Елсіздердің көбейтілу маусымы

Mating season of ruminant mammals

The rut (from the Latin rugire, meaning "to roar") is the mating season of certain mammals, which includes ruminants such as deer, sheep, camels, goats, pronghorns, bison, giraffes and antelopes, and extends to others such as skunks and elephants. The rut is characterized in males by an increase in testosterone, exaggerated sexual dimorphisms, increased aggression, and increased interest in females. The males of the species may mark themselves with mud, undergo physiological changes or perform characteristic displays in order to make themselves more visually appealing to the females. Males also use olfaction to entice females to mate using secretions from glands and soaking in their own urine. Outdoors writer Charles Alsheimer has done research demonstrating the white tailed deer rut is also controlled by the lunar phase and that the rut peaks seven days after the second full moon during October and November (the rutting moon), while elk begin rutting during the September equinox on 21 September. A white tail doe may be in estrus for up to 72 hours and may come into estrus up to seven times if she does not mate. Cows may come into estrus up to four or more times if they do not mate. Some people believe that it is possible that does can enter a second estrus around 28 to 30 days from its first estrus if the doe isn't bred. There are also studies that show that some does actively participate in seeking out possible mates in areas where there are less males to increase the chances of finding males and being bred. The rut can start as early as the end of September and can last all the way through the winter months. Bucks usually begin this process when the velvet is falling off their antlers, and it can last all the way until they start to shed their antlers. The peak of the rut, however, is right in the middle. The average peak day for the white tail rut in the U. S. is November 13. Around this period of time, the bucks and does are very active, with the rut in full swing. For a hunter sitting in a tree stand at this time of the year, it is not uncommon to see many deer pass through his specific area, due to other deer chasing others. There are many behaviors a buck will exhibit during the rut. During pre rut, bucks will spar with each other. Sparring is low intensity aggressive behavior, involving mostly pushing and shoving. Bucks of different sizes will do this to each other. After pre rut is finished, a buck will rub his antlers on a tree (thus making a "rub"), and make scrapes on the ground with his hooves: both of these are ways a buck will mark its territory and proclaim his dominance for other bucks to see. These activities are usually done at night. Bucks will make many different scent markings using different scent glands. These scent glands include pedal glands found between the toes, preorbital glands found in the corners of their eyes, tarsal glands found on the lower inside of their hind legs, and the metatarsal glands found in the outside hind leg between ankle and hoof. The deer spread scent from these glands by rubbing hooves during ground scrapes, rubbing faces on tree limbs, and urinating down legs. The most prominent behavior of all during the heat of the rut is fighting, where bucks show their true dominance to others. In fighting, bucks usually battle against similar sized deer, and small bucks do not normally challenge mature large ones: more often than not, smaller bucks fear the more mature bucks and leave or avoid the dominant deer's territory. These fights can be long in duration with the winner getting the group of does. Some fights result in injuries with some resulting in death. Studies show that males of all age classes increased their search efforts for mates during rut. According to the source, "One year old males seemed to invest less effort searching for females because movement rates (m/h) were 25–30% lower than in older males". This data indicates that the youngest males don't try as hard as older males to find a mate. The energy expenditure of chasing and fighting during the breeding season can result in a buck losing an immense amount of weight, with some research documenting losses of as much as 20% of body weight with some sources showing body mass losses of up to 30%. have stated that after the rut, a buck will go to a bedding spot and will remain "motionless" for a large amount of time, even to the extent of about two days, as he is thoroughly exhausted. After he has rested, he will get up and start to feed extensively, trying to catch up on all the nutrients his body requires. Croplands have much high carbohydrate grain in them, and a buck can be found here often, eating and getting nutrients. When the climate is extremely cold, a buck will sometimes resort to swamps and bogs, because of the warmer temperatures these areas hold.

The timing of the elk rut depends on where they live. In the Northern Hemisphere, it occurs between mid August and mid October. In the Southern Hemisphere it occurs between mid February and mid April. The rut tends to last somewhere between 20 and 45 days. This varies on latitude, which affects the timing of spring and autumn and which can give elk a longer calving season and a longer rut. During the rut, elk frequently use areas around fresh water, and tend to bed in heavy timber five to six hours per day. A cow elk will remain in estrus for 12 to 15 hours, if they are not bred during this time frame they will normally have another estrus cycle 18 to 28 days later. An alarm squeal is made by both sexes of elk when they are on alert, during the rut these are used frequently by young bulls (male elks) being run off by the herd bull. The function behind this acoustic structure of the bugle is directly correlated to the male's physiology and how different frequencies travel through varied environments. In terms of physiology, the larger an animal gets the lower frequency of sound it is able to produce. This is because with an increase in size comes an increase in vocal fold length, and longer vocal folds confer an increased ability to produce lower frequency sounds. The higher pitched section of the call propagates through the environment better, which is why the bull uses it to congregate a harem that is becoming more spatially dispersed and thus harder to defend. As explained above, this is because larger body mass positively correlates with longer vocal folds and thus lower frequency emission. Larger body size also corresponds with a decreased ability to emit high frequency vocalizations. Bull elk constrict their supra laryngeal vocal tract, specifically in the nasal cavity in order to create a smaller opening for exhaled air to pass through. This anatomical development for bioacoustics in elk was discovered upon sonographic analysis of bugle vocalizations which revealed a biphonetic (two simultaneous frequencies) display. When females come to the lek they leave soon after mating but the males will tend to stay in the lek to court other females until the end of the rutting season. However, male fallow deer which are unsuccessful in mating will leave the lek sooner than other males and they will adopt other strategies to compensate for their lack of mating success in the lek. Furthermore, the duration spent in the lek is positively correlated with the behavioral traits of male display frequency and aggression, male hierarchical position and secondary sex characteristics such as antler size. Overall, lekking species such as the fallow deer have a short intense rutting season where the males face intrasexual competition, territory defense and management of females within their territory.

In elephants, the breeding season is less pronounced than in ungulates and it usually spikes when the rains season occurs or shortly thereafter. Its meaning is derived from the Urdu word mast meaning intoxication. The most prominent characteristics of an elephant in rut are heightened sexual and aggressive activity along with copious temporal gland secretion and continual urine discharge. Also it has been observed that males will have a higher concentration of testosterone and an increased likelihood of associating with female groups during musth. Similarly to deer or mountain goats, elephants will tusk the ground throwing vegetation, logs and objects into the air and occasionally at subordinates. Another typical behaviour seen in moose especially during the pre rut stage is mock battling. This is a display meant to scare away other rival males where the bull moose will destroy trees and vegetation prior to engaging in a fight. Also, a behaviour known as displacement feeding is observed in male moose and it refers to the hasty movements made by the moose while it is feeding as it keeps an intense gaze upon rival bull moose. Furthermore, as seen in other deer species male moose will dig mud pits and soak them in urine and the females will fight over possession of these wallows. The mature cow will attempt to stop the younger one from coming near to the wallow in a vicious attack with her forelegs and if the younger female gets to lie in the wallow the older female will drive her out of it only to return to lie in it and take up as much space as possible. During this event the bull moose will not interfere and he will just watch in plain sight.