Baby squirrels, often called kits or pups, undergo a rapid transformation from their fragile birth state to eventual independence. Their size at birth and developmental journey reveal how quickly these tiny animals mature.
Newborn Size and Appearance
Baby squirrels are born remarkably small and undeveloped. At birth, a newborn typically measures 1 to 2 inches (2.5 to 3 cm) in length, excluding the tail. Their weight usually falls between 10 to 18 grams (0.5 to 1 ounce). This minuscule size makes them vulnerable.
Immediately after birth, kits are hairless, displaying pink, almost translucent skin. Their eyes are tightly closed, and their ears are sealed against their heads, making them blind and deaf. Their tiny fingers are often still joined, and their tails are thin with little fur. During this initial stage, they are entirely dependent on their mother for warmth, nourishment, and protection.
Growth and Developmental Milestones
The first few weeks mark a period of rapid growth and significant changes. By 1 to 2 weeks of age, their skin begins to darken, and faint, peach-fuzz fur starts to appear on their bodies, though they remain hairless on their bellies. Their weight can double within their first week, reaching 60-80 grams by 14 days old. Around 3 to 4 weeks, a thin layer of fur covers most of their body, and their ears begin to unpin and open. At this stage, they are approximately 4 inches long, excluding their tail, and their lower front teeth may start to emerge.
By 4 to 5 weeks, the baby squirrels’ eyes typically open, allowing them to begin perceiving their surroundings. They are now fully furred, including their bellies, and their upper teeth begin to appear. Around 5 to 6 weeks old, they measure 5 to 6 inches long (excluding the tail) and weigh between 120-150 grams.
As they approach 6 to 7 weeks of age, their tails become noticeably bushier, resembling miniature adults. They begin to sit up and hold food with their front paws. This is also when they start to explore outside the nest for short periods under their mother’s supervision, and weaning may gradually begin. Full independence is usually achieved around 10 to 12 weeks of age, when they are nearly adult size but often still leaner.
Factors Influencing Baby Squirrel Size
Several factors can influence the size of baby squirrels. Different squirrel species exhibit variations in their adult size, which extends to their offspring. For instance, a newborn gray squirrel might differ in size from a red squirrel kit.
The size of a litter also plays a role; larger litters may result in slightly smaller individual babies due to the distribution of maternal resources. A mother’s nutritional status and overall health affect the size and well-being of her offspring. Adequate maternal diet during gestation and lactation supports proper fetal and infant growth.