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46 The Wildlife Professional, September/October 2022 © The Wildlife Society
It is dawn, and I am walking a spotted skunk trap
line in the central Florida prairie. Except for
alligators lurking in the pools, the open land-
scape of knee-high wiregrass and saw palmetto is
more reminiscent of Kansas or Nebraska. Few people
outside of Florida, a state better known for beaches
and large wetlands, know this landscape exists here.
I have come because it is home to one of the dens-
est populations of eastern spotted skunk (Spilogale
putorius)—and one of the densest concentrations of
any carnivore on earth (Harris et al. 2020).
Six hundred miles to the north, at our study sites
in the rugged deciduous forests of the Appalachian
Mountains, my colleagues and I have struggled
to nd even a handful of spotted skunks to ex-
amine. Biologists in Florida are concerned about
the opposite problem. Spotted skunks here are so
abundant, they are preying on nests and impacting
the viability of a critically endangered grassland
bird—the Florida grasshopper sparrow (Ammodra-
mus savannarum oridanus). Walking back to the
truck to drive to the next trap line I ask myself, why
do I need to travel so far to nd robust populations
of small carnivores to study?
In the early 2000s, around the rise in popularity
of the term “trophic cascade” to describe changes
in ecosystem dynamics following the removal of
apex predators, another term came into use: “me-
socarnivore release.” The theory (sometimes called
mesopredator release) suggests that lower-ranking
By David Jachowski
A Small Carnivore Crisis
 The black-footed
ferret (Mustela nigripes)
was one of the first
species listed under the
Endangered Species
Act and was recently
the subject of one of
the first experiments
with conservation
cloning. One of the
largest carnivore
reintroductions to
date has been the
release of 924 swift
foxes (Vulpes velox) in
Canada over a 14-year
period. Multiple lines
of evidence suggests
that even weasels,
the most widespread
small carnivores in
North America, have
undergone precipitous
declines over the past
60 years. Recent study
groups to conserve
spotted skunks provide
a model for small
carnivore conservation.
Credit: Black-footed ferret – David Jachowski; Swift fox – Craig Miller; Long-tailed weasel – Logan Parr; Eastern spotted skunk – David Jachowski
© The Wildlife Society
carnivores within systems are expanding their range,
increasing or otherwise thriving following the removal
of large apex predators. Applied to mid-sized preda-
tors from raccoons to baboons, the theory became
popularized in multiple review papers in high-impact
journals and a catchy YouTube video, leading to wide
use in popular and scientic publications.
Similar to trophic cascades, the notion of meso-
carnivore release has an inherent appeal in many
conservation circles as further justication for large
carnivore conservation and recovery. This has made
it tricky to disentangle large carnivore conservation
motives from actual data. Did the evidence really
support the conclusion that mid-sized carnivore
populations erupted following the loss of large apex
carnivores around the globe?
Slipping between the cracks
When we recently reviewed evidence of mesocar-
nivore release across North America, less than
half of all published studies claiming to investigate
mesocarnivore release observed strong support for
the phenomenon (Jachowski et al. 2019). Making
the story even more complex, evidence supporting
the occurrence of mesocarnivore release that was
observed among a group of carnivores at one site
was frequently not observed among the same species
group at another site.
Lost in this focus on large and mid-sized carni-
vores has been the plight of small carnivores, which
typically occupy a lower trophic position. Some
endangered small carnivores, like the black-footed
ferret (Mustela nigripes) and San Joaquin kit fox
(Vulpes macrotis), have been the focus of intensive
conservation eorts in North America for decades.
Concern for the Pacic marten (Martes caurina)
and American marten (Martes americana) helped
give rise in 1993 to the Martes Working Group, with
representatives from around the globe working
to conserve species in the Martes complex—sable
(Martes zibellina), sher (Pekania pennanti), wol-
verine (Gulo gulo) and tayra (Eira barbara). In the
Great Plains, the Swift Fox Conservation Team has
been in place since 1994, helping guide restoration
practices across the canid’s historical range across
the U.S. and Canada. Other small carnivores, like the
plains, island and eastern spotted skunks highlighted
in this issue, have only recently been recognized as
undergoing declines and needing conservation at-
tention. Most recently, in assessing historical trends
of weasels, the most widely distributed small terres-
trial carnivores in North America, we found a stark
decline similar to that of the spotted skunk over the
past 60 years, with several large gaps appearing in
the historical range of at least two of the three weasel
species (Jachowski et al. 2021).
Beyond North America, for nearly 40 years the Small
Carnivore Specialist Group within the International
Union for Conservation of Nature’s Species Survival
Commission has been working to address the status
and knowledge gaps of small carnivore species glob-
ally. The group has made great progress, particularly
in identifying hotspots of small carnivore diversity
and endangerment in Africa and Asia, where 74%
of threatened small carnivores reside. In a recent
global review, over half of all small carnivore spe-
cies globally are reported to be declining and a
quarter of all species are threatened with extinc-
tion (Marneweck et al. 2021). For perspective, this
means that small carnivores have undergone similar
declines and are proportionally just as threatened by
extinction globally as large carnivores.
Everywhere we look, data suggest small carnivore
declines are a global issue.
Tiny sentinels
Growing conservation concern for small carnivores
comes at a time when we are also gaining increased
appreciation and understanding for the ecological
role these species play. Around the globe, suites of
smaller carnivores modulate small mammal com-
munities and help control agricultural pests. Small
carnivores also can be good indicators of ecosystem
function. In China, researchers recently found that
leopard cats (Prionailurus bengalensis) and red foxes
(Vulpes vulpes) were excellent samplers of biodiver-
sity due to their diverse diets. In Africa, researchers
Credit: MinuteEarth
release is a widely
popular theory that
predicts “outbreaks”
of mid-sized predators
around the world, which
often lead to negative
impacts on ecosystems
following loss of large
predators. A video
popularizing the concept
has over 1 million views
on YouTube.
48 The Wildlife Professional, September/October 2022 © The Wildlife Society
have found that meerkats (Suricata suricatta)
respond quickly to climate change and are excellent
indicators of it. In South America, ocelots (Leopardus
pardalis) can provide insight into habitat fragmenta-
tion. Otters occur in many aquatic systems globally
and can be sentinels of toxicant bioaccumulation.
Given small carnivores’ faster response times, ease
of monitoring and diversity, with many dierent
potential indicators within a system, some research-
ers consider them ideal sentinel species for assessing
global change (Marneweck et al. in press).
With this new lens of appreciating the ecological role
of small carnivores, some are beginning to wonder
if there is a better way of thinking about how we
measure and assess the functions of ecosystems. A
group of international ecologists recently suggested
a change in focus from the traditional top-down and
bottom-up thinking about ecosystems to more of
a middle-out approach, using small and mid-sized
predators to monitor the structure and function
of ecological systems in response to global change
(Marneweck et al. in press).
As I walk to our next trap line, a grasshopper sparrow
calls out with a familiar trill. It is not by chance that
the highest density of eastern spotted skunks occurs
in a critically endangered ecosystem home to what
is considered North America’s most endangered
songbird. I have seen a similar scenario on the Great
Plains, where patches of habitat for black-footed
ferrets are the most ecologically intact,
containing large populations of prairie
dogs and species of concern, like moun-
tain plovers (Charadrius montanus).
Everywhere I look, the evidence suggests
that a crisis is happening for small car-
nivores. Their decline tells us something
about the health of our planet. Unfortu-
nately, we don’t know enough about most
species to prescribe restoration strategies
or understand what these losses mean to
We need researchers, managers, poli-
cymakers and the public to rise to this
global conservation challenge. As high-
lighted by articles in this special issue on
spotted skunks, at least four key actions
need to be taken now to start addressing
this crisis. First, we need to encourage
wildlife professionals and the general
public to report sightings of small carnivores where
they still occur through platforms like iNatural-
ist. Such data are critical to informing patterns in
species distribution, identifying key locations for
research and highlighting where additional surveys
need to be focused. Second, states and provinces
need to adopt dedicated, standardized monitoring
for small carnivores. Many states still use fur har-
vest records (although trappers now rarely target
small carnivores) or have no dedicated monitoring
for small carnivores, making it dicult to assess
needs and trends. Third, agencies need to begin to
direct funding for research to ll gaps in knowl-
edge about this chronically understudied group of
species. Finally, we need more initiatives like the
Eastern Spotted Skunk and Island Spotted Skunk
Cooperative Study Groups to help enhance commu-
nication, share knowledge and guide conservation
decisions for small carnivore species. These study
groups demonstrate that we can make progress, but
only with the proactive, collective eorts of wildlife
David S. Jachowski, PhD, is
associate professor of wildlife
ecology at Clemson University, founder
and past chair of the Eastern Spotted
Skunk Cooperative Study Group and
Executive Board Member of the South
Carolina Chapter of TWS.
Credit: Courtney Marneweck
 There are at least 6
reasons why ecologists
are beginning to
recognize that smaller
carnivores might be
more appropriate
indicator species for
global change compared
to more traditional
approaches that use
large carnivores.
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