Local Scientists and Their Research:
SAM K. WASSER, PH.D.
(Adapted from the Department of Zoology, University of Washington) Dr. Sam Wasser received his Ph.D. from the University of
Washington in 1981. His research uses endocrinology and molecular biology techniques to address questions concerning
conservation and evolutionary biology in free-ranging wildlife. He has been particularly interested in the evolution of
mechanisms that enable mammals to control the timing of reproduction in response to environmental pressures. To facilitate
these studies, Dr. Wasser pioneered the development of noninvasive techniques to extract steroid hormones from feces of
free-ranging wildlife. Over the years, he began applying these techniques to conservation problems, using fecal stress hormone
measures to demonstrate the relative impacts of various timber harvest techniques on physiological stress in Northern
Spotted Owls. Dr. Wasser, along with other scientists in Africa and the U.S., used these techniques to examine long-term
consequences of poaching on African elephants. Realizing the power of this noninvasive technology, he also developed
techniques to measure DNA in feces. His laboratory has since applied non-invasive fecal DNA techniques in mark/recapture
models to estimate the number and distribution of a variety of wildlife species at risk. They also applied these fecal DNA
techniques to wildlife forensics. The ease of sample collection has enabled scientists to develop highly accurate geographic
maps of gene frequencies for use in tracking the origin of poached ivory from African elephants.
KENINE E. COMSTOCK, PH.D.
Dr. Kenine Comstock recent work at the Fred Hutchinson Cancer Research Center in Seattle involved developing a genetic
method for assessing the geographic origin of ivory that is entering the market. She and other scientists use molecular
techniques to isolate tiny repetitive regions of DNA (called micro-satellites). These DNA fragments are electrophoresed and
used as markers to identify unique populations of elephants. Dr. Comstock’s work will be used to create a geo-genetic map of
Africa that shows the allele frequencies of the elephants and the regions where those alleles are found. Dr. Comstock received
her Ph.D. from the Oregon Health Sciences University in Portland Oregon in 1993 in Biochemistry and Molecular Biology. She
graduated from Oregon State University in Corvallis Oregon in 1984 with her B.S. degree in Biology. Since 1984, Dr. Comstock
has worked as a Research Technologist at the Shriner’s Hospital for Crippled Children in Portland, and then as a Postdoctoral
Fellow at the Cystic Fibrosis and Pulmonary Research and Treatment Center in North Carolina. In 1996, Kenine came to the
Fred Hutchinson Cancer Research Center to continue her Postdoctoral Fellowship in conjunction with the University of
Washington and The Center for Wildlife Conservation at the Woodland Park Zoo. Dr. Comstock has published (or has been a
collaborator for) eight separate articles on her various research projects, and has a patent on a invention for using PCR in
determining a gene deletion status.
Research Overview:
Poaching decimated African elephant populations from ~
1.3 million to 500,000 individuals in the eight years between
1979 and 1987. This prompted the Convention on
International Trade in Endangered Species (CITES) to list
the African elephant as an Appendix I (endangered) species
in 1989. Despite these protections, a higher percentage of
Africa’s remaining elephants are now being killed than ever
before.
We estimate that as many as 50,000 elephants are currently
being killed annually based on the 46.5 tons of African
elephant ivory seized in 2011. Assuming approximately
400,000 elephants remaining in Africa, African elephants
could be virtually extinct in the next decade.
Elephant poaching. (Photo by Karl Ammann)
In 2004, the Center for Conservation Biology began collaborating with INTERPOL and other law enforcement authorities,
applying DNA-based methods pioneered by our laboratory to identify the sources of seized African elephant ivory. Our
investigations uncovered important features of transnational organized wildlife crime that could be used to unravel the
criminal networks that feed this illegal trade. We found that individual large seizures (> 0.5 tons) tend to be composed of ivory
from a localized source that is hit repeatedly over time, generally within a single country. The same sources tend to recur and
appear to be limited in number. Apparently, not many places still have enough elephants to supply numerous multi-ton
shipments of ivory over time where poachers also have low risk of being apprehended. Our current program aims to rapidly
identify most of Africa’s major ivory poaching hot spots by genetically determining the origin of a representative portion of
major ivory seizures.
Decision 16.83 at the last CITES COP (COP16, Bangkok, March 2013) set the stage to put this plan into action. The decision
urged countries to promptly submit ivory sub-samples from all large seizures (> 0.5 tons), made immediately and over the
past two years, for origin assignment by an appropriate forensic laboratory. The UN office on Drugs and Crime (UNODC) was
asked to cooperate with the CITES Secretariat in these investigations (Decision 16.81) and UNODC asked our Center to lead
these DNA-based analyses in collaboration with them, INTERPOL and the World Bank. The information obtained from these
analyses is helping to focus law enforcement efforts on Africa’s major poaching hot spots and the newsworthiness and
excitement that this actionable science brings to the problem is helping to facilitate these objectives.
Research Objectives: Our goal is to identify the major elephant poaching hot spots across Africa by determining the
geographic origin of large volumes of contraband ivory seized by wildlife authorities. These large volume seizures bear the
stamp of organized crime, based on the value of the contraband and all that is required to ship it internationally. Identifying
the origins of these large seizures helps reveal where to most efficiently focus law enforcement as well as key strategies used
by ivory poachers and dealers.
Research Methods: DNA is successfully isolated from small amounts of ivory, sampled anywhere along the length of the tusk
and used to create a unique genetic “fingerprint” of each elephant based on 16 microsatellite DNA loci (Figure 1). We also
extract the same genetic information from elephant feces. Ease of collection to use DNA from feces enabled us to assemble a
geographic-based map of elephant gene frequencies across Africa (Figure 2).
We applied a novel statistical smoothing method to these gene frequencies to create a continuous distribution of elephant
gene frequencies across the continent. This allows us to estimate each poached ivory sample’s position across Africa (see
below), including areas with no reference samples, and provides a confidence estimate for each assignment.
We strive to improve the accuracy of predictions by collecting scat samples to fill the remaining gaps in the gene frequency
map used to determine elephant origin. DNA extracted from feces provides a non-invasive method of rapidly acquiring these
reference samples from across Africa.
Figure 1. DNA is purified from pulverized ivory and
used to create genetic fingerprints.
Figure 2. Locations of forests (green) and savanna (red)
elephant reference samples collected across Africa. Each
location includes 10-50 dung samples, each collected from
separate family groups.
What we learned: Our investigations uncovered important features of trans-national organized wildlife crime in ivory that
could be used to unravel their criminal networks. We found that individual large seizures (>0.5 tons) tend to be composed of
ivory from a localized source that is hit repeatedly over time, generally within a single country. This disproved widely held
beliefs that single large shipments were generally derived from ivory collected from multiple sources, spanning multiple
countries across Africa. More importantly, the source countries we identified have tended to recur and be relatively small in
number.
Our first investigation identified the geographic origin of the largest ivory seizure since the 1989 ivory trade ban—6,500 kg of
ivory seized in Singapore, June 2002, en route from Malawi. This shipment contained 531 tusks, many of which were atypically
large (mean = 11 kg), suggesting it was targeting wealthy buyers. Small tusks were conspicuously absent. The shipment also
contained 42,000 hankos (small solid ivory cylinders used to make individual seals for letters), representing 20% of Japan’s
annual hanko sales.
We also examined ivory scraps seized in a raid of an ivory carving factory in Malawi, two months prior. Confiscated records
suggested these scraps might be from the same ivory that was cut into hankos.
All the ivory was from savanna elephants native to a narrow E-W band of southern Africa, centered on Zambia (Figure 2A).
Then, in 2006, a controlled delivery that appeared to originate from Zambia was seized in Singapore by authorities. This was a
significant seizure as ballistics showed that the elephants were shot from above, implicating machine guns shot from
helicopters. This seizure was also determined to have originated in Zambia. (Figure 3).
Figure 3. Geographic origin assignments of (a) tusks, (b) hankos, and (c) hanko shells (leftover scraps
from which the hankos were cut) from the Singapore and Malawi ivory seizures in 2002, as well as
ivory assigned from a subsequent seizure in 2006.
We examined other seizures in 2006 that told a similar story. Nearly 4,000 kg of ivory were seized in Hong Kong, shipped from
Cameroon. Hong Kong authorities using x-ray discovered the ivory in a false compartment of a container containing sawn
timber. They subsequently seized two more containers returning to Cameroon from Hong Kong, registered to the same
shipper. False compartments were also found in these two containers. The compartments were empty, but a few ivory chips
were found on the floor. Our analyses showed that the tusks and ivory chips were from forest elephants of a common origin,
centered on SE Gabon near the Congo-Brazzaville border. (figure below).
Geographic origin assignments of ivory from (a) tusks from the Hong Kong Seizure and (b) chips remaining from a single tusk
seized in an analogous container on its return to Cameroon from Hong Kong. Click image to enlarge.
Then, in July 2006, four seizures totaling 11 tons were shipped from Tanzania. Two seizures were made in Taiwan, one in
Hong Kong and one in Japan. The Taiwan and Hong Kong seizures all originated from the Selous Game Reserve in Tanzania,
spilling over into Nyasa Game Reserve in northern Mozambique. Japan would not allow their seizure to be examined. However,
the ivory seized in Japan had Swahili writing on it, also supporting a similar origin. (figure below).
Collectively, these seizure assignments led to the hypothesis
that there may currently be fewer major poaching hotspots
across Africa than suspected. These hotspots are likely limited
because not many places still have enough elephants to supply
numerous multi-ton shipments worth of ivory over time where
poachers also have low risk of apprehension. If this hypothesis
is correct, we should be able to identify most of Africa’s major
poaching hotspots in a short time-frame by genetically
determining the origin of a representative portion of major ivory
seizures. This information would, in turn, allow law enforcement
to be effectively focused on these areas, potentially choking the
trade at its source.
We now appear well on our way to acquiring the required
representative portion of seizures necessary to reliably
determine the total number of major elephant poaching hotspots
across Africa. Locating the sources of the major poaching hotspots across Africa is part of a larger collective effort to get the
illegal ivory trade under control. The plan includes programs aimed at reducing short and long-term demand for ivory,
acquisition and DNA-based assignment of a representative number of all recent seizures, and successful implementation of law
enforcement operations in response to this information. Our laboratory is well-positioned to conduct the source identification
portion of this plan. Our experience suggests that the newsworthiness and excitement that this actionable science brings to the
problem will also facilitate the law enforcement component of this program and hopefully the success of the program as
whole.
Geographic origin assessments of ivory from two seizures in Taiwan
and one in Hong Kong, as well as ivory with Swahili writing seized in
Japan (lower right).
Implications: Our approach provides reliable information on where ivory poaching is most concentrated in Africa. Such
information tells authorities where greater enforcement efforts are needed and helps to identify trade routes used to move
ivory inside and outside Africa. Results also create accountability by forcing nations to be more responsive to poaching in their
country.
Ecoguard dung samples from Nduzo Bokomo-Bolungi for our DNA
reference map. Participation of local rangers in sample collections is
pivotal to the success of our project. It also serves to educate local people
that something is being done to combat poaching on a broader scale
(Photo, Left, by Gay Reinartz)
Information gathered from these analyses, and associated increases in
seizure rates, should enable international authorities to more effectively
evaluate the consequences of future trade decisions.
Traffic in forest elephant ivory can also be used to indicate hotspots in the
burgeoning bush meat trade across central Africa. These methods may be
among the only reliable means to monitor trade in forest ivory and bush
meat because poached carcasses are difficult to detect in dense forests.
Additional uses include:
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Detecting whether declared government ivory stockpiles are being sold off and illegally replenished.
Detection of illegally traded tusks from other countries in sanctioned ivory sales.
Similar methods could be readily applied to other wildlife crimes as diverse as the illegal trade in timber or tiger parts.