|Scientific Name:||Podomys floridanus|
|Species Authority:||(Chapman, 1889)|
|Red List Category & Criteria:||Vulnerable A2ac+3c ver 3.1|
|Assessor(s):||Pergams, O. & NatureServe (Hammerson, G. & Jackson, D.R.)|
|Reviewer(s):||Amori, G. (Small Nonvolant Mammal Red List Authority) & Chanson, J. (Global Mammal Assessment Team)|
Listed as Vulnerable because of a population decline of at least 30% over the last ten years. It still occupies much of its former range, but is much reduced in numbers and area of occupancy. Much of its habitat has been lost due to development, agriculture, and fire suppression. Declines in gopher tortoise populations also affect habitat quality for this species, and further decline in its habitat is expected.
|Range Description:||This species' range extends from St Johns, Clay, Alachua, Suwannee, and Taylor counties south to Sarasota County on the west coast (but not documented in Sarasota County in recent years), Highlands County in central Florida in the United States, and, at least formerly, Dade County on the east coast (now south to near Boynton Beach); an apparently isolated population also exists along the Gulf Coast in Franklin County, where its current status was unknown in the early 1990s (Layne 1978, 1992). The species was recorded near Clearwater in 1984, but it probably no longer occurs on the Pinellas peninsula (Layne 1992). It also has been recorded on Merritt Island on the Atlantic coast in Brevard County (see Jones and Layne 1993). Apparently the species is most continuously distributed in north-central peninsular Florida; mainly it is confined to the Lake Wales Ridge in the south-central region and to a narrow strip along the east coast (Layne 1978).|
Native:United States (Florida)
|Range Map:||Click here to open the map viewer and explore range.|
The population size is unknown but is presumably at least several thousand. This species is known from several dozen collection sites (see dot map in Jones and Layne 1993), but populations currently are not extant at all of these locations. Undoubtedly the species is continuing to decline due to habitat loss (Layne 1992). Area of occupancy, number of subpopulations, and population size have declined; populations have been extirpated or greatly reduced in much of its former range (Layne 1978). The species has disappeared from the Miami area and the Pinellas peninsula.
Mean density in scrub and sandhill habitats was about 5-10/ha (up to 28/ha) (Layne 1992). Populations generally are highest in winter-early spring and lowest summer-early winter (Layne 1992)
|Habitat and Ecology:||
This mouse is restricted to fire-maintained, xeric, upland vegetation occurring on deep, well-drained sandy soils, including sand pine scrub, coastal scrub, scrubby flatwoods, longleaf pine-turkey oak (sandhill), south Florida slash pine-turkey oak (southern ridge sandhill), upland hammock, live oak (xeric) hammock, and drier pine flatwoods (Layne 1992). Transients sometimes are found in other habitats. The major habitats are the scrub and sandhill associations, with scrub being the primary habitat. Populations tend to be larger in sand pine scrub than they are in longleaf pine-turkey oak habitats (Layne 1978), apparently due to the greater acorn production in the former (Layne 1992). Populations decline as habitat becomes less openly vegetated, shadier, and more mesic. Habitats that support good populations of the Florida scrub jay indicate high quality Podomys habitat (Layne 1992). Podomys is generally a ground dweller. When inactive, it occupies underground burrows, often made within those of gopher tortoises. In south-central Florida, burrows were exclusively within gopher tortoise burrows (both active and inactive); within a period of 2-19 days, individuals used up to several different locations within a single burrow and used 1-3 different tortoise burrows (Layne and Jackson 1994). Young are born in nests in underground burrows.
Probably breeds throughout the year; reported as breeding June-March in Alachua County, Florida. Breeds mainly in fall and early winter (Layne 1992). Gestation lasts about 3-4 weeks (longer when lactating). Litter size averages around 2-3. Females probably seldom produce more than two litters each breeding season (Layne 1992). Young are weaned at 3-4 weeks. In the wild, only a small percentage of the population lives longer than one year, though longevity of several years is not uncommon in captives.
Home range averages about one acre or less. Mean distances between successive captures of adults in different habitats were 16 m, 25 m, and 40-50 m; home range size evidently is larger in less favourable habitats (see Layne 1992). In optimal conditions, 36 mice have been captured per 100 trap-nights (see Layne  for further data from various habitats).
This species is omnivorous, diet includes seeds, nuts, fungi, insects, and other invertebrates; acorns are an important food source. Predation by various snakes, owls, and Carnivora probably is the major mortality factor (Layne 1992).
Podomys floridanus is moderately dependant on gopher tortoise (Gopherus polyphemus) burrows, and gopher tortoises in Florida are well documented to be in decline, as much as 80% by some estimates due to habitat destruction as well as Upper Respiratory Tract Disease (URTD). Gopher tortoises are listed as Vulnerable on the IUCN Red list and Federally considered Threatened. The resultant decline in new gopher tortoise burrow construction is cause for some concern in relation to Podomys floridanus conservation status. Red imported fire ants (Solenopsis invicta) are a potential predatory threat to gopher tortoises and might be a direct threat to Podomys as well (Wetterer and Moore 2005).
Much of the species' habitat has been lost to real estate development, citrus groves, pine plantations, and vegetation changes resulting from fire suppression (Layne 1992). For example, data compiled for Highlands County by Peroni (1983) indicate that during the period from 1940-44 to 1981, approximately 64 percent of the xeric upland habitat suitable for Podomys was destroyed, and an additional 10 percent was disturbed. Since 1981, the rate of clearing of the remaining scrub and sandhill habitats for development and citrus has escalated sharply. In the northern portion of the range, many former sandhill and scrub sites have been converted to pine plantations. In addition, suppression of fire and the resultant successional changes have resulted in further reduction or elimination of Podomys populations in many remaining sandhill and scrub habitats. [Source: Northeast Florida Regional council; http://www.nefrpc.org/pdfs/srpp/appendixa.pdf]
Protected occurrences include Archbold Biological Station, Merritt Island NWR, Katharine Ordway Preserve, Lyonia Preserve, Ocala National Forest, Highlands Hammock SP, Jonathan Dickinson SP, San Felasco Hammock SP, Tiger Creek Preserve, Withlacoochee SF, and Camp Blanding Training Site. See also Layne (1992) for a listing of preserves and managed areas inhabited by this mouse.
The current distribution, abundance, and population trends of this species need to be determined. Preservation and management of large tracts of suitable habitat are particularly needed. Maintenance of viable populations of gopher tortoises would benefit the mouse.
|Citation:||Pergams, O. & NatureServe (Hammerson, G. & Jackson, D.R.) 2008. Podomys floridanus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 28 January 2015.|