Date: 8/2/22 3:12 pm
From: Bill Tweit <bill.tweit...>
Subject: [Tweeters] ebird begins implementation of a new treatment for non-native species (long)
After a couple of years of development, eBird is beginning to implement a
new approach for handling records of non-native species, which will provide
significant improvements to our understanding of the spread of non-native
species across the globe. It will substantially improve the value of eBird
data for scientists, conservationists, land managers and others who study
and track impacts of non-native species on ecosystems, native species and
our environment.

*What will change?*

All species in eBird will be categorized as either *Native* or *Exotic* in
a region, depending on whether there is evidence that their occurrence is
due to anthropogenic means (Exotics) or whether their occurrence is as a
result of natural processes (Native). This distinction is important, as
typically the rate and the pace of human-assisted spread of species is much
greater than from natural processes, resulting in very different impacts to
ecosystems and native species. Species categorized as Exotic are further
separated into three candidates in each region: Naturalized, Provisional
and Escapee.

*Naturalized* species were introduced by humans in various ways, and have
subsequently established self-sustaining populations. They will continue to
count in eBird lists. In the Pacific Northwest, examples of Naturalized
species include European Starling, Chukar, and Rock Pigeon. Some species,
such as Mountain Quail are categorized as Native in Oregon and in the Blue
Mountains of southeast Washington, and as Naturalized in the Puget Trough,
based on historical records of occurrence and of releases.

*Provisional* species include two different types of records: either
species that were clearly introduced Northern Bobwhite on the prairies of
south Puget Sound, where small populations seem to persist but there is
likely ongoing supplementation from hunter releases, and of the latter the
historical reports of Mountain Quail in Klickitat, Skamania and Clark
counties which might have been the last vestiges of a native population or
might have been the results of failed release programs. Species listed as
Provisional will also count in eBird checklists.

*Escapees* are just that, birds that are known or considered highly likely
to be either intentionally or inadvertently released from captivity. One
frequent example is the numerous reports of Northern but have not clearly
become established or species whose origin is uncertain as the evidence
does not support either human-assisted occurrence or natural processes.
Examples of the former include Bobwhite from areas where hunters often use
them to train their dogs and another is the Monk Parakeets of Yacolt, which
appear to be a handful of survivors from a release years ago. There are
numerous other examples of this category, including Mandarin Duck, Indian
Peafowl and Northern Cardinal. Escapees will not count in eBird totals, but
will appear at the bottom of personal lists.

The initial categorization, as well as ongoing decisions about changes to
categories, are all made at the regional level, by the review teams. The
review team attempted to make the initial categorization as consistent as
possible with published Washington Bird Records Committee decisions, and
was largely successful at that. However, from a countability/listing
perspective, there are some differences at present. For example, the WBRC
treated the pair of Pink-footed Goose that wintered in Hoquaim in 2003/4 as
origin uncertain, so their eBird category is Provisional. If the WBRC
revises its treatment based on new information, the eBird category would be
changed to reflect the new WBRC decision. Similarly, the 2019 Eurasian Tree
Sparrow at Neah Bay is treated as Provisional in eBird, since the WBRC
determined the origin could not be determined with certainty. Neither
species appears on the state list maintained by the WBRC (, but both will appear on the eBird
state list as Exotic: Provisional. The WBRC has had some initial
discussions about this difference, but has not developed a position on it


The first area where eBirders will see these changes is in Illustrated
Checklists and the Species Maps. Provisional species will be displayed at
the end of the ‘main’ section of the Illustrated Checklist, which will
include Native and Naturalized species. Over time, the Illustrated
Checklists will also display hybrids, in a section following Provisional
species. The Species Maps will use different colors to display ranges,
Purple for Native and Orange for Exotics, and the user will be able to
specify whether to display records of Escapees, or just of Naturalized and
Provisional. These changes should be implemented in the next few weeks, and
will be announced and described on the eBird website.

In the coming months, listing displays will be changed as well, starting
with personal lists. The Provisional species will be listed after the
Natives and Naturalized, so if you don’t wish to count Provisionals, it is
a simple matter to stop counting at the end of the main list.

*Bottom Line:*

The bottom line is that this improvement is long awaited by many, and while
it may take some time to get used to the changes, the enhanced value of
eBird data and the increased flexibility for users make this worth the wait
and worth the adaptation. Why are these changes necessary? Scientists
currently rank the spread of non-native species as one of the top five
threat factors for threatened and endangered species, as well as a prime
threat to the integrity of ecosystems. The current eBird structure
discourages eBird users from reporting non-native species that have not
become established, since all species are added to an observer’s listing
totals. This has been an unfortunate weakness of eBird, as citizen science
projects like eBird provide a powerful tool for monitoring the spread and
establishment of non-native species.

As you begin to work with the new approach, the Washington eBird review
team welcomes your input on the initial designation of categories by
species by county. Our initial designations are based on historical
research, review of historical and current data, and WBRC decisions, but
that doesn’t mean that we got everything right on the first attempt and it
doesn’t mean that status and distribution aren’t changing, in some cases
rapidly. Your input will help make sure that the Exotics designations are
both accurate and current. We understand that eBird will provide a form for
suggestions, or drop a note to your local reviewer with suggestions.

Bill Tweit


August 1, 2022

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