Eastern Harvest Mouse

Scientific Name
Reithrodontomys humulis
Also Known As
Eastern Harvest Mouse
Range
Northern and Central Florida
Diet
Seeds, Weeds, Insects
Life Expectancy
5 - 8 Months
Florida Eastern Harvest Mouse

Photo 71474099 (c) Joe Girgente, CC BY-NC

Eastern Harvest Mouse conservation status - Least Concern

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Eastern Harvest Mouse in Central Florida

The eastern harvest mouse (Reithrodontomys humulis) is a small rodent species found throughout the southeastern United States, including central Florida.

Often overlooked due to its tiny size, the eastern harvest mouse plays an important ecological role as prey for raptors and snakes. This guide covers identification features, biology, habitat preferences, diet, health risks, and prevention tips for the eastern harvest mouse in central Florida.

Appearance and Identification

The Eastern Harvest Mouse can be identified by the following juvenile and adult characteristics

The Eastern Harvest Mouse

Photo 71474099 (c) Joe Girgente, CC BY-NC

Adult Eastern Harvest Mice

  • Size: Adults reach about 6-10 cm long including the 4-7 cm tail. They weigh just 4-8 grams.
  • Fur: The dorsal fur is brownish-gray with black tips, providing camouflage. The ventral fur is white to light gray.
  • Tail: Long slender tail with fine hairs and annulated scale pattern. Used for balance.
  • Hind feet: Enlarged hind feet with elongated 4th digit for grasping stems. Front feet are smaller with shorter digits.
  • Ears: Prominent, thin ears.
  • Rostrum: Pointed nose and long mystacial vibrissae (whiskers).

Juvenile Eastern Harvest Mice

  • Size: Newborns weigh just 2-4 grams and are about 2.5 cm long including the tail. They reach an adult size of 4-8 grams and 6-10 cm long with tail by 5-6 weeks old.
  • Fur: Juvenile fur is grayish overall with some brown hues. The underside is paler gray. The fine, soft fur helps them blend into vegetation.
  • Features: Proportionally, juveniles have larger hind feet, ears, and eyes compared to the body which is more rounded. The tail is slender with very fine hairs.

The eastern harvest mouse is distinguished from the similar western harvest mouse by its darker fur and more eastern range. It lacks the climbing adaptions of the white-footed mouse which has shorter limbs and tail.

Maturation Rate

Newborn eastern harvest mice weigh only 2-4 grams but grow rapidly. Their ears open by 3-4 days old and eyes by 5-6 days old. Fine gray fur grows in by 1 week old. They are weaned by 2 weeks of age.

By 3-4 weeks old, the young are completely independent and leave the nest. They reach full adult size by 5-6 weeks old. Reproductive maturity occurs between 6-8 weeks of age and first litters are produced by about 10 weeks old.