horned sheath bucks age? If you look at the B&C books there is a lag in B&C entries from Wyo in the years after drought and severe winterkill. This may only be in isolated locations in Wyoming depending upon the weather.

I would be curious if that makes sense in Alberta?

Other than you speaking American and me speaking Canadian, yes it makes sense.

As Hunting Wife mentioned, I would caution conclusions on the age requirement for bucks to get to B&C size. The little bit of research done in this area tends to show that young (2-3 year old) bucks can make up a significant proportion of big bucks in a particular year's harvest.

Of course this data can't conclude just how big those young bucks Might have become if they lived longer.... It just shows that Pronghorns can reach B&C size at a relatively young age, which is also relative as Pronghorns tend to be a shorter lived animal compared to deer or elk...

 

[88man]

I didn't watch the video yet. However, I am a firm believer in the first year pedicle size having a major role in the lifetime of antler development. I think there has been alot of research proving this with whitetails.