SHORT COMMUNICATION N Castellanos et al.
Hematological and serum biochemical values of Andean bears
in Ecuador
Armando Castellanos1,3, Leonardo Arias2,
David Jackson2, and Roberto Castellanos1
Key words: Andean bear, comparative physiology,
Ecuador, health status, hematology, serum biochemistry, spectacled bear, Tremarctos ornatus
1
Andean Bear Foundation, 60 S Van Dorn ST, F-518,
Alexandria, VA 22304, USA
2
Fundación Espı´ritu del Bosque, Guipuzcoa 439 y
Coruña, Quito, ECUADOR
Ursus 21(1):115–120 (2010)
Hematology and serum biochemistry are valuable
tools for evaluating health and physiological status
of captive and free-ranging wildlife. The limited data
reported in the scientific literature on Andean bear
(Tremarctos ornatus) hematology are restricted to
captive bears (Seal et al. 1967, Dierenfeld 1988,
Nassar et al. 1994, Teare 2002). Andean bears are
classified as vulnerable across their entire range
(International Union for Conservation of Nature
[IUCN] 2009), and endangered according to the Red
Book of Mammals of Ecuador (Cuesta and Suarez
2001). This classification is due to loss and fragmentation of habitat caused by human intervention and
the high number of bears killed in human–bear
conflicts. Recent studies have begun to shed light on
the ecology of Andean bears, but there is much
about their biology that remains to be learned.
In this paper, we present data on hematology and
blood chemistry of captive, rehabilitated, reintroduced, and wild Andean bears. Our objectives were
to: (1) provide reference values for hematology and
serum biochemistry for the Andean bear in Ecuador,
(2) evaluate the variability in these parameters based
on life condition (captive or free ranging), sex, age,
and body mass and (3) compare these results to those
from other Andean bear populations and other ursid
species.
Abstract: We collected blood samples (n 5 49) from
43 Andean Bears (Tremarctos ornatus) in Ecuador
between September 1995 and May 2006 and
analyzed them for 11 serum biochemical and 13
hematological parameters. Results were grouped and
compared according to the bears’ life condition
(captive or free-ranging), sex, age, and body mass.
Free-ranging bears had higher serum glucose and
monocyte levels than captive bears, but slightly
lower mean cellular hemoglobin concentrations.
Male bears had higher serum protein levels than
female bears. Adult bears showed higher levels of
cholesterol, hematocrit, and hemoglobin than subadult bears. In contrast, alkaline phosphatase and
phosphorous levels were higher in sub-adult bears.
Bears with a body mass .80 kg had higher levels of
serum proteins and blood urea nitrogen than lighterweight bears. Plasma triglyceride levels observed in
this study were very high in relation to those
reported for other bear species. Alkaline phosphatase levels were also high in comparison to those of
other bear species, except the giant panda (Ailuropoda melanoleuca). Observed mean values for
glutamic pyruvic transaminase, glutamic oxalic
transaminase, glucose, and calcium were low in this
study relative to those of captive Andean bears from
other countries, whereas the mean alkaline phosphatase value was comparatively high. Mean values
for glutamic pyruvic transaminase, glutamic oxalic
transaminase, glucose, calcium, mean cellular hemoglobin, and mean cellular volume were lower relative
to other bear species. The data presented in this
paper will provide baseline reference values that may
prove useful in the diagnosis of disease and assessment of nutrition in wild and captive Andean bears.
Methods
We collected 49 blood samples from 43 Andean
bears (24 males and 19 females) between September
1995 and May 2006. Samples were obtained as
follows: 30 samples from 28 captive bears (16 males
and 12 females) in zoos and rescue centers in
Ecuador; 9 samples from 7 (4 males and 3 females)
bears in our Andean bear reintroduction program
(Castellanos 2000), sampled at their release back to
the wild; 2 samples from 2 bears (1 male and 1
female) recaptured one year after reintroduction; 8
3
[email protected]
115
116
SHORT COMMUNICATION N Castellanos et al.
from wild bears (4 males and 4 females) captured for
radiotelemetry studies of wild Andean Bears (Castellanos 2004).
Wild bears were captured in the Intag region,
Imbabura Province, in northwest Ecuador. This
region is part of the buffer zone of the CotacachiCayapas Biological Reserve that covers a total of
243,638 ha and consists of 3 vegetation zones: cloud
forest, high montane forest, and páramo that range
across an altitudinal gradient from 2,000 to 4,000 m
(Ministerio del Ambiente del Ecuador 2007).
Wild Andean bears were captured in Iznachi traps
designed by Castellanos (2002). The traps are
reinforced steel boxes (2 m long x 0.8 m wide x
0.9 m high) that can be disassembled into 10 panels
for ease of transport. One or two decomposing cow’s
feet were used as bait. Radiocollars were used as trap
beacons on each trap and were monitored hourly
from 0600 to 2230 because Andean bears move little
at night (Castellanos 2004). Radio signals from traps
were investigated immediately to avoid stress from
long capture.
The 30 samples from zoos and rescue centers
constituted the captive bear group, and the remainder formed the free-ranging group. Wild bears were
classified as either adults (.3 years of age) or sub
adults (,3 years of age), based on morphometric
values, body mass, and denture deterioration and
color. Zoo and rescue center registers were used to
determine the approximate age of captive bears.
Body mass of captive bears was obtained predominantly from zoo and rescue center registers,
although in some cases we had to estimate the body
mass. All bears in the free-ranging group were
weighed using a 150-kg scale, except for 3 wild male
bears whose body mass was estimated visually and
by comparing morphometric data to that of bears
that had previously been weighed. Bears weighing
.80 kg were classified as heavy and bears weighing
,80 kg were classified as light.
Results from bears sampled as sub-adults and
later as adults (n 5 4) or as captive and later as freeranging (n 5 2) following release were used for
calculations for both groups, according to their age
or life condition at the time of sampling. For bears
sampled more than once that did not change
classification during the study, only the first sample
collected was used in comparisons of blood parameters. Hematological comparisons were made
between bears of differing living conditions (captive
or free-ranging), sex (male or female), age (adult or
sub-adult), and body mass (heavy or light). All bears
appeared to be healthy at the time of sampling and
showed no obvious signs of disease or injury.
We anesthetized bears using immobilizing darts
following the protocol proposed by the Canadian
Association of Zoo and Wildlife Veterinarians
(Woodbury 1996) and Safe-Capture International
Inc. (1998). We used a blowpipe to deliver immobilizing drugs to wild bears captured in Iznachi traps
(Castellanos 2002) and an air pistol (TelinjectH,
Romerberg, Germany) for all remaining bears. Bears
were immobilized using a mixture of ketamine
hydrochloride (3–8 mg/kg, Ketamina 50H, HollidayScott S.A., Buenos Aires, Argentina) and xylazine
hydrochloride (2 mg/kg, Xylazine HCl InjectionH,
Phoenix Scientific Inc, St. Joseph, Missouri, USA)
with yohimbine hydrochloride (0.1–0.25 mg/kg,
Reverzine S.A.H, Parnell Laboratories, Alexandria,
New South Wales, Australia) as the antagonist agent.
On other occasions bears were immobilized using
equal parts tiletamine hydrochloride and zolazepam
hydrochloride (ZoletilH, Virbac S.A, Carros Cedex,
France) at dosages of 3–5 mg/kg body weight. Blood
samples were drawn from the femoral artery 10–
15 minutes after immobilization. All samples were
divided into 2 vacutainer tubes, 1 containing EDTA
(ethylenediamine tetra acetic acid) anti-coagulant and
1 without. For the sample without EDTA, we waited
an hour for the serum to separate and transferred it to
a new container. All samples were immediately placed
in a cooler that maintained sample temperatures at
10uC, and were transported to LIVEX laboratories
(Quito, Ecuador) for processing within 24 hrs.
Samples that showed signs of hemolysis were not
considered for analysis.
Blood samples were analyzed on a Coulter T890
analyzer (Beckman Coulter, Fullerton, California,
USA) for hematocrit, hemoglobin, leukocytes, erythrocytes, segmented leukocytes, lymphocytes,
monocytes, eosinophyles, basophiles, band cells,
mean cellular hemoglobin concentration, mean
cellular volume, and mean cellular hemoglobin. A
spectrophotometer Clinicon 4010 (Roche, Nutley,
New Jersey, USA) was used for biochemical
analyses, including cholesterol, total proteins, triglyceride, blood urea nitrogen, glutamic oxalic transaminase, glutamic pyruvic transaminase, alkaline
phosphatase, calcium, phosphorous, glucose, and
urea.
We followed the procedures of Huber et al. (1997)
and Kusak et al. (2005) for statistical analysis of
Ursus 21(1):115–120 (2010)
SHORT COMMUNICATION N Castellanos et al.
117
Table 1. Hematology and serum biochemistry of captive and free-ranging Andean bears in Ecuador, from
samples collected during September 1995–May 2006. Units: mmol = millimoles/liter; U/L = 1 enzyme unit
(1 mmol min21)/liter; fl = femtoliter (= cubic micrometer); pg = pictogram.
All bears
Serum and blood parameters
n
Units
Mean
Minimum
Maximum
SD
SE
Cholesterol
Total protein
Triglycerides
Blood urea nitrogen
Glutamic oxalic transaminase
Glutamic pyruvic transaminase
Alkaline phosphatase
Calcium
Phosphorous
Glucose
Urea
Hematocrit
Hemoglobin
Leukocytes
Erythrocytes
Segmented leukocytes
Lymphocytes
Monocytes
Eosinophiles
Basophiles
Band cells
Mean cellular hemoglobin concentration
Mean cellular volume
Mean cellular hemoglobin
33
27
34
29
38
39
31
32
35
18
38
45
46
44
37
45
44
46
43
43
40
36
38
38
mmol/L
g/L
mmol/L
mmol/L
U/L
U/L
U/L
mmol/L
mmol/L
mmol/L
mmol/L
L/L
g/L
x109/L
x1012/L
x109/L
x109/L
x109/L
x109/L
x109/L
x109/L
g/L
fl
pg
7.98
77.30
7.33
4.77
30.23
21.43
97.57
1.87
1.68
3.56
9.85
0.43
144.45
9.11
7.87
6.47
2.20
0.13
0.16
0.01
0.027
334.17
53.21
18.33
3.32
60.00
4.88
1.96
3.00
3.00
16.00
1.40
0.48
1.11
2.75
0.33
102.00
3.20
4.82
4.28
0.91
0
0.00
0.00
0
243.00
32.00
12.70
11.66
114.0
10.88
8.50
108.00
79.00
239
2.58
3.22
7.66
20.35
0.55
194.00
16.00
10.58
8.11
4.01
0.55
0.82
0.27
0.64
530.00
86.00
26.30
1.97
15.30
1.64
1.51
20.68
19.41
58.21
0.29
0.70
1.46
4.48
0.05
20.89
2.98
1.52
0.94
0.77
0.13
0.22
0.05
0.11
43.10
13.15
3.03
0.34
2.95
0.28
0.28
3.35
3.10
10.45
0.05
0.12
0.34
0.73
0.007
3
0.45
0.24
0.139
0.116
0.0189
0.033
0.007
0.017
7.19
2.13
0.49
hematological and blood chemistry parameters.
Mean values, standard deviations (SD), and standard errors (SE) were calculated for each parameter.
Values that differed from the mean by .2.5 SD were
classified as an extreme outlier and excluded from
further calculations. Mean values, SD, and SE were
recalculated for each parameter after removal of
outliers. However, we did not exclude outliers for
monocyte, basophiles, and band cells because of
their rare occurrence in most samples. P , 0.05 was
considered statistically significant for t-tests. Statistics were analyzed using the Statistica program
(StatSoft Inc., Tulsa, Oklahoma, USA).
Results
We calculated mean and range values for 11 serum
biochemical and 13 hematological parameters for
chemically immobilized Andean bears (Table 1).
Adult mean values differed from those of sub-adults
in 5 parameters: cholesterol (9.33 versus 6.99 mmol/
L; n1 5 14, n2 5 19, t 5 4.14, 31 df, P 5 0.0002);
alkaline phosphatase (78.11 versus 121.20 U/L; n1 5
17, n2 5 14, t 5 2.17, 29 df, P 5 0.037); phosphorous
(1.37 versus 2.05 mmol/L; n1 5 19, n2 5 16, t 5 3.25,
Ursus 21(1):115–120 (2010)
33 df, P 5 0.002); hematocrit (0.45 versus 0.43 L/L;
n1 5 22, n2 5 23, t 5 3.34, 43 df, P , 0.001);
hemoglobin (155.6 versus 132.8 g/L; n1 5 23, n2 5
23, t 5 4.41, 44 df, P , 0.001). Male bears had
higher mean serum protein levels (82.7 versus 68.1 g/
L; n1 5 17, n2 5 10, t 5 2.65; 25 df; P 5 0.013) than
females. Heavy bears had higher mean serum protein
(87 versus 72.4 g/L; n1 5 9, n2 5 18, t 5 2.54, 25 df, P
5 0.017) and blood urea nitrogen (5.74 versus
4.26 mmol/L; n1 5 10, n2 5 19, t 5 2.8, 27 df, P 5
0.009) than light bears. Finally, free-ranging bears
had higher mean serum glucose (4.26 versus
2.87 mmol/L; n1 5 9, n2 5 9, t 5 2.25, 16 df,
P 5 0.038) and monocyte levels (0.18 versus 0.09 x
109mmol/L; n1 5 30, n2 5 19, t 5 2.61, 47 df, P 5
0.012) than captive bears, but a lower mean cellular
hemoglobin concentration (315 versus 345 g/L; n1 5
22, n2 5 14, t 5 2.14, 34 df, P 5 0.038).
Discussion
There is very little information on Andean bear
blood chemistry and hematology with which to
compare data from this study. Consequently, we
used information on other bear species and carni-
118
SHORT COMMUNICATION N Castellanos et al.
vores to enhance the interpretation of these data.
The increased levels of glucose and monocytes in
free-ranging bears observed in this study may be
attributed to the fear, excitement, and stress of
physical capture in a restraint cage. Increased
glucose levels were reported by Brannon (1985a)
for grizzly bears (Ursus arctos) captured using snare
traps, indicating a relation between capture stress
and observed glucose levels. Additionally, increased
glucose (Marco et al. 2000) and monocyte (McCue
and O’Farrell 1987) levels were observed as induced
stress responses resulting from trapping procedures
for captive European wildcat (Felis silvestris) and
San Joaquin kit fox (Vulpes macrotis mutica),
respectively.
Although Andean bears in northern Ecuador have
food sources available year round, they are known to
experience periodic starvation. The year-round food
sources include various bromeliads (Puya spp.,
Greigia spp., Tillandsia spp.), bamboo (Chusquea
spp.), and palms (Euterpe spp., Prestoea spp.) that
are rich in fiber, though have little carbohydrate or
lipid content (Galasso 2002, Castellanos et al. 2005).
For this reason, Andean bears in these areas have to
search for wild fruit (Ficus spp., Nectandra spp.,
Ocotea spp.) to supplement their diet. These fruits
are available at only certain times of year, for
periods not exceeding 2 months. Critically, the fruit
trees are frequently deforested as they are good
sources of timber, leaving an ever-decreasing supply
of fruit each year (Ministerio del Ambiente del
Ecuador 2007). In the Intag region where we
radiocollared a total of 17 wild bears, 10 were
malnourished (capture times varied widely throughout the year). This indicates that although Andean
bears in this area have a variety of year-round food,
their diet is frequently lacking important supplements, leading to periodic starvation (Castellanos et
al. 2005).
Low mean cellular hemoglobin concentrations
among free-ranging bears observed in this study
could illustrate a periodic anemia, similar to that
documented in Brannon’s study (1985b) on grizzly
bears and that of Seal et al. (1967), who reported the
occurrence of periodic anemia in various bear
species. In contrast, higher mean cellular hemoglobin concentration for captive Andean bears could
result from their regular food supply.
Andean bears are sexually dimorphic; adult males
are over twice the size and weight of females (Tirira
1999). This size difference between the sexes could
explain the higher serum protein levels observed for
male individuals in this study. Similarly Tryland et
al. (2002) reported significantly elevated serum
protein levels for obese polar bears (Ursus maritimus)
compared to lean individuals.
Higher levels of cholesterol in adult bears may be
because young bears are growing and are physically
more active. Thus, they have a more rapid fat and
lipid metabolism, and hence lower cholesterol, as is
observed in other mammal species.
We found that alkaline phosphatase levels decreased with age, conforming with observations
made by Brannon (1985a) on grizzly bears, Storm
et al. (1988) and Hellgren et al. (1989) on black bears
(Ursus americanus), and Tryland et al. (2002) on
polar bears. This is probably due to a reduction in
bone growth with age. As in this study, Brannon
(1985a), Storm et al. (1988), and Hellgren et al.
(1989) also found higher phosphorous levels in subadult grizzly and black bears relative to adults, again
likely owing to skeletal development and bone
ossification in juveniles.
Kusak et al. (2005) and Seal et al. (1967) reported
elevated hemoglobin and hematocrit levels, respectively, in adult brown bears and other bear species
compared to younger animals, which is similar to
our findings in this study.
According to Case et al. (1997), urea production is
directly proportional to the daily catabolism of
consumed and body proteins. We observed higher
blood urea nitrogen levels in heavy bears. This could
be a result of heavy bears having more protein-rich
diets, hence a higher urea production and therefore a
higher blood urea nitrogen level. Tryland et al.
(2002) also reported that protein levels were elevated
in heavy polar bears, which conforms with our
findings.
Comparing our blood chemistry and hematology
parameters for Andean bear with those of other bear
species, we found that Andean bear had higher
tryglyceride levels than all other ursid species
recorded in the International Species Information
System (ISIS; Teare 2002). Tryglyceride levels may
be elevated due to the carbohydrate-rich diet of
Andean Bears in captivity and the high intake of
plant protein by wild bears through the consumption
of suro (Chusquea spp.), a bamboo-like plant that
constitutes 53–73% of the diet of wild Andean bears
in our study region (Castellanos 2003, Castellanos et
al. 2005). Although Andean bears do not hibernate,
their high tryglyceride level could indicate that they
Ursus 21(1):115–120 (2010)
SHORT COMMUNICATION N Castellanos et al.
need fat reserves to support the large distances they
cover and during shortages of the bears’ natural food
as reported by Castellanos (2004).
Mainka (1999) reported levels of alkaline phosphatase (125 U/L), blood urea nitrogen (5.36 mmol/L),
and mean cellular volume (59.4 fl) for the giant panda
(Ailuropoda melanoleuca). These are similar to the
levels found in the current study. These results could
reflect the largely vegetarian diet of both species.
The mean alkaline phosphatase value observed in
the current study was higher than the 53 U/L reported
for this species by Nassar et al. (1994) and 66.8 U/L
reported by ISIS (Teare 2002). Nassar et al. (1994) and
ISIS (Teare 2002) described mean glutamic oxalic
transaminase values for the Andean bear of 40 U/L
and 37 U/L, respectively. The mean glutamic oxalic
transaminase value from this study is relatively low
compared to these values. ISIS (Teare 2002) reported a
higher mean glutamic pyruvic transaminase level
(28 U/L) than that found in this study.
Nassar et al. (1994) and ISIS (Teare 2002)
described mean calcium values for the Andean bear
of 2.33 mmol/L and 2.18 mmol/L, respectively. The
mean calcium value from this study is relatively low
in comparison.
Mean values for glutamic oxalic transaminase,
glutamic pyruvic transaminase, calcium, glucose,
mean cellular volume, and mean cellular hemoglobin
concentration from this study are low compared to
those of other bear species (Teare 2002). These may
reflect typical values of the Andean bear.
The reference values in this paper are baseline data
that will be useful for future studies on Andean bears
throughout their range. They will also provide
valuable information for the diagnosis of disease
and malnutrition in free-ranging and captive Andean
bears.
Acknowledgments
We thank LIFEX and LIVEX Laboratories for
blood sample analysis, the Ecuadorian Ministry of
Environment for granting permits, and the zoos and
rescue centers that allowed us to sample bears in
their care, particularly Quito Zoo in Guayllabamba
and Baños Zoo. Field work was carried out under
the auspices of the World Society for the Protection
of Animals (WSPA), Wildlife Conservation Society –
Ecuador Program (WCS), International Association
for Bear Research and Management (IBA), Cleveland Metro Park Zoo, Idea Wild, Aquarium and
Ursus 21(1):115–120 (2010)
119
Zoo Facilities Association’s Clark Waldram Conservation Fund, Rainforest Concern, British Broadcasting Corporation (BBC), Parco Natura Viva, Zoo
Conservation Outreach Group (ZCOG), and the
Dino Veterinary Clinic, Quito. We also thank K.
Noyce for her critical review of this manuscript and
J. Naves, A. Ortega, A. Rubiano, and N. Whiteley
for their comments and suggestions.
Literature cited
BRANNON, R.D. 1985a. Serum chemistry of central and
northern Alaska grizzly bears. Journal of Wildlife
Management 49:893–900.
———. 1985b. Hematological characteristics of grizzly
bears (Ursus arctos) in central and northeastern Alaska.
Canadian Journal of Zoology 63:58–62.
CASE, L., D.P. CAREY, AND D.A. HIRAKAWA. 1997.
Nutrición canina y felina, Manual para profesionales.
Harcourt Brace, Madrid, España. (In Spanish.)
CASTELLANOS, A. 2000. Primeras experiencias en la rehabilitación y liberación del oso andino. Pages 10–16 in
Ukuku, Boletı́n Informativo para la Conservación del
Oso Andino 2(3). http://www.andeanbear.org/papers/
spanish/first-bear-experiences-esp.pdf, accessed 19 February 2010. (In Spanish.)
———. 2002. Captura de osos andinos (Tremarctos
ornatus) con ‘‘Trampa Iznachi’’ en Ecuador. Ukuku,
Boletı́n Informativo Sobre la Conservación del Oso
Andino Año 4(4). http://www.andeanbear.org/papers/
spanish/captura-de-osos-andinos-con-trampa-iznachi-esp.
pdf, accessed 19 February 2010. (In Spanish.)
———. 2003. Datos ecológicos del oso andino (Tremarctos ornatus) en la reserva Alto Choco. Pages 77–78 in
Memorias de las XXVII Jornadas Ecuatorianas de
Biologı́a, ‘‘Pedro Nuñez Lucio.’’ Sociedad Ecuatoriana
de Biologı́a, Escuela de Biologı́a de la Universidad
Central del Ecuador, Quito, Ecuador. (In Spanish.)
———. 2004. Intag Andean bear project update. International Bear News, Quarterly Newsletter of the International Association for Bear Research and Management
and the IUCN/SSC Bear Specialist Group 13(4):27.
———, A. TORRES, AND M. PEÑAFIEL. 2005. Conflictos de
los sistemas productivos con la biodiversidad. Estudio
de caso. Depredación a ganado vacuno por oso andino
(Tremarcos ornatus) en la Cuenca del Rió Cosanga.
Pages 70–80 in Contribuciones de la investigación
participativa al desarrollo sustentable de las comunidades de Montaña. Canton Quijos, Napo, Ecuador. (In
Spanish.)
CUESTA, F., AND L. SUÁREZ. 2001. Oso de anteojos
(Tremarctos ornatus). Pages 68–70 in D. Tirira, editor.
Libro rojo de los mamı́feros del Ecuador. SIMBIOE/
EcoCiencia/Ministerio del Ambiente/UICN. Serie Li-
120
SHORT COMMUNICATION N Castellanos et al.
bros Rojos del Ecuador, Tomo 1. Publicación Especial
sobre los Mamı́feros del Ecuador 4, Quito, Ecuador.
(In Spanish.)
DIERENFELD, E. 1988. Nutritional considerations in feeding
the captive spectacled bear. Pages 114–130 in M.
Rosenthal, editor. Proceedings of the First International Symposium on the spectacled bear. Lincoln Park
Zoological Gardens, Chicago, Illinois, USA.
GALASSO, L. 2002. The spectacled bear’s impact on
livestock and crops and use of remnant forest fruit
trees in a human-altered landscape in Ecuador. Thesis,
University of Wisconsin, Madison, Wisconsin, USA.
HELLGREN, E.C., M.R. VAUGHAN, AND R.L. KIRKPATRICK.
1989. Seasonal patterns in physiology and nutrition of
black bears in Great Dismal Swamp, Virginia–North
Carolina. Canadian Journal of Zoology 67:1837–1850.
HUBER, D., J. KUSAK, Z. ŽVORC, AND R.B. RAFAJ. 1997.
Effects of sex, age, capturing method and season on
serum chemistry values of brown bears in Croatia.
Journal of Wildlife Diseases 33:790–794.
INTERNATIONAL UNION FOR CONSERVATION OF NATURE.
2009. IUCN red list of threatened animals. IUCN,
Gland, Switzerland. http://www.iucnredlist.org/apps/
redlist/details/22066/0, accessed 19 February 2010
KUSAK, J., R.B. RAFAJ, Z. ŽVORC, D. HUBER, D. FORŠEK,
L. BEDRICA, AND V. MRIJAK. 2005. Effects of sex, age,
body mass and capturing method on hematology values
of brown bears in Croatia. Journal of Wildlife Diseases
41:843–847.
MAINKA, S. 1999. Giant panda management and medicine
in China. Pages 410–414 in M.E. Fowler and R.E.
Miller, editors. Zoo and Wildlife Medicine V. W.B.
Saunders Co., Philadelphia, Pennsylvania, USA.
MARCO, I., F. MARTINEZ, J. PASTOR, AND S. LAVIN. 2000.
Hematological and serum chemistry values of the
captive European wildcat. Journal of Wildlife Diseases
36:445–449.
MCCUE, P., AND T. O’FARRELL. 1987. Hematological
values of the endangered San Joaquin kit fox, Vulpes
macrotis mutica. Journal of Wildlife Diseases 23:
144–151.
MINISTERIO DEL AMBIENTE DEL ECUADOR. 2007. Plan de
manejo de la Reserva Ecologica¨Cotacachi Cayapas,¨
Resumen Ejecutivo. Direccion de Áreas Naturales,
Quito, Ecuador. (In Spanish.)
NASSAR, F., R. SÁNCHEZ, L. VEGA, G. CORREDOR, J.
GARDEAZABAL, H. MONSALVE, AND A. GARCı́A. 1994.
Estudio clı́nico del oso de anteojos, Tremarctos ornatus.
Pages 23–35 in Investigaciones en el Parque 1994–1995.
Investigaciones realizadas por el convenio Universidad
de La Salle-Fundación Jaime Duque. Universidad de
La Salle, Bogota, Colombia. (In Spanish.)
SAFE-CAPTURE INTERNATIONAL 1998. Chemical immobilization of animals. Mt. Horeb, Wisconsin, USA.
SEAL, U.S., W.R. SWAIM, AND A.W. ERICKSON. 1967.
Hematology of the Ursidae. Comparative Biochemical
Physiology 22:451–460.
STORM, G.L., G.L. ALT, G.J. MATULA, JR., AND R.A.
NELSON. 1988. Blood chemistry of black bears from
Pennsylvania during winter dormancy. Journal of
Wildlife Diseases 24:515–521.
TEARE, J.A., EDITOR. 2002. Physiological data reference
values. International Species Information System,
Eagan, Minnesota, USA.
TIRIRA, D. 1999. Mamı́feros del Ecuador. Museo de
Zoologı́a, Pontificia Universidad Católica del Ecuador/SIMBIOE. Publicación especial 1, Quito, Ecuador.
(In Spanish.)
TRYLAND, M., E. BRUN, A. DEROCHER, J. ARNEMO, P.
KIERULF, R. ØLBERG, AND Ø. WIIG. 2002. Plasma
biochemical values from apparently healthy free-ranging polar bears from Svalbard. Journal of Wildlife
Diseases 38:566–575.
WOODBURY, M.R., EDITOR. 1996. The chemical immobilization of wildlife. Canadian Association of Zoo and
Wildlife Veterinarians, Manitoba, Canada.
Received: 17 July 2009
Accepted: 30 December 2009
Associate Editor: S. Talbot
Ursus 21(1):115–120 (2010)