Source: http://thefederalregister.com/2012/12/04/2012-29188.html
Timestamp: 2018-03-18 05:33:03
Document Index: 39791456

Matched Legal Cases: ['artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001', 'artz 2001']

[Docket No. FWS-R3-ES-2012-0079; 4500030113]
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 90-day finding on a petition to list the prairie gray fox (Urocyon cinereoargenteus ocythous), the plains spotted skunk (Spilogale putorius interrupta), and a distinct population segment (DPS) of the Mearn's eastern cottontail (Sylvilagus floridanus mearnsi) in Illinois and western Indiana as endangered or threatened species under the Endangered Species Act of 1973, as amended (Act). Based on our review, we find that the petition presents substantial scientific or commercial information that listing the prairie gray fox and the plains spotted skunk may be warranted. Therefore, with the publication of this notice, we initiate a review of the status of the prairie gray fox and the plains spotted skunk to determine if listing either of these subspecies is warranted. To ensure that this status review is comprehensive, we are requesting scientific and commercial data and other information regarding these subspecies. Based on the status review, we will issue a 12-month finding on the petition, which will address whether the petitioned action is warranted, as provided in section 4(b)(3)(B) of the Act.
DATES: The finding announced in this document was made on December 4, 2012.
We request that we receive information on or before February 4, 2013. The deadline for submitting an electronic comment using the Federal eRulemaking Portal (seeADDRESSESsection, below) is 11:59 p.m. Eastern Time on this date. After February 4, 2013, you must submit information directly to the Division of Policy and Directives Management (seeADDRESSESsection below). Please note that we might not be able to address or incorporate information that we receive after the above requested date.
ADDRESSES: (1)Electronically:Go to the Federal eRulemaking Portal:http://www.regulations.gov.Search for Docket No. FWS-R3-ES-2012-0079, which is the docket number for this action. Then click on the Search button. You may submit a comment by clicking on "Comment Now!."
(2)By hard copy:Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS-R3-ES-2012-0079; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042-PDM; Arlington, VA 22203.
We will not accept email or faxes. We will post all information we receive onhttp://www.regulations.gov.This generally means that we will post any personal information you provide us (see the Request for Information section below for more details).
This finding is available on the Internet athttp://www.regulations.govat Docket Number FWS-R3-ES-2012-0079. Supporting documentation we used in preparing this finding is available for public inspection, by appointment, during normal business hours at the U.S. Fish and Wildlife Service, Rock Island, Illinois Ecological Service Field Office, 1511 4th Ave., Moline, IL 61265. Please submit any new information, materials, comments, or questions concerning the finding on the prairie gray fox and the plains spotted skunk to the Rock Island, Illinois Ecological Services Field Office at the above address.
FOR FURTHER INFORMATION CONTACT: Richard Nelson, Field Supervisor, Rock Island, Illinois Ecological Service Field Office, 1511 4th Ave., Moline, IL 61265; by telephone at 309-757-5800; or by facsimile at 309-757-5804. If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800-877-8339.
Species Information Plains Spotted Skunk (Spilogale putorius interrupta)
The plains spotted skunk is one of three recognized subspecies of the eastern spotted skunk (Spilogale putorius); the other two recognized subspecies areS. p. ambarvalis(no common name) andS. p. putorius(no common name) (Kinlaw 1995, p. 1). Spotted skunks are members of the Order Carnivora and Family Mephitidae. Eastern spotted skunks are distinct from western spotted skunks (S. gracilis) based on reproductive and geographic isolation (Kinlaw 1995, p. 1). Little variation in skull or body measurements exists among the plains spotted skunk subspecies (Van Gelder 1959, p. 270). The plains spotted skunk can be distinguished from other subspecies by the reduced amount of white on its body, particularly the entirely black tail (Van Gelder 1959, pp. 269-270). We accept the characterization of the plains spotted skunk as a subspecies because of morphological distinction of its color pattern from other subspecies of eastern spotted skunk (Van Gelder 1959, pp. 269-270). We consider information that refers to the eastern spotted skunk where it occurs in the delineated range of the plains spotted skunk to represent the plains spotted skunk.
Both the plains spotted skunk and striped skunk (Mephitis mephitis) have contrasting black and white markings;however, they are easily distinguished by size (spotted skunks are substantially smaller) and color pattern. The plains spotted skunk is a small, slender mammal with short legs and a tail with prominent, long hairs. Body weight ranges from 300 to 1,300 grams (g) (0.75 to 2.75 pounds (lb)), and total length ranges from 36 to 61 centimeters (cm) (14 to 23.75 inches (in)) (Hazard 1982, p. 143; Schwartz and Schwartz 2001, p. 325). In contrast, the striped skunk's average weight is 6,300 g (14 lb), and its length is 80 cm (31.5 in). The plains spotted skunk is black overall with narrow, white stripes and spots. Four stripes on the neck, back, and sides run longitudinally from the head to the middle of the body. The four white stripes break into patches or spots on the hindquarters. There is a white spot on the forehead and in front of each ear (Hazard 1982, p. 143; Schwartz and Schwartz 2001, p. 325).
Habitat associations of this subspecies are likely influenced by whether it is using a natural or human-dominated landscape. The subspecies lives in a wide range of habitats including forests, prairies, brushy areas, farmyards, and cultivated land (Crabb 1948, pp. 212-215; Edmonds 1974, p. 12; Kinlaw 1995, p. 4; Schwartz and Schwartz 2001, p. 327). Regardless of habitat type used, the plains spotted skunk requires extensive vegetative cover. Brushy borders along fields, fence rows, farm buildings, wood piles, heavily vegetated gullies, leaf litter, or downed logs may provide the required extensive cover, which primarily provides protection from predators (Kinlaw 1995, p. 4; Schwartz and Schwartz 2001, p. 327; Lesmeister 2008, pp. 1517-1518). Nowak (1999, p. 734) notes that spotted skunks avoid dense forests; however, plains spotted skunks are more likely to occur where the landscape is composed of a high proportion of forest cover (Hackett 2008, pp. 52-54), and they use oak-hickory forests more than old fields or glades (McCullough 1983, pp. 40-43). Within forest habitats studied by McCullough (1983, p. 41) and Lesmeister (2007, p. 21), skunks used young, dense forest stands or stands with downed logs and slash more often than mature stands with open understories and clean forest floors. Spotted skunks also require an early successional (process by which ecological communities undergo changes following disturbance) component to their habitat to provide cover and denning areas (Lesmeister 2007, p. 56; Lesmeisteret al.2009, pp. 23-24).
Dens can be located above ground or below ground. In natural landscapes, plains spotted skunks den in grassy banks and crevices or cavities under rock piles, hollow logs, and stumps (Kinlaw 1995, p. 4; Schwartz and Schwartz 2001, p. 327). In landscapes dominated by humans, they den in shelterbelts (row of trees planted to provide shelter from wind), fencerows, farm buildings, haystacks, woodpiles, or corn cribs (Crabb 1948, pp. 214-215; Hazard 1982, p. 144; Joneset al.1983, p. 302; Kinlaw 1995, p. 4; Schwartz and Schwartz 2001, p. 327). Plains spotted skunks might dig their own dens, but they often use burrows excavated by other animals, such as Franklin's ground squirrel (Spermophilus franklinii), thirteen-lined ground squirrel (S. tridecemlineatus), woodchuck (Marmota monax), long-tailed weasel (Mustela frenata), striped skunk, and woodrats (Neotomaspp.) (Crabb 1948, p. 212; Kinlaw, 1995, p. 4; Schwartz and Schwartz 2001, p. 327). Crabb (1948, p. 212) noted that skunks required dens that excluded light and afforded protection from inclement weather and predators. Dens are used by one or more members of the local population of plains spotted skunks, and individuals might den together during cold winter months (Schwartz and Schwartz 2001, p. 327).
During most of the year, individual plains spotted skunks remain in an area of approximately 40 hectares (ha) (98.8 acres (ac)), but the home range can vary based on habitat quality and food availability (Schwartz and Schwartz 2001, p. 327). The home range can vary seasonally as well; in spring, the range of males can expand to as much as 1,040 ha (2,569.9 ac) (Schwartz and Schwartz 2001, p. 327). In Missouri, home ranges varied from 55 to 4,359 ha (135.9 to 10,771.3 ac) (McCullough 1983, p. 34). Lesmeisteret al.(2008, p. 21) reported that home ranges in the Ouachita Mountains of Arkansas varied by gender and season. The home ranges of males (222 to 1,824 ha (548.6 to 4,507.2 ac)) in the spring were 6.4 times larger than those of females (31 to 192 ha (76.6 to 474.4 ac)). Likewise, male home ranges were at least 2.5 times larger than females' ranges in the winter and summer, but not autumn. Overall, home range size varied from 19 to 1,824 ha (47.0 to 4,507.2 ac) for males and 21 to 192 ha (51.9 to 474.4 ac) for females (McCullough 1983, p. 34; Lesmeisteret al.2008, p. 21). Crabb (1948, p. 218) found that spotted skunks on an agricultural landscape in Iowa occurred at a density of approximately 5 skunks per square kilometer (km2) (13 skunks per square mile (mi2)).
The plains spotted skunk is omnivorous, but is primarily an insectivore and feeds on insects during all seasons of the year (Kinlaw 1995, p. 4). The proportion of different types of food items varies seasonally. Arthropods are the major dietary component during summer and autumn, with grasshoppers, crickets, ground beetles, and scarab beetles being the preferred food (Schwartz and Schwartz 2001, p. 328). In the winter, small mammals, including eastern cottontail (Sylvilagus floridanus), voles (Microtus pennsylvanicusandM. ochrogaster),and rats (Rattus norvegicus), are the dominant food source (Chapman and Feldhamer 1982, p. 668; Kinlaw 1995, p. 4). Other foods include birds, eggs, wild ducks that are injured or killed by hunters, fruit, corn, lizards, snakes, crayfish, salamanders, and mushrooms (Schwartz and Schwartz 2001, p. 328).
The plains spotted skunk currently (and historically) occurs between the Mississippi River and the Continental Divide from Minnesota to the Gulf of Mexico (Kinlaw 1995, p. 3). Historical records indicate that the plains spotted skunk was broadly distributed across its range through the early to mid-1900s and was one of the most common mesocarnivores (a carnivore whose diet consists of 50 to 70 percent meat) where suitable habitat occurred (Crabb 1948, p. 203; Choateet al.1973, p. 226; Tyler and Lodes 1980, p. 102; McCullough 1983, p. 19; Wires and Baker 1994, p. 1; Schwartz and Schwartz 2001, p. 327). Likewise, harvest records in the Midwest indicate that population levels in most States were at their highest through the mid-1900s, during which harvest in most years exceeded 100,000 plains spotted skunks (Novaket al.1987, pp. 223-226).
More contemporary records consistently show that the plains spotted skunk underwent declines in the mid- to late 1900s (Choateet al.1973, pp. 227-230; McCullough 1983, pp. 19-25; Gompper and Hackett 2005, p. 196; Nilz and Finck 2008, pp. 5-14). Declines occurred first in Missouri and Oklahoma in the late 1930s and early 1940s, followed by Nebraska in the mid-1940s, and Kansas, Iowa, and Minnesota in the mid- to late 1940s (Wires and Baker 1994, p. 1; Gompper and Hackett 2005, p. 199). Harvest numbers for the plains spotted skunk from 1934-1935 were 248,062 (Service calculated from Novaket al.1987, pp. 223-226, for States in the range of the subspecies). More recent harvest information for 1975-1976 showed that only 1,476 plains spotted skunks were harvested (Service calculated from Novaket al.1987, pp. 223-226, for States in the range of the subspecies), which is less than 1 percent of the 1934-1935 harvest.Gompper and Hackett (2005, p. 199) demonstrated rangewide declines in the plains spotted skunk based on harvest records and found that the decline was not an artifact of reduced trapper effort or demand for spotted skunk pelts.
The subspecies likely still occupies the same habitat types and occurs in all the States within its historical range (Arkansas, Colorado, Minnesota, Missouri, Nebraska, Oklahoma, South Dakota, Texas, and Wyoming), but in lower abundance (Choateet al.1973, p. 231). Range fragmentation and reduced abundance of the subspecies is recorded through trapper records, fur buyer surveys, public surveys, and focused field surveys (Hammond and Busby 1994, pp. 1-4; Wires and Baker 1994, pp. 3-7); these records also document locations where viable populations likely occur (e.g.,Ozark Plateau (McCullough 1983, p. 52; Hackett 2005, pp. 51-52) and Ouachita Mountains (Lesmeisteret al.2010, pp. 54-58)).
Gray fox (Urocyon cinereoargenteus) are mammals of the Order Carnivora and Family Canidae.U. c. ocythousis a recognized subspecies of the gray fox. In this finding, we refer to the subspeciesU. c. ocythousas the prairie gray fox, as this is the common name the petition uses, although there is no recognized common name for this subspecies. The prairie gray fox was first described by Bangs in 1899 (Fritzell and Haroldson 1982, p. 1; Hall 1981, p. 943). We accept the characterization of the prairie gray fox as a subspecies of the gray fox as noted in Chapman and Feldhammer (1982, p. 475), Fritzell and Haroldson (1982, p. 1), and Hall (1981, p. 943). Few references refer specifically, by name, toU. c. ocythous;therefore, we consider information available for the gray fox within the delineated prairie gray fox range to represent the petitioned subspecies.
The following characteristics describe the gray fox species in general, as they are similar to the characteristics of the prairie gray fox subspecies. The gray fox has a distinguishable appearance with gray fur on its upper body; reddish fur on its neck, the sides of the belly, and inner legs; and white on the rest of its underbody. The guard hairs (long, course hairs that protect soft underfur) are banded with white, gray, and black, which gives the fox's fur a grizzled appearance. It has a black tipped tail and a coarse dorsal mane of black-tipped hairs at the base of its tail (Chapman and Feldhammer 1982, p. 476; Fritzell and Haroldson 1982, p. 1; Hall 1981, p. 942; Hamilton and Whitaker 1979, p. 270). Gray fox are also distinguished from other canids by their widely separated temporal ridges that come together posteriorly in a U-shaped form (Chapman and Feldhammer 1982, p. 476; Fritzell and Haroldson 1982, p. 1; Hall 1981, p. 942; Hamilton and Whitaker 1979, p. 270). Gray fox are smaller than the red fox(Vulpes vulpes),with a total length of 80 to 112.5 centimeters (cm) (31.5 to 44. 3 inches (in)), weight of 3 to 7 kilograms (6.6 to 15.4 lb), and males are slightly larger than females (Fritzell and Haroldson 1982, p. 1). The size of gray fox varies with geographic location, with individuals in the northern part of the range larger than those in the south (Hamilton and Whitaker 1979, p. 270).
Gray fox dens are usually located in wooded areas and include underground burrows, cavities in trees or logs, wood-piles, and rock outcrops or cavities under rocks (Joneset al.1985, p. 264; Fritzell and Haroldson 1982, p. 189). Gray fox will use dens year-round, but predominantly when young are born. Gray fox mate at different times of the year, depending on their geographic location (Chapman and Feldhammer 1982, p. 476). For example, for the prairie gray fox, breeding lasts from late January through February in southern Illinois and from late January through March in Wisconsin (Fritzell and Haroldson 1982, pp. 3-4). The average litter size for the gray fox is 3.8 pups per female, with litters ranging from 1 to 7 pups (Fritzell and Haroldson 1982, p. 4).
The gray fox is primarily an opportunistic carnivore, with mammals composing most of its diet in the Midwest (Fritzell and Haroldson 1982, p. 4). According to Chapman and Feldhammer (1982, p. 480), the gray fox's diet depends highly on what is available. Although rabbits have been found to be one of their primary food sources, they routinely feed on small rodents and other mammals, birds, and reptiles (Joneset al.1985, p. 264; Fritzell and Haroldson 1982, p. 4). In the summer, invertebrates have been found to be more important food items, while in the fall, the gray fox consumes more fruit and sometimes corn (Chapman and Feldhammer 1982, p. 476; Fritzell and Haroldson 1982, p. 4; Hamilton and Whitaker 1979, p. 272).
The plains gray fox ranges primarily west of the Mississippi and Illinois Rivers through portions of the central plain States. The historical range for this subspecies included western Wisconsin, Minnesota, Iowa, Missouri, Arkansas, and the eastern sections of North and South Dakota, Nebraska, Kansas, and Oklahoma in the United States, and thesouthernmost sections of Ontario and Manitoba, Canada (Hall 1981, p. 944).
Eastern cottontail (Sylvilagus floridanus) are members of Order Lagomorpha and Family Leporidae. The Mearn's eastern cottontail (Sylvilagus floridanus mearnsi) is a recognized subspecies of the eastern cottontail, as first described in 1894 by J.A. Allen (Hall and Kelson 1981, p. 304; Chapmanet al.1980, p. 1). We accept the characterization of the Mearn's eastern cottontail (S. f. mearnsi) as a subspecies of the eastern cottontail rabbit as described in Chapmanet al.(1980, p. 1), and Hall and Kelson (1959, p. 262). Few references relate specifically to the Mearn's eastern cottontail; therefore, we consider information available for the eastern cottontail to represent the petitioned subspecies.
The eastern cottontail is described as having a total length of 395 to 456 mm (15.6 to 18.0 in) and weighing 801 to 1,411 g (28.3 to 49.8 ounces (oz)) for males, and 400 to 477 mm (15.7 to 18.8 in) and weighing 842 to 1,533 g (29.7 to 54.1 oz) for females (Chapmanet al.1981, p. 136). They have dense fur, ranging from brownish to greyish in color, with white fur on the underside of the body and tail. The average home range for the eastern cottontail varies from approximately 1 to 2 acres (0.4 to 1 ha) in Wisconsin (Trent and Rungstad 1974) to around 4 acres (2 ha) in Pennsylvania, with male home ranges increasing to an average of 17 to 19 acres (7 to 8 ha) in spring and summer (Althoff and Storm 1989). The eastern cottontail is the most widely distributed cottontail species in North America (Scharineet al.2011, p. 885; Hall and Kelson 1981, p. 300; Chapmanet al.1980, p. 2) and occurs sympatrically with six species of the genusSylvilagusand six species of the genusLepus(Chapmanet al.1980, p. 136).
In describing eastern cottontail habitat, Chapmanet al.(1980, p. 2) stated, “This cottontail is generally thought of as a mammal of farmlands, fields, and hedge rows; however, historically it occurred in natural glades and woodlands, deserts, swamps, prairies, hardwood forests, rain forests, and boreal forests.” When comparing the eastern cottontail to the swamp rabbit (S. aquaticus),Scharineet al.(2011, p. 881) stated that the dense understory vegetation provided by early successional cover types are important habitat for both species; however, the eastern cottontail is a habitat generalist and occupies a larger distribution. Mankin and Warner (1999b, p. 960) identified eastern cottontails in old fields, grasslands, hedgerows, cropland, and urban areas, but found that the species preferred open shrub land.
The Mearn's eastern cottontail occurs across a large portion of the eastern cottontail's range, including the entire States of Iowa, Wisconsin, Michigan, Indiana, and Ohio; most of Minnesota, Illinois, and Kentucky; southwestern New York; northern Pennsylvania; western West Virginia; northern Missouri; northeastern Kansas; eastern Nebraska; a small portion of the southeastern corner of South Dakota; and the small portion of the western edge of Virginia (Figure 1) (Hall and Kelson 1981, p. 261; Chapmanet al.1980, p. 3).
EP04DE12.025 Distinct Population Segment Evaluation
(3) The population segment's conservation status in relation to the Act's standards for listing, delisting (removal from the list), or reclassification (i.e.,is the population segment endangered or threatened).
The petitioners assert that the petitioned DPS occupies an ecologically distinct area where intensive agriculture has left only artificial remnants of its original habitat. Mankin and Warner (1999a, p. 940) state that east-central Illinois is one of the most intensively farmed regions in North America. This is supported by the findings of Ribicet al.(1998), which suggest a decrease in the quantity of upland wildlife habitat in Illinois from 1920 to 1987, and an increase in farming disturbance, indicating an intensification of agricultural practices for the State during that time period. They found that the western and southern portions of the State had higher wildlife habitat values than the rest of the State and that harvest of eastern cottontails was higher in counties with the most upland habitat and the lowest amount of farming disturbance (Ribicet al.1998,pp. 307, 311). This differentiation is also supported by Mankin and Warner (1999b, p. 962), who showed that counties in east-central Illinois had the greatest decline in cottontail abundance and the highest increase in intense row-cropping.
The petitioners also cite Mankin and Warner (1999a) in stating that the DPS represents a population of Mearn's cottontail that is broken into small populations and is behaviorally distinct from other Mearn's cottontails. Mankin and Warner (1999a) studied the responses of Mearn's eastern cottontails to intensive row-crop agriculture in Ford County, Illinois, which is in the center of the proposed DPS. They found that the Mearn's eastern cottontail had a home range 2.3 times larger during the growing season for the crops than during the non-growing season (Mankin and Warner 1999a, p. 943). The cottontails in the study also had an overall home range that was 7 to 8 times larger than those found by previous research (Mankin and Warner 1999a, p. 945). Mankin and Warner (1999a, p. 945) specifically compared their findings to home ranges of Mearn's eastern cottontail in Wisconsin by Trent and Rongstad (1974), and indicated they were 8 times larger than Wisconsin males' home ranges and 7 times larger than females'. Chapmanet al.(1980, p. 136) indicate that there have been many studies of home ranges of the eastern cottontail, with a mean for males of 0.95 ha (2.34 acres) to 2.8 ha (6.9 acres) and for females of 0.95 ha (2.34 acres) to 1.2 ha (2.96 acres). Mankin and Warner (1999a, pp. 944-945) found the population of cottontails in the Ford County, Illinois study area to be sparse yet stable. Although the cottontails used the crop ground extensively and 23 percent of the home ranges occurred on farmsteads, farmsteads made up less than 2 percent of the available habitat.
The petitioners assert that the population of Mearn's eastern cottontail in east-central Illinois and western Indiana is significant because it represents approximately 20 percent of the range of the subspecies that was not hybridized by the introductions of other species, and thus its loss would result in a significant gap in the range of the subspecies. The petition cites one reference, Chapman and Morgan 1973, to support their assertion. Chapman and Morgan (1973, p. 6) discuss the introduction of many species and subspecies of rabbits into the eastern United States from 1920 to 1950, and the impacts on the native rabbit species in western Maryland and the nearby portions of West Virginia. They found evidence of hybridization between native eastern cottontails and other rabbit species and subspecies from other parts of the country and the hybridization of the subspeciesS. f. malluruswith other subspecies. The intergrade (hybridization) zone of eastern cottontail in the East has expanded, and it now out-competes the New England cottontail (S. transitionalis) in its traditional habitat (Chapman and Morgan 1973, p. 51). Although the study suggests that the eastern cottontail subspecies interbreed where they overlap, it does not specifically discuss how much habitat may be lost by each subspecies to hybridization. Therefore, when determining how much of the Mearn's eastern cottontail range is included in the petitioned DPS, we used the range from Hall and Kelson (1981, p. 303) as cited in the petition and the hand-drawn map from the original petition to generate the map in Figure 1. Using ArcGIS, we calculated that the area petitioned as a DPS makes up 3.6 percent of the Mearn's cottontail range and not the approximate 20 percent asserted by the petitioners. To calculate the size of the proposed DPS, we scanned the hand-drawn map included in the petition, georeferenced it to a map of the United States, and digitized the DPS boundary from the georeferenced scanned map. We used the same procedures to georeference the range of the Mearn's eastern cottontail from Hall's map (Hall 1980, p. 303). We were able to calculate the total acres of both the DPS and the Mearn's eastern cottontail range with the new digitized georeferenced maps. We then clipped the DPS from the full range to calculate the difference in acres and the percentage of the Mearn's eastern cottontail range that the DPS includes. Although the population of Mearn's eastern cottontail in east-central Illinois and western Indiana is located in the center of the subspecies' range, the petition does not provide substantial information, nor is there information available in our files, to suggest that lossof this population would result in a significant gap in the range of a taxon.
We encourage interested parties to continue to gather data that will assist with the conservation of the population of Mearn's eastern cottontail in east-central Illinois and western Indiana. If you wish to provide information regarding the Mearn's eastern cottontail, you may submit your information or materials to the Field Supervisor at the Rock Island, Illinois Ecological Service Field Office (seeADDRESSES), at any time.
Plains Spotted Skunk (Spilogale putorius interrupta) A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range Information Provided in the Petition
The petitioners claim that threats to the plains spotted skunk include habitat loss and modification. The petition suggests that loss of grassland and early successional habitat has contributed to declining population trends of 90 to 100 percent throughout the subspecies' range (Petition, unpaginated). Plains spotted skunks require some early successional component to their habitat to provide cover and denning areas (Petition, unpaginated; Lesmeister 2007, p. 56; Lesmeisteret al.2009, pp. 23-24). Before European settlement, this need was satisfied by both natural disturbances (e.g.,fire, storms, beaver, elk, and bison) and disturbance by Native Americans (Petition, unpaginated; Sewell 2009, p. 11). Grasslands and successional habitats were prevalent across the landscape. However, anthropogenic changes lead to landscapes that were more conducive to species that need early successional habitat, such as the plains spotted skunk. Such species shifted their use from naturally created, early successional habitats to those that were created by humans, and the species now seem to depend on these human-created habitats to some extent (Petition, unpaginated; Sewell 2009, p. 12).
The information readily available in our files supports the petitioners' claims that the plains spotted skunk may be declining rangewide due to loss, degradation, and modification of early successional habitat. The plains spotted skunk has apparently undergone long-term fluctuations in population (Choateet al.1973, pp. 228-233; Novaket al.1987, pp. 223-226; Gompper and Hackett 2005, pp. 199-200). Increases in abundance in the early 1900s likely were facilitated by human presence and influence on the landscape, as were subsequent declines (Choateet al.1973, pp. 228-233). Construction of houses, outbuildings, haystacks, and brush piles provided shelter, and the storage of crops provided a direct source of food, as well as an indirect food source (mice and rats that were attracted to stored grain) (Choateet al.1973, p. 230). Exploitation of these novel features allowed the expansion and increase of the plains spotted skunk (Choateet al.1973, p. 230). Subsequent removal of anthropogenic features, as small farms were deserted and incorporated into larger farms reduced the amount of available habitat (Choateet al.1973, p. 231). However, the plains spotted skunk has declined throughout its range, not just in the parts of the range where the subspecies exists in anthropogenic landscapes. Harvest by fur trappers has consistently decreased from the mid-1940s to present (Novaket al.1987, pp. 223-226). Gompper and Hackett (2005, pp. 199-200) analyzed harvest data from seven States (Iowa, Missouri, Nebraska, Kansas, Oklahoma, Minnesota, and Arkansas) in the range of the plains spotted skunk and confirmed the population decline, demonstrated that the timing of the onset of decline differed among States, and determined that the decline was not an artifact of harvest effort or pelt demand.
Although there does not appear to be a single cause of decline, a suite of potential factors are suggested consistently in the literature. The decline of small farms, the advent of agriculture practices that encourage removal of fence rows and brush piles, intensive use of pesticides, improved grain management practices, and the end of large haystack construction are implicated as potential causes for the species' decline in landscapes dominated by human activity (Choateet al.1973, pp. 229-231; Gompper and Hackett 2005, p. 199). Following the Great Depression, many small farms were deserted and incorporated into larger agricultural units. Farm buildings were removed that had provided both shelter and sources of prey, such as rodents (Choateet al.1973, p. 230; Nilz and Finck 2008, pp. 19-20). This change in the agricultural landscape was intensified by the drought of 1933-1940, during which thousands of small farmers moved to other areas, abandoning many of the farms that remained. Arid conditions impacted natural riparian habitats of plains spotted skunks along watercourses, likely making them uninhabitable. The continued introduction of technology and mechanization into farming operations caused further decline of small, diverse farms and replaced them with large monocultures (Choateet al.1973, p. 231). Plains spotted skunks avoid expansive open areas, such as pasture lands, that are devoid of overhead cover, and plains spotted skunks are likely intolerant of this habitat type (Lesmeisteret al.2009, p. 23). Finally, the widespread application of insecticides, such as Dichloro-diphenyl-trichlorethane (DDT), in industrial farming might have contributed to the decline in the 1940s. Because the plains spotted skunk is primarily an insectivore, application of pesticide likely reduced the main food source for the subspecies. Foraging opportunities were historically and continue to be further limited by dietary preference; competition with other species, such as striped skunk and weasels, for an alternate food source; or both (Kinlaw 1995, p. 4; Nilz and Finck 2008, pp. 19-20).
Habitat loss or modification might also be currently occurring in more natural forested landscapes where the plains spotted skunk occurs. In the Ouachita Mountains and Ozark Plateau, use of forested areas was limited to young forest stands with closed canopy and dense understory, areas with fallen logs and brushpiles, ravine bottoms, or stands that had undergone timber stand improvement (TSI) and had high levels of ground litter and slash (McCullough 1983, pp. 40-41; Lesmeisteret al.2009, p. 23). Young shortleaf pine stands were the only early successional habitat present in the Ouachita Mountains study area and were preferred over the dominant habitat type, mature shortleaf pine. Mature shortleaf pine stands offer more open canopy conditions and are considered suboptimal habitat for the plains spotted skunk compared to young stands that provide more desirable structural characteristics (Lesmeisteret al.2009, p. 24). Similar to the results in the Ouachita Mountains, plains spotted skunks in the Ozark Plateau preferred young oak-hickory forest stands over mature oak-hickory forest (McCullough 1983, p. 41). Considering that the subspecies seems to require structural complexity provided by early successional habitats, management priorities that endeavor to create landscapes dominated by mature forest stands could negatively impact the plains spotted skunk. For example, such conflicts in habitat management might occur where the ranges of the red-cockaded woodpecker and plains spotted skunk are coincident. Red-cockaded woodpeckers require open, mature pine woodlands and savannahs maintained by frequent fire (USFWS 2003, p. 5). Management for red-cockaded woodpeckers focuses on restoration of pine forests to old, open stands with canopy and herbaceous layers but no hardwood midstory (USFWS 2003, pp. 2, 41). This type of pine restoration is currently occurring in Arkansas on the Ouachita National Forest (Hedricket al.2007, pp. 1-8).
Harvest pressure on the plains spotted skunk during the 1930s has received little consideration for contributing to the decline of the subspecies, but might have been a factor historically (Nilz and Finck 2008, p. 19). Available harvest records from the 1930s to 1940s (Novaket al.1987, pp. 223-226) show high harvest numbers for most States in the subspecies' range, but since the mid-1940s, harvest numbers haveconsistently decreased. The population status and dynamics of plains spotted skunks during this period of heavy harvest are not fully understood, but the plains spotted skunk appears to have been common in most landscapes in the early 1900s (Choateet al.1973, pp. 227-230). Based on information readily available in our files, overutilization appears to be a potential cause of historical decline, but we do not have information to indicate that the overutilization for commercial, recreational, scientific, or educational purposes is presenting an ongoing threat to the plains spotted skunk. However, as we proceed with the 12-month status review, we will further investigate this factor to determine whether overutilization for commercial, recreational, scientific, or educational purposes is an ongoing threat to the subspecies.
The petitioners did not present information regarding diseases that may affect the plains spotted skunk. The petitioners claim that the plains spotted skunk is experiencing unnaturally high levels of predation, mainly by birds of prey, because of loss of protective cover provided by early successional habitat (Petition, unpaginated). Lesmeisteret al.(2009, pp. 23-24) observed 18 mortalities of plains spotted skunks in the Ouachita Mountains, most of which were caused by avian predators and occurred in mature shortleaf pine forests that provide little in the way of protective cover. They noted that stands of young shortleaf pine seem to be less preferred by typical predators of plains spotted skunk, such as coyote (Canis latrans), bobcats (Lynx rufus), and great horned owls (Bubo virginanus), which prefer more open habitats. Open conditions in mature forest stands might be more favorable for the presence of predators and consequently less favorable to plains spotted skunks (Lesmeisteret al.2009, p. 24).
Based on our review of information provided by the petitioners and readily available in our files, the plains spotted skunk may be declining rangewide due to predation. The most common natural predators of the plains spotted skunks are owls and mesocarnivores (Kinlaw 1995, p. 4; Schwartz and Schwartz 2001, p. 329). Lesmeisteret al.(2010, pp. 54-58) observed a relatively low survival rate for plains spotted skunk in the Ouachita Mountains. Sixty-three percent of documented mortalities were attributed to avian predators, 26 percent to mammalian predators, and 11 percent to unknown causes. Eleven of the 12 avian-caused mortalities occurred in mature shortleaf pine stands with an open canopy and herbaceous understory, whereas all of the mammal-caused mortalities occurred in young shortleaf pine stands (Lesmeisteret al.2010, p. 54). These results suggest that there is a difference between the amount and source of predation that occurs in habitat that is considered optimal (young shortleaf pine) and suboptimal (mature shortleaf pine) for plains spotted skunk (Lesmeisteret al.2010, pp. 55-56). Plains spotted skunks avoided use of mature forest stands and selected young forest stands (Lesmeisteret al.2009, pp. 23-24); mortality due to predation was disproportionate to habitat use because the highest mortality occurred in the least-used mature forest habitat. While predation plays a natural role in the life history dynamics of the plains spotted skunk, there is some evidence that it may be occurring at a higher rate that could have a negative affect on populations of the species.