I'm going to disagree with that.
Grizz
As much as I respect mbogo3's opinion, it's the cold and full moon making the Deer, etc more active.
The rut is determined by minutes of daylight anywhere from early to mid September and carries on through into December.
Just take a look at when the fawns are born. April to June.
Deer gestation period 200+days
Moose/Elk -appx 245 days
Intro What is Seasonality Seasonality in: Males Females Different Species of Deer
Comparison to Domestic Animals Practical Implications Sources
Intro:
The physiology of reproduction in the deer (family: Cervidae) can help us understand their behavior. Deer are seasonal breeders, with males exhibiting “rut” behavior in the early fall during the breeding season. The timing of the breeding season also has implications in survival of young. Different species of deer respond differently to seasonal changes. However, deer are not the only animals that exhibit seasonal breeding behavior. There are several practical implications of this reproductive phenomenon; here, we will look at population control.
What Is Seasonality:
Seasonal changes in temperature, rainfall, and day length all contribute to the cause of the breeding season in deer. In climates where seasonal changes are more extreme, seasonal changes in day length are the main cue used to time the breeding season (Lincoln). Puberty occurs at approximately 16 months of age and after this, they exhibit seasonal polyestrous. Deer respond best to short-day lighting, which means that they are not usually cycling during the summer months, but begin to show estrous behavior in late September and October (see diagram below) (Gordon).
The estrous cycle in deer varies from 17 - 22 days, depending on the species, and this cyclical breeding activity may continue for as long as six months in animals which do not become pregnant (Gordon). The seasonal changes in fertility are controlled by the secretion of LHRH (luteinizing hormone releasing hormone) from the hypothalamus, which is influenced by melatonin from the pineal gland. LHRH influences the secretion of LH and FSH from the anterior pituitary (Lincoln).
Seasonality in the Male:
The season when deer breed is called the "rut". Rut usually occurs during October, but some bucks come into rut during December, these are usually younger or weaker bucks. It is possible to advance the onset of the breeding season in bucks by controlling their melatonin levels (Adam). Melatonin is a modified amino acid hormone released by the pineal gland that has been seen to control seasonality in ewes. Less daylight triggers an increase in a buck’s testosterone, which causes antler maturation/growth. Fraction, volume and pH of the ejacuate, as well as sperm concentration and sperm motility change gradually during the pre-mating, mating and post-mating seasons of red deer (Gisejewski). The period of greatest libido (from the end of