Russell L. Burke’s longstanding interest in reptiles was the major influence in his decision to pursue a career in biology. His biggest complaint growing up in northern Ohio was that there were no venomous snakes near where he lived, and he seized the earliest opportunities to visit Florida where they could be found. He earned a B.S. in zoology from Ohio State University. While reading Archie Carr’s work on sea turtles he was especially taken by Carr’s argument that wildlife can be harvested sustainably and pay for their own conservation if they are managed wisely. This led to graduate work on gopher tortoise conservation and an M.S. in wildlife ecology from the University of Florida in Gainesville. Burke earned a Ph.D. in biology from the University of Michigan where his work involved investigations of ecology and evolution of midwestern freshwater turtles.
His main research foci have concerned the ecology, evolution, and conservation of reptiles, particularly the manipulation of populations. This can be valuable when populations are small, such as rare and desirable species; when they are too big, such as for pest and disease species; and when they are valuable, such as for harvested species. His current long-term projects include ecological studies of diamondback terrapins in Jamaica Bay and wood turtles in northern New Jersey, both rare species. He has conducted numerous shorter studies on the ecology of invasive Italian wall lizards on Long Island and in Italy. He has been involved with studies of Lyme disease, its tick vectors, and its wildlife hosts, since 2002. He regularly collaborates with colleagues from the American Museum of Natural History, Queens College, University of Rhode Island, Michigan State University, University of Tennessee (Knoxville), Georgia Southern University, and Museo Civico di Zoologia (Rome). He has received grants to support his research from the Hudson River Foundation, the New York City Environmental Fund, the National Science Foundation, the Environmental Protection Agency, and the National Park Service.
At Hofstra Dr. Burke teaches ecology, evolution, conservation biology, urban ecology, and wildlife disease ecology, and he is one of the coordinators of the new Urban Ecology program. He co-teaches Hofstra’s biennial biology-geology study abroad class on the Evolutionary Ecology and Geology of Ecuador, including the Galápagos Islands. He has an active research laboratory that involves high school students, Hofstra undergraduates, and usually six to eight graduate students in every aspect of his research projects.
About Jack Berlin
Founded Accusoft (Pegasus Imaging) in 1991 and has been CEO ever since.
Very proud of what the team has created with edocr, it is easy to share documents in a personalized way and so very useful at no cost to the user! Hope to hear comments and suggestions at info@edocr.com.
ROOSENBURG, W.M. 1992. Life history consequences of nest site
choice by the diamondback terrapin, Malaclemys terrapin.
PhD Dissertation, University of Pennsylvania, Philadelphia.
STANDING, K.L., HERMAN, T.B., SHALLOW, M., POWER, T., AND
MORRISON, I.P. 2000. Results of the nest protection program
for Blanding’s turtle in Kejimkujik National Park, Canada:
1987–1997. Chelonian Conservation and Biology 3:637–642.
STRICKLAND, J., COLBERT, P., AND JANZEN, F.J. 2010. Experimental
analysis of effects of markers and habitat structure on
predation of turtle nests. Journal of Herpetology 44:467–470.
TEMPLE, S.A. 1987. Predation on turtle nests increases near
ecological edges. Copeia 250–252.
Received: 8 May 2015
Revised and Accepted: 11 August 2015
Handling Editor: Jeffrey A. Seminoff
Chelonian Conservation and Biology, 2015, 14(2): 201–203
g 2015 Chelonian Research Foundation
Pursuing Pepper Protection: Habanero
Pepper Powder Does Not Reduce Raccoon
Predation of Terrapin Nests
RUSSELL L. BURKE1,*, MARIAN VARGAS1,2, AND
ALEXANDRA KANONIK1,3
1Department of Biology, Hofstra University, Hempstead, New York
11549 USA [biorlb@hofstra.edu];
2Department of Environmental Science and Forestry, College of
Environmental Science and Forestry at State University of New York,
Syracuse, New York 13210 USA [mvaelas@gmail.com];
3Department of Conservation and Waterways, Town of Hempstead,
Lido Boulevard, Point Lookout, New York 11569 USA
[akkanonik@gmail.com]
*Corresponding author
ABSTRACT. – We replicated the turtle nest predation-
reducing technique used successfully in 2013 by
Lamarre-DeJesus and Griffin to test its generality
with a different turtle species and a different predator.
We found that the application of habanero pepper
powder to diamondback terrapin (Malaclemys terra-
pin) nests did not reduce predation by raccoons
(Procyon lotor). This suggests that the efficacy of
predator-reducing techniques should be tested for each
combination of turtle and predator species.
Turtle nests commonly experience high rates of
depredation by a wide variety of predator species. In some
situations, depredation of nests is a major factor leading to
the endangerment of
turtle species. However,
the
published literature includes remarkably few evaluations
of attempts to reduce depredation on turtle nests (but see
Yerli et al. 1997; Dutton et al. 2005; Riley and Litzgus
2013). Lamarre-DeJesus and Griffin (2013) compared
the efficacy of traditional screen protection (predator
excluders) to applications of habanero pepper (Capsicum
chinense) on freshly oviposited loggerhead sea turtle
(Caretta caretta) nests in a South Carolina beach where
coyotes (Canis latrans) were the main nest predators.
They found that sea turtle nests treated with pepper
powder on the ground surface within 24 hrs of oviposition
had 2.5 times higher survival than did control nests. Given
the low cost and ease of application of this technique, we
sought to test its efficacy at our long-term diamondback
terrapin (Malaclemys terrapin) study site, where raccoons
(Procyon lotor) are the main nest predators (Feinberg and
Burke 2003; R.L.B. and A.K., unpubl. data, 2009–2015).
We modeled our procedures closely after those of Lamarre-
DeJesus and Griffin (2013) and tested using 2 treatment
levels, 1) whether habanero pepper powder lowered
depredation below background rates, and 2) whether eggs
in nests treated with habanero pepper powder had hatch
and emergence rates similar to control nests.
Methods. — Our study was conducted on the island
of Ruler’s Bar in Jamaica Bay Wildlife Refuge, Queens,
New York, from 26 June to 30 July 2014 in an area where
1000–2000 diamondback terrapins nest annually and
where raccoons depredate 95%–100% of freshly laid
nests, generally in the first 24 hrs after oviposition
(Feinberg and Burke 2003; R.L.B. and A.K., unpubl. data,
2009–2015). The density of raccoons in this area is 0.27
to 0.34 raccoons/ha (Rulison 2009), which is relatively
low for an urban area. We located freshly laid terrapin
nests by observing nesting females. We selected terrapin
nests that were widely distributed over the 1.5-ha nesting
area. We first excavated each nest within 24 hrs of
oviposition to collect egg weight and clutch size data. The
eggs were returned to the nest cavities and covered
entirely. We made no attempt to make the nests
inconspicuous because raccoons find nearly all of these
nests anyway (Feinberg and Burke 2003; R.L.B. and
A.K., unpubl. data, 2009–2015). Pure habanero pepper
powder (, 200,000 Scoville heat units, My Spice Sage,
Yonkers, NY) was applied in 10- or 20-g doses,
equivalent to 67% and 133% of the doses used by
Lamarre-DeJesus and Griffin (2013) for much larger sea
turtle nests, following their protocol for “surface” treat-
ment. We applied the powder over an area of , 0.3 m2
centered on the nest. We used a stick to mix the pepper
and sand until it was only slightly visible. In some cases
we added sand to the measured pepper vials to prevent
dosage inaccuracies when applying in windy conditions.
We applied 10 g of pepper to each of 2 nests we
subsequently caged with predator excluders (“low pepper
caged”), 10 g of pepper to each of 15 uncaged nests (“low
pepper uncaged”) and 20 g to each of 15 uncaged nests
(“high pepper uncaged”). The predator excluders were
metal mesh, square hardware cloth boxes approximately
0.3 m on each side; the open side was buried about 15 cm
deep. A small hole was cut in the side of the cages at the
ground level to allow hatchlings to escape. These caged
nests were monitored until 16 November and then
NOTES AND FIELD REPORTS
201
excavated to determine hatching and emergence success.
All nests (caged and uncaged) were checked daily for
depredation as indicated by excavation and empty egg
shells. Two uncaged treated nests only exhibited the
former; therefore, we excavated these nests to determine
whether they had been depredated (they had not).
Eighteen additional nests without cages or pepper
(“no pepper uncaged”) served as controls to measure
background predation rates. These were monitored for at
least 7 d postoviposition because nests that survive this
long are nearly always safe from depredation (Feinberg
and Burke 2003; R.L.B. and A.K., unpubl. data, 2009–
2015). We used 9 additional caged nests without pepper
(“no pepper caged”) to serve as controls to measure
background hatching success and emergence rates, in the
presence of cages but without pepper. The caged control
nests were excavated 16 November 2014 as described
above.
Results. — We observed terrapin nesting on Ruler’s
Bar from 14 June to 28 July 2014. Eighty-three percent
(15/18) of uncaged, no pepper nests (no pepper uncaged)
were depredated; mean days to depredation of those
depredated was 1.4 d (range, 1–3 d). One hundred percent
(15/15) of uncaged, 10-g pepper nests (low pepper
uncaged) were depredated; mean days to depredation
was 1.3 d (range, 1–5 d). Ninety-three percent (14/15) of
uncaged, 20-g pepper nests (high pepper uncaged) were
depredated; mean days to depredation of those depredated
was 1.8 d (range, 1–7 d). Days to predation were not
significantly different between controls
(no pepper
uncaged) and the 10-g treatment (low pepper uncaged)
(t 5 0.45, df 5 28, 2-tailed p 5 0.66) or between con-
trols and the 20-g treatment (high pepper uncaged)
(t 5 0.81, df 5 27, 2-tailed p 5 0.43). All 9 caged
control nests (no pepper caged) had some egg failure;
successful hatch/emergence rates ranged from 55% to
93% (x¯5 75%). The 2 caged and peppered nests (low
pepper caged) had similar successful hatch/emergence
rates (78%, 83%, x¯5 81%). We found no dead or injured
hatchlings in either caged control nests or caged peppered
nests.
Discussion. — Using nests laid by diamondback
terrapins at Ruler’s Bar, New York, where the primary
nest predators are raccoons, we found no evidence that
habanero pepper powder reduced predation rates, despite
following the protocol described by Lamarre-DeJesus and
Griffin (2013) closely. Thus our results differ dramati-
cally from those of Lamarre-DeJesus and Griffin, perhaps
because the primary nest predators in their study were
coyotes, which might be more sensitive to pepper.
Similarly, Burke et al. (2005) found that marking nests
did not increase depredation on diamondback terrapin
nests by raccoons whereas Rollinson and Brooks (2007)
found that the reverse was true regarding painted turtles
(Chrysemys picta), where eggs were depredated by
corvids (common ravens [Corvus corax] and American
crows [C. brachyrhynchos]). Similar site-to-site variation
in predator behavior may be common, and researchers
should avoid generalizing predation patterns from one site
to another.
We were also concerned that even if habanero pepper
powder reduced depredation, it might affect hatching and
emergence rates because pepper powder this hot is quite
caustic (Culinary Farms 2014) and potentially a risk to
neonate turtles. However, sensitivity to capsaicin, the
active component of pepper powder, may be much higher
in mammals than in birds (Tewksbury and Nabhan 2001;
Jordt and Julius 2002) and perhaps also in turtles.
Alternatively, the powder might degrade over the in-
cubation period. We could not find any information on
this point and Lamarre-DeJesus and Griffin (2013) did not
report emergence data. We found that terrapin nests
treated with 10 g of relatively caustic pepper powder
(measured in Scoville heat units) appeared to undergo
incubation, hatching, and emergence about as successful-
ly as did control nests.
Finally, we urge caution to researchers attempting
similar work. Our study area was often windy, and
working with a caustic fine powder in such conditions can
be dangerous, with a high risk of pepper blowing into our
eyes or being transferred to our hands and later elsewhere.
It is important to take appropriate safety precautions,
especially in fairly remote locations. Also, if turtles
excavate nests at a site where pepper powder had been
used previously, those turtles might be harmed.
LITERATURE CITED
BURKE, R.L., SCHNEIDER, C., AND DOLINGER, M.T. 2005. Cues
used by raccoons to find turtle nests: effects of flags, human
scent, and diamond-backed terrapin sign. Journal of Herpe-
tology 39:312–315.
CULINARY FARMS. 2011. Material safety data sheet. http://www.
culinaryfarms.com/documents/HabaneroChiles-BrinedRed-
Natural_5.18.11.pdf (October 2015).
DUTTON, D.L., DUTTON, P.H., CHALOUPKA, M., AND BOULON, R.H.
2005. Increase of a Caribbean leatherback turtle Dermochelys
coriacea nesting population linked to long-term nest pro-
tection. Biological Conservation 126:186–194.
FEINBERG, J.A. AND BURKE, R.L. 2003. Nesting ecology and
predation of diamondback terrapins, Malaclemys terrapin, at
Gateway National Recreation Area, New York. Journal of
Herpetology 37:517–526.
JORDT, S.E. AND JULIUS, D. 2002. Molecular basis for species-
specific sensitivity to “hot” chili peppers. Cell 108:421–430.
LAMARRE-DEJESUS, A.S. AND GRIFFIN, C.R. 2013. Use of habanero
pepper powder to reduce depredation of loggerhead sea turtle
nests. Chelonian Conservation and Biology 12:262–267.
RILEY, J.L. AND LITZGUS, J.D. 2013. Evaluation of predator-
exclusion cages used in turtle conservation: cost analysis and
effects on nest environment and proxies of hatchling fitness.
Wildlife Research 40:499–511.
ROLLINSON, N. AND BROOKS, R.J. 2007. Marking nests increases
the frequency of nest depredation in a northern population of
painted turtles (Chrysemys picta). Journal of Herpetology 41:
174–176.
202
CHELONIAN CONSERVATION AND BIOLOGY, Volume 14, Number 2 – 2015
RULISON, E. 2009. Diet and movements of raccoons and Norway
rats in Gateway National Recreation Area. MS Thesis,
Hofstra University, Hempstead, NY, 208 pp.
TEWKSBURY, J.J. AND NABHAN, G.P. 2001. Seed dispersal. Directed
deterrence by capsaicin in chilies. Nature 412:403–404.
YERLI, S., CANBOLAT, A.F., BROWN, L.J., AND MACDONALD, D.W.
1997. Mesh grids protect loggerhead turtle Caretta caretta
nests from red fox Vulpes vulpes predation. Biological
Conservation 82:109–111.
Received: 22 January 2015
Revised and Accepted: 5 June 2015
Handling Editor: Jeffrey A. Seminoff
Chelonian Conservation and Biology, 2015, 14(2): 203–204
g 2015 Chelonian Research Foundation
Habanero Pepper Powder as a Potential
Deterrent to Nest Predation of Turtle Nests:
A Response to Burke et al. (Chelonian
Conservation and Biology, 14(2):201–203, 2015)
ABIGAIL S. Lamarre-DEJESUS* AND
CURTICE R. GRIFFIN
University of Massachusetts Amherst, Department of Environmental
Conservation, 160 Holdsworth Way, Amherst, Massachusetts 01003
USA [ablamarre@gmail.com, cgriffin@eco.umass.edu]
*Corresponding author
ABSTRACT. – We applaud the 2015 report of Burke et al.
to broaden the testing of habanero pepper powder as
a potential deterrent to nest predation of turtle nests.
Although we had much success in reducing nest
predation rates by coyotes (Canis latrans) at logger-
head sea turtle (Caretta caretta) nests (Lamarre-
DeJesus and Griffin 2013), our results were based on
only 1 season of data at 1 beach location in South
Carolina. We suspect that the dramatic difference in
the efficacy of habanero pepper for reducing nest
predation rates between our study for loggerheads and
those reported by Burke et al. for diamondback
terrapin (Malaclemys terrapin) may be related pri-
marily to the predators involved.
Although little is known about the specific cues that
predators use to locate turtle nests,
there is much
conjecture about the importance of visual and olfactory
cues (see recent reviews by Bernstein et al. 2015; Geller
2015; Oddie et al. 2015). For example, several studies
reported that soil disturbance was a major visual cue used
by raccoons (Procyon lotor) and other predators to locate
turtle nests (Burke et al. 2005; Strickland et al. 2010;
Bernstein et al. 2015). Wirsing et al. (2012) suggested that
both visual and soil- and egg-related olfactory cues were
important
for raccoon predation at snapping turtle
(Chelydra serpentine) nests. Yet, Geller (2015) reported
that broom sweeping at Ouachita map turtle (Graptemys
ouachitensis) nests did not reduce raccoon predation rates,
and he suggested that raccoons use olfactory cues to find
newly constructed nests. Galois (1996) reported that
captive raccoons used visual, olfactory, and tactile cues to
find artificial nests. Further, he suggested that raccoons
might use tactile cues more frequently when nests are
close together whereas olfactory cues may play a more
dominant role in nests that are spaced farther apart.
Additionally, Oddie et al. (2015) reported that raccoons
located snapping turtle nests using tactile, olfactory, and
visual cues. Yet, they concluded that nests found by
raccoons using olfactory and visual cues had a higher
probability of nest predation where tactile cues were also
present. Consequently, they suggested that nest screening
was the most effective way of protecting turtle nests from
raccoon predation because it removes the tactile cue of
the loose, soft substrate surrounding nests while also
protecting the nest from predation.
Although purely speculative, we suggest that the
dramatic difference in the efficacy of habanero pepper
powder for reducing nest predation rates between our 2
studies may be primarily due to the different predator
species. Our study suggests that coyotes, compared with
raccoons, may have increased sensitivity to the irritating
effects of habanero pepper powder, possibly resulting
from differing olfactory abilities. Secondly, we speculate
that coyotes on Sand Island may use different search
strategies (primarily olfactory) for turtle nests on a long
(8 km) island compared with raccoons (primarily visual,
olfactory, and tactile) on Ruler’s Bar, where terrapin nests
are concentrated into a relatively small (1.5 ha) nesting
area on a small dredge island.
Although probably minor, there were also small
differences in the way each turtle nest was handled prior
to treatment between the 2 studies. Burke et al. (2015)
reported that each nest was fully excavated to collect egg
weight and clutch size data. However, in our study on Sand
Island, we only dug down to the top-most egg to confirm it
was a nest and then immediately covered it back up and
applied our treatments. At the same study site, Burke et al.
(2005) reported that nest disturbance and fresh turtle scent
at terrapin nests were associated with higher nest predation
rates by raccoons. Is it possible that nest excavation
dispersed the scent of the fresh nest while also further
disturbing the soil, therefore increasing raccoon attraction?
Additionally, Burke et al. (2015) reported mixing the
pepper powder and sand prior to treatment, possibly
reducing the concentration and irritant effects of the
habanero pepper powder. Yet, we suspect it is highly
unlikely that these small methodological differences
explain the dramatic differences between our two studies.
We commend Burke et al. (2015) on their excellent
study that suggests that the use of habanero pepper
powder may be largely ineffective for reducing nest
NOTES AND FIELD REPORTS
203