California Tiger Salamander in California's Central Coast Region

From CCoWS Wiki
Jump to: navigation, search

An environmental summary created by the ENVS 560/L Watershed Systems class at CSUMB.

Summary

The California Tiger Salamander (Ambystoma californiense)(CTS) was once thought to be a subspecies of tiger salamander (Ambystoma tigrinum) but has since been reclassified as a genetically distinct species. California's Central Coast Region is home to the Central California Distinct Population Segment (DPS) of CTS, one of three DPS in California. In 2004, the Central Coast DPS was federally listed as threatened under the Endangered Species Act (ESA) and in 2010 received the same listing from the State of California under the California Endangered Species Act (CESA). In 2017 the United States Fish and Wildlife Service (USFWS) released a recovery plan specific for this DPS. [1]

Description

CTS is a large and stocky terrestrial salamander with a broad, rounded snout. Adults range in length from approximately 6 to 9.5 inches and have a black body with white or yellow markings. [2] This color pattern may serve as a warning to potential predators, as adults produce noxious skin secretions from the dorsal surface of the tail. CTS larval coloration can vary, but larvae are generally pale colored. [3] Larvae are fully aquatic with external gills and a fin along the length of their back. Upon metamorphosis, the gills and fin disappear and lungs and four legs are fully developed. [4]

Habitat

Vernal pools

Central Coast Region CTS primarily inhabit coastal grasslands and open woodlands that contain vernal pools and ponds. Vernal pools likely provide higher quality breeding habitat because they are less likely to contain predators that feed on salamander larvae such as aquatic insects, fish, bullfrogs, and non-native salamanders. However, CTS have begun to more frequently occupy livestock ponds and perennial ponds, perhaps due to habitat fragmentation. This species is not known to breed in streams or rivers. [4]

Upland habitat

Large tracts of upland habitat, like oak woodland, are necessary for the survival of CTS. They require areas that are occupied by small mammals such as the California ground squirrel and Botta's pocket gopher because they build underground tunnel systems that are used by the CTS through the year. Large, continuous areas of scattered breeding pools that also contain terrestrial habitat that contains these burrows are ideal to ensure that recolonization can occur if a population at an individual pool is wiped out. [4]

Life History

Breeding

Adult CTS engage in mass migration events during a few rainy nights per year, typically from November through April. [5] [6] During these events, adults leave their underground burrows and return to breeding pools to mate. Trenham et al. found that in Monterey County, males remained in breeding ponds for an average of 44.7 days while females remained for an average of 11.8 days before returning to their underground burrows. [7] Females lay their eggs in the water, attaching their eggs to twigs, grass stems, or other debris. [8] [9] Incubation time is likely related to water temperatures and eggs have been found to hatch anywhere between 10 and 28 days. Peak emergence dates for metamorphs in Monterey County range between May 27 and July 29. Once a metamorph leaves its natal pond and enters a burrow, it spends the majority of its life underground. Little is known about their underground behavior, as they are difficult to observe. [4]

Diet

CTS larvae feed on aquatic invertebrates such as zooplankton, small crustaceans, and aquatic insects. Larger larvae have been known to consume the tadpoles of Pacific chorus frogs, western spadefoot toads, and California red-legged frogs. [10] The diet of terrestrial sub-adult and adult CTS includes spiders, earthworms, and insects. [4]

Predators

Observed predators include: great blue heron, great egret, western pond turtle, various garter snake species, western spadefoot toads, raccoons, striped skunks, ravens, American avocet, Foster's tern, various gull species, giant water bugs, predaceous diving beetles, waterscorpions, dragonfly nymphs, California Red-legged frog, American bullfrog, ground squirrel, Western mosquitofish, barred tiger salamander, and hybrid tiger salamander. [4]

Threats

General

The loss, degradation, and fragmentation of CTS habitat as a result of human activity are the primary threats to the population in the Central Coast Region. Agricultural conversion, urbanization, road construction, and other development projects have degraded critical aquatic and upland habitat. Other major threats include habitat alteration, disease, predation, mortality from road crossings, hybridization with non-native barred tiger salamanders, pond duration and availability, contaminants, livestock grazing, and climate change. [1]

Hybridization in Monterey County

Hybridization with non-native species can have negative effects on CTS populations. This is particularly problematic in the Salinas Valley, where there was a large-scale introduction of non-native barred tiger salamanders to support the region's bass-bait industry approximately 60 years ago. [4] Today, hybrid populations dominate Monterey County. In 2002, four populations of hybrids were found by Shaffer and Trenham, and in 2004 the California Department of Fish and Wildlife (CDFW) found that 78% of the Central Coast Region population was threatened by hybridization due to close proximity (within 1.3 miles) to known non-native and hybridized tiger salamander populations. [11] [12]

In addition to contributing to a genetic loss of pure CTS alleles, hybrids compete with native CTS for habitat and resources. Unlike native CTS, non-native and hybrids prefer permanent ponds which tend to be larger and have more consistent breeding and recruitment opportunities over time, contributing to a much higher reproductive success rate. [13]

In 2009, Ryan et al. observed that non-native and hybrid tiger salamanders were predating on native CTS. All cannibalism observed was unilateral - native CTS did not predate on non-natives or hybrids. [14]. Further, non-native tiger salamanders have kin recognition, meaning that they are less likely to consume individuals that are more closely related to them. [1]

Conservation

Listing history

2004: Ambystoma californiense Central California Distinct Population Segment is federally listed as threatened (69 FR 47212).

2005: U.S. Fish and Wildlife Service publishes a final rule designating critical habitat for the Central California DPS (70 FR 49380).

2010: Ambystoma californiense is listed by the State of California as threatened under the California Endangered Species Act.

Species' recovery priority number

The recovery priority number of the Central Coast Region CTS is 9C, indicating that the species faces a moderate degree of threat but has a high potential for recovery. [1]

Recovery plan

In June of 2017, the Pacific Southwest Region office of the U.S. Fish and Wildlife Service approved a recovery plan specific to the the Central California Region DPS of the CTS.[1]

Recovery goal and objectives:

The goal of the recovery plan is to reduce the threats to the Central California CTS to ensure its long term viability in the wild and allow for its removal from the list of threatened and endangered species. The recovery objectives are:

  1. Secure self-sustaining populations throughout the full range of the DPS, ensuring conservation of native genetic variability and diverse habitat types.
  2. Ameliorate or eliminate current and future threats that cause CTS to be listed.
  3. Restore and conserve a healthy ecosystem that can continually support CTS populations.

Actions needed:

Actions needed to recover the Central California DPS include:

  1. Maintain current distribution of species
  2. Maintain native genetic structure across the species range
  3. Minimize road mortality
  4. Minimize potential for disease introduction
  5. Minimize non-native predator populations
  6. Ensure adaptive management and monitoring of habitat
  7. Conduct research

Responsible parties:

Bureau of Land Management; California Department of Transportation; conservation banks, California Department of Fish and Wildlife; California Department of Parks and Recreation; California Rangeland Trust; Central Valley Project Conservation Program; Federal Highway Administration; local agencies including regional and county park districts, utility districts, HCP/NCCP implementing entities, and county public works agencies; non-governmental organizations; National Park Service; Natural Resource Conservation Service; Resource Conservation District of Monterey County (RCDMC); University of California Natural Reserve System; universities; United States Fish and Wildlife Service (USFWS); California Wildlife Conservation Board.

Estimated date and cost:

Date of recovery: 2067

Cost of recovery: $85,675,000

Sign indicating CTS monitoring in the East Garrison Mitigation Lands of Fort Ord. Photo by Laura Franklin

Fort Ord

Due in large part to its high concentration of natural seasonal pools, the former Fort Ord is home to a pure or nearly pure native CTS population. [15] As part of Fort Ord's decommissioning in the early 1990s, the U.S. Army consulted with the U.S. Fish and Wildlife Service to establish the Fort Ord Habitat Management Plan (HMP) for the area, the goal of which was to "promote preservation, enhancement, and restoration of the habitat and populations of HMP species while allowing development on selected properties that promotes economic recovery after closure of Fort Ord." [16]

Any group, entity, or agency that is approved to move forward with development in designated areas of the former Fort Ord must comply with the HMP as well as the Fort Ord Reuse Plan. One such group is UCP East Garrison, LLC, which in 2015 entered an agreement with the Fort Ord Reuse Authority (FORA) and the County of Monterey to begin 244 acres of residential development in an area known as East Garrison. Because the construction and operation of the project would possibly result in the incidental take of CTS, UCP East Garrison, LLC was required to establish a mitigation monitoring plan.

The Parker Flats Habitat Management Area was created as part of a 2002 land use modification.[17] A portion of the Parker Flats Management Area overlaps with the East Garrison Mitigation Lands, which contains suitable CTS upland habitat and has been set aside through a conservation easement as mitigation for the East Garrison Specific Project Plan. The County of Monterey Resource Management Agency contracted Denise Duffy and Associates, Inc. (DD&A) to assist with the implementation of the East Garrison CTS Interim Mitigation Monitoring Plan, originally prepared by Live Oak Associates, Inc. in 2014.[18] DD&A performs biannual surveys and provides annual monitoring reports for the area.

Links

References

  1. 1.0 1.1 1.2 1.3 1.4 U.S. Fish and Wildlife Service. 2017. Recovery Plan for the Central California Distinct Population Segment of the California Tiger Salamander (Ambystoma californiense). U.S. Fish and Wildlife Service, Pacific Southwest Region, Sacramento, California. v + 69pp.
  2. U.S. Fish and Wildlife Service. 2014. California Tiger Salamander Central California Distinct Population Segment 5-year review: summary and evaluation. U.S. Fish and Wildlife Service, Sacramento Fish and Wildlife Office, Sacramento, California. v + 63pp.
  3. Hansen WH and Tremper RL. 1993. Amphibians and reptiles of Central California. California Natural History Guides. University of California Press.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 U.S. Fish and Wildlife Service. 2014. California Tiger Salamander Central California Distinct Population Segment 5-year review: summary and evaluation. U.S. Fish and Wildlife Service, Sacramento Fish and Wildlife Office, Sacramento, California. v + 63pp.
  5. Hansen WH and Tremper RL. 1993. Amphibians and reptiles of Central California. California Natural History Guides. University of California Press.
  6. Petranka JW. 1998. Salamanders of the United States and Canada. Smithsonian Institution Press, Washington, DC.
  7. Trenham PC, Shaffer HB, Koenig WD, and Stromberg MR. 2000. Life history and demographic variation in the California tiger salamander. Copeia 2000(2): 365-377.
  8. Sorer Ti. 1925. A synopsis of the amphibian of California. University of California Press, Berkeley, California. Pp. 60-71.
  9. Twitty VC. 1941. Data on the life history of Ambystoma tigrinum californiense. Copeia 1:1-4.
  10. Anderson JD. 1968. Comparison of the food habits of Ambystoma macrodactylum sigillatum, Ambystoma marcodactylum croceum, and Ambystoma tigrinum californiense. Herpetologica 24(4): 273-284.
  11. Shaffer HB and Trenham PC. 2002. Distinct population segments of the California tiger salamander, Ambystoma californiense. Section of Evolution and Ecology, and Center for Population Biology, University of California, Davis. Davis California.
  12. U.S. Fish and Wildlife Service. 2004. Endangered and threatened wildlife and plants; determination of threatened status for the California tiger salamander; and special rule exemption for existing routine Ranching Activities; Final Rule. Federal Register 69: 47212.
  13. Fitzpatrick BM and Shaffer HB. 2004. Environment-dependent admixture dynamics in a tiger salamander hybrid zone. Evolution 58(6): 1282-1293.
  14. Ryan ME, Johnson JR and Fitzpatrick BM. 2009. Invasive tiger salamander genotypes impact native amphibians. Proceedings of the National Academy of Sciences 106(27): 11166-11171.
  15. Fitzpatrick BM and Shaffer HB. 2007. Introduction history and habitat variation explain the landscape genetics of hybrid tiger salamanders. Ecological Applications 17: 598-608.
  16. https://fortordcleanup.com/programs/habitat/.
  17. Zander Associates. 2002. Assessment East Garrison-Parker Flats Land Use Modifications Fort Ord, California.
  18. Live Oak Associates Inc. 2014. CTS Preservation and Habitat Restoration Area. Memorandum of Agreement.

Disclaimer

This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of CSUMB, its staff, or students.