STATUS OF THE SPECIES Indiana Bat The Indiana bat was officially listed as an endangered species on March 11, 1967 (32 FR 4001) under the Endangered Species Preservation Act of October 15, 1966 (80 Stat. 926; 16 U.S.C. 668aa[c]). The Endangered Species Act of 1973 extended full protection to the species. The Service has published a recovery plan (USFWS 1983b) which outlines recovery actions. Briefly, the objectives of the plan are to: (1) protect hibernacula; (2) maintain, protect, and restore summer maternity habitat; and (3) monitor population trends through winter censuses. The recovery plan is currently being updated to reflect new information concerning summer habitat use.
Thirteen winter hibernacula (11 caves and two mines) in six states were designated as critical habitat for the Indiana bat in 1976 (41 FR 187). Based on censuses taken at hibernacula, the total known Indiana bat population is estimated to number about 352,000 bats. The most severe declines in wintering populations have occurred in two states: Kentucky, where 145,000 bats were lost between 1960 and 1975, and Missouri, where 250,000 Indiana bats were lost between 1980 and 1995. In Indiana, populations dropped by 50,000 between the earliest censuses and 1980, but have rebounded to former levels in recent years. On the Wayne NF, one abandoned mine, specifically a limestone mine, provides a winter hibernaculum for approximately 150 Indiana bats (USFS 2001a).
A variety of factors have contributed to Indiana bat population declines (USFWS 1983b). Sometimes their winter hibernacula are flooded, ceilings of the hibernacula collapse, or cold temperatures kill the bats through hypothermia. Exclusion of bats from hibernacula through blocking of entrances, installations of gates that do not allow for bat ingress and egress, disruption of cave air flow, and human disturbance during hibernation have been documented causes of Indiana bat declines. Because many known threats are associated with hibernation, protection of hibernacula has been a management priority.
Despite the protection of most major hibernacula, population declines have continued. Continued population declines of Indiana bats, in spite of efforts to protect hibernacula, have led scientists to the conclusion that additional information on summer habitat is needed (Romme et al. 1995). In addition to increased focus on summer habitat, attention is also being directed to pesticide contamination. Insecticides have been known or suspected as the cause of a number of bat die-offs in North America, including endangered gray bats in Missouri (Clark et al. 1978). The insect diet and longevity of bats also exposes them to persistent organochlorine chemicals which may bioaccumulate in bat tissue and cause sub-lethal effects such as impaired reproduction.
Description and Distribution
The Indiana bat is a medium-sized bat with a head and body length that ranges from 41 to 49 mm. It is a monotypic species that occupies much of the eastern half of the United States, from Oklahoma, Iowa, and Wisconsin east to Vermont, and south to northwestern Florida. The Indiana bat is migratory, and the above described range includes both winter and summer habitat. The winter range is associated with regions of well-developed limestone caverns. Major populations of this species hibernate in Kentucky, Indiana, and Missouri. Smaller winter populations have been reported from Alabama, Arkansas, Georgia, Illinois, Maryland, Mississippi, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia. More than 85 percent of the entire known population of Indiana bats hibernates in only nine caves.
Generally, Indiana bats hibernate from October through April (Hall 1962, LaVal and LaVal 1980), depending upon local weather conditions. Bats cluster on cave ceilings in densities ranging from 300-484 bats per square foot. Hibernation facilitates survival during winter when prey are unavailable. However, the bat must store sufficient fat to support metabolic processes until spring. Substantial risks are posed by events during the winter that interrupt hibernation and increase metabolic rates.
After hibernation ends in late March or early April, most Indiana bats migrate to summer roosts. Female Indiana bats emerge from hibernation in late March or early April, followed by the males. The period after hibernation but, prior to migration, is typically referred to as staging. Most populations leave their hibernacula by late April. Migration is stressful for the Indiana bat, particularly in the spring when their fat reserves and food supplies are low. As a result, adult mortality may be the highest in late March and April.
Summering Indiana bats roost in trees in riparian, bottomland, and upland forests. Roost trees generally have exfoliating bark which allows the bat to roost between the bark and bole of the tree. Cavities and crevices in trees also may be used for roosting. A variety of tree species are known to be used for roosts including (but not limited to) silver maple (Acer saccharinum), shagbark hickory (Carya ovata), shellbark hickory (Carya laciniosa), bitternut hickory (Carya cordiformis), green ash (Fraxinus pennsylvanica), white ash (Fraxinus americana), Eastern cottonwood (Populus deltoides), northern red oak (Quercus rubra), post oak (Quercus stallata) , white oak (Quercus alba), shingle oak (Quercus imbricaria), slippery elm (Ulmus rubra), American elm (Ulmus americana), sassafras (Sassafras albidum), and sugar maple (Acer saccharum) (Romme et al. 1995). Structure is probably more important than the species in determining if a tree is a suitable roost site; tree species which develop loose, exfoliating bark as they age and die are likely to provide roost sites. Male bats disperse throughout the range and roost individually or in small groups. In contrast, reproductive females form larger groups, referred to as maternity colonies.
Maternity colonies, which may be occupied from mid-May to mid-September, usually contain 100 or fewer adult female bats. Females each give birth to a single young in late June or early July . Young Indiana bats are capable of flight within a month of birth. They spend the latter part of the summer foraging to accumulate fat reserves for the fall migration and hibernation. Maternity colonies occupy roost sites in trees in forested riparian, flood plain, or upland habitats (Romme et al. 1995). Female Indiana bats exhibit strong site fidelity to summer roosting and foraging areas, that is, they return to the same summer range annually to bear their young. Traditional summer sites are essential to the reproductive success of local populations. It is not known how long or how far female Indiana bats will search to find new roosting habitat if their traditional roost habitat is lost or degraded. If they are required to search for new roosting habitat, it is assumed that this effort places additional stress on pregnant females at a time when fat reserves are low or depleted and they are already stressed from the energy demands of migration.
Indiana bat roosts are ephemeral and frequently associated with dead or dying trees. Most roost trees may be habitable for only 2-8 years (depending on the species and condition of the roost tree) under natural conditions. Gardner et al. (1991a) evaluated 39 roost trees and found that 31 percent were no longer suitable the following summer, and 33 percent of those remaining were unavailable by the second summer. A variety of suitable roosts are needed within a colony's traditional summer range for the colony to continue to exist. Indiana bat maternity sites generally consist of one or more primary maternity roost trees which are used repeatedly by large numbers of bats, and varying numbers of alternate roosts, which may be used less frequently and by smaller numbers of bats. Bats move among roosts within a season and when a particular roost becomes unavailable from one year to the next. It is not known how many alternate roosts must be available to assure retention of a colony within a particular area, but large, nearby forest tracts appear important (Callahan 1993). In addition to having exfoliating bark, roost trees must be of sufficient diameter. Trees in excess of 40 cm dbh are considered optimal for maternity colony roost sites, but trees in excess of 22 cm dbh appear to provide suitable maternity roosting habitat. Male Indiana bats have been observed roosting in trees as small as 8 cm dbh.
In Illinois, Gardner et al. (1991b) found that forested stream corridors, and impounded bodies of water, were preferred foraging habitats for pregnant and lactating Indiana bats, which flew up to 2.4 km from upland roosts to forage. Females typically utilize larger foraging ranges than males (Garner and Gardner 1992). Bats forage at a height of approximately 2-30 meters under riparian and flood plain trees (Humphrey et al. 1977). They forage between dusk and dawn and feed exclusively on flying insects, primarily moths, beetles, and aquatic insects. Riparian habitat is occupied by Indiana bats from mid-April to mid-September. Romme et al. (1995) cite several studies which document that Indiana bats also forage in upland forests.
After the summer maternity period, Indiana bats migrate back to traditional winter hibernacula. Some male bats may begin to arrive at hibernacula as early as July. Females typically arrive later and by September numbers of males and females are almost equal. Autumn Aswarming@ occurs prior to hibernation. During swarming, bats fly in and out of cave entrances from dusk to dawn, while relatively few roost in the caves during the day. By late September many females have entered hibernation, but males may continue swarming well into October in what is believed to be an attempt to breed late arriving females.
Swarming is important to the life history of the bat as most copulation occurs during this time. Females store sperm through the winter and fertilization occurs in the spring. Females are pregnant when they arrive at the maternity roost. Fecundity is low; female Indiana bats produce only one young per year.
Bald Eagle The bald eagle was officially listed as endangered throughout the lower 48 states, except in Michigan, Minnesota, Wisconsin, and Oregon, where it was designated as threatened, on February 14, 1978 (43 FR 6233). On June 12,1995, the Service published a final rule reclassifying the status of the bald eagle from Federally endangered to threatened throughout the lower 48 states (60 FR 36000). No critical habitat has been designated for the species. Currently, the Service has published a proposed rule to remove the bald eagle in the lower 48 states from the Federal list of endangered and threatened wildlife. A final decision on the delisting has not yet been made and may not occur until mid-2001, or later. If delisting should occur, the bald eagle would continue to be protected under the Bald and Golden Eagle Protection Act of 1962, as amended, the Migratory Bird Treaty Act of 1918 and the Lacey Act of 1900.
The bald eagle was listed under the ESA due to population losses caused by pesticide pollution, hunting, and habitat destruction. The use of DDT as a pesticide from 1940 through the 1960=s caused the drastic decline in the bald eagle. Consumption of DDT contaminated prey resulted in eggshell thinning and nesting failures. With the banning of DDT and strong enforcement of recovery measures, the eagle has successfully recovered. However, two major threats to the bald eagle remain: habitat loss and contaminants. Even though the widespread elimination of DDT and reduction of other pesticides has been greatly successful, other contaminants exist on a localized level although these contaminants are not believed to cause widespread suppression of the population. Their habit of returning to the same nesting and winter roosting sites, as well as their tendency to congregate makes each site of great importance to the entire population of bald eagles. Shootings, disease, human disturbance, electrocution and vehicle collisions are also continuing threats to the eagle.
Five recovery regions (Pacific, Southwestern, Southeastern, Chesapeake Bay, and Northern States) have been designated for the eagle in the lower 48 states. Ohio is within the Northern States Recovery Region. The Service published the Northern States Bald Eagle Recovery Plan in 1983. Major recovery steps outlined in the plan include: (1) determine current population and habitat status; (2) determine population and habitat levels needed to achieve recovery; (3) protect, enhance, and increase bald eagle populations and habitats; and (4) establish and maintain communication to coordinate and conduct recovery efforts.
In Ohio specifically, the two problems that continue to threaten the bald eagle are the loss of wetlands and swamp forests, among the preferred nesting and staging areas for the eagle, and damage to the State=s waters. Channelization, erosion, and water pollution all adversely affect the water resource and its inhabitants, which potentially impact the eagle=s food source (ODNR no date (1)).
Description and Distribution
The bald eagle is a large, long-lived bird of prey that occurs only in North America. The adults have brown bodies with white heads and tails. The young are all brown, and can be distinguished from young golden eagles by their lower bare legs (golden eagles have feathered legs all the way to their feet). They do not take on the coloring of the adults or reach sexual maturity until age four (USFWS 1983a).
In Ohio, the highest numbers of bald eagles occur in the marsh region of western Lake Erie. Nesting pairs also occur in northeast Ohio, along the Sandusky River, and in north-central Ohio (ODNR no date (1)). Counties listed as harboring bald eagles are: Ashtabula, Delaware,Coshocton, Erie, Geauga, Hamilton, Henry, Hocking, Holmes, Huron, Knox, Lake, Licking, Lorain, Lucas, Mercer, Mahoning, Marion, Muskingum, Noble, Ottawa, Portage, Sandusky, Seneca, Stark, Summit, Trumbull, Wood, and Wyandot; of which Hocking and Noble contain Wayne NF property. Three additional counties containing bald eagle nests were found in 2000. They are Harrison, Ross and Wayne counties (ODNR 2000b). According to the USFWS (1983a), areas associated with large bodies of water should be studied closely for eagle nests and wintering roosts. If a previously-used site is located or the potential for eagle habitat exists in the absence of eagles, the area should still be considered for protection, because bald eagles are now re-occupying old territory and new habitat as their numbers grow. The bald eagle=s numbers in Ohio have grown significantly since the early 1980=s. In 1982, there were 7 known nesting pairs in Ohio; in 1998 there were 47 documented nesting pairs, and just one year later an additional 16 nesting pairs were counted (ODNR 2000c). In January 2000, a record 193 wintering bald eagles were counted in the 29 counties noted above (ODNR 2000a). Figure 7-3 shows the Ohio range for the bald eagle.
The bulk of the bald eagle=s diet is fish, however they will also feed on waterfowl, small mammals, and carrion, especially in winter (USFWS 1983a).
It is believed that eagles mate for life, but there is little documentation to substantiate this claim. In the event that the mates are separated, new mates likely are found. Pairs of eagles usually raise one to two young per season, originating from one to three eggs. The entire breeding cycle from initial breeding activity to fledging is about six months.
Many do not breed for the first time until they are six years of age or older. The time period before sexual maturity is a time of significant mortality, and many eagles do not reach two years of age. After the first couple of years, chances for survival improve, and eagles are thought to live up to thirty years (USFWS 1983a).
Eagles usually nest near large bodies of water (within one-half mile), although they will occasionally have nests in upland areas where there is good access to food. Bald eagles tend to return to the same breeding area, and often the same nest sites, each year. Although there are reports of nests on the ground or on cliff faces, the majority of eagles build their nests in supercanopy trees with large diameters and canopies (USFWS 1983a). The nests typically occur in live coniferous or dead trees (USFS 1998). They construct the nests of sticks and add to them each year (USFWS 1983a). The nest tree is usually within one-half mile of water and have a clear flight path to water (USFS 1998). Suitable nest site characteristics are found throughout the Wayne NF.
When the nesting period is over, the wintering period begins. At this time, the eagles generally leave their nest site for more protected locales with abundant food supplies. According to the 1981 eagle count done by the National Wildlife Federation, during the months between November and March, bald eagles make their way into all of the contiguous 48 states. As with their nests, the eagles revisit many of the same wintering sites. The sites are chosen for their shelter from the wind to reduce energy use. The wintering population of eagles is split between large groups that congregate at recurring communal sites, and those that have smaller gatherings. Both the large and small wintering meeting and roosting sites are equally important to the survival of the species. In addition to shelter from the weather, roost sites provide isolation from humans. When human disturbance of a night roost occurs, eagles may abandon the location (USFWS 1983a).
Survival of individual bald eagles, particularly those in their first year of life, depends heavily on conditions they encounter during the wintering period. In previous studies, it was thought that their reproduction rate was the most important dynamic for the preservation of the species, but it is now believed that their survival rate may play a more crucial role. It appears likely that eagle populations may be more successful with lower reproduction rates and higher survival rates, than vice versa (USFWS 1983a).
During winter, night roost trees are used by an individual bald eagle or group of eagles for protection from wind and harsh weather. These trees are also thought to aid in mate location and communication of food sources. Night roost trees have a large diameter, dense canopy cover in wind-protected areas and may be located either adjacent to foraging areas or at distances up to 17 miles away (USFS 1998).
Daytime roosts are usually located near foraging areas within 100 feet of shoreline and are used for eating, resting and hunting. Tall dead trees or mature trees with strong branches are the eagle=s preference. The availability of prey is the most important characteristic of wintering sites used by bald eagles (USFS 1998).
American Burying Beetle The American burying beetle was officially listed as endangered, pursuant to the ESA, throughout its historic range on 13 July 1989 (54 FR 29652). The Service has published a recovery plan (USFWS 1991) which outlines recovery actions for the beetle. Briefly, the objectives of the plan are to: (1) protect and manage extant populations, and (2) maintain captive populations for reintroduction.
There has been considerable controversy about the cause of the American burying beetle decline. It has been pointed out that the extirpation of the species in most areas preceded the widespread use of pesticides. An unknown disease vector specific tothe beetle cannot be totally ruled out, but no other species of the genus are affected. The prevailing theory is that because they are the largest species in the genus, and require the largest carcasses, they have been more adversely affected than other members of their genus by habitat fragmentation. As stated in the recovery plan, Afragmentation of large areas of natural habitat that historically supported high densities of indigenous species (exacerbated by the direct taking of birds and other vertebrates) may have been a contributing factor in the decline of the beetle by changing the species composition and lowering the reproductive success of prey species required for optimum reproduction.@ In locations where the American burying beetle has been extirpated or greatly reduced in population, other species of the genus Nicrophorus have increased. It has been noted that some of the species that once probably provided important carcasses for the beetle are now rare. The passenger pigeon is extinct, and greater prairie chicken is much less common than they once were. Scavengers including dogs, cats, and coyotes always increase at forest edges and where civilization occurs and now compete with the American burying beetle for prey. With increasingly localized populations, the American burying beetle=s genetic variability that is important for adapting to changing habitat would have been further reduced by genetic drift. The lack of optimal sized carcasses for reproduction of the species is now seen as the primary cause for the species precipitous decline (USFWS 1991, USFWS 1994).
Description and Distribution
The American burying beetle is the largest member of the group of beetles that breed and raise their larvae on carcasses of vertebrates (mammals and birds). It is 25 to 45 mm in size with a shiny black body and is the only one of the genus Nicrophorus with an orange-red marking on the first thoracic segment (pronotum). Each of the front wings (elytra) has two scalloped orange-red markings and the antennae are red-orange tipped. It is often covered with phoretic mites with which it shares a symbiotic relationship (USFWS 1991).
The range of the American burying beetle has decreased to less than 10 percent of the species historic range. Historic records for the American burying beetle include 150 counties in 35 states in the eastern United States and southern Canada. It ranged from Nova Scotia to Montana and Nebraska, but was poorly documented from the Appalachians and the lower Coastal Plain (USFWS 1991). In 1991, there were several new discoveries of the beetle, which now list wild populations in Rhode Island, Oklahoma, Nebraska, and Arkansas (USFWS 1994). A captive breeding and introduction program is underway using the Block Island, Rhode Island populations from the Roger Williams Park Zoo.
The American burying beetle uses larger carrion, both birds and mammals of 100 to 200 grams in weight, on which to raise their broods. A pair of beetles will stake a claim to a carcass and defend it against congeneric beetles and other competitors, such as flies. After the pair buries the carcass, the female lays 36 to 42 eggs in a side chamber near the carcass. The eggs hatch in six days and the larvae require 12 to 16 days to develop. Both parents initially defend and guard the eggs, and usually the female will remain with and feed the larvae until pupation. The male typically leaves within 10 to 15 days (Keeney 2001, USFWS 1991).
The adults themselves feed on carrion and also consume live prey. They are nocturnal and active only when the temperature is above 60 degrees Fahrenheit, usually from April to September. The beetle spends the winter months below ground. They lay their eggs on the buried carcass in June or July. They are univoltine (have a single yearly brood) animals and usually live only about a year. Prey carcass size is more important than prey species. The carcass must be of the optimal size and weight to raise a maximum brood. American burying beetles will raise a brood on carcasses as small as 35 grams, but research has shown them to raise a smaller number of larvae on the reduced food supply (USFWS 1991).
American burying beetles have been found in pastures, pasture/forest transition areas, old fields, open woodland and forests, specifically oak-hickory forests, and grasslands (USFWS 1991). The beetle does prefer upland ridgetop areas versus riparian areas, since carrion found in the uplands are typically warmer and have a greater odor plume for locating carrion (Keeney 2000). The availability of carcasses of sufficient size appears to be the most important factor in their habitat requirements. Also, their habitat must have soils capable of excavation for the burial of carcasses. Level topography, well-drained soils and a well-formed detritus layer are characteristics noted at American burying beetle sites (USFWS 1991).