Discrepancies in Reported Levels of International Wildlife Trade

Abstract

The international wildlife trade is a principal cause of biodiversity loss, involving hundreds of millions of plants and animals each year, yet wildlife trade records are notoriously unreliable. We assessed the precision of wildlife trade reports for the United States, the world's largest consumer of endangered wildlife, by comparing data from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) with U.S. Customs data. For both U.S. imports and exports, CITES and Customs reported substantially different trade volumes for all taxa in all years. Discrepancies ranged from a CITES-reported volume 376% greater than that reported by Customs (live coral imports, 2000) to a Customs' report 5202% greater than CITES (conch exports, 2000). These widely divergent data suggest widespread inaccuracies that may distort the perceived risk of targeted wildlife exploitation, leading to misallocation of management resources and less effective conservation strategies. Conservation scientists and practitioners should reexamine assumptions regarding the significance of the international wildlife trade.

Full text

Discrepancies in Reported Levels of International
Wildlife Trade
ARTHUR G. BLUNDELL
∗
AND MICHAEL B. MASCIA†
∗
Conservation International Center for Applied Biodiversity, 122 Haida Trail, Nanaimo, British Columbia, V9S 3G1 Canada,
email art.blundell@alum.dartmouth.org
†World Wildlife Fund, 1250 24th Street, NW, Washington, D.C. 20037, U.S.A.
Abstract: The international wildlife trade is a principal cause of biodiversity loss, involving hundreds of
millions of plants and animals each year, yet wildlife trade records are notoriously unreliable. We assessed the
precision of wildlife trade reports for the United States, the world’s largest consumer of endangered wildlife, by
comparing data from the Convention on International Trade in Endangered Species of Wild Fauna and Flora
(CITES) with U.S. Customs data. For both U.S. imports and exports, CITES and Customs reported substantially
different trade volumes for all taxa in all years. Discrepancies ranged from a CITES-reported volume 376%
greater than that reported by Customs (live coral imports, 2000) to a Customs’ report 5202% greater than
CITES (conch exports, 2000). These widely divergent data suggest widespread inaccuracies that may distort
the perceived risk of targeted wildlife exploitation, leading to misallocation of management resources and
less effective conservation strategies. Conservation scientists and practitioners should reexamine assumptions
regarding the significance of the international wildlife trade.
Key Words:
CITES, Customs, endangered species, Harmonized Tariff Schedule
Discrepancias en los Niveles Reportados de Comercio Internacional de Vida Silvestre
Resumen: El comercio internacional de vida silvestre es una causa principal de la p
´
erdida de biodiversi-
dad, ya que involucra a cientos de millones de plantas y animales cada a
˜
no; no obstante eso, los registros
del comercio son notoriamente poco confiables. Evaluamos la precisi
´
on de los registros de comercio de vida
silvestre de Estados Unidos, el mayor consumidor de vida silvestre en peligro en el mundo, mediante la com-
paraci
´
on de datos del Convenio Internacional para el Comercio de Especies de Flora y Fauna Silvestre en
Peligro (CITES) con datos de la Aduana de E.U.A. Tanto para importaciones como exportaciones, CITES y
Aduana reportaron vol
´
umenes de comercio de todos los taxa sustancialmente diferentes en todos los a
˜
nos.
Las discrepancias abarcaron desde un volumen reportado por CITES 376% m
´
as grande que el reportado por
la Aduana (importaciones de coral vivo, 2000) hasta un reporte de la Aduana 5202% mayor que el de CITES
(exportaciones de caracol, 2000). Estos datos ampliamente divergentes sugieren imprecisiones generalizadas
que pueden distorsionar el riesgo percibido por la explotaci
´
on de vida silvestre, lo que conducir
´
aala incor-
recta asignaci
´
on de recursos para la gesti
´
on y a estrategias de conservaci
´
on menos efectivas. Los cient
´
ıficos y
profesionales de la conservaci
´
on deber
´
ıan reexaminar sus suposiciones respecto al significado del comercio
internacional de vida silvestre.
Palabras Clave: aduanas, CITES, especies en peligro, programa de aranceles armonizados
Paper received October 8, 2004; revised manuscript accepted February 1, 2005.
2020
Conservation Biology 2020–2025
C

2005 Society for Conservation Biology
DOI: 10.1111/j.1523-1739.2005.00253.x

Blundell & Mascia Wildlife Trade Discrepancies 2021
Introduction
The overexploitation of wildlife is a principal cause of
global biodiversity loss (Wilcove et al. 1998). For highly
valued species, targeted exploitation for international
trade is a particularly significant threat. This diverse trade
is worth billions of dollars each year (CITES 2004c). Coun-
tries import hundreds of millions of plants and animals an-
nually, including timber (∼65% of the global value of the
wildlife trade), fish (25%), nontimber forest products (7%;
e.g., medicinal and ornamental plants), and other com-
modities (3%; e.g., pets, skins, curios, and bushmeat)
(TRAFFIC 2004).
The Convention on International Trade in Endangered
Species of Wild Fauna and Flora (CITES) is designed
to “protect endangered species... from overexploitation
by regulating or prohibiting their international trade”
(Sands 1995: 373). Appendix I of CITES bans the com-
mercial trade of more than 800 listed species among the
167 CITES member countries (CITES 2004a, 2004b). Ap-
pendix II of CITES permits trade in approximately 32,500
listed species, but each shipment must be accompanied
by an export permit verifying that the shipment was
legally obtained and that its harvest was not detrimental to
the survival of the species. Trade in the nearly 300 species
on CITES Appendix III is less restricted; export permits
must declare only that shipments were acquired legally.
For all CITES-listed species, importing countries must en-
sure that the appropriate permits accompany shipments,
and all countries must report levels of trade.
Although CITES has had notable successes since en-
tering into force in 1975, results of recent research on
ginseng (Panax spp.), coral (various anthozoans), and
mahogany (Swietenia spp.) suggests that the magnitude
of trade reported by CITES may be inaccurate (Robbins
1998; Bruckner 2001; Blundell & Rodan 2003, respec-
tively). If such inaccuracies are widespread, this might
distort perceptions of the relative risk that targeted ex-
ploitation of wildlife poses to global biodiversity, lead-
ing to misallocation of management resources and less-
effective conservation strategies. To better understand
the extent and magnitude of these reporting discrepan-
cies, we examined the precision of wildlife trade reports
for the United States, the world’s largest consumer of en-
dangered species.
Methods
We assessed the precision of U.S. wildlife trade reports
for the period 1997–2002, the most recent years avail-
able. We used the two primary sources of wildlife trade
data in the United States to examine U.S. imports and
U.S. exports of CITES-listed species: U.S. Customs Ser-
vice (Customs) and U.S. CITES Authority. Customs gener-
ally records commodities trade in broad categories that
cover many different species, but in a few cases Customs
reports trade in categories specific to individual taxa.
We generally obtained Customs’ data from the U.S. Inter-
national Trade Commission “dataweb” (www.dataweb.
usitc.gov/scripts/user
set.asp) but received conch ex-
port data from the U.S. National Marine Fisheries Ser-
vice (NMFS; www.st.nmfs.gov/st1/trade/trade
alldstrct
byproducts.html). The NMFS data are derived from U.S.
Customs reports. Independent of Customs, the U.S. CITES
Authority (a division of the U.S. Fish and Wildlife Ser-
vice) collects trade data from the export permits that
accompany shipments of CITES-listed species. We ob-
tained CITES data from the United Nations Environ-
ment Programme—World Conservation Monitoring Cen-
tre (UNEP—WCMC), which are based on annual U.S.
CITES reports. We calculated the precision of reported
trade as percent difference: ([CITES/Customs] − 1)100
when CITES reported larger trade and ([Customs/CITES]
− 1)100 when U.S. Customs reported larger trade.
Although Customs and CITES do not collect data for
the purpose of direct comparison, we identified five
taxa—conch, caviar, live coral, cultivated ginseng, and
mahogany—where the two monitoring systems mea-
sured trade in similar categories, making valid compar-
isons possible. These five taxa represent more than 2,000
species, or 6% of the approximately 33,600 species cur-
rently regulated by CITES. Mahogany was listed on Ap-
pendix III throughout the 1997–2002 study period; the
remaining four taxa were listed on Appendix II.
We excluded several taxa from our analysis for which
comparisons initially appeared possible: cultivated gin-
seng imports; caviar, live coral, and mahogany exports;
and all trade in wild ginseng, orchids, cetaceans, parrots,
and primates. We excluded these taxa for the follow-
ing reasons. For cultivated ginseng imports and caviar,
live coral, and mahogany exports, Customs categories in-
cluded species in addition to the focal taxa, making com-
parison to taxa-specific CITES data impossible. Customs
reports trade in orchids in kilograms, whereas CITES re-
ports in individuals. There is no conversion formula that
would permit valid comparisons. Customs reports Gin-
seng panax and G. quinquefolius imports from all coun-
tries, whereas CITES tracks only G. panax imports from
Russia, making comparisons of the total trade impossible.
We excluded wild ginseng exports because Customs does
not track these exports in a taxa-specific category, making
comparison to taxa-specific CITES export data impossi-
ble. For cetaceans, parrots, and primates, Customs began
collecting data comparable to CITES reports for each of
these taxa in 2002, precluding the requisite longitudinal
analysis.
Results
For both U.S. imports and exports, CITES and Customs
reported substantially different trade volumes for all taxa
in all years (Table 1; Fig. 1). Discrepancies ranged from a
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2022 Wildlife Trade Discrepancies Blundell & Mascia
Table 1.
Sources of discrepancies in reported volumes of U.S. trade in CITES-listed wildlife, 1997–2002.
a
Sources of discrepancy
Taxa intrinsic methodological
Caviar
b
Some CITES import records did not specify units
(Williamson 2003) (1–17 shipments/yr [1–8%
shipments/yr]).
Analyses did not include CITES records that failed to
specify units. If analyses assume records without
specified units are in kg, then import discrepancies
would increase to from 29–91% to 29–272%.Smuggling (De Meulenaer & Raymakers 1996;
Williamson 2003)
Recording errors (C. Hoover, pers. comm.)
Taxa miscategorization (De Meulenaer & Raymakers
1996; Williamson 2003; C. Hoover, pers. comm.)
Conch
c
Taxa miscategorization; additional conch-like species
(e.g., Busycon spp.) may be included in Customs but
not CITES (N. Daves, R. Robinson, pers. comm.).
Some CITES records did not specify units (imports: 1–13
shipments/yr [4–28%]; exports: 0–1 shipments/yr
[0–50%]).
CITES reports all trade as re-exports, whereas Customs
reports only 5% of volume as re-exports. This
suggests discrepancies between sources.
Recording errors
d
Smuggling
d
Analyses include only S. gigas exports from U.S. ports
within home range (Florida, S. Carolina, Louisiana).
(S. Koplin, pers. comm.). This assumption may
exclude some S. gigas exports and include some
non-S. gigas exports.
Non-S. gigas imports may appear in Customs data (S.
Thiele, pers. comm.), underestimating discrepancy
for all but 1998.
Analyses did not include CITES records that failed to
specify units. If analyses assume records without
specified units are in kg, then import discrepancies
would increase from 9-102% to 12–120% and export
discrepancies would still range between 9 and 5202%.
Coral (live)
e
Most CITES records did not specify units (imports:
548–947 shipments/yr [84–95%]; exports: 296–357
shipments/yr [88–92%]).
Noncoral spp. may be included in Customs.
In some cases (% unknown), reported trade is for
entire volume allowed by CITES permit, rather
than actual exported volume (Bruckner 2001).
Analyses did not include CITES records that failed to
specify units. If analyses assume records without units
are in kg, then import discrepancies would increase
from 52–376% to 254–819%.
Possible inclusion of noncoral trade in Customs data
may underestimate actual discrepancy, so reported
discrepancy is a conservative estimate.
Taxa miscategorization (Green & Hendry 1999)
Recording errors
d
Smuggling
d
Ginseng
(cultivated)
f
CITES does not report trade in derivatives
(e.g., powder) (Robbins 1998); may underestimate
trade by 10% “or a lot higher” (K. Drath, pers.
comm.).
Analysis did not correct for derivative trade, so reported
discrepancy is a conservative estimate.
All CITES export reports of cultivated ginseng included
units of measure.
Recording errors
d
Smuggling
d
Taxa miscategorization (Robbins 1998)
Mahogany
g
Some CITES records did not specify units (0–2
shipments/yr [0–<1%]).
Recording errors
Smuggling
Taxa miscategorization (∼1 shipment/yr)
In some cases (% unknown), reported trade is
for entire volume allowed by CITES permit rather
than actual exported volume.
a
Intrinsic sources of discrepancy result from CITES and U.S. Customs measurement and reporting systems. Methodological sources of discrepancy
result from research methods and analytic assumptions.
b
CITES definition: Acipenseriformes spp., roe (27 species). Customs definition: caviar and sturgeon roe. Harmonized Tariff Schedule (HTS) codes:
03027020, 16043020, 03038020, and 03052020.
c
CITES definition: Strobus gigas, meat, live (one species). Customs definition: conch, live, fresh or chilled, including flours, meals, and pellets.
HTS: 0307910030 (imports); NFMS (exports).
d
Predicted, but not documented.
e
CITES definition: Helioporacea Heliopora coerulea, Stolonifera, Tubiporidae spp., Antipatharia, Scleractinia meat, live (2000+ species). Customs
definition: molluscs and aquatic invertebrates, excluding snails, oysters, scallops, cuttlefish, squid, octopus, urchin, clams, and conch. HTS:
0307910090.
f
CITES definition: Panax quinquefolius and P. ginseng from Russia, whole and parts of roots (two species). Customs definition: ginseng roots,
cultivated, fresh or dried, whether or not cut, crushed or powdered. HTS: 1211200020.
g
CITES definition: Swietenia spp. sawnwood (three species). Customs definition: Swietenia spp. sawnwood. HTS: 4407240025 and 4407240030.
Source for all mahogany discrepancies is Blundell and Rodan (2003).
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Blundell & Mascia Wildlife Trade Discrepancies 2023
Figure 1. Discrepancy (% difference) in volume of U.S.
wildlife trade (1997–2002) reported by CITES and U.S.
Customs for caviar (
), conch (•,◦), live coral (),
mahogany (×), and cultivated ginseng (
). Export
values are open symbols, imports are closed symbols.
Year is depicted by color: 1997, red; 1998, orange;
1999, green; 2000, black; 2001, blue; and 2002,
purple. Values are in kilograms, except for mahogany
(in cubic meters).
CITES-reported volume 376% greater than that reported
by Customs (live coral imports, 2000) to a Customs re-
port 5202% greater than CITES (conch exports, 2000).
Differences varied significantly by taxon (log-transformed
analysis of variance; F
4,29
= 3.0, p = 0.04), with conch
exports having the largest mean difference (1202% ±
SD = 2001%) and cultivated ginseng exports having the
smallest (34 ± 21%). Differences were also observed in
the reported trade of caviar imports (mean = 59% ±
27%), conch imports (65% ± 37%), coral imports (205% ±
120%), and mahogany imports (41% ± 17%). Discrepan-
cies did not decrease over time (F
1,29
= 1.4, p = 0.48).
Our analyses are generally conservative (Table 1). The
CITES categories for cultivated ginseng, live coral, and
conch are more narrowly defined than the Customs cate-
gories, yet CITES still reported greater trade volume than
Customs. Customs records all cultivated ginseng in trade,
including derivative products (e.g., powder), whereas
CITES records only trade in roots. The nonroot ginseng
trade that CITES fails to count may represent 10% of the
overall trade “or a lot higher” (K. Drath, personal commu-
nication). Despite this partial count, CITES totals were
still 1–64% greater than Customs reports. Similarly, the
Customs category we used for coral may have included
some noncoral species, thus inflating the Customs’ es-
timate of the coral trade. Despite the potentially more
inclusive Customs category, CITES still reported a vol-
ume 52–376% greater than Customs. According to trade
expert Rich Robinson of Chesapeake Bay Packers (per-
sonal communication), Customs may include nonconch
species such as the whelk (Busycon spp.) in their re-
ports of conch exports. This miscategorization would
lead to an overestimation of the volume of trade in the
true conch, Strobus gigas,byCustoms. To minimize this
error, we included reports only from ports within the
range of S. gigas (i.e., we excluded reports of conch ex-
ports from all ports but those in Florida, South Carolina,
and Louisiana). These ports correspond with the reports
of exports in the CITES database. Furthermore, CITES re-
ported that all exports from the United States were re-
exports (i.e., conch that originally came from outside the
United States), whereas only 3% of Customs’ reports were
reported to be re-exports. This suggests that Customs in-
cluded other species native to the United States in the
reports for true conch. Despite the potentially more in-
clusive Customs category, CITES still reported a greater
volume of conch exports in 2002 (Fig. 1), indicating that
categorical differences cannot fully explain observed dis-
crepancies.
Discussion
The widespread discrepancies between Customs and
CITES trade data have several probable sources (Table
1). Some error is random, such as typographic mistakes.
CITES sometimes failed to record the units that specify
shipment size, which influenced observed disparities.
Additional discrepancy may arise from taxonomic mis-
categorization and other recording errors. Smuggling—
the intended or unintended avoidance of legal obliga-
tions and trade-monitoring mechanisms associated with
CITES and/or Customs—leads to under-reporting of trade.
If traders smuggle to avoid both Customs and CITES, then
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2024 Wildlife Trade Discrepancies Blundell & Mascia
the lower overall trade volume would exaggerate any rel-
ative differences in reported trade. For example, consider
reported trade volumes of 1005 kg and 1010 kg (5 kg; 0.5%
difference) compared with reported volumes of 5 kg and
10 kg (5 kg; 100% difference), where a smuggler avoided
both CITES and Customs with a 1000-kg shipment in the
latter case. Selective smuggling to avoid either CITES or
Customs, however, would increase discrepancies in both
absolute and relative terms. Using the same hypothetical
example, the reported volumes of 1005 kg and 1010 kg
(5 kg; 0.5% difference) might instead be reported as 5
kg and 1010 kg (1005 kg; 20,100% difference) if a trader
with a 1000-kg shipment selectively avoided either CITES
or Customs. From the data, we could not determine if or
when traders smuggled to avoid CITES, Customs, or both
trade monitoring systems.
The role of smuggling in our results is unclear, although
we hypothesize that traders are more likely to avoid CITES
than Customs. Of the five taxa studied, only caviar is sub-
ject to a U.S. tariff (15% import tax), which suggests that
most traders would have little incentive to bypass Cus-
toms. On the other hand, CITES permits are onerous to
obtain, especially in countries where government bureau-
cracies are cumbersome or corrupt. This suggests that
many traders may have an incentive to avoid CITES regu-
lations.
Evidence suggests that other countries and trade mon-
itoring systems experience reporting problems similar to
the ones we describe here. Taxonomic miscategorization,
unitless data, and other recording and data management
errors are known from Southeast Asia, the United King-
dom, and the global coral trade (Scoffin & Le Tissier 2001;
Clarke 2002; Hariott 2003). Smuggling is widespread
(e.g., former Soviet states; Raymakers & Hoover 2002).
Several studies note that exporting and importing coun-
tries often report different trade figures for the same ship-
ment. This phenomenon is observed when examining na-
tional trade statistics (e.g., Canadian mahogany [Gerson
2000]; Southeast Asian marine wildlife [Clarke 2002]) and
CITES-reported trade (e.g., U.S. mahogany [Blundell & Ro-
dan 2003]). Similarly, a review of national trade statistics
indicates that the global trade in shark fins is “likely to be
more than double” the volume reported by the U.N. Food
and Agriculture Organization (Clarke 2002: 75).
The pervasive discrepancies described here suggest
that reported levels of international wildlife trade are
highly uncertain. For at least some taxa, discrepancies
between CITES and Customs differ by more than an or-
der of magnitude, suggesting that the targeted exploita-
tion of wildlife may represent a greater threat to bio-
diversity than is generally recognized. Such uncertainty
makes it difficult for governmental and nongovernmen-
tal organizations to allocate their resources efficiently
or develop effective conservation strategies. To ensure
that decision makers have the accurate data necessary
to make informed conservation policy choices, national
and international wildlife trade authorities should move
to eliminate common sources of reporting discrepancies
through training, compliance assistance, and automated
record keeping. Government agencies should also ex-
plore the potential for harmonization of wildlife trade
reporting systems and for cross-agency notification of
wildlife shipments, which would foster greater preci-
sion in trade estimates and reduce smuggling. (To ad-
dress observed discrepancies in mahogany trade, for ex-
ample, U.S. Customs modified its computer system to no-
tify CITES agents automatically upon arrival of mahogany
shipments.) At the same time, given the uncertainty and
potentially widespread discrepancies indicated by our
analysis, it is incumbent upon scientists and conservation
organizations to reexamine longstanding assumptions re-
garding the magnitude and conservation significance of
the international wildlife trade.
Acknowledgments
Data and interpretive assistance were provided by
UNEP—WCMC (H. Corrigan), U.S. Customs (T. Brady),
U.S. CITES (P. Thomas and M. Albert), Wisconsin Gin-
seng and Herb Cooperative (K. Drath), Chesapeake Bay
Packers (R. Robinson), U.S. National Marine Fisheries Ser-
vice (S. Koplin), TRAFFIC North America (C. Hoover), and
TRAFFIC Europe (S. Thiele).
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