Choctawhatchee Beach Mouse

Peromyscus polionotus allophrys

5 Characteristics of Living Things1. Metabolic Processes

Nutrient Uptake: Uses energy from the intake or eating of seeds and fruits of dune plants such as sea oats, bluestem, dune spurge, evening primrose, oaks, magnolias, and youpon hollies. Also eats invertebrates such as beetles when seeds are scarce, especially in the late winter or early spring.

Nutrient Processing: Uses the nutrients from the food sources through chemical reactions to produce energy necessary to for movement, growth and to carry out other activities

Waste elimination: Useless nutrient portions from the food sources are expelled from the mouse as waste in the form of urine and defecation.

5 Characteristics of Living Things2. Generative Processes

Growth: Increases in size from birth to adultReproduction: Beach mice are monogamous,

meaning mated pairs stay together as long as they both live. Reaches sexual maturity by 6 weeks of age. Reproduction peak time is during November, December and January. The mice have between 2-7 offspring per littering averaging 3-4 babies and usually have about 3 litters a year. The average female is capable of producing a litter every 26 days and usually produces 80 or more young over her lifetime.

5 Characteristics of Living Things3. Responsive Processes

Irritability: Has a rapid response to stimuli such as loud noises, predators, or threats and retreats into burrows

Individual adaptation: Lighter-colored or pale fur to blend in with the habitat of sand dunes

Population adaptation: Nocturnal to avoid predators during the day, digs underground burrows for protection, pale fur to camouflage

5 Characteristics of Living Things4. Control Processes

Coordination: Chemical reactions within the beach mouse are coordinated and linked together in a specific pathway. Maintains an internal homeostasis. Internal activities occur at the right time.

Regulation: Enzymes are produced in the beach mouse to increase and control the rate at which life’s chemical reactions occur. Maintains an internal homeostasis. Internal activities occur at the proper rate

5 Characteristics of Living Things5. Structural Similarities

Beach mice are composed of eukaryotic cells with an outer cell membrane and internal organelles with specific functions.

They consist of trillions of specialized cells that form an independently functioning organism.

It has cells that make up tissues, which make up organs, which make up organ systems within the beach mouse

Specialized Cells or StructuresThe Choctawhatchee Beach mouse has a

genetic mutation that produces a sand matching coat to help the it camouflage from sky predators.

The single mutation that causes this color variation alters the melanocortin-1 receptor (Mc1r) that has been associated with the different colors of many mammals.

Specialized CellsThis only appears in mice on the coast, not in

mainland mice. The specialized cells make it easy for the

beach mouse to blend in with the sugary white sand and evade predators.

Specialized Cells in Action:Can you find the Beach Mouse?

Inherited Genetic TraitsAllele for lighter coat color pattern (Mc1r)

present in beach miceControlled by single amino acid mutation in

the melanocortin-1 receptor geneBeach mice are have much lighter fur when

compared to mainland mice.

Unusual Genetic IssuesLighter coat color mutation leads to loss of

genetic information

Here you can see a Peromyscus DAPI-stained hair follicle with melanocytes stained in green. (Photo credit: Marie Manceau, Harvard)

Genetic Diseases

Diseases pose no known threat to the beach mouse populations at this time.

Genetic conditions that prevent the beach mouse from thriving

If moved to different environment besides the beach, lighter fur color would not be an advantage

This mutation is considered a loss of ability to adapt to other environments

Forming of hybrids by interbreeding with other organisms

Interbreeding with mainland Oldfield mice could produce a single species whose traits are a blend of the optimal adaptations for the range of habitats that both occupy.

Many subspecies of the beach mouse exist and interbreeding makes it hard to identify the genetic differences of the subspecies (intra-specific crossbreeding)

Interbreeding with other subspecies makes it hard to know what species is being protected

Ecosystem/BiomeRestricted to coastal sand dune ecosystemOpen sandy areasDunes just above the high-tide lineChoctawhatchee Beach mice live on Florida

Gulf Coast

Habitat Range

Niche

Eats mainly seeds and fruits of plants that grow in the dunes

Diet can include invertebrates such as beetles, especially in the spring and summer

Prey to foxes, herons, owls, and snakesFeral cats also feed on the beach mouse

Food Web DistinctionClassified as consumer (eats other living

things to get energy)Specifically an omnivore (feeds on both

plants and animals

Adaptations Over TimeNocturnalDigs underground burrows for protectionPale coloration of fur has developedLight coat color is said to be a product of

natural selection: easier to camouflage with the light sand

Environmental FactorsFeral cats living in or around the beach

mouse habitat contribute to decline of speciesHurricane Opal drowned many beach mice

and severely degraded or destroyed much of the dune habitat in October of 1995

Estimated 75-80% of Choctawhatchee beach mice were killed from Opal

Human Impact on Ecosystem(Deliberate)

Coastal real estate boom in Florida takes away suitable dune habitats

80% of the range of beach mice has been lost to development since 1940

Human Impact on Ecosystem(Inadvertent)

Intensive recreational use destroyed habitats as well

Erosion and loss of plants that help to stabilize the dunes due to vehicle and human traffic

Survival depends on the conservation of preserving the dunes ecosystem

Laws and Protections to Help with Chance at Survival and Recovery

Coastal Zone Development PlanIncludes dune preservation to benefit the landowners and the

miceFlorida Coastal Setback Law: prohibited

construction within set limits to protect Florida’s coastline has helped slightly

Translocation program launched in 1987 by the Florida Game and Freshwater Fish Commission (now called the Florida Fish and Wildlife Conservation Commission)This involved the adding of beach mice to small, existing

populations from larger groupings in hopes of increasing the numbers

What can you do?If you live in a beach community: Keep your cat

indoorsDo not feed stray cats as this will encourage

permanent residency in beach mouse habitatStay off of the dunes to help preserve the habitatRemain in designated visitor areas or on walkwaysEncourage the growth of native plants on the

dunes and dune regenerationEducate others on the fascinating Choctawhatchee

Beach mouse

Beach Mouse Tracks: Still here FOR NOW…

Awareness is the first step towards SURVIVAL for this unique and tiny

species!

References A Single Amino Acid Mutation Contributes to Adaptive Beach Mouse Color Pattern. (2006, July

7). Retrieved March 14, 2011, from http://notes.genotypic.com/index.php?option=com_content&task=view&id=473&Itemid=57

An Evolution Saga: Beach Mice Mutate and Survive. (2006, July 7). Howard Hughes Medical Institute. Retrieved March 7, 2011, from http://www.hhmi.org/news/hoekstra20060707.html

Bird, B., Branch, L., & Hostetler, M. (2009, November). Beach Mice. Electronic Data Information Source of University of Florida, Institute of Food and Agricultural Sciences. Retrieved March 7, 2011, from http://edis.ifas.ufl.edu/uw173

Choctawhatchee beach mouse. (2000). Beach to Bay Connection. Retrieved March 7, 2011, from http://beachtobay.org/html/choctawhatchee_beach_mouse.htm

Choctawhatchee beach mouse. (2004, August 9). Beachmouse.com. Retrieved March 7, 2011, from http://www.beachmouse.com

Evolutionary and Ecological Genetics of Adaptation and Speciation. The Hoekstra Laboratory at Harvard. Retrieved March 14, 2011, from http://www.oeb.harvard.edu/faculty/hoekstra/Links/ProjectsPage.html#Behavior

Gibbons, W. (2002, October 28). Do We Know How Many Kinds of Animals There Are? University of Georgia. Retrieved March 14, 2011, from http://www.uga.edu/srel/ecoviews/ecoview021028.htm

Purdom, G. (2006, August 23). Mutation leads to better survival in beach mice. Answers in Genesis. Retrieved March 14, 2011, from http://www.answersingenesis.org/articles/aid/v1/n1/evolution-or-adaptation