Wild animals can be very successful at breeding. Deer are one of those animals.
Deer are super-cute animals, very graceful and peaceful. If you live in areas with deer, you know that there isn’t a more beautiful sight than looking out of your windows on a fall morning and seeing two or three does searching for food and passing near your house.
However, there is some confusion when it comes to the way deer reproduce. Some say that deer hatch, while others claim that they give birth. Which one is it then; do deer lay eggs?
In this post, we’ll address some widespread misconceptions and explain if deer really lay eggs.
Do Deer Lay Eggs?
No, deer do not lay eggs. Deer are mammals that give birth to live young. Female deer (doe) will usually give birth to one to three babies that are born with their eyes open and fully furred. The fawn will stand on its legs in 10 minutes and start walking in 7 hours.
There are several options for animals to bring their offspring into the world.
They could lay eggs and have no physical connection with the baby (oviparity), or they might let the embryo (later fetus) develop inside them, and when the time is right, give birth to a live young (viviparity).
Deer are, just like sharks, dogs, cats, bears, and many other animals, viviparous and do not lay eggs.
Both of these styles of reproduction have some advantages, but also drawbacks.
Advantages And Disadvantages Of Deer Laying Eggs
The main advantage of a deer hatching would be freedom and mobility; the mother would not be slowed down by having to carry lots of eggs in her belly.
She could more easily escape danger and also hunt for food. If a deer were a reptile rather than a mammal, it could just bury the eggs in the sand or the mud and walk away, without feeling guilty about abandoning its young.
The biggest disadvantage of laying eggs would be the exposure of the deer eggs to predators, weather, and other environmental changes.
Letting the baby develop inside the reproductive tract allows the deer mother to protect it until it’s ready to be born. The baby would be more mobile and not as helpless.
Why Don’t Deer Lay Eggs?
Deer don’t lay eggs because it is more beneficial to them to give birth to live offspring.
Millions of years ago, every animal laid eggs.
As time passed, some animals slowly evolved and started giving birth to live babies because that was what helped them survive and get their species to the next generation.
The switch took some time.
Before they stopped laying eggs, mammals had been producing milk for their young. A study on the loss of egg yolk genes in mammals concluded that lactation reduced dependency on the egg as a source of nutrition for developing offspring, and many animals abandoned the egg completely in favor of the placenta.
This was what most likely happened with deer. It was dangerous for deer and their ancestors to have their shell-covered offspring sitting out in the environment, so they adapted to keeping their babies inside them for as long as possible, up to 290 days in some deer species.
How Do Deer Give Birth?
Deer reproduce sexually and there is internal fertilization. After around 200 days, a doe will give birth to one to three fawns that are well developed and can walk after a few hours.
Two strong and well-nourished deer can produce as many as 30 offspring in 7 years. A doe usually gives birth to twins; triplets, while not unknown, are uncommon.
Male deer, called bucks, reach sexual maturity around the age of two; females a lot earlier, they can reproduce as early as seven months old.
The breeding season in deer usually starts in November, when the males and females get into heat (oestrus).
During that period, males’ testosterone increases, causing their antlers to grow and their libidos to skyrocket. They become aggressive and fight other males to determine who will mate with the specific doe. Females go into heat for short periods of around 24 hours.
After the successful copulation and the long gestation period, the female becomes restless, leaves the herd, and finds a secluded place.
During labor, the female will stand and sit repeatedly, using gravity as help to give birth. In most cases, the young are born head first and the female will lick it to clean and dry off its newborn. The doe will also eat the afterbirth as it has some nutrients and reduces the risk of predators picking up its scent.
Baby deer are typically born in the spring when there is lots of vegetation high in nutrients to ensure there’s enough food available and to increase the chances of survival.
In the largest deer species, the moose, adults weigh up to 1,500 pounds; the fawn are between 20 and 30 pounds at birth. In the Southern Pudu, one of the smallest deer species, the young weighs just 10.5 oz at birth.
Weaning happens between months 6 and 8. However, the young will stay with their mothers until she gives birth to another baby deer, usually a year after they were born. After becoming independent, males will usually leave and never see their mothers again, while some females might come back with their fawns and form small herds.
Deer are uniparental species: only the does will take care of fawns, the bucks are not present during the birth or the caregiving for the offspring.
Animals That Lay Eggs
According to the University of Georgia, over 99% of the world’s animals reproduce by laying eggs. That’s because most of the animals in the world are insects, and most insects hatch from eggs.
Over 99% of mammals give live birth, including deer. Out of around 6,500 known mammal species, only the platypus and the echidna lay eggs.
Most reptiles lay eggs. Out of approximately 11,000 known species of reptiles, over 80% lay eggs. The only exceptions are some snakes and lizards that give live birth.
Most fish lay eggs. Out of around 34,000 known species of fish, less than 400 are livebearers. This includes guppies, mollies, platies, swordtails, and some sharks.
All species of birds lay eggs. This includes all of the 10,000 recognized species of birds. Some ornithologists claim there are twice as many bird species, around 20,000.
Almost all amphibians lay eggs. Out of around 8,000 amphibian species, most will lay eggs in freshwater habitats. There are only a few amphibian species that give live birth (several frog species).
Almost all insects reproduce by laying eggs. Out of around 1 million known species of insects, of which 350,000 are beetles, all lay eggs. The only exceptions are a beetle from Borneo, another from South America, and some aphids. Scientists speculate that there are between 5 and 10 million species of insects in existence today.
Read More: Do moose have tails?
Final Thoughts – Do Deer Lay Eggs?
In conclusion, deer do not lay eggs. These hoofed ruminant mammals of the animal family Cervidae (cervids), reproduce viviparously and give birth to one to three babies in one litter.
The main reason why deer do not lay eggs is evolution; giving birth to live young helped deer procreate and survive to this day.
Animals that hatch will have eggs that come in different forms! Some will have blue or white color, speckled patterns, and different textures, while others will be hard, soft, or even gooey. Animals may decide to lay them in the water, underground, or a nest. Deer are not such animals.
If you were pondering on the question “do deer lay eggs”, we hope this article removed all doubts.
And if you enjoyed it, here’s a recommendation on another popular read on deer: are moose and camels closely related animals?