Pronghorn Biology,
Behavior, and Management
Ken Cearley
Extension Wildlife Specialist- High Plains, Trans-Pecos
Texas A & M University
Canyon
Objectives
 Overview of pronghorn basic life history


Reproduction
Behavior
 Pronghorn habitat requirements
 Management practices
Emphasis on Panhandle
Recommended Resources
 Pronghorn Ecology and Management.
Bart W. O’Gara and Jim D. Yoakum. 2004.
 Common Rangeland Plants of the Texas
Panhandle. NRCS. 2005.
 A Handbook for Pronghorn Antelope
Management in Texas. Tommy Hailey,
TPWD. 1986.
 Pronghorn Management Guide. R. E.
Autenrieth, et al. 2006.
Distribution of Pronghorns
TPWD 1986
Trans-Pecos Pronghorns
 <12” precipitation typically
 Vegetation


Grama grasslands
Creosote-tarbush shrublands

Tobosagrass
Lower Plains Pronghorns
 ~16” precipitation
 Vegetation






Bluestem
Buffalograss
Tobosagrass
Mesquite
Lotebush
catclaw
Panhandle Pronghorns
 High Plains
 15-21 “ annual precipitation
 Mixed prairie
 Short-grass prairie
 Tall-grass prairie
 Vegetation
 Buffalograss
 Blue grama
 Mesquite
 Sand sage
 Shin oak
 Yucca
Panhandle Pronghorns
 Rolling Plains
 22-30” precipitation
 Tallgrass prairie
 Mid-grass prairie
 Vegetation
 Little bluestem
 Sand bluestem
 Sideoats grama
 Mesquite
 Sand sage
 Shin oak
Description





70-140 lbs.
Adult size by 2 years
Does typically breed year two
Both sexes horned
Males have forked horns

sheath shed annually
 Males have cheek/neck patch
 Abnormally large eyes
 Placement on skull beneficial
 Excellent eyesight
 Long legs- 45 plus mph
Physiology
 Thermal regulation by counter-current blood
flow to brain

Cools blood supply
 Maximized airflow- by design



Lungs
Diaphragm
Esophagus
 High hemoglobin concentration in blood
Other design features
 Concentrated urine
 Water conserved by concurrent exchange of
oxygen
 Water intake reduced by decreasing food
intake in stressful / critical times
Reproduction
 Breeding begins late summer
 Polygynous breeders


Few males breed all adult females
Resource-defense polygyny


Resources clumped and predictable
Female-defense polygyny


Resources are evenly distributed and
unpredictable
Harems gathered
Reproduction
 Breed as early as 16 months
 Breed annually until 8-10 years of age
 Rut onset varies with weather

Photo-period driven, basically
 Length breeding season


South- ~3 months
North- ~ 3 weeks
 Does cycle until bred
Reproduction
 250 day gestation
 Nutrition during pregnancy and lactation
critical
 112:110 males to females at birth
• Twinning
common on
healthy rangeland
Food Habits
 Nutritional requirements
 Provision depends on availability
 Rainfall
 Competition
 Crop depredation
 Concentrate selectors
 Forbs- rank first in consumption, typically
 more nutrients, in small package
 Forbs high in water content
 Browse ranks second
 ~8 % of diet is grasses
 Water provided from free-standing, pre-formed, and
metabolic processes
Behavior
 Foraging affected by “build”



Small frame
Small organs
Small mouth, muzzle
 Foraging affected by social behavior
Behavior
 Herding
 Tighter as move north
 Selfish herds
 Predator avoidance
 Increases feeding efficiency
 White rump patch makes each individual highly visible
 TX- nomadic
 Farther north- more migratory
 Seasonal movements in response to habitat
 Most move less than 10-20 miles
Restrictions to movement
 Fences

~18” clearance best; net wire restricts
 Highways
Disease Implications
 Carriers of abortive diseases?
 Brucellosis?
 Leptosirosis?
 IBR?
 10 years of sampling by TPWD 1060-1970
 N=827



No brucellosis
No lepto
N=75 IBR

5 false positives, end result- no IBR
Management
 Inventory

Aerial



Mid to late summer, usually
Strip flying
Some important parameters




Total count
Doe:Fawn ratio
Exceptional animals
Overall range and animal condition
Management
 Harvest
 Permit issuance determined by TPWD
 Surplus taken if necessary to maintain
carrying capacity
 Parameters

Age
 4 1/3 years+ best horns
 1:2 buck:doe ratio conducive
 1:4 more conducive to larger number young
animals



Habitat conditions
Carrying capacity
Objectives and goals
Aging Pronghorns
 Fawns


Short jaw length
Molars not fully erupted
 Yearling

1 yr 4 mos
TPWD
Aging Pronghorns
 2 yrs 4 mos
TPWD
Aging Pronghorns
 3 yrs 4 mos
TPWD
Aging Pronghorns
 4 yrs 4 mos
TPWD
Aging Pronghorns
 ~8 yrs 4 mos
TPWD
Management
 Keep watering facilities functional
 Maintain range condition to provide adequate
food supply

Fawning cover


Thwarts predation efforts
Adequate nutrition

Especially during spring and summer when peak
demands from gestation, then lactation
Management
 Provide unrestricted movement

Pronghorn friendly fencing
Management
 Deter crop
depredation
Management
 Supplemental feeding


May be beneficial in nutritionally stressful
periods
Feed not readily accepted
Summary
 Inventory
 Plan the harvest
TPWD determines permit issuance
Monitor range condition and pronghorn condition to determine
carrying capacity
Maintain water even when livestock not present, including
breaking ice
Fencing conducive to goals
 Restriction or movement
Age determination of harvested animals
Utilize supplemental feeding as required
Manage predators when necessary (coyotes primarily)
Maintain good range condition to provide physical protection
(thermal, predation) and food requirements.







