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How to Tell the Age of a Baby Squirrel (With Pictures)
Baby squirrels age quite quickly. If you find a baby squirrel, it is essential to determine its age accurately in order to determine your next steps. Depending on the squirrel, it will need different care or perhaps no care at all. Age is important for determining what to feed your squirrel when to release it, and whether it actually needs any care.
There are many methods used by scientists and vets for determining the age of squirrels. Many of these are not appropriate for most ordinary people to do. For instance, X-rays can determine the current level of bone growth and fusion, which can help determine the age of the squirrel. There are other ways that vets can determine their age accurately, such as weighing their eye lens.
Such methods aren’t helpful for us, though, as these require extensive equipment or dissection. Luckily, there are alternative options, though they often provide a slightly less accurate age. Use multiple methods for the most accuracy.
1. Time of Year
Most squirrels are born about the same time each year. For this reason, you can determine the age of a squirrel based on when the squirrel was born. In most areas, squirrels are born between March and July. Based on this information, you can count backward to determine the age of your squirrel to the nearest month.
Squirrels generally become self-sufficient around 10-12 weeks, though they may not look full-grown at this point. You shouldn’t find helpless squirrels that are older than 3 months.
2. Physical Development
Like every other animal, squirrels meet certain developmental stages at different times. You can use these stages to determine how old the squirrel is. This will give you a somewhat accurate idea of your squirrel’s age, as they age quickly and go through many milestones in only 6 weeks.
It can be much more difficult to determine the age of your squirrel after this 6-week period. The squirrel’s development slows down, which makes it difficult to get an accurate determination of the animal’s age.
A squirrel’s ears do not open until they are between 3-4 weeks old. If a squirrel’s ears are not yet open, they are likely younger than a month. If they are open, they are older than a month. This can be a simple starting place, as this is easy to check for.
Squirrels are born without teeth, like most mammals. Their lower front incisors don’t appear until they are about 3 weeks old. If your squirrel doesn’t have any teeth, they are not yet 3 weeks. The upper incisors don’t come in until about 4 ½ weeks.
You can use this information to accurately determine a squirrel’s age if they are between 3 and 5 weeks. For instance, if they have their lower incisors and not their upper incisors, then they are between 3 and 4 ½ weeks. If they have no teeth, they’re less than 3 weeks.
This is less accurate, as the development of a squirrel’s eyes tends to vary significantly. Many squirrels will open their eyes by the time they’re 5 weeks old. This isn’t completely accurate, though. They can be either clear or cloudy at this point.
Squirrels can open their eyes anywhere between 3 ½ weeks to 6 weeks. If the squirrel’s eyes are open, then they are probably older than 5 weeks. If the squirrel doesn’t have their eyes open yet, it is significantly more difficult to determine their age.
A squirrel is born completely hairless. Their hair doesn’t start growing until around 2 weeks of age. By their 3rd week, it should be about 1 mm long. The white fur on their tail will reach about 2 mm long by the time they’re 4 weeks old. Their underside should be covered by fur by the time they’re 6 weeks old.
You can use the measurement of their fur to determine their age pretty accurately until they turn 6 weeks. After this, their fur doesn’t develop more. Therefore, it is significantly more difficult to determine their age past this point.
3. Level of Care Needed
Based on the squirrel’s age, the level of care that they need will differ. You can sometimes use this to determine their age.
At 6 weeks, squirrels often look like small adult squirrels, standing upright and taking part in many adult activities. However, squirrels are not weaned until they are 10 to 12 weeks. For this reason, they still require extensive care at this point. They are different from baby birds in this regard.
By 12 weeks, the squirrel will be difficult to tell apart from an adult. They are completely self-sufficient at this point. If a squirrel is effectively staying away from you, they are likely older than 12 weeks and able to take care of themselves.
Determining a squirrel’s age after 6 weeks is difficult, as they don’t change quite as much from week to week. This can make it difficult to determine when to release the squirrel, as well as whether it needs extra care at all. Squirrels that are around 8 to 9 weeks may be able to survive if they fall from their nest, as the parents may locate the baby and continue to care for it. The best thing that you can do at this age is to return the squirrel to the nest, as they are sturdy and likely able to thrive despite their small excursion from the nest.
A squirrel that is sitting upright and moving around is likely at least 6 weeks. If they are jumping and generally acting like an adult, they may be as old as 10 weeks. Before 6 weeks, squirrels aren’t that mobile.
4. Type of Squirrel
Most of the information in this article relates to Eastern Grey Squirrels, which are the most common in most areas. However, other squirrels age at different rates. It can be difficult to determine the species of a squirrel before it is an adult unless you’ve handled squirrels extensively. For this reason, determining how exactly the squirrel should be aging can be difficult. You often won’t know the age of your squirrel until they are older and their species has been revealed.
This is one reason that it is important to work with a professional who can determine the species. Otherwise, you may be using the wrong developmental pattern, which can throw off your estimate. A professional will likely be able to determine the breed of squirrel, even when the squirrel is very little.
Furthermore, in most areas, it is illegal to take care of a squirrel.
Through a combination of physical development, amount of care needed, and the squirrel’s species, you can typically make a pretty accurate determination of a squirrel’s age. You can use this to determine whether the squirrel is old enough to care for itself (although, if you caught a squirrel, it is probably still in need of care and considered a baby) or if you need to care for it until a professional can do so.
Usually, you can determine the age of a younger squirrel down to the week based on fur growth and other developmental milestones. Once the squirrel reaches 6 weeks, it can be difficult to determine the age because their development slows down substantially. Before 6 weeks, they are changing every day. Afterward, they often stay the same for weeks at a time.
Luckily, you often don’t need to determine a squirrel’s exact age — within the week is often plenty for feeding purposes.
Featured Image Credit: Jim Combs, Pixabay
Kristin is passionate about helping pet parents create a fulfilling life with their pets by informing them on the latest scientific research and helping them choose the best products for their pets. She currently resides in Tennessee with four dogs, three cats, two fish, and a lizard, though she has dreams of owning chickens one-day!