endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (250-20,000 square km (about 100-8000 square miles)) Throughout much of peninsular Florida east of the Suwannee River and north of Tampa Bay and Lake Okeechobee (Layne 1978); west to Gilchrist and Levy counties (Kantola 1992); north to the piedmont of Georgia (Turner and Laerm, pers. comm., cited by Kantola 1992).
Length: 66 cm
Weight: 1000 grams
Differs from subspecies AVICENNA in being larger (head plus body averages 315 mm vs. 278 mm in AVICENNA; hind foot averages 85 mm vs. 75 mm in AVICENNA) (Humphrey and Jodice 1992). Differs from subspecies NIGER in lacking a white or whitish belly.
Comments: Longleaf pine sandhills and flatwoods; best habitat contains both pines and oaks, such as along the edge of longleaf pine savanna and live oak forest (Kantola and Humphrey 1990), especially where there are large, mature trees and fires occur at intermediate frequency (enough to prevent extensive hardwood invasion at the expense of the pines). Nesting and feeding may occur in different habitats. Occurs in reduced numbers (compared to optimal habitat) in turkey oak forest and in some ecotonal situations (e.g., where bayhead meets slash pine flatwoods and on the margins of flatwoods cypress ponds) (Layne 1978). Population viability and reproductive potential in secondary habitats are poorly known.
For rearing of young and refuge, uses mostly leaf nests rather than cavities, up to 30 nests used per year; most nests are on low slopes of sandhills (Kantola 1992), in oak, pine, sweet bay, loblolly bay, etc.; often builds leaf nests in large oaks, using Spanish moss for insulation (Kantola 1992). Readily uses large tree cavities if they are available. In the past, use of gopher tortoise burrows for cover was observed when squirrels were pursued.
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Comments: Diet varies seasonally with food availability, often includes primarily pine seeds in late summer and acorns at other times (Layne 1978). Live oak acorns may be important when turkey oak acorn crop fails (Kantola and Humphrey 1990). Other foods include various nuts, fruits, hypogeous and epigeous fungi, bulbs, buds, insects, and staminate pine cones (Kantola 1992). Caches some acorns for later use.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 6 - 80
Comments: Survey underway in FL (see state ranking files).
Basically solitary. Widely dispersed compared to gray squirrel. Large home range. Home range over one year in Florida averaged 43 ha for males, 17 ha for females; average about 20 ha in Georgia (see Kantola and Humphrey 1990). Density has been estimated at 38/sq km and 8-15/sq km (see Kantola 1992). Folk (1993) estimated density at 2-5/100 ha and 19-63/100 ha on two TNC preserves in Florida.
Predation probably is not a limiting factor (Kantola 1992), but food supply probably limits fox squirrel populations in some areas (Weigl et al. 1989). Populations may decline if pine cone and acorn crops fail.
Fox squirrels contribute to the dispersal of spores of hypogeous mycorrhizal fungi, which are important facilitators of nutrient absorption by longleaf pines (Trappe and Maser 1977, Weigl et al. 1989).
Life History and Behavior
Most litters are born January-February and June-August. Gestation lasts about 44 days. Litter size is 1-4 (average 2-3). Young spend up to 2.5 months in brood nest, weaned in about 90 days. Sexually mature in about nine months. Individual adult females usually produce one litter per year, sometimes two. Low food supply may limit both litter size and number of litters produced. May not breed after acorn crop failure. Relatively long-lived, with low reproductive rate. See Moore (1953), Layne (1978), Nixon et al. (1986), Weigl et al. (1989), and Kantola (1992).
NatureServe Conservation Status
Rounded Global Status Rank: T3 - Vulnerable
Reasons: This subspecies occurs patchily in fragmented habitat throughout much of peninsular Florida and adjacent southern Georgia, often in reduced numbers; in many places it exists outside of its original, primary habitat (longleaf pine-turkey oak forest) as a result of habitat destruction, which continues to be a major threat; very few occurrences are large enough to assure population viability even if managed effectively.
Other Considerations: Listed by USFWS as Category 2 candidate, and by FL as Species of Special Concern. This subspecies requires a very large home range for a rodent and correspondingly maintains low population densities. Hence, very large tracts are needed to assure population viability. Recruitment is typically low and closely tied to acorn and cone crops. Logging of longleaf pines destroys hiding places of squirrel and makes them vulnerable to predators and hunters.
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
Global Short Term Trend: Decline of 30 to >90%
Comments: Occupied area probably has declined 85% from presettlement levels (Kantola 1992).
Degree of Threat: A : Very threatened throughout its range communities directly exploited or their composition and structure irreversibly threatened by man-made forces, including exotic species
Comments: Has experienced habitat loss and fragmentation due to extensive logging; conversion to pasture and short-rotation forestry; agricultural, commercial, and residential development; and lack of fire; these threats are on-going (Kantola 1992). Hunting may threaten some local populations (Reinman, in Kantola 1992).
Management Requirements: Maintain habitat via fire and uneven-aged forest management.
Management Research Needs: Determine effects of hunting, environmental variability, and habitat management on recruitment and recovery.
Global Protection: Few to several (1-12) occurrences appropriately protected and managed
Comments: Many occurrences in Florida occur in Managed Areas (see state ranking files). However, many may be too small to assure long-term viability.
Needs: Preserve longleaf pine-turkey oak forests, with native groundcover. Enlarge managed areas that contain squirrel. Ban hunting. Encourage uneven-aged management of longleaf pine.
Names and Taxonomy
Comments: May not be highly differentiated from S. N. NIGER to the north. Taxonomic distinctiveness has been confirmed by rigorous statistical evaluation of cranial characters (Turner and Laerm, in Kantola 1992).