Supplemental Feeding Of Big Game – Utah

by Philip J. Urness

To avoid adding to the public’s confusion, this review seeks to assemble the pertinent information on winter feeding programs in regions of cold climates and to place it within the Utah context. The reader is encouraged to read the bibliographical citations and verify the relationships summarized here.

The idea of supplemental feeding of big game in Utah is far from new. In fact, many of the same problems we debated at length last winter (1978-79) were investigated rather thoroughly in the 1930’s and 1940’s by the Utah Fish and Game Department (now Utah Division of Wildlife Resources) and the Cooperative Wildlife Research Unit at the Utah Agricultural College (now Utah State University, [USU]). A lengthy paper reporting on both research experimentation and actual applied feeding experience was published by Doman and Rasmussen in 1944. The old saying that “those who ignore history are bound to repeat it” appears valid here. It is untenable to be telling our public today that deer do not possess the ability to digest alfalfa hay, when Doman and Rasmussen demonstrated that they can over 40 years ago (and they are by no means the first to do so)!

For us, the Doman and Rasmussen paper is a veritable gold mine because it dealt specifically with our area, namely northern Utah, and with our Rocky Mountain mule deer, not whitetail deer in New York State. Not surprisingly, the conclusions that they reached after about 8-10 years experience have not been altered much by more recent activities.

Where do feeding programs fit into present day management? Deer on winter ranges today face more severe conditions, generally, than they did in the 1930’s and 1940’s not so much because of poorer quality range but, rather, that there is much less of it and they are more restricted in its use than formerly. Housing, highways, intensive agriculture, recreation, energy exploration and other developments are but some of the causes of greater range restriction, all too familiar to the reader (Wallmo et al. 1976).

There are, in my. opinion, good arguments for and against supplemental feeding. Those against have usually been:

(1) Added damage to already heavily used native forages brought about by concentrating animals at central feeding stations (Mautz 1978a; Doman and Rasmussen 1944).

(2) Potential for increased disease problems.

(3) Behavioral modifications, which reduce the “wild” character of our wildlife and make them increasingly dependent upon man as dispossessed wards (Wolfe 1978).

(4) Tendency of the public to accept this as a solution to habitat degradation or loss on a broad front, not as a last gasp measure of mitigation.

(5) Very high cost.

(6) Increased vulnerability to predation by domestic dogs and natural predators.

Certainly, it would seem unwise to promote supplemental feeding where deer are scattered over a winter range in small groups and generally have been able to support themselves with reasonable survival and subsequent reproduction on native forages. Finally, it is my view that we seldom, if ever, are justified in artificially feeding deer as a means of avoiding the issue of managing our herds within the carrying capacity of the range through legal harvest. Such a definition of “emergency” feeding damages our professional credibility and does nothing useful for the resource, even in the near-term.

A case can be made for supplemental feeding under certain circumstances and some of these occur in Utah. First, and most obvious, are situations necessary to reduce land-use conflicts that cannot be resolved in another way. The Hardware Ranch elk feeding operation is an example where artificial feeding keeps elk from damaging private property. Secondly, there might occasionally be emergency situations of a limited nature, pockets of deer caught in deep snow, that are innately temporary and of small scope where a feeding effort may be justified. Such cases should usually be weather created. not winter habitat limited (Menzies 1979). That is, when weather moderates, there should be ample natural feed for the deer. Another example would be where highway construction activity or mining might temporarily block migration routes.

The third case that I can identify where Utah maybe forced in the future to feed deer on an intensive scale could be sections of the Wasatch Front where urban sprawl has completely usurped the normal winter range. Areas around Provo, Orem, Salt Lake City and Ogden come immediately to mind. Here we have an intact, large and high-quality summer range which could, in time, given current trends, be made unusable by anything more than token numbers of deer. Herd size and production under such conditions are not a “natural” limitation imposed by regional climate or vegetation (Menzies 1979). To carry deer in sufficient number to permit harvestable surpluses may require a supplemental feeding program to substitute for lost winter range (Dean 1976). It is not a very satisfactory alternative, but possibly the only option open to us in certain areas. Costs would be high and special permit assessments may have to be made to underwrite/ such operations. Conceptually, however, it does not significantly depart from our fish hatchery programs which recognize the lack of suitable habitat for satisfactory reproduction of trout, although there is an abundance of growth habitat.

Therefore, my message is that we should adopt a reasonable position in regards to winter feeding of deer or big game generally. One that is based on doing no more than is absolutely necessary, yet not precluding it as a management tool if circumstances dictate. As Wolfe (1978) has said, we are professionally constrained from substituting artificial feeding where natural food supplies can be increased or maintained through habitat improvement and where we have failed to adjust harvest systems to maintain herds within carrying capacity

If feeding programs are adopted, either as a Division of Wildlife Resources, organized sportsmen’s group, or individual citizen’s activity, there are some aspects for which research has developed answers that should be understood.

One is that such programs must be started early before deer become severely stressed and therefore have a better chance to adjust to the new feed. Doman and Rasmussen (1944) indicated that supplemental feeding should begin in January. Numerous other authors have verified this regardless of kind of feed offered (Mautz 1978a; Nagy et al. 1967; Pearson 1969; Dean 1976); yet other recent studies have demonstrated that deer generally can adjust quite rapidly if feed is properly formulated (deCalesta et al. 1975; Dean 1973, 1976; Schoonveld et al. 1974).

Indeed, rumen bacteria capable of digesting both roughage and concentrate diets survive long periods of deer starvation. deCalesta et al. (1974) starved mule deer up to 47 days and found bacteria numbers not significantly lower than those in unstarved deer and their capacity to digest alfalfa hay and pelleted concentrate diets unimpaired or only slightly reduced. Both deCalesta (1973) and Ozoga and Verme (1970) demonstrated successful refeeding of deer starved for long periods (from 2-9 weeks). Thus, it is certain that the buildup of rumen micro fauna capable of effectively using artificial feeds is rapid, and the transition period from starvation or poor quality browse to such feeds is less critical than once thought.

A balance of supplements and roughage should be maintained to avoid digestive upsets possible if excessive concentrates are consumed. Roughage can be either natural browse, good quality alfalfa hay or both. Dean (1973) indicated that malnourished deer can handle abrupt changes to pelleted diets, but high protein content may result in their developing diarrhea. Wobeser and Runge (1975) reported starving whitetail deer developed rumen acidosis or rumenitis when fed concentrates (cereal grains high in rapidly digested carbohydrates). Several balanced diet formulations in pelleted form have been reported successfully fed to deer, but our experience with them at Logan suggests it is advisable to offer good quality alfalfa hay in addition to assure adequate intake early. Available browse may negate the need for hay.

Deer have been shown to readily accept leafy alfalfa hay and to digest the leaves and small stems as efficiently as livestock (Dean 1973,1976; Nagy et al. 1967). However, deer should be started on hay early before they become malnourished for it to be beneficial by itself. Very poor quality alfalfa, alone, caused severe digestive upsets (Schoonveld et al. 1974) when fed in pelleted or cubed form. Mixtures of pelleted rations and hay are recommended.

Feeding stations should be placed away from human activity to assure deer unimpeded access. Deer are behaviorally constrained much more than elk by such activity and this may reduce intake, which is what a feeding program attempts to optimize. Moving feeding stations periodically may be a means of minimizing impacts on surrounding vegetation leading to unacceptable deterioration. Such damage was quite localized at a feeding site northwest of Snowville maintained by Idaho Fish and Game Department and used only one winter. Damage has been more severe on similar sites where feeding occurred over several consecutive winters.

Research into deer physiology, nutritional requirements and behavior has yielded some useful understanding of winter adaptation and survival (Wallmo and Gill 1971). Again, this appears to be an area of some confusion as exemplified by statements made to or by the media last winter and spring (1978-79). To begin with, we might quickly review the annual cycle of deer condition as caricatured (Figure 1) by Mautz (1978b). An important point is that we tend to overemphasize the winter diet to some extent, and underestimate the value of summer and fall range. It is the condition of deer going into the winter that is most critical to survival since winter foods, even when relatively abundant, are at best maintenance and often sub maintenance quality (Leckenby 1978). Thus, the animal begins a downward slide in body condition regardless of the winter range. If good fat stores are accumulated by fall, then chances are good that the animal will last out the winter. Winter food or supplements act in the analogy as a brake on the sled.

Maximum weight losses sustainable from starvation and refeeding studies are about 28-30 percent of fall body weights (deCalesta et al. 1975; Baker 1976). Weight loss is faster in older animals and fawns, and maximum weight loss sustainable by this group is probably lower (e.g., 25 percent of fall body weight); significantly lower if fall body condition is mediocre. Supplementation, if it occurs late in winter, acts as a sanded strip at the bottom of the hill which the sled hits and frequently tumbles over the edge. Feeding programs started in January would be analogous to sanding the whole slope and be much more effective in minimizing weight losses and subsequent mortality.

At greenup, if it arrives on schedule, the animal can begin the upward ascent again, but energy demand (for late gestation and particularly lactation) is heavy so upward progress is slow for females. Timing of spring greenup is extremely critical according to Moen (1978) and usually occurs gradually enough to allow conditioning of animals to head off digestive problems. That is, the animals begin to use green grass and forbs as soon as they appear, but in small quantities that are mixed with hardened browse. Amounts of green forage consumed are then gradually increased. Amorphous feces at such times do not indicate digestive problems. In fact, sheep men have told me that soft or even wet feces indicate animals on good quality feed; whereas, hard pellets indicate lower quality. Another purported problem with early spring forage that is often bandied about is the so-called excessive water content restricting forage value to the animal. Moen, in a recent seminar at USU, flatly stated that ruminants like deer have no problems excreting high volumes of excess water and demonstrate very high digestibility coefficients and turnover or passage rates of green feed. Thus, it is erroneous to say that green feed is of limited value to deer (Table 1), except that they seldom can get enough of it in early spring. Work at USU has shown that deer consume large amounts of green crested wheat grass in spring (Table 2) and digest it quite well (63-65 percent). Weight response was less than that predicted for wild deer with access to a mixture of feeds in addition to grass (Fierro 1977).

Figure 1. An analogy of the 12-month energetics of deer and other big game species in northern temperate climates such as Utah (from Mautz 1978b).

Table 1. Nutritive content of green crested wheatgrass-Croydon, Utah.

Table 2. Digestibility of green crested wheat grass consumed in pure diet by mule deer.

‘Oven-dry weight basis: 

Another element of deer metabolism needs to be reviewed. This is the apparent evolutional adaptation of probably several of our wild ungulates, including deer, to reduce their metabolic activity, physical activity and forage

intake rate (Figure 2) in winter (Moen 1973, 1976, 1978). Captive animals have been shown to reduce their intake in winter even when unlimited amounts of high quality feed are available (Mautz 1978a). These animals are attuned to poor quality and quantity of winter feed. Their response is to “hunker down” and outlast winter by minimizing energy demand and conserving stored energy (fat) by various means including consumption of foods that yield an energy return, avoiding those that do not. Much has been made of the insulating properties of the hollow guard hair of winter coats and this is a very real factor in winter survival. Reduction of surface area by spending much time bedded down with head tucked around the body to reduce convectional heat loss is also characteristic of winter behavior. Sometimes deer will wait out storms for several days in this posture without ever feeding, since energy costs of activity in conditions of extreme chill factor would be many times greater than energy yielded from most browse of moderate or low digestibility.

Hormonal changes in March trigger increased intake of forage especially in pregnant females entering the last trimester of gestation. As green feed of much greater digestibility and energy yield become available, intake may decline until parturition and the greatly accelerated demands of lactation occur (Figure 2).

Finally, socioeconomic factors enter into any discussion of supplemental feeding. Once started, feeding programs are almost impossible to abandon because of. public pressures; another reason to approach them with great caution, even reluctance. Costs are high, although data are fragmentary at best. For example, John Kimball, Utah Division of Wildlife Resources, calculated from data supplied by the Idaho Fish and Game Department that the cost of feeding one deer for 75 days would be $9 excluding transportation and labor. These costs would raise the ante to at least $12-15 per deer. Estimates calculated from a Colorado study in 1974, quoted by Dean (1976), indicated it cost $13.53 per deer for only 21 days. If refigured for a 75-day feeding period, that would mean almost $50 per deer.

Where would the money come from to pay this cost? Traditionally, we have, of course, generated our funds through sale of licenses. If we get $7 per deer license, it is readily seen that the ratio of cost to income is rather wide. I set up a brief and gross table based on the meager data on costs under several assumed conditions (Table 3). The results begin to fade into the Twilight Zone. Even under the most liberal of hunting systems, present costs and returns are badly weighted to the debit side of the ledger. Scenario III is probably about where we stand in Utah presently in terms of harvest percentage of the fall population. At the lowest feeding cost figure, it still approximates four times income under existing conditions. Consequently, I see no reasonable basis at the present time on which to initiate such programs in Utah for anything more than a very limited emergency or for very restricted localized areas.

BIBLIOGRAPHY

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