Podomys floridanusFlorida mouse

Geographic Range

Florida mice (Podomys floridanus) are native to Florida in the Nearctic region. They are found in areas of Lake Wales Ridge region and the Atlantic Coastal Ridge in counties such as St. Johns, Putnam, Alachua, Suwannee, and Taylor. There are two disjunct populations: one in south-central Florida in Franklin County and the other in Merritt Island on the Atlantic coast in Brevard County. (Depue, 2001; Jones, 1995; Jones and Layne, 1993; Packer and Layne, 1991)

Habitat

Florida mice are most common in sand pine (Pinus clausa) scrub and high pinelands, which are sandhills dominated with longleaf pine (Pinus palustris) and turkey oak (Quercus laevis). They also inhabit slash pine (Pinus ellioittii), scrubby flatwoods, and coastal scrub associations.

Florida mice are exclusively burrow dwellers, although they do not dig these burrows themselves. They have been found in gopher tortoise (Gopherus polyphemus), nine-banded armadillo (Dasypus novemcinctus), oldfield mouse (Peromyscus polionotus), hispid cotton rat (Sigmondon hispidus), and pocket gopher (Geomys bursarius) burrows. The length of the burrows in sand pine scrub and high pinelands can range from 3.72 to 6.1 meters.

In the Ordway Preserve in Florida, these mice inhabit high pine sandhills that have high burn frequencies during the summer months. Due to these high burn rates, Florida mice retreat towards vegetation surrounding wetlands. Published elevations for these habitats are between 30-60 meters, but upper and lower limits are unreported for Florida mice.

Florida mice are primarily a terrestrial species. Although they are capable of climbing, they more often forage in areas that do not necessitate climbing.

In building their nests, Florida mice use oak leaves, specifically sand live oaks (Quercus geminate), Darlington oak (Quercus hemisphaerica), and wiregrass (Aristida stricta). Florida mice use fewer nesting materials compared to other mice such as cotton mice (Peromyscus gossypinus) and oldfield mice. Also, Florida mice have smaller and flatter nests compared to cotton mice and old-field mice. ("Environmental report", 2013; Jones, 1995; Jones and Franz, 1990; Jones and Layne, 1993; Layne, 1992; Layne and Jackson, 1994; Lukanik, 2007; Packer and Layne, 1991; Schmalzer, et al., 1999; Silva-Lugo, 2014; Stark, 2009)

  • Average elevation
    30-60 m
    ft

Physical Description

Florida mice can range in total length from 178mm to 197mm. Their tail length (79-90mm) makes up half of their body length. In both sexes, ear measurements are between 16mm and 21.5mm, their hind foot is 23-27mm, and have they have five toe pads on their feet. They have molars with deep crowns with short roots, some which have a small elevation on the crown of the tooth. Their dental formula is 1003/1003, and they have a total of 16 teeth. Their metabolic rate is 1.51 to 1.85cm^3 oxygen/hour. Across both males and females, mass can range from 25-49g.

As adults, Florida mice have a brown or tan color coat with a brighter brown on the sides of their face, shoulders, and lower sides. Their tails are white on their ventral side and brown on their dorsal side. Sexes can look alike externally, although males have an enlarged sex gland (ampullary gland), and a prostate gland which can be palpated.

Juveniles are hairless other than their whiskers and very little hairs on their abdomen. Florida mice are born with their ears folded and their eyes closed. According to Layne (1966), their ears start unfolding at around three days. At one week they start to gain dark grey fur on their dorsal side and pinkish-white abdomen. Their juvenile coloring starts to show at 14 days and consists of a dark grey goat and grey or white abdomen. The post-juvenile molt in Florida mice begins between 36 to 42 days after birth. The length and weight of juveniles has not been reported. (Jones and Layne, 1993; Layne, 1966; Layne, 1992; Lukanik, 2007)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    25 to 49 g
    0.88 to 1.73 oz
  • Range length
    178 to 197 mm
    7.01 to 7.76 in
  • Range basal metabolic rate
    1.51 to 1.85 cm3.O2/g/hr

Reproduction

Florida mice are polygynandrous. Mating information is extremely limited. They copulate by only one intromission thrust and ejaculate on a single insertion. However, finding of mates and mating rituals are unreported.

Their nests are made in gopher tortoise (Gopherus polyphemus) burrows with dried oak leaves (Quercus), pine needles (Pinus), grass stems, inner fibers of Spanish moss (Tillandisia usneoides), and small feathers. Their nests were located 1.2-5.5 m from the entrance of the burrow. The shape of the nests are flat or open cups. (Jones and Franz, 1990; Jones and Layne, 1993; Layne, 1992; Layne and Jackson, 1994; Punzo, 2003a; Punzo, 2003b; Silva-Lugo, 2014)

Although Florida mice can breed throughout the year, most breeding efforts are concentrated from late fall to winter. They usually breed twice a year. Florida mice are viviparous and iteroparous. The number of offspring in the wild ranges from 1 to 5, and averages of 3.1 and 3.4 have been reported. The most common range of offspring per litter in a laboratory is 1-3. The gestation period for Florida mice is 30-34 days. Rood (1966) found that female Florida mice had a specific time they are most likely reproduce and the months with the highest producing litters was February (where out of 12 females, 35% mated), and in August and September (out of 16 in each, 20% mated.)

Their weight at birth is unreported but other closely-related mice in the genus Peromyscus weigh one to two grams at birth. The young are nursed almost continually for the first two weeks and weaned between 3 and 4 weeks old. The post-juvenile molt begins between 36 and 42 days and is associated with reaching sexual maturity. (Jones and Layne, 1993; Layne, 1992; Rood, 1966)

  • Breeding interval
    Florida mice breed twice a year.
  • Breeding season
    July to early October but can be year-round.
  • Range number of offspring
    1 to 5
  • Average number of offspring
    2.5
    AnAge
  • Range gestation period
    30 to 34 days
  • Range weaning age
    3 to 4 weeks
  • Range time to independence
    3 to 4 weeks
  • Range age at sexual or reproductive maturity (female)
    36 to 42 days
  • Range age at sexual or reproductive maturity (male)
    36 to 42 days

Florida mice are altricial. Maternal care includes creating nests, nursing the young, plugging entrances to nest boxes, cleaning the young, and herding them into the nests. After the mothers finish nursing them, there is no information on how the juveniles acquire their food. There appears to be a bond between nursing and the adult activity cycles suggesting that long term bonds form between mothers and semi-independent offspring. Males provide no parental investment beyond the act of mating. (Jones and Layne, 1993; Punzo, 2003a; Punzo, 2003b; Rood, 1966)

  • Parental Investment
  • altricial
  • female parental care
  • pre-hatching/birth
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

The longest lifespan of a Florida mouse in captivity was 7.4 years. Florida mice in the wild have a mean survival time of 4.2 months as adults, 3.6 months for subadults, and 2.4 months for juveniles. Predation is the major mortality factor. (Austin and Roach, 2019; Jones and Layne, 1993; Nowak, 1999)

  • Range lifespan
    Status: captivity
    7.4 (high) years
  • Average lifespan
    Status: wild
    4.2 months
  • Average lifespan
    Status: captivity
    7.4 years
    AnAge

Behavior

Florida mice are motile but non-migratory. They also do not hibernate, as their southern range affords them suitable temperature year-round. They are nocturnal, concentrating their foraging at night. Florida mice are polygamous, and no pair bonds remain after the act of mating. Female Florida mice care for the juveniles up until after the post-juvenile molt. They are exclusively burrow-dwellers. They make use of the gopher tortoise (Gopherus polyphemus) burrows because the mice are poor nest-builders.

Until females give birth to young, they are solitary. Pups do not leave the nest until after they reach sexual maturity. The only time they move home ranges is when they emigrate from their mother’s burrow to find their own home territory. (Jones and Franz, 1990; Jones and Layne, 1993; Punzo, 2003a; Punzo, 2003b; Rood, 1966)

Home Range

Jones (1990) reports that female Florida mice have a home range of 2601 meters^2, while males have a home range of 4042 meters^2. There is no information on if Florida mice defend a territory. (Jones, 1990; Jones, 1995; Jones and Franz, 1990; Jones and Layne, 1993)

Communication and Perception

Florida mice are nocturnal, and their relatively large eyes assist with vision, taking in more light.

Mothers use touch to take care of their young by cleaning them, nursing them, and moving them if they are in danger. Adult Florida mice use touch for mating and they use their vision to see their mate and gain their mate’s attention along with acoustic signals. They use chemical perception channels to choose which food is safe for them to eat. Although not efficient diggers, they use their paws to dig tunnels in the existing burrows of gopher tortoises (Gopherus polyphemus), nine-banded armadillos (Dasypus novemcinctus), oldfield mice (Peromyscus polionotus), hispid cotton rats (Sigmodon hispidus), and pocket gophers (Geomys bursarius).

They have relatively large ears so they can process sounds. They also can vocalize with their larynx. Little is known regarding pheromones of Florida mice; however, both sexes of California deermice (Peromyscus californicus) and white-footed mice (Peromyscus leucopus) use urine to scent- mark. The function of scent markings is for mating and co-housing. (Becker, et al., 2018; Dodd Jr. and William, 2007; Jones and Layne, 1993; Layne and Jackson, 1994; Punzo, 2003a)

Food Habits

Layne (1970) reported the main food source for Florida mice include mostly oak (Quercus) acorns in years where they were abundant. They also eat other seeds, fungi, and plant materials. While this species is primarily granivorous, they also consume insects like crickets (superfamily Grylloidea) and beetles (order Coleoptera). Milstrey (1987) stated that Florida mice consume soft body ticks (Ornithodorosturicata americananus) which can be found on the animals that dig their burrows. (Jones and Franz, 1990; Layne, 1970; Layne, 1992; Milstrey, 1987; Packer and Layne, 1991; Punzo, 2003b)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • seeds, grains, and nuts
  • Other Foods
  • fungus

Predation

Florida mice are often preyed upon by snakes like coachwhips (Drymarchon masticophis), raptors (order Falconiformes), red foxes (Vulpes vulpes), gray foxes (Urocyon cinereoargenteus), raccoons (Procyon lotor), domestic and feral cats (Felis catus), and bobcats (Felis rufus). Further, 56% of litter loss in Florida mice is due to cannibalism.

Florida mice avoid predation by being camouflaged, being brown on their dorsal side and white on their ventral side. When these mice are threatened, they will often create chimneys in their burrows (lined with oak leaves [Quercus] and wire grass [Aristida stricta]) so they can escape to these burrows. Another way Florida mice can evade a predator, is by dropping the skin off of their tail to escape. (Dodd Jr. and William, 2007; Jones and Franz, 1990; Jones and Layne, 1993; Layne, 1992; Silva-Lugo, 2014)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Florida mice eat acorns, seeds, insects, nuts, and fungi. They are often preyed upon by snakes, raccoons (Procyon lotor), bobcats (Lynx rufus), raptors, and foxes.

They also are hosts to many parasites including nematodes (Capillaria hepatica, Aspiculuris americana, Syphacia peromysk, Pterygodermatites peromiski), fleas (Polygenis floridanus), and cestodes (Raillietina bakeri). (Austin and Roach, 2019; Jones and Layne, 1993; Kinsella, 2011; Layne, 1992)

Commensal/Parasitic Species
  • flea (Polygenis floridanus)
  • nematode (Capillaria hepatica)
  • nematode (Aspiculuris americana)
  • nematode (Syphacia peromyski)
  • nematode (Pterygodermatites peromiski)
  • cestode (Raillietina bakeri)

Economic Importance for Humans: Positive

Florida mice have no positive economic impacts on humans.

Economic Importance for Humans: Negative

There are no negative economic impacts of Florida mice on humans.

Conservation Status

Florida mice are listed as "Near Threatened" on the IUCN Red List. Florida mice have no special status on the State of Michigan List, the US Federal List, and CITES.

Habitat fragmentation and destruction by humans are threats to Florida mice. Population sizes have decreased significantly from collection sites in Florida that were formerly documented with Florida mice activity. This species is declining due to habitat loss and has vanished from the Pinellas peninsula and Miami area. They have lost their habitat to real estate development and agricultural use in the xeric uplands. Areas of sandhill vegetation have been converted to citrus groves leaving only small areas of suitable land for Florida mice. Between the years of 1940-1944 to 1981 approximately 64% of xeric upland habitat was destroyed. Also, the results of fires have reduced the habitat of Florida mice. Red invasive fire ants (Solenopsis invicta) and domestic cats (Felis catus) are also threats towards Florida mice. Climate change is also another threat towards Florida mice, but identification of appropriate strategies is not yet documented.

Conservation efforts in Florida that have affected Florida mice include conservation actions for gopher tortoises (Gopherus polyphemus), Florida scrub-jays (Aphelpcoma coerulescens), and red-cockaded woodpeckers (Picoides borealis). Many conservation efforts and management efforts, such as increasing the quality of habitats and maintaining a viable tortoise population, have also benefitted Florida mice habitats. Florida mice are identified as a focal species in Florida Fish and Wildlife Conservation, Prioritization, and Recovery program, with the goal of improving habitat quality of the Florida mice. Also, the Development of Regional Impact reviews by Regional Planning Councils and the Florida Game and Fresh Water Fish Commission proposed that suitable areas for Florida mice be preserved on public and private land. (Austin and Roach, 2019; Jones, 1990; Jones, 1995; Jones and Layne, 1993; Layne, 1992; Lukanik, 2007)

Contributors

Tessa Harmon (author), Radford University, Sierra Felty (editor), Radford University, Bianca Plowman (editor), Radford University, Karen Powers (editor), Radford University, Victoria Raulerson (editor), Radford University, Christopher Wozniak (editor), Radford University, Genevieve Barnett (editor), Colorado State University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Florida Department of Transportation. Environmental report. 411011-3-52-01. Hernando Country, Florida: Florida Department of Transportation. 2013. Accessed February 11, 2022 at http://www18.swfwmd.state.fl.us.

Austin, J., N. Roach. 2019. "Podomys floridanus" (On-line). The IUCN Red List of Threatened Species 2019: e.T17830A22339074. Accessed April 08, 2022 at https://dx.doi.org/10.2305/IUCN.UK.2019- 1.RLTS.T17830A22339074.en.

Becker, E., F. Castelli, C. Yohn, L. Spencer, C. Marler. 2018. Species differences in urine scent-marking and counter-marking in Peromyscus. Behavioral Processes, 146: 1-9. Accessed April 05, 2022 at https://doi.org/10.1016/j.beproc.2017.10.011.

Depue, J. 2001. Responses of the Florida Mouse (Podomys floridanus) to Habitat Management (Master's Thesis). Orlando, Florida: University of Central Florida, Orlando.

Dodd Jr., K., B. William. 2007. Movements of large snakes (Drymarchon masticophis) in north-central Florida. Florida Scientist, 70/1: 83-94.

Jones, C. 1990. Microhabitat Use by Podomys floridanus in the High Pine Lands of Putnam County, Florida (Ph.D. Dissertation). Gainesville, Florida: University of Florida, Gainesville.

Jones, C. 1995. Habitat use and home ranges of Podomys floridanus on the Ordway Preserve. Bulletin Florida Natural History, 38/27: 195-209.

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Jones, C., R. Franz. 1990. Use of gopher tortoise burrows by Florida mice (Podomys floridanus) in Putnam County, Florida. Florida Field Naturalist, 18/3: 45-68.

Jones, C., J. Layne. 1993. Podomys floridanus. Mammalian Species, 427: 1-5.

Kinsella, J. 2011. Comparison of helminths of three species of mice, Podomys floridanus, Peromyscus gossypinus, and Peromyscus polionotus, from southern Florida. Canadian Journal of Zoology, 69/12: 3078-3083.

Layne, J. 1992. Rare and Endangered Biota of Florida. Gainesville, Florida: University of Florida Press.

Layne, J. 1966. Postnatal development and growth of Peromyscus floridanus. Growth, 30/1: 23-45.

Layne, J. 1970. Climbing behavior of Peromyscus flouridanus and Peromyscus gossypinus. Journal of Mammalogy, 51/3: 580-591.

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NatureServe, 2022. "Podomys floridanus" (On-line). NatureServe. Accessed March 01, 2022 at https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.102175/Podomys_floridanus.

Nowak, R. 1999. Walker's Mammals of the World. Baltimore, Maryland: Johns Hopkins University Press.

Packer, W., J. Layne. 1991. Forging site preferences and relative arboreality of small rodents in Florida. The American Midland Naturalist, 125/2: 187-194.

Punzo, F. 2003. Behavioral interactions between the shrew Blarina carolinensis and four species of Florida mice in the presence and absence of mouse nestlings. Florida Scientist, 66/1: 63-67.

Punzo, F. 2003. Effects of dietary restriction and aging on the concentration of monoamines in the cerebral cortex of the Florida mouse, Podomys floridanus. Florida Scientist, 66/1: 1-7.

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Silva-Lugo, J. 2014. Small mammal use of refugia, population recovery, and survival following prescribed burning in scrubby flatwoods ecosystem, Florida, USA. International Journal of Ecosystems, 4/3: 135-149.

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Warren, M., R. Clein, M. Spurrier, E. Roth, J. Neunuebel. 2020. Ultrashort-range, high-frequency communication by female mice shapes social interactions. Scientific Reports, 10: 2637. Accessed January 25, 2022 at https://doi.org/10.1038/s41598-020-59418-0.