How Long are Deer Pregnant?

Deer gestation periods mainly vary with species and seasons, but several other factors affect the periods. Therefore, on average, deer stay pregnant for approximately 180 to 200 days. However, the pregnancy duration may exceed up to between 230 and 286 days.

Although this topic may not seem a concern for most deer hunters, they must understand the doe reproductive process. This article will provide insights regarding the same, including a few facts about the deer’s gestation cycle.

Length of Deer Pregnancy

It takes 180 to 200 days for them to give birth after deer mating season. This majorly depends on the species and seasons.

For example, the whitetail deer, found in parts of South America and Canada have an average gestation of 200 days. They sire one to three fawns at a time during spring. The mule deer on the other hand are adapted to survive in hot areas, e.g., in western America. For this particular species, the pregnancy takes approximately 7 months. Their first pregnancies carry a single while subsequent ones are mostly twins, especially in the USA.

The red deer thrive best in parts of Asia, northwest of Africa, America and Europe. They remain pregnant for approximately 236 days, eventually giving birth to 1 to 3 fawns during late spring. Male and female red deer are known closely only then breeding. Otherwise, the bucks and does live separately.

The roe deer, on the other hand, have longer gestation periods of about 290 days. This is because it takes about 4 to 5 months for eggs in the uterus to develop into a fetus. This species is mostly found in Europe and does sire 1-3 fawns as well.

Last but not least is the fallow deer. Their gestation period runs from 230 to 245 days. Initially, these deer were only found in Europe but have since been introduced to Asia and the USA. Unlike the other mentioned species that can give birth to up to 3 fawns at a go, the fallow deer only sires one.  

When it comes to  how seasons affect deer gestation periods, a study shows these periods would be longer in warmer regions. This is a result of reduced feed intake, which subsequently slow fetal development. It therefore lengthens the gestation period.

How to Spot a Pregnant Deer

During the first and second trimesters, it is very hard to identify a pregnant deer. However, one can easily tell during the third trimester because of the significant bulging on the lower caudal abdomen.

The behavior of pregnant deer can also give a hint. During the gestation period, the pregnant does keep cleaning their skin. As a cautionary measure and as a sign of alertness, they also keep looking around from time to time.

During early spring and late winter, the chances are that almost every doe you spot is pregnant. Pregnant deer also tend to roam with other pregnant does.

Should We Hunt Pregnant Deer?

People always carry different opinions regarding the harvesting of pregnant does. To some, it sounds a bad idea, while for others, it is just but okay. Consequently, the harvesting subject of does in late seasons seems to be heated and with so much disagreement. However, nothing wrong biologically about harvesting expectant does if it helps meet your management goals from a management perspective.

Those that argue against late season doe harvesting might take supporters of the same as greedy and unethical. They may also think of poor management killing two or more deer with a single shot.

Besides, there is no significant difference in harvesting does in October or in January. In all scenarios, the doe will not reproduce in the next summer. This can be interpreted as the same net loss of deer from the property of the subsequent year.

Those who oppose are afraid of the deer population in the future, which is still good. This argument is not well-founded because research shows 0.75 of little yearling bucks disperse in their first year with 0.5 of the fawns being does. Therefore, the probability of any buck fawn currently on your property living in your hunting area is insignificant.

A valid argument of hunting does in late seasons solely depends on the objectives of the harvest. Low and moderate harvest goals may not necessitate a late-season doe harvest. On the contrary, with a high doe harvest objective, no offense harvesting does across all seasons.

As a reasonable hunter, one should know that the next deer generation depends on the pregnant deer. As a result, hunting pregnant does is prohibited by law in some places. Therefore, it is advisable to avoid trouble at all costs. Please keep checking the state to know where it is legal or where it isn’t.

Deer Birth and Infancy

When Do Deer Give Birth?

As a hunter, you should be furnished with knowledge about seasons affecting your prey. Upon studying deer reproduction psychology, they have been classified as seasonal breeders. This means deer’s breeding season is totally dependent on weather, day length, and rainfall.

Deer’s reproductive cycle is quite unique since it is designed to give birth when the conditions favor fawns’ survival. In North America, most does give birth between late May and early June. During this period, flourishing lush vegetation offers a broad range of nutritious forage for the fawns. It also provides excellent hiding places to keep the fawns safe.

How Do You Know When a Deer is Ready to Give Birth?

When a doe is about to give birth, it isolates itself from the rest of the herd. It selects an area with dense vegetation to hide the fawns from predators. Hidden in the thickets, the doe lies on her side to facilitate easy birth. Once the fawn is exposed, say by two thirds, she stands up for the fawn to slide out on its weight. It is also worth mentioning that female deer labor for 24-48 hours, although it fluctuates depending on the individual does.

When Are Fawns Ready for Pregnancy

Generally, most doe fawns breed and conceive by the end of their first fall. At this time, they are usually between 6 to 8 months of age. Since not all of them follow the mentioned timelines, nutrition tends to be a primary determinant. In fact, the fawns attain sexual maturity after meeting some specific weight threshold.

In America, fawns in the south are ripe for sex and breeding upon reaching approximately 70 pounds. On the other hand, northern fawns are ready to start breeding at about 80 pounds. For the fawns that manage the said weight in their first fall, it happens so late. Either in December or January. This is one of the reasons 2nd ruts are witnessed regularly in many areas.

In this regard, it’s clear that the percentage of sexually active fawns is mainly based on weight rather than age. This serves as an indicator of the health of a herd. One can monitor this index by checking the location status of harvested yearling does. If you kill a 1.5-year old fawn by the jawbone and find milk in its udder, it was a bred fawn.

Therefore, herds that easily access high-quality forage in plenty, and moderate winters, can breed over 50% of the doe fawns. On the contrary, herds experiencing severe winters or with poor habitat record less than 5% fawns reaching the weight threshold.

What Happens to Does Before, During and After Estrus

Before Estrus

The rut is a magical period for the deer. The estrus period starts from fall, October to December, and it is very short. In fact, the does are short breeders. 

In the south, the estrus period begins early in October, and as you go up to the north, the period delays. For instance, the whitetail deer in the northern regions are in heat in late November. This is deer’s natural adjustment so that when the fawning season comes, the little ones won’t be exposed to too much cold.

Before estrus, the bucks are filled with testosterone. The restless animals chase as their very species depends entirely on it. However, hours just before peak estrus are very stressful for both does and bucks. The does experience a 24-hour heat period, and their tails turn flat. They also urinate frequently.

At this time, does are in complete control, and wherever they go, the bucks follow. This justifies the reason why bucks tend to be more vulnerable in the rutting seasons. In some instances, though not all, some bucks push does to areas where they feel safer. Bucks spend 48-72 hours with the does since does are receptive for about 24 hours.

During Estrus

During estrus, it is time for the actual breeding. A doe stands still to allow breeding with the buck it finds impressive. In fact, you might be tracking a young doe and abruptly change your mind and settle for a buck with impressive antlers. No doe will accept a mate without a spectacular pair of antlers. Remember, the bigger the antlers, the older the buck.

These are moments that break and make your deer hunt. When an estrus doe is close to your tree stand, it is the prime time to act. Otherwise, you will be in for a pretty quiet day.

The female deer express signs of estrus a bit prematurely. For this reason, bucks attempt breeding during the 24-hr period to the actual 24-hr window when does are receptive. In some cases, the bucks may extend attempts for another 24 hours after the does finish estrus. Thus, the two to three days that bucks stick around the does. During estrus, a buck is very protective of its counterpart, mate.

After Estrus

After estrus, a doe will quickly stop being receptive to the buck. At this point, a buck will leave and then reunites with the fawns, including the rest of the doe group. Opposed to the does, bucks will embark into searching for other does on heat.

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Conclusion

Various deer species, especially the highly regarded whitetail, are amazing beasts. Before fitting in your gear and heading to your hunting field, you need to consider a number of factors, including deer gestation periods. This is because it determines the number of deer that are out during certain times.

Competent hunters should know when deer are pregnant, who long it the gestation period is, and the best hunting seasons. In fact, there exists a correlation between deer pregnancy and best game availability. As illustrated in this article, it is essential to understand the rut, pregnancy, and fawning processes. This plays a major role in bagging that trophy hunt you’ve always dreamt of.

Also, the debate and various opinions from hunters about hunting pregnant deer should not worry you. The good news is, here in the United States, hunting seasons are set during the rut. This is to minimize if not to eradicate the chances of risking the lives of pregnant does and their unborn fawns.