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Calf Mortality After Cow Dies

COEngineer

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There was a short piece in the most recent Bugle issue that stated something along the lines of, "If a cow dies during the first year of a calf's life, the calf has a near 0% chance of survival." I looked online for some data to back that up and can't find anything. There are lots of studies on calf mortality, but none that have specific correlation to the lack of a mother, at least that I could find. Anyone have a reference?
 
I've more than once found a lone calf bedded near a dead cow days after "firing line" herd shoots.
 
I have always been told that a calf can survive on its own after their spots are gone. That is coming from my dad who had said he was told by a wildlife biologist. As many times in my life I have found my dad is full of S### but it adds up when you look into how big game seasons are structured. Sure seems like odds are lower if it is a lone calf but if it stays with a herd, I see no reason why it wouldn't continue on.
 
Maybe if it's already been weaned and it stay with the heard of cows and other calves it might have a decent chance to make it.
 
I would say herd animals like deer and elk are much better off if the mother dies. I'm sure some calves still don't make it though.

When it comes to more solitary animals like moose and bear, you might as well as killed the mother and the calves/cubs yourself...
 
I appreciate all the hearsay and barstool 'knowledge,' but I'm still waiting for a creditable citation.
Try Craig Jourdannais at the MPG Ranch here in Montana. He's a former biologist and runs the Ranch now. They only allow cow hunts I believe. mtmuley
 
I have no citation for you, and I'm not sure the research exists. And I realize most of this post is unhelpful...

A quick browse of elk research suggests that more calf mortality occurs when they are younger, but the research focus is generally on predators.

"We documented 57 deaths of resident elk calves and 10 deaths of migrant calves (Table 2), with predation being the most frequent cause of mortality (n = 48). During the first 90 days of life, bears caused the highest mortality rate, killing 29 calves" - https://wildlife.onlinelibrary.wiley.com/doi/full/10.1002/jwmg.22330

"The effect of carnivores on juvenile ungulate recruitment varies across ecological systems depending on relative carnivore densities. Mountain lions may be the most important carnivore for ungulates, especially where grizzly bears (Ursus arctos) and wolves (Canis lupus) are rare or recovering. Finally, managers may need to reduce adult female harvest of elk as carnivores recolonize to balance carnivore and ungulate management objectives, especially in less productive habitats for elk." - https://fwp.mt.gov/binaries/content...f-survival-in-a-multiple-carnivore-system.pdf

"Forty-one of the 192 calves (21 percent) retaining their radio transmitters died during their first 13 weeks (Table 1). Predation was the greatest source of mortality, accounting for 27 (66 percent) of all known mortalities. Bear predation was the only source of mortality that differed across years (÷2 = 24.80, df = 4,P < 0.001,), occurring more often in 2002 than in all other years. In addition, bear predation (27 percent of all mortalities) was the greatest single source of mortality in elk calves across years. Mortality varied temporally throughout the summer with 76 percent of all mortalities occurring during the neonatal period from capture to 6 weeks post capture (Figure 2). Most bear predation (91 percent) and malnutrition (86 percent) mortalities occurred early in the summer during the neonatal period, while the first lion mortality occurred 5 weeks after capture. Marked calves also died from malnutrition (17 percent), abandonment (5percent) and disease (5 percent) in addition to predation. Calves died from malnutrition (n = 7, where n represents the sample size) in every year of the study except in 2003" - https://wildlifemanagement.institute/sites/default/files/2016-09/13-Cause-Specific_Mortality.pdf


Obviously the following is not the species you are looking for, but provides the kind of study that can answer your question. The Erebus Bay, Antarctica Weddell seal population provides an ideal study opportunity as researchers have been able to mark and document generational successes. I've linked just one of their findings.

Effects of pup age, maternal age, and birth date on pre-weaning survival rates of Weddell seals in Erebus Bay, Antarctica


"Identifying factors affecting juvenile survival is important to understanding the dynamics of populations and may also provide insights into life history theory and the selective forces shaping evolution. Quantifying the relative influence of the various potential selective forces for the post-birth, maternal dependency, and independent periods is difficult and often limits investigators to estimating a single juvenile survival rate for the first year of life, or from birth to recruitment"
 
That’s why you double when you have two cow/calf tags! The cow/calf combo is the way to go! That calf meat is tasty and I wouldn’t want it to suffer all winter! 😉
So a calf of the year is about the same size as a whitetail doe. I've often wondered why men who drive jacked up trucks always want to shoot the biggest and oldest cow in the bunch.
There's a study for you.

I found a website from MSU that says calves that make it until fall are recruited, but the same article says that wolves fart rainbows and only kill the most pathetic of the herd. Wolves don't fart rainbows and they kill elk at every demographic. As they should. It's what they do. Like it or not. MSU lost me at "Wolves use special hunting techniques. . ." If you mean, "Wolves kill the ones they can catch.", fine. Sometimes that is a cripple and sometimes its a snow-bound, depleted, post-rut bull. Intelligent they may be, but they don't have a clipboard and spotting scope looking for the least herd-impacting kill. Gary Larson should have made a cartoon of that.
 
Not sure. Last year my friends and I had 3 cow/calf tags for Wyoming. First morning out, found a solo calf bedded along a fence line. None of the herd to be found nearby - my guess is that it had a hard time jumping the fence and got left behind. My friend shot the calf and enjoyed some great tasting meat.
 
I think it depends almost 100% with predator density and if the calves are left on their own or can keep up with the rest of the herd. I also think later in the year it's less of an issue and most survive because they've moved to winter range.

That said, I try hard to not shoot cows with calves. I try to pick 1.5 year old cows or ones standing away from the main herd with no other elk near them. It's pretty obvious even in large herds to recognize the cow/calf pairs.
 
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