Mammals

 

Mammals of Cabrillo National Monument and Point Loma Peninsula

Cabrillo National Monument and the Point Loma peninsula are home to several species of mammals. Many mammals become active later in the day, especially near closing time – they seem to know when it’s time for visitors to go home and they can regain the park for their nocturnal wanderings.

Common Mammals

• Raccoons: These efficient predators make their way around the park at night, preying on both terrestrial and intertidal organisms.
• Coyotes: Rarely seen in the park, coyotes prefer the northern end of Point Loma.
• Cottontails and Squirrels: Frequently seen throughout the year, their populations spike after particularly rainy winters due to the abundance of flowers and new plant growth which makes for easy foraging.
• Bats: Eleven species of bats visit Point Loma regularly, including the smallest species in North America, the canyon bat, and the largest, the Western mastiff bat. Recent research suggests that bats may be using the peninsula as a migratory stopover, particularly in the fall.
• Pocket Mice: Common and most abundant during the summer months.
• California Mouse: The largest white-footed mouse in the country, often mistaken for a small woodrat.

Non-Native Mammals

• Virginia Opossum: A non-native species present in the park.
• Feral and Free-Range Cats: These non-native mammals are also found in the area.

 

Desert Cottontail (Sylvilagus audubonii)

NPS photo.

Desert Cottontail (Sylvilagus audubonii)

Overview

The desert cottontail, also known as Audubon's cottontail, is a common mammal found at Cabrillo National Monument and the Point Loma peninsula. This small, adaptable rabbit thrives in various habitats, including grasslands, deserts, and urban areas.

Physical Description

• Size: Desert cottontails are relatively small, typically weighing between 1.5 to 2.6 pounds.
• Appearance: They have a light grayish-brown fur coat with a white underbelly. Their large ears are one of their most distinctive features, helping them detect predators and regulate body temperature.
• Tail: The cottontail's name comes from its fluffy white tail, which resembles a cotton ball.

Behavior and Ecology

• Activity: Desert cottontails are crepuscular, meaning they are most active during the early morning and late afternoon. However, they can also be seen foraging during the day, especially in cooler weather.
• Diet: Their diet primarily consists of grasses, herbs, leaves, and twigs. After rainy winters, the abundance of flowers and new plant growth provides ample food, leading to population spikes.
• Reproduction: These rabbits are prolific breeders. Females can have multiple litters per year, with each litter containing up to six young. The young are born blind and helpless but grow rapidly and are weaned within a few weeks.

Habitat

Desert cottontails prefer open, brushy areas where they can easily find food and shelter. At Cabrillo National Monument, they are often seen in grassy fields, coastal scrub, and near the park's trails.

Adaptations

• Evasion of Predators: Desert cottontails rely on their speed and agility to escape predators. They can run in a zigzag pattern at speeds up to 18 miles per hour.
• Thermoregulation: Their large ears help dissipate heat, which is crucial for surviving in hot environments.

Role in the Ecosystem

Desert cottontails play a vital role in the ecosystem at Cabrillo National Monument. They are a key prey species for various predators, including coyotes, hawks, and snakes. Additionally, their foraging habits help control plant growth and contribute to seed dispersal.

Observation Tips

Visitors to Cabrillo National Monument can spot desert cottontails throughout the year. Here are some tips for observing these fascinating creatures:

• Early Morning and Late Afternoon: Visit during these times for the best chance of seeing cottontails when they are most active.
• Stay Quiet and Still: Approach slowly and quietly to avoid startling them.
• Look Near Vegetation: Cottontails are often found near shrubs and tall grasses where they can quickly hide if threatened.

Conservation

Desert cottontails are currently not considered a threatened species. However, like all wildlife at Cabrillo National Monument, they benefit from the park's conservation efforts, which protect their natural habitat and ensure a healthy ecosystem.

By understanding and appreciating the desert cottontail, visitors can gain a deeper connection to the diverse wildlife that calls Cabrillo National Monument home.

 

Crawford’s Gray Shrew (Notiosorex crawfordi)

NPS photo

Crawford’s Gray Shrew (Notiosorex crawfordi)

Seldom seen, the Crawford’s gray shrew has adapted to the dry slopes of Point Loma. This shrew is actually an insectivore, not a rodent, and is more closely related to hedgehogs than to mice. Unlike some species of shrews, Crawford’s gray shrew is not venomous.

Overview

Characteristics

• Habitat: Crawford’s gray shrews spend much of their time underground or hunting at night. They are well adapted to the dry, arid environments of Point Loma.
• Senses: With poor vision, these shrews rely on their excellent sense of smell to navigate and find prey. Additionally, like bats, they can echolocate, producing high-pitched sounds that help them map their surroundings.
• Size: One of the smallest desert mammals, a baby shrew is about the size of a honeybee at birth. They grow rapidly, reaching adult size—about 2 inches long, including the tail—within four weeks.
• Diet: Due to their high metabolism, Crawford’s gray shrews are voracious eaters, consuming about 75% of their body weight every day. Their diet includes a variety of invertebrates, lizards, and small mice.

Behavior and Ecology

• Activity: These shrews are primarily nocturnal, becoming active at night to hunt for food. Their small size and rapid movements help them avoid predators.
• Adaptations: Crawford’s gray shrews have developed several adaptations to survive in their harsh environment. Their burrowing behavior helps them escape the heat of the day and retain moisture. Their echolocation ability is particularly useful in the dark, subterranean world they inhabit.

Conservation and Importance

While not currently considered endangered, Crawford’s gray shrews benefit from the protection of their habitat at Cabrillo National Monument. These shrews play a crucial role in the ecosystem by controlling insect populations and serving as prey for larger predators.

Observation Tips

Due to their nocturnal and subterranean habits, spotting a Crawford’s gray shrew can be challenging. However, understanding their behavior and habitats can increase your chances:

• Night Visits: Observing the park at dusk or after dark, with appropriate permissions and safety precautions, may offer a rare glimpse of these elusive creatures.
• Look for Signs: Signs of shrew activity, such as small burrows or tracks, can indicate their presence even if the animals themselves are not visible.

Cabrillo National Monument's Unique Habitat

Cabrillo National Monument provides a unique habitat for Crawford’s gray shrews and many other mammals. The preservation of this environment is crucial for maintaining the biodiversity of the area. Visitors can gain a deeper appreciation for the delicate balance of this ecosystem by learning about and observing its inhabitants.

By protecting and understanding species like Crawford’s gray shrew, we can ensure that Cabrillo National Monument remains a sanctuary for wildlife and a place of natural wonder for future generations.