Understanding the Whitetail Deer Rut Cycle

1. The Rut Original Power Point Created by Andy Harrison Modified by the GA Agriculture Education Curriculum Office July 2002

2. Driven By Need to Reproduce • Must pass on traits to offspring • They then reproduce

3. Basics • Whitetail evolved primarily as forest animals in the eastern United States • First record of deer was recorded by explorers from the old world • Reported in New England and Atlantic coastal states • Whitetail were the primary source of food for settlers and Indians

4. Basics • Mating animals have various methods for attracting mates • Birds: colorful plumage • Monkeys: screeching calls

5. Basics • Population of deer at time of colonization • 7 deer/square mile (640 acres) • Deer do not thrive in virgin forest land or dense vegetation • Need areas that have been disturbed • For example: fires, storms, tornadoes, or ice storms • These create openings and new vegetation

6. Basics • Deer have a developed system for announcing their availability for mating • Scent: attracts opposite sex • Visual signs: e.g. markings • Deer not known for vocalization • Elk are the exception • Deer evolved to rely heavily on scent cues and visual cues • These are the basis for rut

7. Pre-Rut • In late summer food quality poor or declining • Deer enter fall in fairly poor condition • Must get into breeding condition fairly fast • Fruit, nuts, and acorns mature about this time • High in energy and fat

8. Bucks: Pre-Rut • Have expended a lot of energy for: • Antler growth • Shedding their velvet • Caused by short term loss of blood flow to antlers • Shedding summer coat and subsequent growth of heavier winter coat • Developing muscles for upcoming combat period

9. Bucks: Pre-Rut • Nutrient resources shunted to growing antlers • Minerals and protein come from the bones of the body • Shedding of coat and growth of grayish winter coat

10. Bucks: Pre-Rut • Shedding of velvet • Bur forms at base which shuts off blood supply to velvet • Process occurs inside of the antlers • Similar to hardening of arteries • In only a matter of hours, the velvet dies and falls off • The buck can now get ready for rutting and combat

11. Bucks: Pre Rut • Many anatomical and physiological changes take place at this time • Remain in their summer sanctuaries and move very little • Yearling bucks tend to roam because of no habitat • Yearling bucks also attempt to become associated with buck groups

12. Bucks: Pre-Rut • Most of initial rutting signs occur in and around their summer habitats • Size and strength important • Must work on strength • Male hormone levels increase • More belligerent and often take out frustration on saplings

13. Bucks: Pre-Rut • Enlarged neck due to strengthened neck muscles from rubbing, not enlarged glands • Mock combats with trees strengthen shoulder and ham regions • Usually attack trees with light colored bark in order to leave signposts • Signposts are generally near the primary bedding spot

14. Bucks: Pre-Rut • Scent communication is important to the Whitetail • Body is covered with scent glands • Communication occurs from one deer to another • There is still little known about scent communication

15. Bucks: Pre-Rut • Scraping allows the buck to release information: • He is in area • He is in breeding condition • Scraping usually begins in mid-summer • Not all bucks scrape • During pre rut bucks perform mock scrapes

16. Late Pre-Rut • Last few days prior to actual rut • Bucks extremely aggressive and agitated • Full scales fights are easily provoked and are characterized by: • Slow stiff-legged approach • Ears laid back, hair standing on end, and becoming darker • Presentation of a broadside in order to appear larger • Circling each other

17. Late Pre-Rut • Fight • One or both may “Snort-wheeze”, signals intent on fighting • Violent coming together of antlers • Durations from minutes to hours • Largest antlered buck not always winner • Defeated buck pursued by victor

18. Rut • Full rut begins with response to light conditions • Bucks move and roam farther from summer area • They expand the rubbing and scraping area • This expansion continues as season progresses

19. Rut • Doe social groups are, for the most part, related • Bucks roaming away from related social groups prevents inbreeding • In overpopulated areas inbreeding is common

20. Rut • Vagrant (roaming) bucks set up lines of scrapes as they move along from one group to another

21. Full Scrape Sequence • Begin by pawing-out a depression in the ground beneath a bush • Urinates in the depression • Urine carries male secretions • Signals other bucks that he is in the area • Signals the does that he is available for mating • He may also refresh his signpost markings

22. Full Scrape Sequence • Information is left from the forehead gland or glands around antlers • This information is picked up by other bucks either by smell or by taste (licking the scrapes) • Buck follows the series or line of scrapes • If scrape produces a doe he sticks with it • If no doe appears, he moves on

23. Rut • No special time of day • If does are in heat, bucks move • If does are in good condition, they come into heat about the same time as the buck comes into rut

24. Doe Estrus • Well-managed herds or herds with low populations have 2 – 3 distinct periods of rut • 1st: strongest; early in season • 2nd: 20 – 30 days later; includes does that became pregnant in primary rut plus younger does that did not come into heat • 3rd: small group; includes a few fawn does

25. Doe Estrus • Up to 40% of fawn does have ability to reproduce in well-managed herds or low population densities

26. Buck: Doe Behavior • Communication • Scrapes • Bucks can trail does over great distance • Some believe that does show preference to selected bucks

27. Buck: Doe Behavior • Pheromones are chemical communicators • Sex hormones: source is not urine • Does also make scrapes • Signposts are most often located in open areas visible to each sex

28. Buck: Doe Behavior • Buck approaches doe • Struts • Antlers held high • Walks stiff-legged • Could come running with a wagging tail • Doe initially not willing to cooperate

29. Buck: Doe Behavior • Vocalizations • Several pig-like grunts when buck approaches doe • Variable in pitch and delivery • May also attract other bucks • Does do not make grunting sounds during mating

30. Buck: Doe Behavior • Once contact is established the buck and doe stay together for several days • Mating occurs during this time • Only after the doe decides to mate • Doe positions more easily for mating • Mating may take place several times over short period • Buck may breed 6 to 8 does

31. Post-Rut • Instinct for survival takes over • Bucks become wary of hunters • Spend much of their time in sanctuaries • Limit movement to when hunters are not out • Lose a good portion of their weight and fat reserves

32. Post-Rut • As high as 40% mortality rate in northern US and Canada • Does do not experience this high rate because of a lower level of rutting activity • Bucks seek out high carbohydrate and high fat foods • Higher acorn production years • Agricultural crops

33. Post Rut • Light conditions and breeding activity cause buck to lose interest in rutting • Loss of male hormones cause a “breaking layer” • Break between the base of the antler and the skull • Antlers fall off singularly or as a set • Bucks may continue scraping out of habit