Mule Deer on the Edge

[robby denning]

Mule Deer on the Edge

Robby hosts Troy Fieseler and Luke Schultz of the Wyoming Game & Fish Department. Troy and Luke manage the habitat of the Wyoming Range mule deer herd. They explain the concept of mule deer on the edge.

www.rokslide.com

 

[Bull_n_heat]

Thanks for putting this together @robby denning! This is Luke here - I wanted to let folks know if there was additional comments and conversation here, I'm happy to share more info!

 

[robby denning]

Thanks for putting this together @robby denning! I wanted to let folks know if there was additional comments and conversation here, I'm happy to share more info!

Hey! Troy or Luke?

 

[Bull_n_heat]

Hey! Troy or Luke?

Good catch Robby - this is Luke (updated the post accordingly)

 

[Mag_7s]

@Bull_n_heat With the nutritional load loosing it's value sooner ~20 days has there been any observed shifts in mule deer behavior? For example, has peak rut activity been observed to be happening earlier or fawns dropping sooner as a result?

 

[Bull_n_heat]

@Bull_n_heat With the nutritional load loosing it's value sooner ~20 days has there been any observed shifts in mule deer behavior? For example, has peak rut activity been observed to be happening earlier or fawns dropping sooner as a result?

Good question. To preface everything, the study I mentioned on air was one a good friend of mine was a co-author on and we have talked about it frequently (he was one of the co-authors; the article is here: https://iopscience.iop.org/article/10.1088/2752-664X/ac7fb0). So I can't claim to be an expert, but I can provide some insights that are hopefully helpful.

I tend to think of rut timing to be a little bit "hard wired" in a particular herd. We see trends in it across the mule deer range that are largely driven by climatic conditions. For example, deer in say New Mexico are likely to rut later than deer in say Montana. I think this is mostly driven by conditions for the fawns hitting the ground and not so much the nutritional condition of the does. It also seems to be triggered often by photoperiod in the fall (how much light there is). My understanding (and my guess) is that this timing has evolved in individual herds over many, many years, in that fawns are hitting the ground to match timing with an "average" set of conditions that maximize their chance of survival (conditions include forage for mom, warm enough to not freeze fawn, etc.).

The timing of breeding is then just the difference between fawn drop and the gestation period. For instance, in western WY fawns and elk calves drop about the same time in early June, but the ~2 month longer gestation of elk means they breed in mid-September and not mid-November. Similar timing differences occur for deer. It's also interesting to note that often all deer drop their fawns within a couple days of each other essentially as a predator swamping strategy (I'm glazing over some details in this, but go with me on it). All of this is to say that I would guess that most deer populations would be much slower to change birth dates in the short term. But, given enough time, I'm sure they would start to (how much time is way beyond my realm of expertise though).

There's a fair amount of work out there on mismatches between long term averages in conditions and shorter term deviations from that (call it climate change if you like, the bottom line is it is real and very different), and what that has for consequences to animal populations. I'm familiar with lots of work for fish, but there is no shortage on deer too I'm sure. I did a quick search (I searched: "mule deer phenological mismatches") and you'll see a bunch of work in Wyoming dealing with timing of spring migration. I didn't look in great detail, but I would guess the studious among us would find something about adult condition and fawn survival if you poured through some of those studies.

 

[AlpineMuleys]

Hey Luke, Loved the podcast.
Pinedale resident here…

My question for you is about the cloud seeding/weather modification they are doing around here. I know it’s been going on for quite some time, but it worries me and lots of other people. Do you have any data about this? What effects does it have on our winter ranges? I’ve always been told that they try to make it snow only on the peaks but there’s just no way in my mind that it doesn’t blow down into the foothills. Obviously with our harsh winter last year it makes you wonder. Also curious if the salt or chemical that they use comes down into the soil and if there has been any change in the soils, vegetation ect..?

 

[Bull_n_heat]

Hey Luke, Loved the podcast.
Pinedale resident here…

My question for you is about the cloud seeding/weather modification they are doing around here. I know it’s been going on for quite some time, but it worries me and lots of other people. Do you have any data about this? What effects does it have on our winter ranges? I’ve always been told that they try to make it snow only on the peaks but there’s just no way in my mind that it doesn’t blow down into the foothills. Obviously with our harsh winter last year it makes you wonder. Also curious if the salt or chemical that they use comes down into the soil and if there has been any change in the soils, vegetation ect..?

I'm not overly familiar with the specifics of cloud seeding, other than to know it happens. I think the "they" that is doing the cloud seeding in Wyoming is the Water Development Office (some info here: https://wwdc.state.wy.us/weathermod/weathermod.html). My understanding though is that it is very common throughout the West (different agencies do it in other states of course). I believe that the evidence that it actually works at producing more snowpack is dubious at best (my opinion), but its one of those things where if your neighboring mountain ranges are doing it, by golly we better all be doing it. And the cost of doing so is pretty miniscule.

As to what it means for wintering deer... I guess I just really don't think it has much of an impact. The cloud seeding chemicals (silver iodide) are administered (dumped from airplane or shot up from ground centers) probably 3000' higher in the mountains than the deer are wintering. IF there was more snow produced, it likely would not be blown around enough to wind up on winter range at any measurable (let alone appreciable) amount. With prevailing west winds, it seems like it would blow it UP the mountain (if not over to Lander) if anything.

As for the chemical. I believe it's released in very small quantities and scientists haven't been able to detect it in watersheds or other environmental samples above background levels with these operations. I kind of feel like if there was any kind of a problem, someone would be clamoring about it, and I just don't hear that. I guess I just wouldn't consider it a big deal on the spectrum of potential big deals for deer. Incidentally, ski resorts use bacteria and not silver iodide to make snow. Never hear anything about that either.

-perhaps a hydrologist's take is warranted here: @Josh Boyd ? The link I shared above has some studies referenced, but I wouldn't mind having a look at some of the actual research papers. It seems like there is a fundamental difficulty in measuring the effectiveness: If one "seeds" a cloud, there's no way to go back and measure how much moisture would have fallen from a cloud if you hadn't seeded it. There's also a very small effect size (how much more water you get in a seeded cloud vs non-seeded cloud is only ~10%) to seeding that can obfuscate findings. I'm sure there's ways around this, but would love to take a look at the actual work.

Deep dives are available to those suffering from insomnia starting here: https://cen.acs.org/articles/94/i22/Does-cloud-seeding-really-work.html

 

[mtnrunner260]

Any reseeding efforts on these cheatgrass sites?
Great podcast.

 

[Bull_n_heat]

Any reseeding efforts on these cheatgrass sites?
Great podcast.

Appreciate the listen and glad you enjoyed it.

For reseeding.... Typically not. We basically have to weigh the risk of introducing additional invasive species into the treated patch against jumpstarting the new plants. Often, what the cheatgrass sprays do is just impede rooting/germination of existing seed in the soil. So, other species in the soil should (I say should, but there is probably some negligible effect on those seeds too) be unaffected and can germinate on their own.

For a deeper dive on cheatgrass efforts, check out a thread started by @Jimss here: (https://rokslide.com/forums/threads/cheatgrass-vs-mule-deer.339140/#post-3404180). Jim, feel free to correct me if I am wrong with anything above and keep up the good work!

 

[Jimss]

Great podcast! It is exciting that the word is finally getting out about the impacts cheatgrass has on native species, species diversity, wildfires, and the health and productivity of wildlife! Great job guys!

One thing I would like to add is how resilient and quickly native species respond to the removal of cheatgrass competition where there is still remnant native species and native seed in the soil. We have found that the diversity of these species (including annual and other short-lived native species) increases every year after application. Obviously, the sooner areas are sprayed after cheatgrass invasion, the quicker the recovery.

The trick with long-term cheatgrass control is to beat seed longevity in the soil (since it's an annual). I'd say 85 to 90% of cheatgrass seed in the soil germinates the first 2 years after seed is shed from plants. There is some seed that persists in the soil for 3 to as many as 5 years. With 4 to 5+ years of cheatgrass control there should be no cheatgrass seed left in the soil. Obviously, seed can make its way back into areas but with native plant competition these sites are extremely resilient to drought and re-invasion.

This was year 7 of the large-scale sites we've been monitoring, and we still are getting 88 to 100% cheatgrass control. The only areas we see cheatgrass returning are from skips or borders that weren't sprayed. Spraying with no skips and with the highest gallonage/acre of water is key. There are other tips I would recommend but I'll try to keep this short.

As mentioned at the end of the podcast. I really think it's important for the public (and hunters) to get involved. Public support of wildlife enhancement projects to county commissioners and land management agencies allows many of these projects to run smoothly and effectively. Whether it is volunteering for fence removal or offering financial support, it is time and money well spent!

Again, great job with the podcast guys! If you haven't already listened to the podcast, I would highly recommend taking a few minutes to listen in on it.

 

[Bull_n_heat]

One thing I would like to add is how resilient and quickly native species respond to the removal of cheatgrass competition where there is still remnant native species and native seed in the soil. We have found that the diversity of these species (including annual and other short-lived native species) increases every year after application. Obviously, the sooner areas are sprayed after cheatgrass invasion, the quicker the recovery.

As mentioned at the end of the podcast. I really think it's important for the public (and hunters) to get involved. Public support of wildlife enhancement projects to county commissioners and land management agencies allows many of these projects to run smoothly and effectively. Whether it is volunteering for fence removal or offering financial support, it is time and money well spent!

Thanks for the follow up info here - definitely sounds like Rejuvra is even more promising for longer term cheatgrass control than I had initially thought (and I already thought it was the bee's knees!). Keep it up and hopefully we can keep making things better for deer (and all the other native wild life).

I probably glossed over this a bit in the show, but with the "getting involved" piece, I would recommend folks reach out to elected officials and other people of influence if you want to see more of this. I sometimes reflect on the meetings last spring with Governor Gordon about our winter mortalities on deer in western Wyoming. It was definitely a good thing to see, but if we could have this type of groundswell from communities about making habitats more productive, I could just imagine what that would have for impacts and how much more of this work we could do. Calls, letters or emails to these officials (done respectfully of course) can have a ton of influence on what squeaky wheel gets the grease. It doesn't happen overnight, but they pay attention if enough folks let them know this is what they care about.

Secondly, pay attention to large scale planning efforts that management agencies have, and get involved early. Game and Fish, BLM, and the USFS all go through these efforts in some areas from time to time. Effective comments are always considered (not always implemented), so you can make them as long or as short as you would like. Something as simple as "I support option X because it will have positive benefits on Area Y where I like to go hunting" can do the job.

Thirdly, on the Time, Talent or Treasure part of involvement.... if you don't have time to stay up to speed on every RMP or Forest plan revision, financially support organizations that will do it on behalf of our community. WY Wildlife Federation is a great one that comes to mind in Wyoming, but there are ump-teen others across the country. When you join those groups, take the time to both research how well they support what you are interested in, AND tell them what in particular you want to see them support and what matters to you. WWF for instance will spend a lot of time fighting bills that are bad for wildlife, but if you want them to advocate more strongly with decision makers to do habitat work (or whatever), let them know.

Lastly, on the talent part... If you have a helicopter, heavy equipment skills, are a budding scientist with a great idea, et cetera reach out to folks that are doing this work. Many of the costs of doing this work are hiring highly trained people to get it done (if you saw me run equipment you would know why we hire people!). If you are willing to do it at cost, or for free, there is no shortage of people that would love to have you help out. You'll get to see really cool country, learn it better, and contribute a ton to the resources we love.

Robby talks often about how hob-knobbing with wildlife folks will make you a better deer hunter, and that may be true. But making more deer habitat for darn sure goes a lot further at doing just that than hanging out with me and learning the difference between basin big sage and Wyoming big sage!

 

[Mag_7s]

@Bull_n_heat in regards to the early green up, is there any evidence to suggest that mule deer digestive systems my have a more difficult time transitioning to the lush feed earlier?
If there is a negative impact will they be able to adapt over time?
If there is no difference in digestive function with earlier green up, are there any positive or advantageous possibilities such an increase in antler growth or a more nutritional milk for fawns?

 

[Bull_n_heat]

@Bull_n_heat in regards to the early green up, is there any evidence to suggest that mule deer digestive systems my have a more difficult time transitioning to the lush feed earlier?
If there is a negative impact will they be able to adapt over time?
If there is no difference in digestive function with earlier green up, are there any positive or advantageous possibilities such an increase in antler growth or a more nutritional milk for fawns?

Good questions. A deer's digestive system is a complicated and somewhat sensitive monster. The microbe community in their gut is very adapted to what they are currently eating and responds very poorly to rapid changes in feed type/quality. If a deer goes from eating shrubs and other low quality browse to immediately eating something rich like green vegetation or (worse yet) alfalfa, it can kill them. Essentially they will die with a full stomach, and it can be even more severe if the animal is already stressed. This is one of the reasons we encourage people not to feed deer. Every year we lose some deer to the effects of switching to green food, but it can vary based on how quickly snow leaves and greenup occurs*.

I don't know that there is evidence that a specifically earlier greenup affects this processes, but rate of change sure does. I always hope for a slow transition from winter to spring. It would definitely make sense that an earlier greenup would translate to a nutrition boost for does which would help fawns in utero, and probably in milk production (as long as the lush feed remained available after birth).

As for antlers, I think people make a big to do about "genetics", but I think it really comes down to nutrition, both at an early age and throughout life (for more: https://rokslide.com/forums/threads/growing-big-mule-deer.308416/). I think a longer growing season is particularly important for this as well, so yeah, any time the buck could start growing antlers earlier should give some advantages (provided the duration of lush forage is extended too). This is one of the reasons highly migratory herds tend to grow big bucks - not because "genetics" are any better, but because they can follow green vegetation all the way up the mountain for a much longer period of time (think elevational changes like in Colorado too). However, I think the "growing season" for antlers is somewhat hardwired as well. It's not like if there was a freak greenup in February that bucks could capitalize on that with bigger antlers.

*This is what we see in the big snow country of western Wyoming. I imagine something like this occurs in other parts of the mule deer range, but I would imagine it is somewhat less of an issue where most of the winter range is free of snow. In this way, I suppose it is possible that (on the extreme end) and earlier greenup might actually be advantageous to deer, but I am really out on a limb with my speculation with this.