Source: www.fws.gov

 

1. Taxonomy:
   

Here are the major taxonomical attributes of the beetle:

1. It is metallic brown to dark-olive green with a metallic dark green underside;
   
2. It measures about 0.5 inch in total length, and is native to eastern Nebraska’s saline wetlands; and
   
3. Tiger beetles are active, ground-dwelling, predatory insects that capture smaller or similar-sized arthropods in a “tiger-like” manner, grasping prey with their mandibles or mouthparts.  
   

 

Because of their interesting behaviour and variety of forms and habitats, tiger beetles as a group have extensively been studied.

 

The Nebraska Salt Creek Tiger beetles are speedy, often colourful, and voracious predators. Many live in the sandy soils of stream banks and are highly susceptible to changes in their environment. These insects can be excellent indicators of the overall health of an ecosystem, as they may be one of the first animals to decline with habitat changes. According to NatureServe, tiger beetles are one of the most endangered groups of insects – second only to stoneflies – approximately 19 percent of all tiger beetles are either vulnerable to extinction, imperilled, or extinct.

 

1. Habitat: 
   

According to the report, Recovery Outline for the Salt Creek Tiger Beetle, the Salt Creek tiger beetle has very specific habitat requirements and occurs in saline wetlands—on exposed saline mud flats or along mud banks of streams and seeps that contain salt deposits and are sparsely vegetated.  Larvae have been found only on moist salt flats and salt-encrusted banks of Little Salt Creek in northern Lancaster County and saline wetlands associated with Rock Creek in the southern margin of Saunders County.  Salt Creek tiger beetles require open, barren salt flat areas for construction of larval burrows, thermoregulation, foraging, and as dispersal corridors. The Salt Creek tiger beetle is adapted to brief periods of high water inundation and highly saline conditions.

 
 

The U.S. Fish and Wildlife Service announced on April 6, 2010, a final rule designating approximately 1,933 acres of land in Lancaster and Saunders Counties, Nebraska, as critical habitat for the endangered Salt Creek tiger beetle.  The four areas designated as critical habitat are:

1. Upper Little Salt Creek North in Lancaster County;
   
2. Little Salt Creek – Arbor Lake in Lancaster County;
   
3. Little Salt Creek – Roper in Lancaster County; and
   
4. Rock Creek – Jack Sinn Wildlife Management Area in Lancaster and Sounders Counties.
   

 

Critical habitat is a term defined in the Endangered Species Act. It identifies geographic areas containing features essential for the conservation of a threatened or endangered species and may require special management considerations or protection.  Saline wetland and stream complexes found along Little Salt Creek and Rock Creek comprise the critical habitat designation.

 

The Salt Creek tiger beetle has one of the most restricted ranges of any insect in the United States and the habitat currently occupied is highly limited and isolated.  Low population numbers and the limited number of populations, as well as the close proximity of the populations, greatly increase the risk of extinction of the Salt Creek tiger beetle due to a single human or natural occurrence.  Therefore, in addition to the currently occupied areas on Little Salt Creek, the Service has designated currently unoccupied habitat on Rock Creek.  This is an area where a beetle population can be reintroduced and where it would have the best opportunity to survive and grow.

 

1. Rationale:
   

Here are some reasons for protecting the Nebraska Salt Creek Tiger Beetle:

• The reason it is considered a “Bio-Indicator” species, it represents the existence of a healthy saline wetland and stream system.  Intact, these systems provide numerous benefits for people as well as wildlife, including water purification, flood control, and outdoor recreation opportunities;
  
• It is also considered a subspecies, a geographically isolated population of a species, and it has been speculated that it has been isolated from other populations from the last glaciations (10,000+ years ago).  Morphologically, it is distinct from other subspecies within the species, as far as subspecies go. It has been suggested that over time, the Salt Creek tiger beetle could develop into a distinct species;
  
• The Salt Creek tiger beetle feeds on other insects, some of which may cause harm to humans, such as mosquitoes and deer flies. It is therefore considered beneficial to humans;
  
• The eastern Nebraska saline wetland is an ecosystem, with animals and plants interacting in many complex ways.  Tiger beetles feed on other insects and arthropods, and are in turn fed on by robber flies and other predators.  It is not known what effect, if any, removal of the Salt Creek tiger beetle from the ecosystem would be; and
  
• Tiger beetles make excellent models for studying many components of science, such as ecology (including population dynamics, competition, etc.), physiology, anatomy, evolution, behaviour, conservation, and genetics.
  

 

4. Survey Type:

I chose “Data-Gathering Survey” for my site, which will allow me to deal with:

• The collection of existing or new information (secondary data), often from others, rather than surveying the fauna directly.
  

 

It may involve web and literature searches, or a data trawl involving a diverse number of individuals and organisations ranging from specialist entomologists to participatory work with keen individuals or the public. For example, a web-based contributory survey of an easily identified particular species, which can generate good publicity as well as useful data?

 

5. Existing Data Analysis:

According to the data presented in the report, Recovery Outline for the Salt Creek Tiger Beetle by Nebraska Ecological Services Field Office in November 2009, intensive visual surveys conducted by the University of Nebraska – Lincoln (UNL) entomologists since 1991 have documented Salt Creek Tiger beetles at 13 sites in northern Lancaster County and the southern margin of Saunders County; although beetles were not found, nor were surveys conducted, at all sites in all years (Spomer et al. 2002, 2004a, 2004b).

 

It was determined these 13 sites be grouped into six discrete populations of Salt Creek Tiger beetles (70 FR 58335, October 6, 2005). Half of these populations have been extirpated since annual surveys began in 1991 (A population is considered extirpated after two consecutive years of negative survey results). Here are those six discrete group populations:

1. Little Salt Creek/Arbor Lake Population:
   

   The Little Salt Creek-Arbor Lake population contains the largest number of Salt Creek tiger beetles. This population occurs across a large, relatively intact saline wetland complex. The Little Salt Creek-Arbor Lake population is located approximately 1.6 kilometres (1 mile) north of the Interstate 80 and North 27^th Street Interchange on the northern city limits of Lincoln, Nebraska. It exists along the saline stream edge of Little Salt Creek and on the barren salt flats of an adjacent saline wetland. This population was monitored at a maximum of three survey sites. The population averaged 299 individuals per year over that 18-year period.
   

2. Little Salt Creek/Roper Population:
   

   The Little Salt Creek-Roper population is the second largest remaining population of Salt Creek tiger beetles. This population is located immediately south of the Interstate 80 and North 27^th Street Interchange, and approximately 1.6 km (1 mi) downstream of the Little Salt Creek-Arbor Lake population. Similar to the Little Salt Creek-Arbor Lake population, this population is associated with a saline wetland and stream complex located along Little Salt Creek. Visual surveys were conducted at a maximum of four survey sites. The population averaged 101 adult beetles during the 15-year survey period;
   

3. Upper Little Salt Creek – North Population:
   

   The Upper Little Salt Creek-North population is the third and last extant (i.e., existing) population of Salt Creek tiger beetles. This population is located approximately 7.2 km (4.5 mi) upstream from the Little Salt Creek-Arbor Lake population, and exists only on the saline stream edges of Little Salt Creek. Although former saline wetlands exist adjacent to this population, these wetlands are degraded (Drained because of the incisement of Little Salt Creek) and no longer provide suitable habitat for the Salt Creek tiger beetle. This population is comprised of four sites along Little Salt Creek. From 1991 to 1996, the number of adult beetles found in the Upper Little Salt Creek-North population averaged 32 individuals per year (Spomer and Higley 1993; Spomer et al. 1997). Since then, the number of adult beetles surveyed in the population has averaged 18 individuals per year;
   

4. Upper Little Salt Creek – South Population:
   

   The Upper Little Salt Creek-South population was located approximately 5 km (3 mi) upstream from the Little Salt Creek-Arbor Lake population. Degraded and non-functioning saline wetlands exist adjacent to Little Salt Creek. Although this site was once devoid of vegetation, saline stream edge habitats here are now vegetated. This population was surveyed at its only known site. The Upper Little Salt Creek-South population is considered to be extirpated; no Salt Creek tiger beetles have been found there since 1995;
   

5. Jack Sinn WMA Population:
   

   This population was made up of one survey site located on Rock Creek in southern Saunders and northern Lancaster Counties, approximately 20 km (10 mi) northeast of the Little Salt Creek-Arbor Lake population. This population of Salt Creek tiger beetles was on property owned by the Nebraska Game and Parks Commission (NGPC). The Jack Sinn Wildlife Management Area Population is considered to be extirpated; no Salt Creek tiger beetles have been found there since 1998. Loss and fragmentation of barren salt flats and stream habitats likely resulted in the loss of this population (Spomer et al. 2004a); and
   

6. Capital Beard Population:
   

   Capitol Beach was once one of the largest saline wetland tracts in eastern Nebraska, with a size of approximately 162 hectares (ha) (400 acres (ac)) (Cunningham 1985). Although we do not have historic population estimates from this site, historic records indicate that Capitol Beach (i.e., Salt Basin) was once home to a large, sustainable population of Salt Creek tiger beetles. All that remains of suitable habitat at Capitol Beach now is a 10- to 20-meter (m) (40- to 50-foot (ft)) wide ditch that parallels Interstate 80 for approximately 0.8 km (0.5 mi), southwest of the Interstate 80 and Airport Interchange. No individuals have been found at Capitol Beach since 1998 (Spomer et al. 2002, 2004a, 2004b; Allgeier et al. 2003), leading us to conclude that this population is now extirpated.

 

The table presented below illustrates a summarized view of the populations for 18 years from 1991 to 2008, indicating the number of species recorded at the end of each year.

My analysis indicates that out of18 years of surveys data, there were only 6 years when the population was increased. The following shows the percentage of population increase for each year:

1. 1994        311.3%    The population jumped from 115 species to 473 species, an increase of 358
   
2. 1995        34.7%    The population jumped from 473 species to 637 species, an increase of 164
   
3. 2000        14.0%    The population jumped from 309 species to 271 species, an increase of 38    
   
4. 2001        68.0%    The population jumped from 309 species to 519 species, an increase of 210
   
5. 2002        49.7%    The population jumped from 519 species to 777 species, an increase of 258
   
6. 2006        252.3%    The population jumped from 153 species to 539 species, an increase of 386
   

Whereas the population was decreased for the remaining 12 years. The following shows the percentage of population decrease for each year:

1. 1991        –
   
2. 1992        34.5%    The population decreased from 229 species to 150 species, a decrease of 79
   
3. 1993        23.3%    The population decreased from 150 species to 115 species, a decrease of 35
   
4. 1996        1.1%        The population decreased from 637 species to 630 species, a decrease of 7
   
5. 1997        12.7%    The population decreased from 630 species to 550 species, a decrease of 80
   
6. 1998        44.0%    The population decreased from 550 species to 308 species, a decrease of 242
   
7. 1999        12.7%    The population decreased from 308 species to 271 species, a decrease of 37
   
8. 2003        4.1%        The population decreased from 777 species to 745 species, a decrease of 32
   
9. 2004        25.1%    The population decreased from 745 species to 558 species, a decrease of 187
   
10. 2005        72.6%    The population decreased from 558 species to 153 species, a decrease of 405
    
11. 2007        51.4%    The population decreased from 539 species to 262 species, a decrease of 277
    
12. 2008        37.0%    The population decreased from 262 species to 165 species, a decrease of 97
    

 

The total decrease in populations based on the 12 out of 18 year’s survey data is calculated to be 1,478 Species

The total increase in populations based on the 6 out of 18 year’s survey data is calculated to be:    1,414 Species

The net loss is calculated to be:                                    64 species

.

7. Potential Questions:

The Salt Creek Tiger beetle provide some functions to people like food control, water quality, aesthetics, recreation, etc. It is important to understand that just protecting the Salt Creek Tiger beetle is not good enough to take advantage of these benefits as its saline wetland habitats also needed to be protected.

 

Based on the result of the analysis, the following questions can be articulated:

1. What were the contributing factors to the increase in the populations for the 6 years, recorded and reported?
   
2. How can those factors be re-created and maintained in order to continue to increase populations?
   
3. What were the contributing factors to the decrease in the populations for the 12 years, recorded and reported?
   
4. How can those factors be eliminated in order to help protect those species?
   
5. What can be done to monitor the beetle and their habitats in the interest of sustainability?
   

 

8. Proposed Approach:

In order to answer these questions, a recovery plan needed to be articulated. The focus of this plan should be not only to protect the Nebraska Salt Tiger beetle but also to protect the saline wetlands and stream habitats.

The recovery framework is based on the Recovery Outline for the Salt Creek Tiger beetle.

 

8.1    Select Two Population Groups:

All six populations groups listed under the Existing Data Analysis were analyzed based on the following criteria and the objective of this exercise was to understand the trends:

1. A group where an increased population was reported for the year 2008 in comparison with the year of initial survey (1991); and
   
2. A group where a decreased population was reported for the year 2008 in comparison with the year of initial survey (1991).
   

 

As a result, the following two population groups were selected:

1. Upper Little Salt Creek-North Population – The population reported for this group for the year 2008 was 39 species which is greater than the population reported for 1991 (24 species); and
   
2. Little Salt Creek/Arbor Population – The population reported for this group for the year 2008 was 109 species which is lower than the population reported for 1991 (171).
   

 

8.1.1    Upper Little Salt Creek-North Population:

The first survey results indicated a population of 24 species in 1991. There was an increase of 15 species, totalling 39 species reported in 2008. This population is comprised of four sites along Little Salt Creek. From 1991 to 1996, the number of adult beetles found in the Upper Little Salt Creek-North population averaged 32 individuals per year (Spomer and Higley 1993; Spomer et al. 1997). Since then, the number of adult beetles surveyed in the population has averaged 18 individuals per year.

 

The following graph illustrates the population for each year from 1991 to 2008.

 

Here is a graph that illustrates 11 out of 18 years when there was increase in the populations whereas there were only 7 out of 18 years when there was decrease in the populations:

 

The net gain is calculated to be (170 – 155) 15 species.

 

8.1.2    Little Salt Creek/Arbor Lake Population:

The first survey results indicated a population of 171 species in 1991. There was a decrease of 62 species, totalling 109 species reported in 2008. The Little Salt Creek-Arbor Lake population contains the largest number of Salt Creek tiger beetles. This population occurs across a large, relatively intact saline wetland complex. This population was monitored at a maximum of three survey sites. The population averaged 299 individuals per year over that 18-year period.

 

The following graph illustrates the population for each year:

Here is a graph that illustrates 7 out of 18 years when there was increase in the populations whereas there were 11 out of 18 years when there was decrease in the populations:

The net loss of population is calculated to be (1,064 – 1,002) 62 species.

 

Here is a graph that illustrates the trends of both populations:

8.2    Define Recovery Vision:

The vision of the recovery initiative is:

• Multiple viable Salt Creek tiger beetle populations that persist on conserved habitat with connectivity between populations.
  

However, the recovery outlook for the Salt Creek Tiger beetle will likely depend on the success of reintroductions within other stream segments and focused restoration projects that provide Salt Creek Tiger beetle microhabitat requirements.

 

Here is the Recovery Area:

8.3    Set Recovery Priority:    

This ranking indicates that:

1. The Salt Creek tiger beetle is a subspecies of Cicindela nevadica;
   
2. It faces a high degree of threat;
   
3. It has a high potential for recovery; and
   
4. It is in conflict with development activities or other forms of economic activities.
   

 

Here is a graph that illustrates priorities – High, Moderate, and Low:

 

The high potential for recovery is based on the likelihood that conservation can be achieved through known habitat protection and management techniques and research results that demonstrate the capability of captive rearing for reintroduction.

 

8.4    Identify Threats/Obstacles:

It is critical to assess and understand the threats/obstacles for the success of a recovery plan.

 

The high degree of threat is linked to biological constraints that the species faces such as reduced number of individuals and abundance and distribution of populations, genetic diversity, ability to colonize unoccupied areas, as well as anthropomorphic threats, such as excessive freshwater intrusion and sedimentation, cattle-grazing, stream entrenchment, pesticide application, and wetland loss and degradation. A number of these threats are related to development activities or other forms of economic activities.

 

The Salt Creek tiger beetle is threatened by the destruction of its saline wetland and stream habitats. The saline wetlands of eastern Nebraska and associated saline streams used by the Salt Creek tiger beetle have undergone extensive degradation and alteration for commercial, residential, transportation, and agricultural development since the late 1800s, and are the most restricted and imperilled natural habitat type in the State. Like many insects, the Salt Creek tiger beetle’s close association with specific habitats—salt barrens and stream edges—leaves it particularly vulnerable to habitat destruction and alteration through direct and indirect means.

 

Allgeier et al. (2004) concluded that a species-specific preference for specific salt and soil moisture regimes is important to habitat partitioning and reduction in competition between the Salt Creek tiger beetle and other tiger beetles. Hoback et al. (2000) also discovered that changes in salinity and hydrology might alter the abundance of prey and cause the loss of suitable larval habitat for saline wetland-dependent species of tiger beetles, including the Salt Creek tiger beetle. We believe that further degradation or loss of suitable habitats will further reduce the likelihood that Salt Creek tiger beetles will be able to move and recolonize other sites and establish additional populations.

 

Based on 2004 population surveys and a review of U.S. Geological Survey topographic maps showing population distributions, 99 percent of the remaining Salt Creek tiger beetles are located within a 1.6-km (1-mi) radius of the Interstate 80 and North 27th Street Interchange. This area continues to experience ongoing residential and commercial development. Excessive freshwater storm water runoff from nearby residential and commercial developments also can result in the dilution of existing saline wetlands and seeps and input of excess sediment and it encourages establishment of invasive plants.

 

Although tiger beetles are mobile and can fly, the lack of suitable habitat along little Salt Creek within movement limits for the Salt Creek tiger beetle (distances of less than 805 m (2,640 ft)) prohibits recolonization of other suitable habitats on other stream segments. The loss of travel corridors along Little Salt Creek has occurred because of bank sloughing, establishment of invasive plants, and loss of mid-stream gravel bars. Such loss of travel corridors eliminates genetic interchange and the ability to repopulate after catastrophic events.

 

Furthermore, local extinctions caused by habitat deterioration and stochastic weather events are frequent for species such as the Salt Creek tiger beetle, whose life histories are characterized by short generation time, small body size, high rates of population increase, and high habitat specificity. Potential stochastic events of greatest concern may include:

1. Heavy rain storms and severe flooding which drown and scour larvae away, dilute salinity, and result in sediment deposition;
   
2. Accidental spillage of hazardous materials due to a nearby, up-slope traffic accident;
   
3. Recently applied insecticide flowing into habitats occupied by the Salt Creek tiger beetle along Little Salt Creek; or;
   
4. Stream bank sloughing which buries larvae in their burrows.
   

 

Other negative effects of habitat fragmentation and loss on the total number of individuals within a population include the Allee effect (the phenomenon where a population’s density becomes so low that individuals fail find mates and reproductive success declines sharply) and the loss of genetic diversity (Lacy 1987). These risks are expected to increase as existing occupied habitats become reduced in size and degraded.

 

8.5    Protect Existing Populations:

All authorities must be available to protect currently occupied Salt Creek tiger beetle habitat along Little Salt Creek. Recent declines in populations numbers and habitat quality and quantity must be arrested. Once ongoing declines are halted, habitat restoration should be used to expand these areas’ ability to support large, viable populations. Conservation efforts should include both permanent habitat protections, such as fee title acquisition or easements, as well as protection of the ecosystem function through preservation or restoration of hydrology function.

 

8.6    Re-Introduce Species:

At present, uncertainty exists about the suitability and recoverability of unoccupied sites to provide for the species’ biological needs. The number of sites necessary to achieve recovery also is undetermined. Initial efforts to identify suitable habitat has located nine potential reintroduction areas including five potentially large recovery areas and four potential satellite recovery areas.

 

Potential large reintroduction areas include the Upper Salt Creek, Rock Creek, Middle Creek, Lower Salt Creek, and Haines Branch recovery areas. These recovery areas are believed to be of sufficient size that through habitat management, restoration, and protection, they could sustain source populations of the Salt Creek tiger beetle.

 

Satellite populations include Roca, Hickman, Oak, and Ashland recovery areas. Satellite populations are important to the conservation of the Salt Creek tiger beetle because they contribute to metapopulation longevity, contribute genetically and morphologically distinct traits to central populations (such as the Little Salt Creek-Arbor Lake population), and spread the risk so that unfavourable conditions in one or a few habitats do not threaten the entire species.

 

Reintroduction areas should be conserved as resources become available. As with existing populations, conservation efforts should include both permanent habitat protections, such as fee title acquisition or easements, as well as protection of the ecosystem function through preservation or restoration of hydrology function.

 

8.7    Establish Sustainable Populations:

At present, we believe each viable Salt Creek tiger beetle population should be maintained a minimum of 500 to a 1,000 individuals (Hill and Knisley 1993, 1994; Lacy 1987; Thomas 1990). This minimum population goal is preliminary and could be revised if additional information indicates such a revision is necessary.

 

8.8    Conduct Research:

The following topics are identified for research:

1. Monitor Salt Creek tiger beetle populations;
   
2. Determine the specific role of groundwater in the conservation of the saline wetlands and streams;
   
3. Evaluate microhabitat characteristics of larval habitat including salinity and hydrology to aid in reintroduction of the Salt Creek tiger beetle;
   
4. Expand research on rearing and propagation methods to aid in reintroduction efforts;
   
5. Conduct studies to determine the minimum sustainable population size for the Salt Creek tiger beetle and the amount and distribution of habitat necessary to preserve a population of this size; and
   
6. Evaluate restoration practices to restore suitable Salt Creek tiger beetle habitat.
   

 

8.9    Monitor the beetle and their Habitats:

The monitoring of invertebrates is undertaken to identify trends in abundance, and changes in distribution. It necessitates the use of reliably quantitative methods of finding and counting them, in the secure knowledge that the resulting data bear a genuine relationship to their real abundance in the field.

 

In addition to repeated survey to monitor and report the status of the beetle and their habitats, land use planning will be an important activity to protect, improve, and sustain the populations as well as the habitats.

 

Evaluate potential conflicts between land development and identified locations of recovery areas to determine the feasibility of habitat restoration and Salt Creek tiger beetle reintroduction efforts. Some proposed recovery areas include areas of ongoing and proposed urbanization (namely, the occupied Little Salt Creek sites and the adjoining unoccupied Lower Salt Creek recovery area). Such urban development will present a unique challenge, as reintroduction would subject the tiger beetle to potential urban impacts such as lighting and runoff. It also will create new species locations that will influence development and planning decisions of the local communities. Such recovery areas will need additional and special efforts of cooperation to best benefit all parties and mitigate impacts. Urban and future urban reintroduction sites should be treated as a second level of opportunity after sites that are more rural have been fully exploited.

 

9.    Critical Success Factors:

It is critical for the success of the recovery plan that:

1. The recovery plan should include objective, measurable criteria which, when met, will result in a determination that the species be removed from the Federal List of Endangered and Threatened Animals;
   
2. The recovery criteria should address all threats meaningfully impacting the species; and
   
3. The recovery plan also should estimate the time required and the cost to carry out those measures needed to achieve the goal for recovery and delisting.