Hine's emerald

Before reproduction can occur, a male must first establish a territory. These territories range from 2–4 metres (6.6–13.1 ft) in area and sit close to bodies of water. Male dragonflies patrol these areas and defend them from dragonflies of both their own and other species. Females initiate mating by flying into a male's territory. A male responds to this behavior by chasing after the female. Once the male reaches the female, he latches onto her body. The two then fly to nearby shrubs, and copulation begins.[15] Post-copulation, the female repeatedly dips her abdomen into shallow water to deposit her fertilized eggs.[9] Hine's emeralds reproduce once and die shortly thereafter.[9] Hine's emeralds reproduce during the months of June, July, and August.[9]

Hine's emeralds are carnivorous during both the larval and adult stages of their lives.[9] Adult Hine's emeralds feed upon small flying insects such as mosquitoes and gnats. Adults usually forage for their prey while in-flight and appear to favor foraging along forest edges.[9] These forest edges typically run alongside roads. During the pre-reproductive stage, these flights last 1–3 minutes.[9] During the reproductive stage, these flights last up to 15 minutes.[9] Reproductive adults may fly up to 1.2 miles (1.9 km) during these flights.[9] At times, reproductive adults also forage in large swarms. Hunting in these swarms may protect dragonflies from predators.[15] Nymphs are nocturnal feeders and prey upon other aquatic larvae, such as those belonging to mosquitoes or mayflies[13] Researchers suspect that nymphs prey upon different species throughout their development.[9] While hunting, nymphs remain still and wait for prey to approach them.[16]

Hine's emerald dragonfly was first proposed as an endangered species in October, 1993.[20] The U.S. Fish and Wildlife Service cited three main reasons why Hine's emerald warrants federal protection. Fragmented habitats and small, highly-distributed populations were significant concerns.[20] By January 1995, Hine's emerald was officially added to the ESA and listed as an endangered species.[15] Last assessed in 2008, the Hine's emerald dragonfly was the only dragonfly species included in the Endangered Species Act.[21]

The Recovery Plan by the U.S. Fish and Wildlife Service was published in 2001.[9] Its ultimate recovery goal is "[restoring the dragonfly] to viable populations".[9] The plan established the Northern Recovery Unit and Southern Recovery Unit.[9] To be downgraded in the Endangered Species Act, certain criteria must be met. Each Recovery Unit must contain at least three subpopulations with 500 reproducing adults for at least 10 years.[9] Additionally, there must be two breeding sites per subpopulation.[9] These areas must have federally protected habitat.[9]

In the Recovery Plan, the Fish and Wildlife Service suggests various ideas to increase Hine's emerald survivorship. This includes watershed protection and deed restrictions.[9] Land acquisition and nature preserve creation are also potential ways to protect the species.[9] The Fish and Wildlife Service details the importance of managing existing populations and researching demographic changes. To do this, there must be searches for undiscovered Hine's emerald populations as well as organized education programs.[9] Additionally, the Recovery Plan outlines the importance of protecting and maintaining known populations and habitats.[9] Augmentation programs and evaluations of recovery progress must be conducted.[9] The Recovery Plan's objective is clear: "assure the long-term viability by arresting or reversing the decline of Hine's emerald populations and addressing its threats to survival".[9]

In the Five Year Review conducted in 2013, four major criteria for reclassification are listed.[13] First, each Recovery Unit must meet the population requirements as specified in the initial Recovery Plan. At the time of publishing, some populations in the Northern Recovery Unit exceed this.[13] No populations in the Southern Recovery Unit meet this goal.[13] Only one population in the Southern Recovery Unit was quantified at time of publication.[13] Second, there must be at least 2 breeding habitats per subpopulation.[13] Each breeding habitat must be fed by different water sources.[13] As of 2013, this criterion has not been met, and only 12 of 27 subpopulations have more than one breeding site.[13] Third, the habitat to support subpopulations must be formally protected and managed.[13] This includes control of invasive species and restoration of local water sources. Actions to minimize vehicle presence are also suggested.[13] Lastly, the Review requires the creation of a monitoring plan for each population.[13] This must include annual population estimates.[13] This final criterion has not been met due to lack of knowledge of breeding and habitat structure.[13] Many regions are lacking resources needed to evaluate population sites.[13]

In Canada, the Hine's emerald is listed on Schedule 1 of the Species at Risk Act as endangered, having received this status in 2017.[8] It appears to have a small area of occupancy within Ontario, restricted to the Minesing Wetlands.[19] The population's continued existence is jeopardized by urban development and the spread of invasive plants such as European common reed (Phragmites australis subsp. australis) and glossy buckthorn (Frangula alnus).[8]

Hine's emerald dragonfly was last assessed by the IUCN Red List on June 8, 2018.[12] At this point, it was listed as Least Concern.[12] This contradicts the ESA's older classification of Endangered.[15][13]

The current critical habitat for Hine's emeralds contains 26,531 acres of land.[22] This land is concentrated in various counties in Illinois, Michigan, Missouri, and Wisconsin.[22] Expected costs for protection range from $10.5 million to $25.2 million over 20 years when adjusted.[22] This version of the critical habitat ruling was finalized in 2010.[22] However, this ruling differs significantly from the initial proposal and the first critical habitat ruling.

In the 2006 Critical Habitat Proposed Rule, 27,689 acres were proposed for protection.[23] This proposal considered the exclusion of all Missouri populations and two from Michigan.[23] In 2007, the original ruling designated only 13,221 acres for protection.[24] The 2010 ruling doubles the critical habitat range for HED.

The Hine's emerald dragonfly recovery plan was published in 2001. At that time, the major threats to the species were habitat loss/alteration and contamination. Hine's emerald dragonflies inhabit marsh and wetland habitats, which are already rare. Further loss of habitat would disrupt the surviving populations of the species. The recovery plan explains the habitat loss. Industrial, agricultural, and commercial development caused the most damage. This damage contributed to the decline of the species.[9] A 5-year review was completed in 2013. It includes more recent evaluations of the threats to Hine's emerald populations. It includes a table (pp. 27–29) which details the threats present at each of the Hine's emerald dragonfly sites. There are a few common threats between sites. These threats are fragmentation, changes to water flow, contaminants, vehicle mortality, and invasive animals and plants.[13]

Hine's emerald dragonfly populations are susceptible to habitat fragmentation. As of 2012, studies were being conducted to investigate barriers to Hine's emerald movement, such as roads and bridges. They studied how these barriers can influence the flight behavior and dispersal ability of the dragonflies. If Hine's emeralds are unable to disperse properly it may lead to isolated populations of lower population size. Poor dispersal also reduces genetic diversity, and low genetic diversity will make the Hine's emeralds more vulnerable to other threats they face.[13]

Invasive animal species pose a threat to Hine's emerald habitats. Beavers, feral hogs, and armadillos are the major potential threats. They can contribute to Hine's emerald habitat destruction. Beaver dams have the potential to flood the wetlands of Hine's emerald populations. When feral hogs forage for food, they have the potential to damage Hine's emerald habitats. As of 2013, feral hogs were only considered a threat in Missouri. However, their populations have grown in other states with Hine's emerald populations. Lastly, nine-banded armadillos also impact Hine's emerald habitats when they forage. Armadillos dig up soil looking for insect larvae and forage in burrows as well. The impact of armadillos on Hine's emerald habitats will require monitoring as the armadillo's range continues to expand.[13]

Invasive plants have the potential to affect Hine's emerald habitats, behaviors, movements, and breeding. The invasion of woody vegetation and cattails into Hine's emerald habitats could affect adult flight behaviors. Invasive woody species can decrease the amount of subsurface water.[25][13] This is a vital component of Hine's emerald larval habitats. The invasion of species like the common reed may decrease crayfish populations. Thus, decreasing the number of crayfish burrows that are a place of refuge for Hine's emerald larvae.[13]

Humans can impact Hine's emerald dragonflies in a variety of ways. Most human impact involves habitat destruction/alteration. Reduction in habitat area fragments populations. Quarrying, filling wetlands, and creating landfills are examples of harmful human actions. Contamination is another way humans can harm Hine's emerald populations. Landfills have the potential to leach harmful chemicals and contaminate surface and groundwater. Both surface and groundwater are critical to Hine's emeralds in the larval stage. Recreational activities and agriculture may also impact Hine's emerald populations. The insecticides, herbicides, and fertilizers used in these practices could harm Hine's emerald populations. Fertilizers may lead to changes in Hine's emerald habitats that could impact the species.[9]

Hine's emerald is listed on the Federal list of Endangered and Threatened Wildlife and Plants. This means that the species is protected under the Endangered Species Act of 1973 (ESA). Hine's emerald is also listed as endangered in Illinois, Wisconsin, Missouri, and Michigan. This provides the species with State level protections and Federal protections.[13]

Many agencies help protect Hine's emerald habitats. State and County agencies protect the habitats of three subpopulations in Illinois. The University of Wisconsin and the Wisconsin Department of Natural Resources (WDNR) help protect Hine's emerald habitats, one such being the Gardner Swamp Wildlife Area. They protect the habitat of the population in Ozaukee County, Wisconsin. The WDNR also protects the habitat of the population in Southwest Wisconsin. The U.S. Forest Service or Missouri Department of Conservation protects Hine's emerald habitats in Missouri. These agencies protect most of the habitats for two of the Missouri subpopulations. State and Federal agencies protect habitats in the Northern Recovery Unit. They protect the habitats of five out of the 16 subpopulations.[13]

Groundwater recharge areas make an important contribution to Hine's emerald habitats. Researchers have worked to outline the areas that contribute to many Hine's emerald habitats. However, they have not mapped recharge areas for all Hine's emerald habitat sites yet. More research is necessary to identify recharge areas for all Hine's emerald sites. Sections 7 and 9 of the ESA protect all identified groundwater recharge areas. The Illinois Natural Areas Preservation Act protects identified areas in Illinois.[13]