The California Tiger Salamander, Ambystoma californiense - it is cute, colorful, and unfortunately a threatened species. The species, which is endemic to many parts of California, has federally endangered population segments in the Northern Bay Area, Santa Barbara, and on the Central Coast.
This blog will discuss the reasons of why the California Tiger Salamander has become a vulnerable species, provide ways to help support the survival of this amphibian, and spread awareness on the species' endangerment.
Who is the California Tiger Salamander?
The California Tiger Salamander is a very distinct creature in regards to both its appearance and the habitats it lives and reproduces in. Its bright yellow spots that pop against its muddy black skin makes this amphibian a unique animal. Previously mentioned, the California Tiger Salamander is endemic to California. Below is a graphic of the species' distribution.
The specific areas where the California Tiger Salamanders live have habitats called vernal pools and/or seasonal ponds that are necessary aquatic breeding sites for the salamander's reproductive cycle. These specific environments are usually fish-less, and are also diminishing. We will go more in depth on the habitat fragmentation that is damaging their ecosystems in a little bit.
The life cycle of the California Tiger Salamander is a transient one. Adult salamanders spend a majority of their lives living in underground burrows that are abandoned by the other animals that made them, such as ground squirrels or gophers. Adults adopt these burrows because they do not have physical features that are good for digging. Scientists know little about their time underground, and consider it an estivation period. The diet of adult salamanders includes earthworms, snails, insects, some fish, and even small mammals.
The wet season that occurs in late fall and early winter brings adult salamanders out of their underground burrows and into the vernal pools and ponds for breeding. The adults' journeys can take several days, with some traveling as far as 1.3 miles to reach these breeding sites. Once the eggs are laid and fertilized, it takes larva around three to six months to transform into an adult. By then, the pools and ponds they lived in will dry up. The larva are forced to resorb their gills, develop lungs, and leave to find a burrow to claim.
Endangerment & Recovery Plan
The loss, degradation, and fragmentation of habitat as the result of human activities are the
primary threats to the California Tiger Salamander. Aquatic and
upland habitat available to California Tiger Salamanders has been degraded and reduced
in area through agricultural conversion, urbanization, road construction, and other projects. California Tiger Salamander populations occur in scattered and
increasingly isolated breeding sites, reducing opportunities for inter-dispersal with other ponds. Below is a video providing an example of just how life threatening human activities are to California Tiger Salamanders. This video is an expose on how the salamanders in Sonoma County are being tragically run over because they have to cross a busy road in order to reach their breeding sites.
WARNING: this video contains some graphic content.
WARNING: this video contains some graphic content.
Besides the habitat loss and alteration due to human use, the California Tiger Salamander is also threatened by disease and predation. Ranaviruses are pathogens which are known to
infect amphibians, reptiles, and fishes. Ranaviruses such as ATV (Ambystoma tigrinum virus),
have caused tiger salamander die-offs throughout western North America. Diseases such as ATV and other ranaviruses are considered a potential threat because non-native salamanders carrying these diseases can easily be brought into California through the
amphibian pet trade or for use as fish bait, and many of these non-native tiger salamanders are
known carriers of ATV.
Bullfrogs and the introduction of mosquitofish, largemouth bass, crayfish, and blue gills in vernal pools and ponds have threatened California Tiger Salamanders through predation. These predators mainly consume salamander larvae. Mosquitofish also compete with salamander larvae and adults for food.
The recovery plan drafted by the U.S. Fish and Wildlife Service focuses on efforts to reduce habitat loss and fragmentation, and to increase the management and conservation of the California Tiger Salamander's current habitats. Because the species range throughout California, the recovery plan separates distinct population segments into four recovery units so each endangered population can receive proper conservation efforts. These four units are The Central Valley Unit, The Southern San Joaquin Valley Unit, The Bay Area Unit, and The Central Coast Range Unit. The ultimate goal of the recovery plan is to outline specific actions that, when implemented, will
sufficiently reduce the threats to the California Tiger Salamander, ensure its long-term
viability in the wild, and allow for its removal from the list of threatened and endangered species.
Some solutions the recovery plan highlights include ending road mortality by building underground bridges for the salamanders to travel in, implementing management plans that monitor the introductions of ranaviruses and other pathogens, keeping their breeding habitats ephemeral so bullfrogs, fish, and other non-native species cannot establish breeding populations.
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| Original Artwork by Molly Eckler. What You Can Do for The California Tiger Salamander
A variety of conservation organizations, such as the Pacific Forest Trust, are raising money to help the California Tiger Salamander. To learn more about this organization and donate click here.
The Center for Biological Diversity is working on a Pesticides Reduction Campaign, challenging the Environmental Protection Agency's registration and authorization-for-use of 46 toxic pesticides in and upstream of habitats for San Francisco Bay Area endangered species, including the California tiger salamander. Click on the link above to read more about their campaign and to support their organization.
If you would like to take on more direct action, you can write to the California Fish and Game Commission to express your support of protections for the California Tiger Salamander and the conservation of its habitats. You can write to them here:
California Fish and Game Commission
P.O. Box 944209
Sacramento, CA 94244-2090
Lastly, creating awareness for these creatures will help them immensely. Talking about their endangerment with friends, family, and colleagues will increase the California Tiger Salamander's popularity and inspire others to protect these amazing amphibians.
Resources:
https://ecos.fws.gov/docs/recovery_plan/Signed%20Central%20CTS%20Recovery%20Plan.pdf http://www.biologicaldiversity.org/species/amphibians/California_tiger_salamander/index.html https://www.fws.gov/sacramento/es_species/Accounts/Amphibians-Reptiles/es_ca-tiger-salamander.htm http://www.californiaherps.com/salamanders/pages/a.californiense.html https://www.sacsplash.org/critter/california-tiger-salamander |
Ending road mortality by building underground bridges seems like an effective way to help the salamander species survive. Good job!
ReplyDelete-Marina Enriquez
DeleteThis comment has been removed by the author.
ReplyDeleteI also found the fact that they are trying to build underground bridges for this species most interesting. It reminds me of the bridge that biologists constructed for the deer species from the video we watched in class.
ReplyDelete- Kyla Cooper
Being from California, I enjoyed learning about this species and how they plan to remedy the issues brought about by road construction and agricultural development. The video about Sonoma County helps make conservation more tangible. I think improving and protecting the salamander's habitat is a good start for recovery.
ReplyDelete-Erika DiLeva