Updated: Jan 21
A Giant Kangaroo Rat is leaving its burrow for the night and is about to hop. Find the original here.
Population: >100,000 adults, ↓DECREASING↓
In California, the largest kangaroo rat in the World ranges from Fresno to San Louis Obispo Counties. The Giant Kangaroo Rat, Dipodomys ingens, now lives within six recorded fragmented communities. They are only 5.9 to 7.9 inches (15-20 cm) with a tail as long as or longer than their bodies at 7.1 to 8.5 inches (18-21.5 cm). Unlike other kangaroo rat species, the Giant Kangaroo Rat possesses five toes with a white underbelly and white stripes on the sides of the dark tail. Weighing between 4.6 to 6.4 ounces (131 to 161 grams), these mammals mate during the late winter with a gestation period of about a month before reproducing one to six offsprings. These offsprings are weaned for 15 to 25 days and eventually leave the burrows when they become sexually mature within 2-3 months.
They burrow themselves in desert with a uniform composition where store their seeds. Typically, they burrow in desert lands with a 10 degree slope, but the continual extortion of their land forces them to live on shrubland with a 22 degree slope. According to a report by the U.S. Wildlife Services, they exist as keystone species by altering the composition of their environments and creating micro habitats with their burrows. As granivorous creatures, or animals who consume seeds, they must scavenge for seeds and may steal seeds from local farms if close enough to store within their burrows. Also, they extract water from their seeds as their sole source of water. Due to their solitary nature in their burrows, they live as isolated creatures with few interactions with people.
Currently, the Giant Kangaroo Rats face the challenges of the expanding industrialization, urbanization, and agriculture. The harvesting of petroleum requires their lands that remain unprotected and available to claim. The growth of cities has demanded these animals of their lands to sustain the ever-growing demands of the modern world. Cattle grazing can also harm local populations because the cattle often steps on top of the fragile burrows and crushes them with any of the Giant Kangaroo Rats in it. Although agricultural pressures have declined drastically due to the lower value in the weaker land with burrows, the exploration for minerals and new infrastructure pose as critical threats to their survival linking to multiple extirpation or the extinctions of local populations.
In a 2014 study posted in the Southwestern Naturalist, the Giant Kangaroo population dramatically dwindled within the year of 2012 due to surplus-killing by another endangered species, the San Joaquin Foxes. Despite most surplus-killings possibly resulting from the high population density, the Giant Kangaroo Rats experienced heavy predation due to individuals of the San Joaquin Foxes specifically hunting for them.
Graph 1. Population Density of Giant Kangaroo Rats vs. Time between 2008 to 2012 in Studied Areas. The graph above shows the decline of population densities of Giant Kangaroo Rats from the surplus-killing and predation of San Joaquin Foxes. Find the original here.
In 1980, the California Fish and Game Commission designated the Giant Kangaroo Rat as endangered with the United States and Wildlife Service following suit in 1987. Since then, three of the six regional habitats remain unprotected with no public or conservation lands subject to the potential of random or recurrent disasters like floods or fires and to humans’ degradation of the land. Giant Kangaroo Rats at the moment only occupy 2% of their original geographic range.
Written by — Edward Keenan
Walt Disney introduced the rats in the 1953 feature documentary The Living Desert
They’re nicknamed kangaroos because they hop on their hind feet like kangaroos
They hold the record of having the most concentrated urine of all North American mammals
They can hop quickly at 10 feet/second using their tails for balance
To communicate with other members or scare off predators, these mammals can beat their hind legs against the ground repeatedly up to 18 beats/second for a maximum of 100 beats
From their protective natures of their burrows, they only leave their burrows 15 minutes/day during the night as nocturnal animals
How You Can Help
To help the Giant Kangaroo Rat, the U.S. Fish and Wildlife Service manages a recovery plan for this species and conducts surveys to evaluate the survival of the populations and the impact of commercialization on these animals. Donate or volunteer to help save this amazing species.
L. Endicott, Rachel & Prugh, Laura & Brashares, Justin. (2014). Surplus-killing by endangered San Joaquin kit foxes ( Vulpes macrotis mutica ) is linked to a local population decline of endangered giant kangaroo rats ( Dipodomys ingens ). The Southwestern Naturalist. 59. 110-115. 10.1894/N01-JKF-39.1.