Daily Rules, Proposed Rules, and Notices of the Federal Government
We also evaluated whether the petition presents substantial information to indicate whether or not the Mearn's eastern cottontail in east-central Illinois and western Indiana qualifies as a DPS that may be warranted for listing. Based on our review, we conclude that the petition does not provide substantial information indicating that population of Mearn's eastern cottontail in east-central Illinois and western Indiana is a listable entity under the Act. Because the petition does not present substantial information indicating that the population of Mearn's eastern cottontail in east-central Illinois and western Indiana may be a listable entity, we did not evaluate whether or not the information contained in the petition regarding threats to that population was substantial. We are not initiating a status review in response to this petition for Mearn's eastern cottontail in east-central Illinois and western Indiana. However, we ask the public to submit to us any new information that becomes available concerning the status of, or threats to, the Mearn's eastern cottontail or its habitat at any time.
We request that we receive information on or before February 4, 2013. The deadline for submitting an electronic comment using the Federal eRulemaking Portal (see
We will not accept email or faxes. We will post all information we receive on
This finding is available on the Internet at
Amy Salveter, Field Supervisor, Missouri Ecological Services Field Office, 101 Park DeVille Drive, Suite A, Columbia, MO 65203; by telephone at 573-234-2132; or by facsimile at 573-234-2181. If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800-877-8339.
When we make a finding that a petition presents substantial information indicating that listing a species may be warranted, we are required to promptly initiate review of the status of the species (status review). For the status review to be complete and based on the best available scientific and commercial information, we request information on the prairie gray fox and the plains spotted skunk from governmental agencies, Native American tribes, the scientific community, industry, and any other interested parties. We seek information on:
(1) The species' biology, range, and population trends, including:
(a) Habitat requirements for feeding, breeding, and sheltering;
(b) Genetics and taxonomy;
(c) Historical and current range, including distribution patterns;
(d) Historical and current population levels, and current and projected trends; and
(e) Past and ongoing conservation measures for the species, its habitat, or both.
(2) The factors that are the basis for making a listing determination for a species under section 4(a) of the Act (16 U.S.C. 1531
(a) The present or threatened destruction, modification, or curtailment of its habitat or range;
(b) Overutilization for commercial, recreational, scientific, or educational purposes;
(c) Disease or predation;
(d) The inadequacy of existing regulatory mechanisms; or
(e) Other natural or manmade factors affecting its continued existence.
(3) Information regarding overharvest and disease as potential ongoing threats to the plains spotted skunk and prairie gray fox.
(4) Information regarding the impacts of pesticides on food availability for the plains spotted skunk.
(5) Information regarding the impacts of predation by coyotes and bobcats on the prairie gray fox.
If, after the status review, we determine that listing the prairie gray fox or the plains spotted skunk is warranted, we will propose critical habitat (see definition in section 3(5)(A) of the Act) under section 4 of the Act, to the maximum extent prudent and determinable at the time we propose to list the species. Therefore, we also request data and information on:
(1) What may constitute “physical or biological features essential to the conservation of the species,” within the geographical range currently occupied by the species;
(2) Where these features are currently found;
(3) Whether any of these features may require special management considerations or protection;
(4) Specific areas outside the geographical area occupied by the species that are “essential for the conservation of the species”; and
(5) What, if any, critical habitat you think we should propose for designation if one or both of the species are proposed for listing, and why such habitat meets the requirements of section 4 of the Act.
Please include sufficient information with your submission (such as scientific journal articles or other publications) to allow us to verify any scientific or commercial information you include.
Submissions merely stating support for or opposition to the action under consideration without providing supporting information, although noted, will not be considered in making a determination. Section 4(b)(1)(A) of the Act directs that determinations as to whether any species is an endangered or threatened species must be made “solely on the basis of the best scientific and commercial data available.”
You may submit your information concerning this status review by one of the methods listed in the
Section 4(b)(3)(A) of the Act requires that we make a finding on whether a petition to list, delist, or reclassify a species presents substantial scientific or commercial information indicating that the petitioned action may be warranted. We are to base this finding on information provided in the petition, supporting information submitted with the petition, and information otherwise available in our files. To the maximum extent practicable, we are to make this finding within 90 days of our receipt of the petition and publish our notice of the finding promptly in the
Our standard for substantial scientific or commercial information within the Code of Federal Regulations (CFR) with regard to a 90-day petition finding is “that amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted” (50 CFR 424.14(b)). If we find that substantial scientific or commercial information was presented, we are required to promptly initiate a species status review, which we subsequently summarize in our 12-month finding.
On July 18, 2011, we received a petition from Mr. David Wade and Dr. Thomas Alton, requesting that five or six entities of grassland thicket species or subspecies be listed as endangered or threatened under the Act. The petition clearly identified itself as such and included the requisite identification information for the petitioners, required at 50 CFR 424.14(a). However, while reviewing the petition, we determined that the petition did not clearly state which species were included in the petition. Therefore, in a September 2, 2011, letter to the petitioners, we provided the petitioners with an opportunity to revise the petition to clearly identify the petitioned entities, which the petitioners accepted in a September 12, 2011, response to our letter. On January 23, 2012, we received a revised petition from Mr. David Wade and Dr. Thomas Alton, requesting that the prairie gray fox (
To date, no Federal actions have been taken with regard to the prairie gray fox, the plains spotted skunk, or the Mearn's eastern cottontail.
The plains spotted skunk is one of three recognized subspecies of the eastern spotted skunk (
Both the plains spotted skunk and striped skunk (
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; Lesmeister
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; Jones
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). Lesmeister
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 (
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; Choate
More contemporary records consistently show that the plains spotted skunk underwent declines in the mid- to late 1900s (Choate
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 (Choate
Gray fox (
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
Gray fox are generally associated with wooded habitats (Haroldson and Fritzell 1984, p. 226; Fritzell and Haroldson 1982, p. 3; Hamilton and Whitaker 1979, p. 270). Gray fox use oak-hickory forests almost exclusively in southern Missouri, and are frequently found in dense stands of young trees during the day (Haroldson and Fritzell 1984, pp. 226-227). This study noted, however, that forest habitat was the most abundant habitat type in their study area and the importance of wooded habitat is dependent on its availability, and will be used disproportionately to its abundance when wooded habitat is scarce (Haroldson and Fritzell 1984, p. 226). Gray fox use woody cover in deciduous or pine forest, but they also use edge habitat and early old-fields (open habitats that are transitioning from field to forest and are dominated by forbs, grass, and shrubs and small trees) (Fritzell and Haroldson 1982, p. 3). The gray fox tends to select against agricultural areas (Fritzell and Haroldson 1982, p. 3). Cooper (2008, p. 24) found a greater relative abundance of gray fox in Illinois, where there was a greater dispersion of grassland patches into forested areas, and lower densities in areas with larger patches of agricultural fields. A notable characteristic of the gray fox is their ability to climb trees; gray fox are capable of climbing a tree trunk using their claws to grasp and pull themselves up or bounding from branch to branch (Fritzell and Haroldson 1982, p. 5; Hamilton and Whitaker 1979, p. 270). This behavior is used during foraging, predator avoidance, or resting (Fritzell and Haroldson 1982, p. 5).
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 (Jones
The home range of the gray fox varies depending on the season and geographic location (Fritzell and Haroldson 1982, p. 4). Males in southern Illinois were found to have a home range of 136 ha (336.1 ac), and females a home range of 107 ha (264.4 ac) (Fritzell and Haroldson 1982, p. 4). A study by Haroldson and Fritzel (1984, p. 225) conducted in a Missouri oak-hickory forest indicated that nightly range use by gray fox was a fraction of the total monthly range. They also found composite (multiple month) home ranges (average 676 (+/−) 357 ha (1,670 (+/−) 882 ac)) are much larger than the individual month home ranges (average 299 (±) 155 ha (738 (±) 383 ac)) (Haroldson and Fritzel 1984, p. 223). Haroldson and Fritzel (1984, p. 226) also indicated that gray fox home ranges vary among populations. Gray fox are more active at night, with activity at sunrise sharply decreasing and increasing again at sunset (Haroldson and Fritzell 1984, p. 224).
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 (Jones
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 the
The petition asserts that prairie gray fox numbers have declined in many of the States within its range (Petition, unpaginated). The petition mentions that the Department of the Interior used scent stations to track the relative abundance of several predators, including the gray fox, in many western States. The average Statewide indices between the 1980 and 1981 surveys showed a decline in Minnesota from 2.4 to 1.9, and in Oklahoma from 2.0 to 1.0 (U.S. Department of the Interior 1981, pp. 42, 70; U.S. Department of the Interior 1980, pp. 44, 72). The Statewide indices for Kansas, Nebraska, North Dakota, South Dakota, and Wisconsin were zero in both 1980 and 1981 (U.S. Department of the Interior 1981, pp. 38, 52, 66, 78, 98; U.S. Department of the Interior 1980, pp. 40, 54, 68, 80, 100). There was an increase in the numbers of gray fox between 1980 and 1981 in Illinois; however, all of the scent stations recorded were outside the range of the prairie gray fox subspecies, so they were likely a different subspecies (U.S. Department of the Interior 1981, p. 36; U.S. Department of the Interior 1980, p. 36). The petitioners cite these numbers when asserting that the prairie gray fox was rare to absent in the plains States by 1980 (Petition, unpaginated). The petitioners cite the Minnesota Department of Natural Resources' annual carnivore scent station survey as including gray fox in their “fox” numbers (Petition unpaginated); however we can find no indication in this reference that gray fox were counted during those surveys (Erb 2010, p. 43-57).
The Missouri Department of Conservation's annual Archer's Index to Furbearer Populations shows a 75 percent decline in gray fox numbers since 1983 (petition unpaginated; Blair 2011, p. 31). The petitioners state that the number of gray fox in Wisconsin, as observed by the Wisconsin Department of Natural Resources during routine field work, was comparable to the badger, which is listed by the State as endangered (Petition, unpaginated). The report does indicate that the number of gray fox observed in 2010 was 0.78 observations per respondent, which is higher than the long-term average (during the 23 years of the study) of 0.42 observations per respondent (Kitchell 2010, unpaginated). The number of gray fox counted during the annual Bowhunter Observation Survey in Arkansas have been low but stable from 2005-2010 (Petition, unpaginated; Sasse 2011, unpaginated). The numbers of gray fox counted during the Iowa 2010 Bowhunter Observation Survey were fewer than the margin of error for some of the regions and showed an overall decline in the State (Petition, unpaginated; Roberts and Clark 2011, unpaginated). The petitioners attribute this decline to the loss of preferred habitat and the increase in agricultural habitat, which gray fox avoid (Petition, unpaginated; Cooper 2008, p. 24; Fritzell and Haroldson 1982, p. 189). Although the evidence included in the petition and within our files shows a decline in the population of the prairie gray fox for several States, there are no studies included that specifically indicate what the population of the prairie gray fox was prior to human settlement or how much the population has declined rangewide.
Eastern cottontail (
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 (Chapman
In describing eastern cottontail habitat, Chapman
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; Chapman
Under the Service's Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered Species Act (61 FR 4722, February 7, 1996), three elements are considered in the decision concerning the establishment and classification of a possible DPS. These are applied similarly for additions to or removal from the Federal List of Endangered and Threatened Wildlife. These elements include:
(1) The discreteness of a population in relation to the remainder of the taxon to which it belongs;
(2) The significance of the population segment to the taxon to which it belongs; and
(3) The population segment's conservation status in relation to the Act's standards for listing, delisting (removal from the list), or reclassification (
Our understanding of the petitioners' requested action is that the population of Mearn's cottontail in east-central Illinois and western Indiana (Figure 1) be considered a DPS and listed as endangered or threatened under the Act. Therefore, in this analysis, we evaluate whether the petition provides substantial information that the Mearn's eastern cottontail in east-central Illinois and western Indiana may constitute a DPS.
Under our DPS Policy, a population segment of a vertebrate species may be considered discrete if it satisfies either one of the following conditions:
(1) It is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors. Quantitative measures of genetic or morphological discontinuity may provide evidence of this separation.
(2) It is delimited by international governmental boundaries within which significant differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act.
The petitioners describe the area of the petitioned DPS in the revised petition submission (dated January 23, 2012) as follows: “this region covers the former Grand Prairie region of Illinois and western Indiana.” However, the submitted description does not provide exact boundaries or reference maps for the petitioned DPS. Therefore, the DPS we consider in our evaluation is based on a hand-drawn map submitted by the petitioners in the original petition submission (dated July 18, 2011) (not paginated). For our DPS evaluation, we considered references provided with the original July 18, 2011, petition submission, references provided with the revised January 23, 2012, petition submission, and other information readily available in our files.
The petition cites one study (Mankin and Warner 1999a) as the supporting evidence that the population of Mearn's eastern cottontail in east-central Illinois and western Indiana is: (1) Physically discrete from the rest of the subspecies; (2) ecologically distinct due to intensive agriculture leaving only artificial remnants of its original habitat; and (3) behaviorally distinct because individuals require home ranges averaging 7 times larger than other members of the eastern cottontail species.
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 Ribic
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'. Chapman
Based on the information submitted with the petition and information in our files, we find that the petition presents substantial information to suggest there may be a markedly separate population of Mearn's eastern cottontail in east-central Illinois and western Indiana due to behavioral differences when compared to the subspecies located elsewhere. The population of Mearn's eastern cottontail in east-central Illinois and western Indiana may be discrete from the rest of the Mearn's population because they occupy an area of intensive agriculture that leads to the behavior of maintaining different home-range sizes than the subspecies in the rest of the range. Therefore, this population of Mearn's cottontail may meet the discreteness criterion that it is markedly separated from other populations of the same taxon based on behavioral reasons.
There are no international governmental boundaries associated with this subspecies that are significant. The population of Mearn's eastern cottontail in east-central Illinois and western Indiana lies wholly within the United States. Because this element is not relevant in this case for a finding of discreteness, it was not considered in reaching this determination.
If a population segment is considered discrete under one or more of the conditions described in our DPS policy, its biological and ecological significance will be considered in light of Congressional guidance that the authority to list DPSes be used “sparingly” while encouraging the conservation of genetic diversity. In making this determination, we consider available scientific evidence of the discrete population segment's importance to the taxon to which it belongs. As precise circumstances are likely to vary considerably from case to case, the DPS policy does not describe all the classes of information that might be used in determining the biological and ecological importance of a discrete population. However, the DPS policy does provide four possible reasons why a discrete population may be significant. As specified in the DPS policy (61 FR 4722), this consideration of the population segment's significance may include, but is not limited to, the following:
(1) Persistence of the discrete population segment in an ecological setting unusual or unique to the taxon;
(2) Evidence that loss of the discrete population segment would result in a significant gap in the range of a taxon;
(3) Evidence that the discrete population segment represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historical range; or
(4) Evidence that the discrete population segment differs markedly from other populations of the species in its genetic characteristics.
A population segment needs to satisfy only one of these criteria to be considered significant. Furthermore, the list of criteria is not exhaustive; other criteria may be used as appropriate.
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 subspecies
The petition does not present information to suggest the population of Mearn's eastern cottontail in east-central Illinois and western Indiana may persist in an ecological setting unusual or unique to the taxon, evidence that the population represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historical range, or evidence that the population differs markedly from other populations of the species in its genetic characteristics. Additionally, we do not have information in our files to indicate that these characteristics are met.
Substantial information is not presented in the petition, nor is it available in our files, to suggest that the population of Mearn's eastern cottontail in east-central Illinois and western Indiana is biologically or ecologically significant to the remainder of the taxon. Therefore, we determine, based on the information provided in the petition and in our files that the population of Mearn's eastern cottontail in east-central Illinois and western Indiana does not meet the significance criterion of the 1996 DPS policy.
We reviewed the information presented in the petition and evaluated that information in relation to information readily available in our files. On the basis of this review, we find that neither the petition, nor information readily available in our files, suggests that the Mearn's eastern cottontail population in east-central Illinois and western Indiana meets the criteria for being significant under our DPS policy. Although the population may meet the criteria for being discrete under the DPS policy, neither the information in the petition, nor the information readily available in our files, suggests that this population of Mearn's eastern cottontail may be significant to the remainder of the taxon. Because both discreteness and significance are required to satisfy the DPS policy, we have determined that the Mearn's eastern cottontail population in east-central Illinois and western Indiana does not satisfy the elements of being a DPS under our 1996 policy and, therefore, is not a listable entity under section 3(16) of the Act. Because the petition does not present substantial information that the population of Mearn's eastern cottontail in east-central Illinois and western Indiana is a DPS, we did not evaluate whether the information contained in the petition regarding the conservation status was substantial.
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 (see
Section 4 of the Act (16 U.S.C. 1533) and its implementing regulations at 50 CFR part 424 set forth the procedures for adding a species to, or removing a species from, the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act:
(A) The present or threatened destruction, modification, or curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued existence.
In considering what factors might constitute threats, we must look beyond the mere exposure of the species to the factor to determine whether the species responds to the factor in a way that causes actual impacts to the species. If there is exposure to a factor, but no response, or only a positive response, that factor is not a threat. If there is exposure and the species responds negatively, the factor may be a threat and we then attempt to determine how significant a threat it is. If the threat is significant, it may drive or contribute to the risk of extinction of the species such that the species may warrant listing as an endangered or threatened species as those terms are defined by the Act. This does not necessarily require empirical proof of a threat. The combination of exposure and some corroborating evidence of how the species is likely impacted could suffice. The mere identification of factors that could impact a species negatively may not be sufficient to compel a finding that listing may be warranted. The information must contain evidence sufficient to suggest that these factors may be operative threats that act on the species to the point that the species may meet the definition of an endangered or threatened species under the Act.
In making this 90-day finding, we evaluated whether information regarding threats to the prairie gray fox and the plains spotted skunk, as presented in the petition and other information available in our files, is substantial, thereby indicating that the petitioned action may be warranted. Our evaluation of this information is presented below.
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; Lesmeister
The petition claims that the plains spotted skunk has since declined (Petition, unpaginated; Gompper and Hackett 2005, pp. 199-200) because of changes in agriculture, silviculture, and climate. Because plains spotted skunks rely on early successional habitat, management activities or lack of management that reduce the occurrence of dense vegetative stands or modify forest structure to more open, mature stands could be detrimental to the subspecies (Petition, unpaginated; Lesmeister 2007, p. 56; Lesmeister 2009, pp. 23-24).
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 (Choate
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 (Choate
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; Lesmeister
In summary, we find that the information provided in the petition, as well as other information available in our files, presents substantial scientific or commercial information indicating that the petitioned action may be warranted due to historical and currently ongoing habitat loss and degradation due to modifications of early successional habitat. Further assessment of population declines due to the loss of early successional habitat caused by changes in agricultural practices, changes in silvicultural practices, and reduction in food availability by intensive use of pesticides is necessary.
The petitioners did not present information regarding the overutilization of the plains spotted skunk for commercial, recreational, scientific, or educational purposes.
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 (Novak
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). Lesmeister
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). Lesmeister
Diseases affecting the subspecies include pneumonia, coccidiosis, and rabies (Kinlaw 1995, p. 4). The plains spotted skunk, however, is often overrated as a carrier of rabies; fewer cases were documented in spotted skunks than in domestic cats, cattle, dogs, or striped skunks (Hazard 1982, p. 145). Viral disease, such as parvovirus, or mink enteritis virus, may contribute to localized population declines, and some viral diseases can exhibit rapid spread and long-term impacts to local population viability, but do not appear to impact the species as a whole (Gompper and Hackett 2005, p. 200). Based on information readily available in our files, disease may have been a cause of historical decline, but we do not have information to indicate that disease is presenting an ongoing threat to the plains spotted skunk. As we proceed with the 12-month status review, we will further investigate whether disease is an ongoing threat to the subspecies.
In summary, the petition and information in our files identifies excessive predation that may be occurring at a higher rate than naturally expected as a threat to the plains spotted skunk. Therefore, we find that the information provided in the petition, as well as other information readily available in our files, presents substantial scientific and commercial information to indicate that the plains spotted skunk may warrant listing due to predation.
The petitioners state that there currently is no mechanism to protect habitat or garner appropriate resources for species conservation.