Habitat and Life History. The Sicklefin Redhorse is currently known to occupy cool to warm, moderate gradient creeks and rivers and, during at least parts of its early life, large reservoirs (Xxxxxxx 1999, p. 19; Xxxxx 2012, p. vi). In streams, adults of the species are generally associated with moderate to fast currents, in riffles, runs, and well-flowing pools (Xxxxxxx 1999, pp. 15, 17, and 19; Xxxxxx 2008, pp. 49, 62-64, and 80), while juveniles show a preference for moderate to deep pools with slow currents and large boulder crevice cover (Xxxxx 2012, pp. vii and 18-19). Adults feed and spawn over gravel, cobble, boulder, and bedrock substrates with no, or very little, silt overlay (Xxxxxxx 1999, pp. 15, 17, and 19; Xxxxxx 2008, pp. 49, 62-64, and 80). Like many other redhorse species, the Sicklefin Redhorse is known mainly from flowing streams; however, also like many other redhorse species, the Sicklefin Redhorse appears to have adapted to spending at least part of its early life stages in the near-shore areas of impoundments (Xxxxxxx 1999, pp. 19 and 20; Xxxxx 2012, pp. 23 and 29). Current observations indicate that adults are year-round residents of rivers and large creeks (Jenkins, pers. comm., 2007; Xxxxxx 2008, pp. 2 and 39; Xxxxx 2012, p. 23) and that young, juveniles, and sub-adults occupy primarily the lower reaches of creeks and rivers and near-shore portions of certain reservoirs (Xxxxxxx 1999, p.20; Xxxxx 2012, p. 23 and 29). After emerging from the stream substrata, it is likely that many of the larvae and post-larvae are carried downstream to the mouths of streams or into reservoirs (Xxxxxxx 1999, p.20). The fish are believed to mature at around 5 to 8 years of age (males 5 to 7 years, females 7 to 8 years), and newly matured fish appear to migrate from the reservoirs to spawn; after which, most remain in the streams with the other adults (Xxxxxxx 1999, p. 20). Although a few adult Sicklefin Redhorse have been observed in the Hiwassee and Fontana Reservoirs, Xxxxxx’x (2008, pp. 2 and 39) study of movement and habitat utilization within the Hiwassee River system indicated that he was unable to detect radio-tagged adult Sicklefin Redhorse using the Hiwassee Reservoir for extended periods between occupying a spawning tributary and the Hiwassee River or Valley River. This suggests that these fish were only inhabiting the reservoirs as they migrated between streams, and the currently impounded reaches likely provided habitat for the Sicklefin Redhorse before they were...
Habitat and Life History. Goose Creek milkvetch typically occurs on sparsely vegetated outcrops of highly weathered volcanic-ash (tuffaceous) soils from the Salt Lake Formation. These tuffaceous outcrops, also referred to as Salt Lake Formation “ashy” outrcrops in Table 1, appear to constitute the optimal habitat for the species throughout its range. Goose Creek milkvetch also occurs in the xxxxx loam and gravelly xxxxx loam soils surrounding some but not all of these tuffaceous outcrops (Xxxxxxx and Xxxxxxx 1991; Xxxxx 2013). Goose Creek milkvetch presence and scattered distribution on the sandier soils appears to be associated with the proximity to occupied tuffaceous outcrops and other unstudied factors related to how favorable the habitat conditions are for the species. The species ability to colonize the xxxxx soils adjacent to the tuffaceous outcrops indicates that Goose Creek milkvetch has some physiological or ecological ability to tolerate the conditions that exist outside of the tuffaceous outcrops within its historic range. The dominant native species within the general surrounding plant community include: Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), Utah juniper (Juniperus osteosperma), green or yellow rabbitbrush (Chrysothamnus viscidiflorus), Xxxxxxxx’x bluegrass (Poa secunda), and needle and thread grass (Hesperostipa comata) (Baird and Xxxx 1991). The habitat can vary from stable areas with little erosion to washes or steep slopes where erosion is common. Goose Creek milkvetch appears to be a short-lived perennial, but information on longevity is lacking. Reproductive plants flower from late May to early June; fruit set begins in early June, and fruits remain on the plants for several months. Plants in full flower were observed in late fall, presumably induced by late summer moisture. Mechanisms of seed dispersal are not known, but may include wind dispersion of seed pods and insect or bird agents (Baird and Xxxx 1991). Clusters of seedlings are occasionally observed on abandoned ant hills, suggesting that ants may also assist with dispersal (USFWS 2006). Additional monitoring information for Goose Creek milkvetch can be found in the USFWS 12-month finding (74 FR 46521, September 10, 2009) and the USFWS Candidate Notice of Review (77 FR 70103 70162). The breeding system and specific pollinators of Goose Creek milkvetch are not known at this time, but we assume that pollinators are important to support maximum reproduction for the species based u...
Habitat and Life History. Georgia aster occupies woodlands or piedmont prairies dominated by native plant species. Soils vary from sand to heavy clay, with pH ranging from 4.4 to 6.8 at the sites sampled for a 1993 study on the species (Xxxxxxxx 1993, p.20). The primary controlling factor appears to be the availability of light. The species is a good competitor with other early successional species, but tends to decline when shaded by woody species. Populations can persist for an undetermined length of time in the shade, but these rarely flower (Xxxxxxxx 1993, p.20) and reproduce only by rhizomes. A genetic study completed in 2013 supports the hypothesis that Georgia aster is a perennial outcrossing species due to the majority of its genetic variation being partitioned within populations (87.5 %) with less (12.3 %) partitioned among populations within states. The genetic relationships among populations roughly reflected geographic proximity, with populations grouping into three groups: Alabama, Georgia, and the Carolinas. This genetic survey suggests no difference in genetic variation or seed fitness between large and small populations of Georgia aster (Xxxxxxxxx 2013, p. 4-5). A seed viability analysis study, done by the Atlanta Botanical Garden, showed that across the range of the species, the percent filled seed ranged from 77 to 99 % with a trend for smaller populations to have higher percentages of filled seed. The range in germination percentage ranged from 20 to 90 % with seeds from North Carolina populations having significantly lower germination percentages than seeds from other states (Xxxxx-Xxxxxxx 2013, p. 1).
