Pacific pond turtle

Emys marmorata

  • Species of Special Concern, California Department of Fish & Game
  • Sensitive Species, US Forest Service

The Pacific pond turtle occurs along the entire west coast, but a genetically unique ‘subunit’ of the turtles is restricted to Santa Barbara and Ventura counties. Found throughout the Los Padres National Forest, these Pacific pond turtle populations are concentrated in Piru Creek, Sespe Creek, the Indian Creek/Mono Creek area, the Sisquoc River/Manzana Creek area, Alamo Creek, the Nacimiento River, and Arroyo Seco Creek. They also occur in most of the small coastal drainages of Santa Barbara and San Luis Obispo Counties.

Natural History

Pacific pond turtle range in red

Pacific pond turtles inhabit a wide variety of aquatic habitats from sea level to elevations of 6,500 feet. The turtles use their resident creeks, rivers, wetlands, lakes and ponds primarily for foraging for food, regulating their temperature, and for shelter to avoid predators. They use dry sunny basking sites for warming themselves such as rocks, logs, or thick floating vegetation. The turtles will engage in aggressive behaviors when competing for basking sites; they push and ram each other, threaten one another with open-mouthed gestures, and occasionally bite.

 

>> Watch a video of  Pacific pond turtles competing for basking rights

 

One report states that the Pacific pond turtle is “an omnivorous feeder, opportunistic predator, and occasional scavenger”, so in other words they eat just about everything and anything!  The majority of their diet consists of crustaceans, midges, dragonflies, beetles, stoneflies, and caddisflies, but they will also feed on carrion and plant matter. They are often seen clinging to rocks in riffles, where they are feeding on chironomid (blackfly) larvae.

Turtle juvenile, photo Jason Jones

In some parts of its range the Pacific pond turtle is seasonally active, hibernating from around October/November through March/April. However, along the central and southern coast of California, the Pacific pond turtles may be active throughout the year. When hibernating they will choose both aquatic and terrestrial areas, perhaps undercut areas along a stream bank or in upland burrows in leaf litter or soil (sometimes moving up to 500 meters from their usual aquatic homes).

Turtle eggs, photo Patrick Briggs

The Pacific pond turtle does not start reproducing until 7-10 years of age! They will lay eggs in late spring to early summer, with their clutch size determined by age/size of the female and ranging from just 1 egg to 13. The juveniles hatch in late fall, but remain buried in the nest until the following March or April.   Nest predation rates are high and total loss of a clutch of eggs is common.  Large fish, bullfrogs, garter snakes, wading birds, and some mammals will prey on young turtles, but raccoons are the principal nest predators.

 

Threats

The primary reason for population declines in southern Pacific pond turtles is loss of suitable habitat exacerbated by intense nest predation. The availability of persistent, pooled water along low-elevation streams has been greatly reduced as the result of agricultural activities, urbanization, flood control and water diversion projects. Raccoon densities are artificially high within a mile or two of housing areas, and illegal transport and release of trapped raccoons at Forest Service campsites maintains raccoon densities even in remote areas.

Other general threats include introduced nonnative fish and bullfrogs that prey on young turtles, livestock and recreational activity that can destroy nesting habitat, and collecting of turtles in some easily accessible areas. Siltation (from intense grazing, mining, off-highway vehicles, or the aftermath of fires) is also a threat as it can eliminate good habitat in streams.

Conservation

The Pacific pond turtle is found in our forest’s waterways, which are some of the most ecologically sensitive and heavily impacted areas of the Los Padres. The Forest Service proposes providing increased stream and riparian area protection through management standards in the Forest Plan; such as by designating Riparian Conservation Areas which have their own set of special management requirements. While a good starting place in theory, the proper implementation of these standards and guidelines needs to be monitored to meet goals for protecting the species.

ForestWatch will continue to closely monitor proposed projects on the Los Padres National Forest to ensure that Pacific pond turtles and their aquatic and upland habitats receive full protection.