The Rut

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