It is hard to guess what a Rock pocket mouse weights. But we have the answer:
An adult Rock pocket mouse (Chaetodipus intermedius) on average weights 15 grams (0.03 lbs).
The Rock pocket mouse is from the family Heteromyidae (genus: Chaetodipus). When reaching adult age, they grow up to 10.5 cm (0′ 5″). Usually, Rock pocket mouses have 3 babies per litter.
As a reference: An average human weights in at 62 kg (137 lbs) and reaches an average size of 1.65m (5′ 5″). Humans spend 280 days (40 weeks) in the womb of their mother and reach around 75 years of age.
The rock pocket mouse (Chaetodipus intermedius) is one of 19 species of pocket mice in the genus Chaetodipus. (It is sometimes grouped in the genus Perognathus.)Found mainly in rocky outcrops in the deserts of the southwestern United States and Mexico, the rock pocket mouse is medium-sized (length ~18 cm, weight ~12–18g) and nocturnal. It eats mainly plant seeds and makes small burrows in soil close to or under rocks to evade owls, its main predator. The breeding season spans a few months, starting in February or March, and the litter size is typically between three and six. As with most pocket mice, the tail is longer than the body (~10 cm).Historically, rock pocket mice have been subdivided into as many as ten subspecies (Benson 1933; Dice and Blossom 1937) based on geographical distribution and coat colour. Most rock pocket mouse populations have light, tawny fur consistent with the colour of the desert rocks on which they live. However, darker coloured rock pocket mice are found living amid black, basaltic rock formations.In 2003, scientists sampled DNA from both light- and dark-coloured rock pocket mice from areas in Pinacate Peaks, Mexico and New Mexico, USA. In the Pinacate mice, they discovered a perfect association between different versions of the Melanocortin-1 receptor (Mc41r6) gene and coat colour . Subsequent studies demonstrated that there is strong selective pressure maintaining Mc1r allele and coat colour frequencies across the short geographic distances between the light- and dark-coloured rock islands.Thus melanism in rock pocket mice is considered a fabulous example of adaptation by natural selection. Changes in the Mc1r gene sequence are not responsible for the colour difference in the mice sampled from New Mexico, however, leading the researchers to conclude that the almost identical dark coat colours developed multiple times in rock pocket mice, an example of convergent evolution.
Animals of the same family as a Rock pocket mouse
We found other animals of the Heteromyidae family:
- Chisel-toothed kangaroo rat with a weight of 56 grams
- Stephens’s kangaroo rat with a weight of 68 grams
- Heermann’s kangaroo rat with a weight of 63 grams
- Goldman’s spiny pocket mouse with a weight of 85 grams
- Arizona pocket mouse with a weight of 11 grams
- California kangaroo rat with a weight of 85 grams
- Great Basin pocket mouse with a weight of 24 grams
- San Quintin kangaroo rat with a weight of 84 grams
- Gulf Coast kangaroo rat with a weight of 49 grams
- Agile kangaroo rat with a weight of 60 grams
Animals with the same weight as a Rock pocket mouse
As a comparison, here are some other animals that weight as much as the Chaetodipus intermedius:
- Miller’s long-tongued bat bringing 13 grams to the scale
- Velvety free-tailed bat bringing 13 grams to the scale
- Northern ghost bat bringing 16 grams to the scale
- Feathertail glider bringing 13 grams to the scale
- Common blossom bat bringing 17 grams to the scale
- African smoky mouse bringing 17 grams to the scale
- European pine vole bringing 17 grams to the scale
- Rainey’s shrew bringing 14 grams to the scale
- Microryzomys altissimus bringing 13 grams to the scale
- Chestnut short-tailed bat bringing 13 grams to the scale
Animals with the same litter size as a Rock pocket mouse
Here is a list of animals that have the same number of babies per litter (3) as a Rock pocket mouse: