White-tailed Deer Habitat: - Caesar Kleberg Wildlife Research Institute

Graduate and UndergraduateStudents• Garrett Timmons• Mark Richman• Aaron Foley• Reagan Gage• Nate Newman• Eric Grahmann• Matthew Moore• Will Moseley• Ryan Darr

Supplemental Feeding• Widespread in Texas• Many landowners maintain high deerdensities

Supplemental Feeding• What is effect of supplemental feeding,high deer densities on habitat?

Specific Questions• Does supplemental feeding allow managersto increase deer densities without harmingvegetation?• What is an appropriate deer density that isin balance with natural forages--with andwithout supplemental feeding?• Does supplemental feeding cause greaterconsumption of highly nutritious “icecream” plants preferred by white-taileddeer?

Overall Research Objectives• Determine effect of supplementalfeeding, high deer densities on– habitat– deer productivity– population dynamics– nontarget species• 10 year study; initiated in 2003

Experimental Design

Experimental Design200 acres200 acres200 acres200 acres 200 acres 200 acres

Experimental Design• Target densities – 10, 25, or 40deer/enclosure• Represent low, medium, and highdensities for south Texas• Approximates helicopter count of 60,24, and 15 acres/deer• Deer added or removed to maintaindensities as close to target as possible

Experimental DesignNot fed10 deerFed10 deerFed25 deerFed40 deerNot Fed25 deerNot Fed40 deer

Measuring Effects on Vegetation• Forb species richness (number of forbspecies/enclosure)• Canopy cover of forbs

Measuring Effects on Vegetation• Canopy cover of woody plants– 1 st , 2 nd , and 3 rd choice• Browse and forb biomass• Stem count index

Stem count indices• Jimmy Rutledge, Ty Bartoskewitz,Daniel Kunz, Alan Cain, Evan McCoy,Kyle Brazil• Estimated % use in Feb and Aug 2004 –2006

• Percentage oftwigs showingevidence ofbrowsingStem Count Index

Supplemental feeding effects:Preliminary results• Forb species richness– similar on fed and unfed• Forb canopy cover and biomass– similar on fed and unfed• Browse canopy cover– similar on fed and unfed

Supplemental feeding effects:Preliminary results• Percent of twigs browsed similar infed and unfed for all 3 browseclasses

Summary of PreliminaryResults• Supplemental feeding– does not appear to increase or decreasefeeding pressure on forbs– does not appear to increase or decreasefeeding pressure on 1 st , 2 nd , and 3 rdchoice browse– does not appear to result in increaseduse of “ice cream” plants

Deer density effectsPreliminary results

25Forb species richness2004-2006 average20Species/enclosure151050Low Medium HighDeer density

25Forb canopy cover2004-2006 average20%151050Low Medium HighDeer density

120Forb biomass200510080kg/ha6040200Low Medium HighDeer density

%8765432101 st choice browse canopy cover2004-2006 averageLow Medium HighDeer density

%353025201510502 nd choice browse canopy cover2004-2006 averageLow Medium HighDeer density

%4540353025201510503 rd choice browse canopy cover2004-2006 averageLow Medium HighDeer density

kg/ha350300250200150100500Browse biomass2005Low Medium HighDeer density

First Choice BrowseBitten (%)50403020100BeforeDensitiesAdjustedLow Medium High**2004-Feb2004-Aug2005-Feb2005-Aug2006-JanSampling date

Second Choice BrowseBitten (%)403020100BeforeDensitiesAdjustedLow Medium High2004-Feb2004-Aug2005-Feb2005-Aug2006-JanSampling date

Third Choice BrowseLow Medium HighBitten (%)3020100BeforeDensitiesAdjusted2004-Feb2004-Aug2005-Feb2005-Aug2006-JanSampling date

Summary of Preliminary• Deer DensityResults– Increasing density decreases number offorb species, forb cover, forb biomass– Reduces canopy cover of 2 nd choicebrowse

Summary of Preliminary• Deer DensityResults– Trend for heavier use of 1 st , 2 nd , and 3 rdchoice browse species with increasingdensity– Availability of supplemental feed doesnot alter impact of deer on plants

Deer response to supplementalfeeding and density• Samples sizes too small to makepreliminary conclusions

Deer response to supplementalfeeding and density• Current research:– Productivity: antler size, body mass,reproduction– Population dynamics– Amount of feed in diets using stableisotopes– DNA studies to determine what bucks aredoing the breeding

Deer response to supplemental• Questions:feeding and density– If deer density reduces forbs, what is theeffect of this forb reduction on the antlersizes and fawn survival of deer?– Does the availability of supplemental feedalter that effect on antler size and fawnsurvival?

Additional experiments• Feeding effects on raccoons– Home range sizes, movements– Estimates of feed consumption

http://www.tamu.edu/upress/Spanish versionavailable inMarch 2007Amazon (searchfor timothyfulbright)

Unique Features• 1. Deals with managing deer in theleast productive, semiarid portion oftheir range• 2. Compiles information from researchin Mexico and the US• 3. Range management for deer

Chapters• 1. Habitat requirements of white-taileddeer– Food habits– Sexual segregation– Cover requirements– Home range sizes– Water requirements

Chapters• 2. White-tailed deer nutrition– Nutritional needs of deer– Energy is the most limiting nutrient– Effects of secondary chemicals inbrowse– Why do deer eat what they do?

Chapters• 3. Ecological Principles UnderlyingHabitat Management– Ecological theory is the foundation ofhabitat management– Responses of deer and vegetation tomanagement differ in semiaridenvironments compared to higherrainfall areas– Importance of plant species diversity

Chapters• 4. Estimating Carrying Capacity– Methods of estimating carryingcapacity– Monitor use of important deerforages

Chapters• 5. Livestock and White-tailed DeerHabitat– How to manage cattle for optimumdeer habitat– Competition between deer and exoticwildlife

Chapters• 6. Food Plots– How, when, where, and what to plant– How much to plant

Chapters• 7. Brush Management for White-tailedDeer– How much brush do you need?– How to design brush management– What methods to use

Chapters• 8. Harvest and Management Planning– Harvest management approaches– Establishing goals– Developing a management plan