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Deer Density and Supplemental Feed in Deer Management: Conclusions from Comanche-Faith Study Charles A. DeYoung, Timothy E. Fulbright, David G. Hewitt, and Don A. Draeger
Deer Density and Supplemental Feed in Deer Management: Conclusions
from Comanche-Faith Study
Charles A. DeYoung, Timothy E. Fulbright, David G. Hewitt, and Don A. Draeger
Primary FundingT. D. Friedkin, S. Stedman, Stedman West Foundation, Comanche Ranch, Faith Ranch
Other FundingRené Barrientos Educational Assistance FundStuart Stedman Endowed Professor in White-tailed Deer ResearchMeadows Professorship in Semiarid EcologyHispanic Leaders in Agriculture and the EnvironmentSouth Texas Chapter of the Quail CoalitionHouston Safari Club
Wack Ezzell and Matt MooreDavid Wester, Graduate Students
Density Dependence
Deer
Par
amet
ers
Deer Density
Density Dependence
Deer
Par
amet
ers
Deer Density↓Performance à ↓ Density
Management Prescription
Density Dependence
Deer
Par
amet
ers
Deer Density↓Performance à ↓ Density
Management Prescription
NutritionSouth Texas Rangelands• Nutritionally challenging– Soil fertility
NutritionSouth Texas Rangelands• Nutritionally challenging– Soil fertility– Variable precipitation
March 2010
March 2011
Supplement and Deer Foraging
Objective
Assess the effects of deer density and supplemental feed
on deer and vegetationin southern Texas rangelands
Comanche
Study 2004 - 20132 study sites6 enclosures/site200 acres
Faith
25 25
25
25
40
4040
40
Study 2004 - 20132 study sites6 enclosures/site200 acres3 deer densitiesSupplement trmt
10 deer
10 deer
10 deer 10 deer
Supplement
• Pelleted• 22% CP• 3.0 kcal DE/g• Mineral
fortified• Ad libitum• 1 feed site with 2
feeders/enclosure
Methods - Deer• Deer marked with ear tags• Autumn and winter camera
surveys • Helicopter capture or
harvest twice/year to maintain population size
• Morphometric measurements of all deer handled
Photo by Lindsey Phillips
Methods - Vegetation
Methods – Deer diets
200 acres
Objectives
Determine the effect of: • deer density• supplemental feedon deer diet composition and quality
Drought Effects on Deer Diets
0.0
0.2
0.4
0.6
0.8
1.0
Dry Wet Dry Wet Dry Wet Dry Wet
Summer Fall Winter Spring
Prop
ortio
n of
Die
t
Shrub
Shrubs increased in the diet during drought
Drought Effects on Deer Diets
0.0
0.2
0.4
0.6
0.8
1.0
Dry Wet Dry Wet Dry Wet Dry Wet
Summer Fall Winter Spring
Prop
ortio
n of
Die
t
Forb
Shrub
Forbs decreased in the diet during drought
Drought Effects on Deer Diets
0.0
0.2
0.4
0.6
0.8
1.0
Dry Wet Dry Wet Dry Wet Dry Wet
Summer Fall Winter Spring
Prop
ortio
n of
Die
t
Mast
Forb
Shrub
Drought Effects on Deer Diets
0.0
0.2
0.4
0.6
0.8
1.0
Dry Wet Dry Wet Dry Wet Dry Wet
Summer Fall Winter Spring
Prop
ortio
n of
Die
t
Other
Mast
Forb
Shrub
Deer Density
0.00.10.20.30.40.50.60.70.80.91.0
Low High Low High Low High Low High
Spring Summer Autumn Winter
Prop
ortio
n of
die
t
Shrubs
Deer Density EffectsShrubs in the diet not affected by deer density
0.00.10.20.30.40.50.60.70.80.91.0
Low High Low High Low High Low High
Spring Summer Autumn Winter
Prop
ortio
n of
die
t
Forbs
Shrubs
Deer Density EffectsForbs in the diet not affected by deer density
0.00.10.20.30.40.50.60.70.80.91.0
Low High Low High Low High Low High
Spring Summer Autumn Winter
Prop
ortio
n of
die
t
Mast
Forbs
Shrubs
Deer Density EffectsMast in the diet not affected by deer density
0.00.10.20.30.40.50.60.70.80.91.0
Low High Low High Low High Low High
Spring Summer Autumn Winter
Prop
ortio
n of
die
t OtherSub-shrubsGrassesCactiMastForbsShrubs
Deer Density EffectsCactus in the diet was affected by deer density
0.00.10.20.30.40.50.60.70.80.91.0
Low High Low High Low High Low High
Spring Summer Autumn Winter
Prop
ortio
n of
die
t Other
Cacti
Mast
Forbs
Shrubs
Deer Density Effects
• Diet Quality• No change in digestible protein– 10 vs. 9%
• No change in metabolizable energy– About 2.25 vs. 2.20 kcal/g
Deer Density Effects
Supplement and Deer ForagingVegetation portion of the diet only!
Supplemental Feed Effects
00.10.20.30.40.50.60.70.80.9
1E
nhan
ced
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Spring Summer Autumn Winter
Prop
ortio
n of
die
t
Shrubs
Shrubs in the diet increased with supplement
Supplemental Feed Effects
00.10.20.30.40.50.60.70.80.9
1E
nhan
ced
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Spring Summer Autumn Winter
Prop
ortio
n of
die
t
Forbs
Shrubs
Forbs in the diet not changed with supplement
Supplemental Feed Effects
00.10.20.30.40.50.60.70.80.9
1E
nhan
ced
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Spring Summer Autumn Winter
Prop
ortio
n of
die
t
Mast
Forbs
Shrubs
Mast in the diet decreased with supplement
Supplemental Feed Effects
00.10.20.30.40.50.60.70.80.9
1E
nhan
ced
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Enh
ance
d
Nat
ural
Spring Summer Autumn Winter
Prop
ortio
n of
die
t
Other
Mast
Forbs
Shrubs
Flowers in the diet decreased with supplementDead leaves increased with supplement
Dead leaves
• Diet Quality of vegetation portion of diet• No change in digestible protein– 10 vs. 9%
• Metabolizable energy lower with supplemental feed during spring and summer of 1 year– About 2.3 vs. 2.5 kcal/g
Supplemental Feed Effects
Summary
Effects on deer diets• Drought had large effect
• Deer density had no detectable effect
• Supplement increased shrubs and reduced mast
