Should You Cull Young Bucks? Insights from the West-East Yana Project at the Faith Ranch

Should You Cull Young Bucks? Insights from the West-East Yana Project at the Faith Ranch

Spikes

How to Lose Control of a Feeding Program On 1,000 Acres With a fawn survival of 65%, production far exceeds natural mortality. Growth of the deer herd is exponential. The problem is worse at a 100% fawn survival. In an unfed environment, populations would crash. On protein feed, deer numbers and feed costs keep rising.

How to Lose Control of a Feeding Program On 1,000 Acres Protein Feed Cost: $400 per ton A deer consumes 3.5 pounds per day of protein feed. We feed 290 days per year. Annual feed cost: $200 per deer per year.

How to Lose Control of a Feeding Program On 1,000 Acres

How to Lose Control of a Feeding Program On 1,000 Acres The common first step to an out of control feeding program: Start shooting females. If you started shooting females in year 5. You have built up a surplus of bucks mostly young bucks. And you don t have many mature (5 ½) bucks. In effect, you created a surplus of bucks beyond what you need or can afford.

So what do you do about the bulge of bucks? You can think about shooting spikes. Is it possible that you are killing future giants?

The East-West Yana Data Can Help You Decide Whether to Shoot Spikes We have captured 164 yearlings that we recaptured at 4 ½ years and older. 41 of those yearlings (25%) were spikes 123 of those yearlings (75%) had 3 or more points as yearlings For each yearling, we identified the maximum score that buck reached from 4 ½ to 8 ½: We compared yearling points to the MAX B&C score of each buck from 4 ½ to 8 ½.

Another Look at the Data: A Scatterplot of Yearlings Max 4.5+ B&C Score 240 230 220 210 200 190 180 170 150 140 130 120 110 100 90 142 181 178 171 167 158 159 146 147 148 149 150 151 152 153 140 141 142 144 135 136 131 132 125 126 127 128 121 122 113 107 92 Max 4.5+ B&C Score v. Number of Points as a Yearling and above: low risk with 2 pts. and and some risk with 3 point yearlings 194 190 180 169 166 156 157 151 146 142 143 140 126 128 123 120 95 236 208 204 185 181 183 176 170 167 162 157 152 153 154 147 141 139 134 135 132 129 126 121 122 119 216 202 184 185 181 170 171 173 162 157 158 159 147 143 144 140 128 0 1 2 3 4 5 6 7 8 9 10 11 207 196 193 188 171 172 173 174 167 161 151 147 148 143 144 145 139 140 141 135 132 118 119 Yearling Antler Points 201 183 178 168 159 156 152 141 228 207 208 196 197 182 175 173 168 165 161 163 154 151 147 142 136 133 227 213 199 190 218

Yearling Harvest Conclusions 1. You do not want to shoot yearlings with 4 points or more if you want to raise giants. 2. Spikes at maturity simply don t produce the antlers measured by both the average and the maximum that yearlings with 4 or more points produce. 3. 3 point yearlings are riskier: average mature antlers are low but one 3 pointer grew 194 points. The two 190 class mature bucks that were 3 pointers as yearlings were sired by DMP sires.

What about 2 ½, 3 ½, and 4 ½ Year Olds?

Max 4.5+ B&C Score 240 230 220 210 200 190 180 170 150 140 130 120 110 100 90 Another Look at the Data: A Scatterplot of 2 ½ Year Olds 2.5yr Old Total Points vs. 4.5+ Max B&C Score 165 and above: lower risk with 7 point 2 ½ yr olds 146 147 144 124 120 92 162 152 126 127 113 105 107 103 95 170 148 145 142 143 132 128 194 183 173 175 156 157 158 159 162 147 148 149 150 151 152 153 154 131 132 133 134 135 136 138 139 140 141 142 143 144 145 128 129 121 122 123 124 125 126 118 119 4 5 6 7 8 9 10 11 12 13 14 236 227 228 213 208 201 202 198 196 188 184 180 181 178 174 175 171 166 167 168 163 156 158 150 151 152 154 146 147 148 Total Points at 2.5yrs 199 197 195 190 185 181 178 172 167 168 169 165 163 151 152 153 146 147 148 143 218 204 185 182 183 181 174 216 207 193 159 207 208 173

Max 4.5+ B&C Score 240 230 220 210 200 190 180 170 150 140 130 120 110 100 Another Look at the Data: A Scatterplot of 3 ½ Year Olds 3.5yr Old Total Points vs. 4.5+ Max B&C Score 121 and above: almost no risk with 8 point 3 ½ year olds 151 105 162 159 154 156 157 149 151 152 138 139 140 141 142 143 144 145 146 147 132 133 120 121 122 124 125 126 127 128 129 112 113 114 107 103 204 190 174 175 171 167 162 152 146 147 148 140 141 142 135 132 128 129 122 118 119 236 213 201 195 196 183 185 181 176 173 168 165 161 162 163 159 156 157 151 152 153 154 146 147 148 144 139 136 131 128 119 197 183 184 179 180 175 173 171 167 168 169 156 153 150 151 147 141 231 216 207 208 188 185 183 174 167 163 156 151 152 143 193 182 181 178 172 156 194 159 227 208 199 161 207 202 218 90 92 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Total Points at 3.5yrs

240 Another Look at the Data: A Scatterplot of 4 ½ Year Olds 4.5yr Old Total Points vs. 4.5+ Max B&C Score Max 4.5+ B&C Score 230 220 210 200 190 180 170 150 140 130 120 110 100 90 121 and above: almost no risk with 9 point 4 ½ year olds 126 92 162 147 148 149 151 152 138 139 140 141 142 143 144 145 133 134 135 126 128 122 124 119 120 112 113 114 105 107 162 159 157 152 153 154 146 139 140 142 135 136 132 128 129 124 121 118 95 201 173 168 156 157 158 159 161 162 152 153 150 151 146 147 148 144 139 140 141 142 136 128 129 131 132 125 123 121 119 103 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 188 185 181 176 167 165 163 156 151 146 147 142 Total Points at 4.5yrs 213 204 196 183 178 179 180 181 173 175 163 156 142 143 216 195 190 184 174 171 167 168 154 151 152 141 199 197 190 171 162 158 227 207 193 194 196 190 185 183 181 172 159 153 218 208 207 178 231 202 228

My Conclusions 1. IF you have high fawn survival as a result of a feeding program, I would recommend that you shoot spikes. At $200 per deer per year, you save $1,000 compared with waiting until 5 ½ years old. Risk: some spikes will become big bucks but most spikes compared to 4 point or more yearlings will not. 2. Three pointers are riskier, but the two 3 pointers that scored in the 190s at maturity were DMP sired bucks. 3 pointers are probably safe to harvest.

My Conclusions 3. A big surprise from the East-West Yana Dataset: If the goal is to save all + bucks, there are clear cutoffs in number of total points at various younger age classes. 2 ½ year old bucks: Low risk of shooting a future + at 7 total points or less. 3 ½ year old bucks: Almost no risk of shooting a future + at 8 total points or less. 4 ½ year old bucks: Almost no risk of shooting a future + at 9 total points or less.

My Conclusions CAVEATS: 1. This spike and young deer data may not be valid on an unfed ranch. Or one with only sporadic feeding. 2. DO NOT CULL YOUNGER BUCKS OF ANY KIND ON AN UNFED SOUTH TEXAS RANCH: You don t get any feed savings. You are NOT making genetic improvement to your herd. Unless you like shooting tiny young bucks for fun, you simply limit the number of mature culls you can harvest in the future. 3. South Texas v. Other Parts of the Country: South Texas (and particularly western South Texas) is unique: variable rainfall limits deer numbers in the absence of feed (a density independent environment) so shooting younger bucks does not result in a habitat benefit (hunting mortality is additive). So do not shoot younger bucks in the absence of feed. In higher (or more consistent) rainfall environments, deer population increases in the absence of hunting mortality, often putting pressure on habitat (a density dependent environment). Culling younger bucks in the absence of feed has the benefit of reducing the population so that it better matches the habitat (hunting mortality is compensatory). Shooting younger bucks does have a benefit in density dependent environments.

My Conclusions CAVEATS: 4. NEVER WIPE OUT AN AGE CLASS Limit spike harvest to 20% of an age class. Limit 2 ½, 3 ½, and 4 ½ year olds to the very lowest of the number of points, but don t wipe out those age classes either. You want to have a number of bucks at maturity even culls.

So now you have some harvest guidelines How on earth do you determine age?

A Threshold Issue: Spike Harvest is NOT about Genetics 1. Spikes are bucks almost always yearlings with two scorable points. 2. Spikes are NOT genetically inferior: That is, while they may be inferior to other bucks during their lifetime (as we will see), They will not necessarily pass on those inferior physical traits to the next generation. Genetic inferiority means they pass the undesirable traits to their offspring. 3. If genes don t create most spikes, why do spike antlers appear? Answer: environmental influences such as: Timing of birth Health of the mother A twin or triplet sibling Early stress General environmental impacts in the first few months of life

The Critical Question: What will a spike s antlers be at maturity (5 ½+)? There is already strong evidence that yearlings with spike antlers on average will have smaller antlers at maturity than yearlings with multiple points: John Lewis study in the wild: Random capture of yearlings (known age) in South Texas and recapture at maturity. Results: 3 points or spikes: average Gross B&C score of 124.9 at maturity (5 ½ +). 4 or more points: average Gross B&C score of 140.0 at maturity (5 ½ +). Other studies Lewis cites show this relationship between yearling antler size and antlers at maturity.

So did I shoot spikes based on Lewis s work? 1. No. 2. My goal was to raise giants. 3. Some spikes can grow into huge bucks. 4. I didn t want to take the chance that I was killing a future giant. 5. Besides, most people get more pleasure shooting a 130 class management buck than a spike. 6. But that was before I lost control of my deer population on our fed pastures.

Michael Deane was Right! Michael Deane owns and manages a ranch in Live Oak County. He feeds protein and has annual fawn survival of 100% or more. At a Deer Associates meeting a few years ago, Michael Deane told me that you get to the point that you HAVE to shoot spikes. I didn t get it. I was still focused on raising giants and the relative pleasure of shooting a 130 class buck versus a spike. But then I lost control of our feeding program.

How to Lose Control of a Feeding Program 250 200 Total Deer on 1,000 Acres Fawn Survival = 65% & Natural Mortality Only Total deer numbers still high after doe harvest 1.20 1.00 Number of Deer 150 100 50-37 37 44 44 52 52 Few mature bucks So no harvest 86 73 62 62 73 86 Doe harvest 102 53 109 113 116 119 122 125 127 129 47 46 45 45 45 45 45 45 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Year 0.80 0.60 0.40 0.20 - Total Deer Bucks Does Doe:Buck Ratio After 5 years you wake up and start shooting does. You have built up a surplus of young bucks. After shooting does, you soon have twice as many bucks as does. But you don t have many mature bucks to shoot. Feed costs are out of control.

How to Lose Control of a Feeding Program On 1,000 Acres $50,000 Annual Protein Feed Cost on 1,000 Acres Fawn Survival = 65% & Natural Mortality Only $45,000 $40,000 $35,000 $45,822 $37,978 $38,668 $40,856 $40,402 $39,911 $39,380 $38,808 Annual Cost of Feed $30,000 $25,000 $20,000 $32,631 $27,537 $23,238 $38,198 $37,582 $37,154 Annual Protein Feed Cost $15,000 $19,610 $10,000 $5,000 $- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Year