Pacific Pocket Mouse

Pacific Pocket Mouse

(Perognathus longimembris pacificus)

By: Adam Roge

(http://www.zooborns.com/.a/6a010535647bf3970b019aff3ab053970b-800wi)

Description & Ecology

The Pacific Pocket mouse is a subspecies of the "little pocket mouse" species, which is a part of the rodent family. The mouse is covered in brown silky fur, and lives in sandy coastal areas. Weighing as little as .25 oz, this small mouse is endemic to the coast of southern California. Historically, the population of these mice ranged from Los Angeles down to San Diego county, and have not been recorded farther than 2.5 miles away from the ocean. The Pacific Pocket mouse is nocturnal, and mainly eats small insects and seeds, which they burrow for when it's dark out to avoid the sun. The pocket mouse then saves these seeds in their burrow for when they hibernate during the winter. The Pacific Pocket mouse's name is due to its external "pockets" in its cheeks, which are used to temporarily store these seeds. Besides finding a mate, the Pacific Pocket mouse does not engage in direct social interaction with other mice. Female Pacific Pocket mice typically give birth to one litter per year, with each litter containing somewhere between 2-8 babies. The ideal breeding season for the mouse is in the spring, usually sometime between April and June. In captivity, the lifespan of the Pacific Pocket mouse is usually between 4-6 years, however in the wild, the mouse's lifespan is reduced to 3-5 years. The picture below shows the historic localities of the Pacific Pocket mouse, showing both the number recorded in the specific location, as well as the year recorded.

Geographic & Population Changes

The Pacific Pocket mouse was originally thought to have gone extinct, up until 1993, when they were re-discovered after a 20 year period during which the mice were not detected. Currently, these mice are known to exist in three locations in California: Dana Point headlands, Orange County, and San Diego County. The current occupied habitat for the Pacific Pocket Mouse is estimated to be less than 400 hectares (or 1,000 acres) at the three locations combined. The geographic range of the Pacific Pocket mouse has been greatly affected by urban and suburban development along the coast of California, and unfortunately, this development is expected to continue indefinitely. Using the mark and recapture strategy to determine the population of the Pacific Pocket mouse, it is believed that there are about 150 of these mice left in existence shared among the three locations.

Listing Date & Type of Listing

The U.S Fish and Wildlife Service listed the Pacific Pocket mouse as endangered under the Endangered Species Act on September 29th, 1994, after rediscovering a single population at the Dana Point headlands.

Cause of Listing & Main Threats to Continued Existence

The main cause of the Pacific Pocket mouse being listed under the Endangered Species Act, is due to urban and suburban development along the coast of California. Off-road vehicle activities, constructing highways and roads, and urbanization of the coast have all contributed and continue to degrade and fragment habitats within the historic range of the Pacific Pocket mouse. Industrial and agricultural development have also aided in the decline of the species. Currently, the vast majority of the California coast has been developed and urbanized, and the percentage that is still undeveloped is decreasing every year. The picture below shows us how developed the coast of California has become.

(http://stophermosabeachoil.com/the-california-coastal-commission/)

Description of Recovery Plan

The ultimate goal of the recovery plan is to protect and maintain sufficient populations and habitats of the Pacific Pocket mouse, which will allow the U.S Fish and Wildlife Service to de-list the subspecies under the Endangered Species Act. However, the recovery of the mice will involve a two stage process, that begins with re-classifying the subspecies from endangered to threatened status. It is estimated that the recovery of the Pacific Pocket mouse will take approximately 25 years (until the year 2023), and the cost will amount to 7.5 million dollars. The recovery plan was initiated in 1998.

Details of the Recovery Plan

Step number one: Identify all extent populations and essential habitat. As I stated above, the Pacific Pocket mouse currently only lives in three locations of California. Loss or degradation to any of the habitats in these locations will only further increase the probability of the mice going extinct. The plan makes it clear that it is critical to protect and secure the remaining mice populations and habitats. COST = $511,000

Step number two: Prepare and implement habitat management plans. This includes controlling and removing the exotic and invasive plants that grow in the Pacific Pocket mouse's habitat, which threaten the mouse's habitat. This also includes controlling house and feral cats, as these are predators of the Pacific Pocket mouse. Furthermore, vulnerable habitat should be fenced when necessary to ensure the habitat is not disturbed by humans. The management plan depends on the location of the population/habitat, and will be enacted accordingly using the techniques I listed above. Each management plan for each location will be monitored closely to ensure its effectiveness. COST = $2,900,000

Step number three: Enhance and expand the Pacific Pocket mouse habitat. This includes controlling and even manipulating vegetation in selected target sites to enhance their habitat by reducing floral cover. This also includes ensuring that there are adequate seed sources in the habitats, as these seeds are the main source of food for the Pacific Pocket mice. The overall objective of this step is to give the mice an ideal habitat so they can flourish and grow their population. COST = $698,000

Step number four: Conduct research on the life history, ecology, and population biology of the Pacific Pocket mouse. The information that is collected will be used to guide recovery actions and construct mathematical models that can help predict the likelihood of the persistence of the species over time. Understanding how the populations of Pacific Pocket mice live is critical to ensuring the longevity of the species, and to ensure they don't become endangered again. COST = $1,053,000

Step number five: Identify and implement measures to create additional populations. Simply protecting and enhancing all existing mice habitats and populations may not be enough to ensure full recovery. The plan states that it may be necessary to establish a captive breeding population that can later be released into existing or unoccupied habitat. Most current mice populations occur in small and fragmented habitats, however potential unoccupied habitat has been identified on publicly owned land that may be suitable for the Pacific Pocket mouse. The establishment of populations in these unoccupied habitats could help contribute to the species recovery. COST = $2,096,000

Step number six: Enhance public awareness of, and appreciation for, the Pacific Pocket mouse recovery program. This will mainly be done through educational and interpretive programs. Public awareness of recovery efforts will help reduce impacts to protected populations. Interpretive signs and exhibits should be erected near Pacific Pocket mice populations to guide human behavior near the se habitats. COST = $211,000

What can YOU do to help?

The biggest thing you can do to help is to be respectful and careful when entering territory with local Pacific Pocket mice habitats nearby. Don't litter, or drive vehicles on or near habitat sites, as this will further degrade the habitat. Pay attention to instructional signs and follow proper behavior when treading on mice-populated land. You can also help create awareness of species and their recovery status by posting on social media, or creating an article or blog about them, just like I am doing. If you really want to help, and have a couple million dollars to spare, donating money to the U.S Fish and Wildlife service would tremendously help the recovery efforts of the Pacific Pocket mouse.

Lastly, if you would like to help one of the monitoring programs for these mice located in Camp Pendleton, you can contact the principle investigator for this project below, Robert Fisher. A link for further details on this project can be found here --> http://www.werc.usgs.gov/Project.aspx?ProjectID=116

Contact Info:

Robert Fisher

Email: rfisher@usgs.gov

Phone Number: (619) 225-6422

Address: San Diego Field Station

4165 Spruance Road Suite 200

San Diego, CA 92101

(http://cdn.sandiegouniontrib.com/img/photos/2014/12/08/mouse_t837.JPG? 5df2a6e0ac564ff4ddc2702f3c8561935b88c24b)

References

http://ecos.fws.gov/docs/recovery_plan/980928c.pdf

http://www.werc.usgs.gov/Project.aspx?ProjectID=116

The Southern Sea Otter

BY: NATALIE RAMOS

About the sea otter
There are two distinct sub species of otters in the United States, the Northern sea otter and The Southern sea otter, also known as the California sea otter. The Southern sea otter lives in the waters along the California coastline, ranging from San Mateo County in the north to Santa Barbara County in the south.The sea otter evolved to inhabit a narrow ecological zone leading them to prefer a rocky shoreline with kelp beds. 

Sea otters wrap themselves in kelp to keep from floating away

The sea otter is the smallest species of marine mammals in North America, yet the heaviest member of the weasel family; adults average 65 pounds for male and 45 pounds for female. They average in length at about 4 feet, with their tail accounting for less than one third of their body length. Watch the sea otter live at the Monterey Bay Aquarium here!

Males can live up to 15 years while females can live up to 20 years. Sea otters are the only marine mammal who have no layer of blubber for energy storage, instead air trapped in their dense underfur serves as an insulator from cold water, in fact, sea otters spend hours each day grooming their coats in order to keep it waterproof. Other than primates, sea otters are one of the known mammals to use tools! Sea otters use rocks to open up shellfish.

Sea otter using a rock to pry open a shellfish

Watch this cute video to see why otters hold hands

Sea otters are a keystone species! They are critical to maintaining the near-shore kelp ecosystems; without sea otters, the animals sea otters prey on would eat all the kelp, which provides habitat and cover for many other marine animals. Kelp forests are active in capturing carbon in coastal ecosystems, therefore, by keeping kelp forests alive, sea otters are saving other marine animals and reducing levels of atmospheric carbon dioxide, a harmful green house gas. 

Population changes

Due to the fur trade in the 1700's, numbers of sea otters plummeted from several hundred thousand down to a total of about 2,000 in the early 1900's; there are currently about 2,150 Southern sea otters living along the coast of central and southern California.

Listing and threats

The southern sea otter species was listed as threatened in 1977 due to its small distribution and potential jeopardy to the remaining habitat and population by oil spills. Besides the harmful toxicity of oil that causes liver and kidney failure, when sea otters' fur comes into contact with oil, it becomes matted which prevents it from insulating the otter; without insulation the sea otters will die from hypothermia. Since listing, white shark bites, pollution and incidental take in fisheries have also been recognized as substantial problems. Due to the sea otter's diet which involves sea urchin, lobster, and crab, sea otters often find themselves close to fisherman who view the sea otter as competition and often will intentionally trap them in fishing nets.

What the future holds for the Southern Sea Otter

The main objective is to manage human activities that may jeopardize the continued existence of the southern sea otter or damage or destroy habitat critical to its survival. The population goal is 3,000 members, once this number is achieved, the species can be removed from the List of Endangered and Threatened Wildlife. The current population of southern sea otters has remained constant despite the lack of oil spills, which makes it uncertain to determine if sea otters will be delisted. For a complete and detailed version of the recovery plan visit here.

REDUCE YOUR PERSONAL INTERACTION WITH SEA OTTERS!!!!

There is nothing we can do about the white shark attacks because they are also a protected species in California, however reducing your personal interaction with sea otters can have a large impact on their behavior; therefore the next time you are at the beach and you see sea otters stay away! Do not disturb them, otherwise you can be sentenced like this man. 

You can help save them, adopt a sea otter today or donate funds through your California tax form.

WORKS CITED

"Basic Facts about Sea Otters." Defenders of Wildlife. N.p., 19 Mar. 2012. Web. 18 Nov. 2015.

Final Revised Recovery Plan for the Southern Sea Otter (Enhydra Lutris Nereis). Portland, Or,: U.S. Fish and Wildlife Service. Region 1, 2003. Web. 18 Nov. 2015.

The Sierra Nevada Bighorn Sheep

Sierra Nevada Bighorn Sheep. 2009. Seattle, Washington.

The Sierra Nevada Bighorn Sheep; Road to Recovery

By: Gwen Wagner

Sierra Nevada bighorn sheep is distinct subspecies of bighorn sheep which is unique to the Sierra Nevada mountains of California. Sierra bighorn range in color from white to dark brown, with a white rump and dark tail. They have specialized hooves with special adhesive like soles which provide traction in the steep rocky terrain of their habitat. Female bighorn have shorter, narrow horns, while male bighorn have massive, curving horns both of which are composed of a dense layer of keratin covering a bone core. Because of their specialized mountain habitat, they eat a variety of plant species that span the Sierras. Males can weigh up to 220 pounds and female can reach up to 150 pounds. The average lifespan is about eight to twelve years for both males and females.

Prescott, Ed. 2007. N.p.

Sierra bighorn choose to habitat areas which consist of open areas of rocky land which is sparsely vegetated, and areas of steep slopes and canyons. Sierra Nevada bighorn sheep utilize a highly specialized habitat, specifically in elevations above 4,000 meters or 13,120 feet along the highest crests of the Sierra Nevada, and to winter ranges at the eastern base of the Sierra Nevada which can be as low as 1,450 meters or 4,760 feet.

The Sierra Nevada bighorn sheep was listed as endangered on January 3, 2000 in response to an emergency listing on April 20, 1999 due to
incredibly low population numbers. 

Sierra Nevada bighorn sheep population was at an all time low in 1995, with only 100 individuals spread across five different areas in the central and southern Sierra Nevada mountain range in California and Nevada. Since being listed, population numbers have experienced favorable growth and now sits around 600 as measured in 2014. The Sierra Nevada bighorn sheep recovery plan faces several key limiting factors such as disease, low population numbers, mortality caused by predators, loss of genetic diversity due to low population size, habitat availability, and limited distribution.

The objective of the Sierra Nevada bighorn sheep is raise population numbers and make it so that the geographic ranges they populate will be able to assure long-term viability of the overall population. Through following the recovery plan, the overall goal is delisting the Sierra Nevada bighorn sheep as an endangered species. 

To insure the recovery of the Sierra Nevada bighorn sheep, several key things need to happen. 

1. The existing herds and populations need to be protected through managing predator activity and keeping predator mortality low as well as maximizing population growth. 

2.Enlarging small herds so that they can fare better and make more adequate use of winter range

habitat. This is also essential because it can make the herds more resilient to the effects of predation. 3. Keeping the Sierra Nevada bighorn sheep away from other species of domestic sheep or goats. 

In short, this recovery plan calls for development of a captive breeding contingency plan and separate implementation plans for: monitoring; translocation; predator management; genetic and disease management. For the best case scenario, the hope of the Sierra Nevada bighorn sheep is for

them to be downlisted by 2017, and eventually delisted ten years later in 2027.

So what can we do to help? Well, there isn't much that the average person can do because of the highly specialized range of their habitat. The personal actions that can be taken to contribute to the Sierra Nevada bighorn sheep recovery plan are mostly monetary in the forms of donations to organizations such as the Sierra Nevada Bighorn Sheep Foundation. They also need to be left alone so anything you can do to limit human contact ad interaction in their habitat is important to keep the recovery plan working as well as it has been over the last fifteen years. 

The (Last but Not) Least Bell's Vireo

By: Joelle Saute

Photo by Brian E. Small

Have You Seen This Bird?

If this bird looks at all familiar, chances are you have probably seen it. The Least Bell's Vireo is a migratory songbird that resides in California and Baja California. It is a subspecies of the Bell's Vireo.

Although they might not have many distinctively attractive aspects, this little bird is still recognizable. The head is ashy grey with pure white under wing coverts. The breast can be slightly brown or white with a hint of yellow on the sides of the body under the wings.  

If you have spotted this insectivore, it was most likely while you were in a riparian habitat. This is the only habitat in which they breed. Riparian habitats are located along bodies of water, especially where the soil is damp and sandy. There are many niches within a riparian ecosystem, but these birds tend to stay in the lower canopies, especially in willows. They also need dense shrubs in order to protect their nests. 

Interestingly enough, this type of ecosystem actually supports more bird species than any other type of habitat in California. Sadly, only about 10% of these areas that were present in the 1850's remain in California. 

Riparian Habitat
Photo from Sharing the Horizons 

What is the Least Bell's Vireo Like?

For such a small bird, they can really travel. The distance from their wintering to breeding ground is about 2,000 miles. They reach the breeding ground in Southern California around mid-March.

They can also live up to 7 years. Unfortunately, a large percentage of the young die before they become 1. 

Since they are indeed songbirds, this is the main way in which males establish their .5-.75 acre territory. Each male has anywhere from 5 to 15 unique songs.

Check out what their song sounds like!

 The females are in charge of choosing the nesting site. Once one is chosen they build their nest out of spider webs, bark, and various other materials. The nest is shaped like an open cup.

Nest with a Vireo inside.
Photo from Arkive

They lay the eggs in the nest a few days after completion of construction. The 3-4 eggs incubate for 14 days. The parents will care for the hatchlings for about 2 weeks after they have fledged. Each breeding pair will fledge as many as 5 nests per breeding season. This season ends around September.

                                            What's Changed?

Present and Historical range
 of the Least Bell's Vireo
Map from US Fish and Wildlife
 Recovery Plan

The Least Bell's Vireo has been found in less and less areas throughout the state. The largest population that still remains can be found in San Diego County. This is a large shift from its historical range along most of the southern coast and all throughout central California. The vireo does still winter in Baja California, but the range they occupy is significantly smaller.

Their populations began to noticeably decline after 1940. By 1986 there were only about 300 pairs found in California. 

They're In Luck!

After being federally listed as endangered in the Endangered Species Act (ESA) on May 2, 1986, a recovery plan was formulated. The plan was published on May 6, 1998, but action was taken to protect critical habitats in 1994 . This plan proved to be a success because by 1996 there were 1,346 pairs of Least Bell's Vireos in California. They have even expanded their regions in some areas they had left. In order for these birds to be delisted, they need to have stable populations of several hundred breeding pairs in the Salinas River, San Joaquin Valley, and Sacramento Valley for at least 5 years. Conversely, the IUCN Red List only has them listed as Near  Threatened. 

Why Were They Listed?

Brown-headed Cowbird
Photo from Audubon

As with a vast majority of species on the ESA list, the main cause of the Least Bell's Vireo population decline was a result of habitat destruction. Riparian habitats were removed to provide land for agriculture, livestock grazing, commercial development, and many other human centered purposes. Sadly, this was not the only reason for their decline. In fact, another bird, the Brown-headed Cowbird, caused catastrophic destruction for the Least Bell's Vireo. Cowbirds are known as brood parasites. These birds lay their eggs in the nests of other birds and have the adults of those nests raise their young. The cowbird eggs hatch before the Least Bell's Vireo eggs and thus gain a majority of the food from the adults, leaving the other hatchlings to starve and die.  Cowbirds have even been expanding their ranges, increasing their harm towards the endangered species. To add to the intensity of the issue, the Least Bell's Vireos are also currently living in smaller populations so this increases their risk of extirpation. 

Example of Brood Parasitism from the
 Brown- headed Cowbird (2 large brown spotted eggs) in a Least Bell's Vireo nest.
Photo from Arkive

What's Being Done?
The main course of action currently being done is in regards to the riparian ecosystem. Since this is one of the most critically endangered ecosystems in the US, efforts are being placed to conserve what remains as well as improve the conditions.

Riparian Habitat Restoration
Photo from Enviornmental
 Collaborative

There are also efforts in regards to removing cowbirds from the vicinity of Least Bell's Vireo habitats. Some of the less intense measures being taken include developing management plans for the remaining populations of the vireos, controlling non-native plant species that pose some type of risk to the nesting areas, reintroducing vireos to locations they used to occupy, and emphasizing public education of the issue at hand. The full recovery plan provides more details on these specific efforts. 

And You Can Help!
By donating to either the Audubon Society or the Center for Biological Diversity you can aid in the efforts to preserve this delicate bird. 

And if money is not an option, you can always choose to educate others on the issue. 
As the Audubon Society says, 
"Spread the word. It's the least you can do."

*This species still has a long way to go!*

For Additional Information please visit these helpful sites:
California Partners in Flight Riparian Bird Conservation Plan
Interesting Article about their breeding in the Central Valley
Want to get involved with bird watching?


References

"Bell's Vireo." , Life History, All About Birds. N.p., n.d. Web. 16 Nov. 2015.

Least Bell's Vireo. Center For Biological Diversity, n.d. Web. 16 Nov. 2015.

Patten, Michael A. "Least Bell's Vireo." US Bureau of Land Management (n.d.): n. pag. Print.

"Species Profile for Least Bell's Vireo (Vireo Bellii Pusillus)." Species Profile for Least Bell's Vireo (Vireo Bellii Pusillus). N.p., n.d. Web. 16 Nov. 2015.