New Jersey’s Species Status Review Process

HOW A SPECIES BECOMES LISTED AS “ENDANGERED” IN NEW JERSEY

By Michael Davenport, GIS Program Manager

How does the state’s Endangered and Nongame Species Program (ENSP) determine whether a species is imperiled or secure within the state? The process for determining a species’ state status is known as the “Delphi” method of species status review and it is a process which Conserve Wildlife Foundation of NJ (CWF) staff assists the state with.

Monarch adult edit
In 2015, the NJ Endangered & Nongame Advisory Committee approved that the monarch butterfly be added to the state’s list of Special Concern species. Photo courtesy of Thomas Gorman.

The ENSP endeavors to complete a review of all species currently included on the Endangered and Nongame lists every 5-10 years. In addition, other species groups not currently included on those lists may be reviewed for status as well. At any given time, there may be several status reviews being conducted.

The first step taken in conducting a status review is to identify experts and invite them to participate as a member of a review panel. Members of the panel may be comprised of experts within academia, government agencies, non-profits, or private consultants as well as others.

Once a sufficient number of experts have agreed to participate, staff within the ENSP and CWF will compile background material for the species being reviewed. This may include reports, survey data, and data contained within the state’s Biotics database which is the electronic warehouse for all imperiled species data in New Jersey. This background data, as well as a list of the species being reviewed, and definitions of the status options, are then sent to the panelists for Round 1 of the review.

Delphi reviews are comprised of multiple “Rounds”. For each round, each panelist will choose a status for each species based upon that panelist’s expertise as well as the background material. The panelist then sends their selections and justification regarding each species to ENSP or CWF staff who compile the results submitted by all panelists. The review is completed anonymously, so the panelists do not know the identities of the other participants.

In 2016, the NJ Endangered & Nongame Advisory Committee approved that the eastern hognose snake be added to the state's list of Special Concern species. © Thomas Gorman
In 2016, the NJ Endangered & Nongame Advisory Committee approved that the eastern hognose snake be added to the state’s list of Special Concern species. © Thomas Gorman

For each species, the panel must reach consensus of at least 85% of the respondents for a species’ status to be determined. If consensus is not reached during the first round, then that species will move on to be reviewed in Round 2. For each new round, the panelists’ status choices during the prior round, as well as all the comments made, are available to the panel, so that reviewers can consider the weight of evidence and other reviewers’ opinions on status as they prepare to vote again. This continues until consensus is reached for all species under review.

Once consensus is reached for all species or, if after four rounds have passed and consensus could not be reached for some species, ENSP or CWF staff will take the compiled Delphi results to the Endangered and Nongame Species Advisory Committee (ENSAC). ENSAC reviews the results and makes the final recommendations on status for those species for which consensus was not reached by the expert panel. Based upon ENSAC’s recommendations, any changes to the Endangered and Nongame lists must go through a formal rule-making process before those changes can be made official.

The Delphi review process is a science-based, anonymous review by those with the most expertise on the species within New Jersey. A great deal of thought and time go into preparing for and carrying out a review and CWF has played a major role in assisting with the process. From the blue whale to fairy shrimp, each species will ultimately receive a state status, leading the way for conservation action.


The following are state conservation status categories; the last, “Not Applicable”, is used only during the status review and is not a legal status category.

  • Endangered
    Applies to species whose prospects for survival within the state are in immediate danger due to one or several factors, such as loss or degradation of habitat, overexploitation, predation, competition, disease or environmental pollution, etc. An Endangered species likely requires immediate action to avoid extinction within New Jersey.
  • Threatened
    Applies to species that may become Endangered if conditions surrounding it begin to or continue to deteriorate. Thus, a Threatened species is one that is already vulnerable as a result of small population size, restricted range, narrow habitat affinities, significant population decline, etc.
  • Special Concern
    Applies to species that warrant special attention because of inherent vulnerability to environmental deterioration or habitat modification that would result in their becoming Threatened. This category would also be applied to species that meet the forgoing criteria and for which there is little understanding of their current population status in the state.
  • Secure/Stable
    Applies to species that appear to be secure in New Jersey and not in danger of falling into any of the preceding three categories in the near future.
  • Undetermined/Unknown
    Applies to a species that cannot be assigned a status of endangered, threatened, special concern or secure/stable because not enough information exists on which to base a judgment.
  • Not Applicable
    Applies to species that do not occur in New Jersey, including occasional non-breeding strays and transient breeders that fail to persist.

Changes to the Endangered Species List

Rare species Conservation in New Jersey

by Margaret O’Gorman, Executive Director

The golden-winged warbler is uncommon to rare and declining throughout most of its range. © MacKenzie Hall

Yesterday, the New Jersey Department of Environmental Protection released a rule proposing certain changes to endangered species list and other considerations about rare wildlife in the state.

The list of species protected on the Endangered Species list has not been updated since 2003. This new proposal reflects years of work by wildlife biologists engaged in endangered species protection.

The rule change proposes to add five species to the list of endangered species in the state and change the consideration of eight other species to offer different levels of protection for breeding and non-breeding populations.

The species being added to the list are the black rail, golden-winged warbler, red knot, Indiana bat and gray petaltail (a dragonfly). The Indiana Bat is being added because it is on the federal endangered species list and any species on this list also found in New Jersey is, by default, considered endangered in New Jersey. The other species are being added to the list as a result of a review of their status using something called the Delphi Technique.

The Delphi Technique is an iterative process whereby wildlife biologists and academics, using the best available data, come to consensus agreement of the status of the species under consideration. This review is then approved by the Endangered and Nongame Species Council which is made up of wildlife biologists, academics and other interested parties. Delphi Reviews of birds, freshwater mussels, butterflies, dragonflies and damselflies were carried out between 2000 and 2005. The results of these reviews inform this proposed rule change.

In addition to adding five species to the endangered species list, the Department is proposing to modify the endangered status of eight species of birds for either the breeding or non-breeding populations.

A female Northern harrier flies low over the marsh in search of prey. © Steve Byland

The bald eagle is currently classified as endangered for both breeding and non-breeding populations. The classification of the bald eagle will continue to be endangered for the breeding population, which includes all bald eagles present in the State during the breeding season. However, the non-breeding population, which includes all bald eagles present in the State outside of the breeding season, will be reclassified as threatened.

Six bird species – the pied-billed grebe, northern harrier, northern goshawk, peregrine falcon, short-eared owl and vesper sparrow – currently listed as endangered for both breeding and non-breeding populations will continue to be classified as endangered for breeding populations but will be listed as special concern for their non-breeding populations.

The Endangered Species List is not a one-way street and while we worry about the removal of protections for species, we must recognize and celebrate the recovery and return of these species. In the 1950’s, no peregrine falcons nested east of the Mississippi River, today our non-breeding population is strong and growing. In the late 1980’s, one pair of bald eagles remained in New Jersey, today the winter population is counted in the high 200’s and the breeding population approaches 100 pairs. Species recovery can succeed and with this proposed rule change, we should celebrate these successes.

But, we should mourn the additions to the list and wonder why, since the Endangered Species Act passed in 1973, we still see declining populations and we still add species to the Endangered Species List in New Jersey.