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Consistent individual behavior: evidence of
personality in black bears
Patrick J. Myers
Utah State University
Julie K. Young
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Vol.:(0123456789)
1 3
Journal of Ethology (2018) 36:117–124
https://doi.org/10.1007/s10164-018-0541-4
ARTICLE
Consistent individual behavior: evidence ofpersonality inblack bears
PatrickJ.Myers1· JulieK.Young2
Received: 16 November 2017 / Accepted: 18 February 2018 / Published online: 28 February 2018
© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2018
Abstract
Personality is defined as consistency in individual differences in organismal behavior across time or context, a phenomenon
of interest within behavioral and evolutionary ecology. Empirical data have revealed an ever-increasing number and diver-
sity of taxa that display these phenotypic patterns in both wild and captive settings. Moreover, these behavioral traits are
frequently linked to wild behavior, life history strategies, and measures of individual fitness. Understanding personality is of
particular importance for some animals, such as large carnivores, which may express maladaptive behavior that can lead to
conflict with humans. To date, few studies of personality exist on large carnivores and none have investigated the presence
of personality in black bears (Ursus americanus). Through focal animal sampling, and open field, novel object, and startle
object tests, we investigate the potential for personality in captive black bear cubs. Results indicate the presence of personal-
ity, with consistency in behavior across five metrics for the bold-shy axis, and eight sampling events measuring responses
for the activity axis. Information presented here reveals the presence of personality in black bear cubs, and may provide a
framework for future investigations into relationships of personality with ecology and life history.
Keywords Novel object· Open field· Repeatability· Ursus americanus· Captive· Startle object· Activity
Introduction
An ever-growing body of empirical data demonstrates that
individual animals display consistency in behavior across
time or context (Bell etal. 2009; Stamps and Groothuis
2010). Repeatable individual behavior has been recognized
for more than a century within the discipline of human psy-
chology (Caspi etal. 2005), but only of late has attention
been drawn to this in studies of non-human animal behavior
(Gosling 2001; Bell etal. 2009; Réale etal. 2010). Influ-
enced in large part by the seminal work of Wilson etal.
(1994), studies of personality in non-human animals (here-
after, “animal personality” or, simply, “personality”) fre-
quently include measurements along continua within one of
several broad behavioral traits, such as boldness, exploration,
activity, aggression, or sociability. These metrics are often
used to define personality or behavioral profiles of individual
animals (Réale etal. 2007). Observations of behavioral con-
sistency within individual animals provide an alternative to
the long-standing perspective that organisms are phenotypi-
cally plastic in response to repeated stimuli (West-Eberhard
1989). Between-individual differences in behavior are now
being recognized as indicative of individuality and no longer
considered mere deviations from the population mean (Wolf
and Weissing 2012). Moreover, many studies have identi-
fied that personality traits are not always expressed in isola-
tion, but as suites of correlated behaviors called behavioral
syndromes (Sih etal. 2004); for example, an organism may
consistently display aggression in one context and boldness
in another (Kortet and Hedrick 2007).
Animal personality is now garnering attention regarding
its implications for organismal life history and evolution
(Wolf and Weissing 2012). For instance, personality traits
have been linked to some of the most fundamental of animal
behaviors, including reproduction (Cote and Clobert 2007;
Réale etal. 2009), foraging (Johnson and Sih 2005), and
dispersal (Cote etal. 2010), as well as to some of the most
basic life processes, such as metabolism (Careau etal. 2008)
and growth rate (Adriaenssens and Johnsson 2010). With
* Julie K. Young
julie.young@usu.edu
1 Department ofWildland Resources, Utah State University,
5230 Old Main Hill, Logan, UT84322-5230, USA
2 USDA National Wildlife Research Center, Predator Research
Facility, Department ofWildland Resources, Utah State
University, 5230 Old Main Hill, Logan, UT84322-5230,
USA
118 Journal of Ethology (2018) 36:117–124
1 3
animal behavior so closely linked to fitness (Dingemanse
and Réale 2005), advances in conservation and evolution-
ary biology necessitate a more thorough understanding of
animal personality and behavioral variation, including their
ecological and evolutionary implications.
Assessments of animal personality have relied on several
principal testing strategies. Open-field trials, which are used
to assay a variety of behavioral traits, consist of observa-
tions of individuals’ behavior in environments to which they
are naïve (Valle 1970; Walsh and Cummins 1976; Burns
2008). One such behavior, “wall-hugging,” is an anxiety-
related response along the bold-shy axis, in which less bold
subjects avoid the interior of unfamiliar or stressful environ-
ments. This has been observed in many taxa, including fish
(Sharma etal. 2009), rodents (Treit and Fundytus 1988), and
humans (Kallai etal. 2007). Exploration is measured as the
inclination of animals to investigate novel environments, and
has been demonstrated to be correlated with risk-taking and
negatively related to neophobia (Meehan and Mench 2002;
Mettke-Hofmann etal. 2002; van Oers etal. 2004; Ding-
emanse etal. 2010; Cole and Quinn 2014). Assays whereby
animals are presented with an unfamiliar object which may
be interpreted as a threat, are referred to as novel-object
tests, and are commonly used to measure fear, with bold sub-
jects less fearful of the object (Burns 2008). Similarly, startle
objects, such as light or sound, are used to measure behavior
along the bold-shy axis, whereby flight from or latency to
return to an object following a stimulus often correspond
with levels of boldness (van Oers etal. 2004; Ward etal.
2007). Finally, extended periods of detailed observation
on individual subjects is often referred to as focal-animal
sampling (Altmann 1974). Such sampling is a form of non-
manipulative, observational research that has been widely
used for a variety of species in captive and field settings, and
allows for the incorporation of a vast array of behavioral data
(Coleman and Wilson 1998; Stoinski etal. 2003; Rieucau
etal. 2012; Seyfarth etal. 2012), including activity levels
(Renner 1990; review in Réale etal. 2007).
Bears (family Ursidae), despite their large brain size and
demonstrated cognition (Vonk etal. 2012; Benson-Amram
etal. 2016; Johnson-Ulrich etal. 2016), have been largely
unexamined with regard to personality (Gosling 2001; Bell
etal. 2009; but see Fagen and Fagen 1996). Understanding
bear behavior is critical, given that they often spatially over-
lap with human populations (Bateman and Fleming 2012),
are known to utilize anthropogenic resources (Beckmann
and Berger 2003; Hostetler etal. 2009), and can threaten
human lives and property (Treves and Karanth 2003). The
American black bear (Ursus americanus), for instance, is
the most widely distributed North American bear, possesses
many traits that allow persistence in human-dominated
landscapes (Stirling and Derocher 1990; Larivière 2001;
Beckmann and Berger 2003; Johnson etal. 2015), and is
frequently involved in human-wildlife conflict (Can etal.
2014). Thus, elucidating bear personality may contribute to
our understanding of the many ecological and evolutionary
consequences of behavior, facilitate an understanding of the
mechanisms inherent to the phenomenon (Wolf and Weiss-
ing 2012), and, ultimately, benefit wildlife management and
conservation efforts (McDougall etal. 2006).
Here, we present the first investigation into personality of
American black bears (U. americanus). Through the use of
open-field, novel object, and startle object tests, and focal-
animal sampling, we examine the existence of repeatable,
across-context, individual differences in behavior along the
bold-shy and activity axes of black bear cubs. We predicted
that the bears would exhibit intra-individual consistency and
inter-individual variation in behaviors across assays for each
axis. Similar to previous studies (Huntingford 1976; Lantová
etal. 2011; Herde and Eccard 2013), we anticipated cor-
relation between the bold-shy and activity axes. Our study
aimed to facilitate a better understanding of black bears and
their behavior, include black bears in the ongoing pursuit of
personality research, and broaden the tools with which we
approach wildlife ecology and conservation.
Methods
Between 1 July and 29 August 2014, six orphaned black
bear cubs were captured by Utah Division of Wildlife
Resources personnel and transported to the US Department
of Agriculture (USDA) National Wildlife Research Center′s
(NWRC) Predator Research Facility in Millville, Utah,
USA for rehabilitation. The housing structure contained
two open-air enclosures, each 16.5m long, 7m wide, and
2.5m tall (288.8m3), separated by a 7.5-m-long, 2-m-wide,
and 2.5-m-tall transitional pen, called a “shift” (Fig.1). The
walls and ceilings of the pens and shift were chain-link fenc-
ing. Solid-metal, guillotine-style doors, operated by observ-
ers from an adjacent area, allowed for entrance and egress
of bears between the pens and shift. Both pens were func-
tionally identical and contained wooden climbing structures,
logs, a large pool of water, two den boxes, natural vegetation,
and a constantly flowing source of fresh water. To reduce
familiarity with humans, the cubs had one primary caretaker
and all bear-human interactions were minimal. All captive
care was provided in accordance with the NWRC Animal
Care Protocol, derived from widely accepted procedures
(Beecham and Ramanathan 2007), administered NWRC-
SOP no.ACUT-006.00, with research permitted under the
Institutional Animal Care and Use Committees at NWRC
QA-2354 and a Utah State University permit (#2434).
Bears were given at least 7days to acclimate to vari-
ous aspects of their captive environment (i.e., structures,
119Journal of Ethology (2018) 36:117–124
1 3
conspecifics, feeding schedule, and human caretaker) before
behavioral assays began. No enrichment items were prof-
fered to the bears during the acclimation or testing peri-
ods. Prior to the start of trials, the bears had been allowed
access to one pen and the shift, but remained naïve to the
second pen, which was used as the arena for several assays
that would measure their responses related to the bold-shy
behavioral axis. After testing that required a novel environ-
ment was completed, and the bears became familiar with
both pens, we then administered bold-shy and activity tests
that were not reliant on novelty of environment, with the
trial pen selected opportunistically based on ease of bear
isolation. Trials were ordered in a manner that preserved the
novelty of individual testing paradigms; for instance, novel
object trial date preceded that of the startle object, given that
potential trepidation in response to introduced objects would
be expected to wane with each occurrence. For all behavioral
assays, we randomized dates of trials (although these were
adjusted opportunistically according to weather conditions),
times from all possible times during daylight hours, and sub-
ject order. As some studies have reported that olfactory or
chemical cues from previous subjects or human caretakers
may influence behavior (Whittier and McReynolds 1965;
McCall etal. 1969), the arena and all of its contents were
sprayed with high-pressure water and left to dry and ven-
tilatefor ≥1h between all tests. All trials were conducted
in mild weather between 31 August and 21 November, and
administered and recorded by the same human observer.
Open-field trials were preceded by subjects being indi-
vidually isolated in the shift, and all non-participating
individuals confined to one pen. Following an acclimation
period of 900–1800s, we opened the door on the opposite
side of the shift to allow entry into the novel pen. Prior to
this point, bears did not have access to the arena, although
we could not limit all arena visibility. The start of the open-
field trial was delineated by the point at which the subject
had entered the novel environment, defined by all four feet
of the subject being on the ground of the arena. The time
and duration of several coded behaviors were used to assess
three measures of boldness: two variants of “wall-hugging”
behavior, i.e., latency to the interior and thigmotaxis; and
exploration. Latency to the interior was measured accord-
ing to the number of seconds between the start of the trial
and the time at which the individual entered the middle of
the arena (>2m from the perimeter), with boldness nega-
tively related to the number of seconds. Thigmotaxis was
measured as the proportion of time an individual spent at
the perimeter (<2m from the fence), with the proportion
inversely related to boldness. Exploration was measured as
the time during which subjects actively moved about and
inspected the novel environment, with boldness positively
related to active behaviors. We terminated open-field trials
after each subject had been in the arena for 300s, in order to
mitigate for the animals becoming familiar with the environ-
ment. Open-field trials were recorded via four video cameras
(SDR-H85; Panasonic, Osaka, Japan) placed on the exterior
Fig. 1 One of two black bear
cub rehabilitation enclosures at
the US Department of Agricul-
ture National Wildlife Research
Center’s Predator Research
Facility in Millville, Utah, USA,
displaying approximate loca-
tions of object placement for
two of the behavioral tests
120 Journal of Ethology (2018) 36:117–124
1 3
of the pen, and later analyzed using VLC software (Vide-
oLAN, Paris).
Novel-object tests were preceded by subjects being indi-
vidually isolated in the shift, and all non-participating indi-
viduals confined to the pen previously used for open-field
trials. To avoid confounding subject responses to the novel
object with responses associated with a stress-inducing
arena, we administered novel-object tests in the familiar
pen. The novel object was represented by an orange traffic
cone (1m high) placed on the floor of the arena (Fig.1). We
used a black bag to conceal the object during placement and
situated the object behind a familiar solid, wooden climbing
structure, until the subjects were in the arena. We recorded
observations from behind visual barriers outside the arena.
Following an acclimation period of 15–30min, we opened
the shift door to allow subjects access to the arena. The
novel-object trial phase began when the subjects had fully
entered the arena, and terminated when the subject wasat
≤1-m distance from the object, with the differential in time
termed as latency to approach, and scores inversely related
to boldness.
We conducted startle-object trials 2days after novel-
object trials. The startle object consisted of two items: a
22-cm-diameter, blue plastic ball, used to attract the interest
of the test subjects; and an acoustics playback device (FOX-
PRO Crossfire; FOXPRO, Lewiston, PA). We situated both
objects<1m outside of the arena fence, with the speaker
directly behind the ball and, similar to the novel object test,
obfuscated by a visual barrier until the subject had entered
the arena (Fig.1). When the subject reached the fence in
front of the object, the human observer, recording behavior
from behind visual barriers outside the arena, remotely acti-
vated the acoustic device. The device was programmed to
emit a sound at~70dB(A) (at 1m), a volume loud enough
to elicit a response from the test subjects, but not be heard by
conspecifics in the adjacent pen. We selected an animal (rac-
coon Procyon lotor) growling/fighting noise as the stimulus
because of its potential to produce a fear-induced response
and for its novelty; unlike common testing stimuli, such as
beeps, sirens, or lights, this noise would likely not have been
encountered by the bears in the wild, or during capture and
transport. We recorded the time between the flight response
of the subjects after the sound was emitted and the subject
returning to the object, with the number of seconds inversely
proportional to boldness.
Focal-animal sampling occurred on days on which no
other tests were administered, after all bears had been fully
acclimated to both pens, and with no restrictions to pen
access or conspecific interaction; these measures were to
ensure that no unintended, confounding stimuli, threats, or
novelty were present (Réale etal. 2007). We conducted eight
focal-animal sampling events per subject, each 900s in dura-
tion, with an interval average of 6days (SE=1.3) between
trials. The human observer recorded behaviors from behind
visual barriers outside the arena. Active behaviors included
locomotion, climbing, and playing alone or with conspecif-
ics, while inactivity included sitting, lying down, or other-
wise remaining stationary. We recorded time and duration
of behaviors in seconds and converted these to proportions
to reflect activity scores.
We conducted statistical analyses using program R 3.2.3
(R Development Core Team 2016). We first transformed
bold-shy data for intuitive directionality, with high scores
corresponding to high degrees of boldness, and rescaled
data to standardize scores around a mean of 0 and a SD
of 1. Because activity scores were proportions, no rescal-
ing or transformations were necessary. We first tested for
individual consistency, or repeatability, in behavior. As
described by Lessells and Boag (1987), repeatability can be
characterized by the proportion of variance in responses for
one individual, relative to the variance among individuals.
We calculated intraclass correlation coefficients (R package
irr) (Gamer etal. 2012), derived from the variance compo-
nents produced by one-way ANOVA, to assess consistency
of responses for each individual among the suite of tests
for each of the two behavior axes. As bold-shy tests were
designed to provide multiple measures for responses along
the same axis, we looked for correlation between scores for
each individual by performing principal component analysis
(PCA). PCA reduced and enhanced directionality of vari-
ables, and illustrated relationships between variables. The
number of components retained was determined according
to the Kaiser–Guttman criterion (Kaiser 1991), variance
contributed, and scree plot visualization. Using the loadings
matrix from the retained components, composite scores were
generated for each individual, representing single values for
the subjects along the bold-shy continuum. Unlike bold-shy
scores, activity-level scores consisted of repeated focal-
animal samplings with identical measurements and units
across each sampling occasion; as such, composite scores
of captive activity level for each individual were achieved by
averaging the eight scores. Using Spearman’s rank correla-
tion, we tested for rank-order consistency between bold-shy
composite scores and activity-level composite scores.
Results
Six orphaned black bear cubs (two females, four males),
approximately 8months of age, were tested. The bears dis-
played intra-individual consistency and between-individual
variation with regard to responses within each of the suite
of tests for both the bold-shy and activity axes (Table1).
Intraclass correlation coefficients for analysis of the five
bold-shy measurements indicated that some subjects were
consistently more bold than others, across time and context
121Journal of Ethology (2018) 36:117–124
1 3
(F5,20=3.61, P=0.017). Similarly, intraclass correlation
coefficients indicated that activity tests revealed some sub-
jects to be consistently more active than others (F5,35=3.61,
P=0.052).
PCA allowed us to retain two components, each
with eigenvalues greater than 1 which, when combined,
accounted for 87% of the total variance (Table2). The first
principal component explained 53% of the variance and was
characterized by the three metrics measured in the open-
field tests. PCA loadings for latency to the interior (0.550),
thigmotaxis (0.529), and exploration (0.555) all contributed
equally to the first principal component. Conversely, the two
metrics that were associated with novel objects—latency to
approach and startle object response—were the primary
contributing variables for the second principle component
(−0.664 and 0.616, respectively), which accounted for 34%
of the variance.
Discussion
We present an important finding within the fields of animal
behavior, ecology, and evolution—that black bears exhibit
consistent individual behavioral differences. To our knowl-
edge, this study represents the first application of testing
to reveal individual personality for black bear cubs or any
other species in the family Ursidae. Responses to a suite of
behavioral assays commonly utilized in the field of person-
ality research (e.g., focal-animal sampling, and open field,
novel object, and startle object tests) to explore consistency
of animal behavior (Bell etal. 2009) revealed that some bear
cubs are consistently more bold or more active than oth-
ers across contexts in captive settings. Provided that this is
the first instance of such testing for bears, and considering
the captive nature of bears subjected to these tests and the
forms of rapid assays used (Butler etal. 2006; Biro 2012),
we contend that all relevant correlations to ecological traits
should be investigated further after rehabilitated bears are
released into the wild.
The concept of individual variation has existed for a con-
siderable time (Darwin 1861), and assessments of bear per-
sonality have been previously considered (Fagen and Fagen
1996). However, we are unable to compare our results to
the Fagen and Fagen (1996) study, given that the authors
conducted observations of brown bears (U. arctos) at a wild
feeding site and considered nearly 70 subjective behavio-
ral classifications to identify individuality among observed
bears. Fagen and Fagen (1996) acknowledge several short-
comings of their study, and given that, prior to our study,
this is the sole investigation into bear personality research,
we highlight how this taxon has been largely overlooked.
Our study focused on black bear cubs rehabilitated in
captivity until reintroduction, providing a contextual gen-
erality at a given age, time, and life experience (Stamps
Table 1 Scores from assays measuring responses of six black bear cubs for personality along the bold-shy and activity behavior axes with indi-
vidual rankings (R; 1 boldest or most active, 6 least bold or active)
a Open-field trial
b Novel object trial
c Startle object trial
d From bold-shy assays and first PC
e Mean of activity-level scores from eight focal-animal sampling trials
Bear Latency to interioraRThigmotaxisaRExplorationaRLatency to
approachbRLatency to returncRComposite
bold-shydRActivity scoreeR
1401 −0.090 5 −0.351 4 0.817 2 0.432 3 −1.389 6 −0.055 4 0.823 1
1402 −1.907 6 −1.263 6 −1.624 6 −0.707 5 −0.025 4 −2.769 6 0.637 3
1403 0.174 4 0.660 3 −0.032 5 −1.546 6 1.027 2 0.380 3 0.290 6
1404 0.302 3 1.158 1 0.297 4 −0.131 4 0.276 3 0.989 2 0.584 4
1405 0.562 2 −0.964 5 0.584 3 0.953 2 −0.927 5 −0.573 5 0.377 5
1406 0.957 1 0.760 2 1.125 1 0.999 1 1.037 1 2.028 1 0.694 2
Table 2 Results from principal component (PC) analysis of responses
to captive tests of bold-shy behavior for six black bear cubs
The first two components were retained, explaining 87% of the over-
all variance. Loadings in italic represent those that contributed heav-
ily to the formation of respective components
Behavioral test PC1 PC2
Latency to interior 0.550 −0.201
Thigmotaxis 0.529 0.335
Exploration 0.555 −0.165
Latency to approach 0.204 −0.664
Startle response 0.260 0.616
SD 1.627 1.302
Proportion of variance (%) 52.9 33.9
Cumulative proportion 52.9 86.8
122 Journal of Ethology (2018) 36:117–124
1 3
and Groothuis 2010). The personality of young animals is
commonly assessed, but whether personality traits are con-
sistent across ontogeny needs further study (Groothuis and
Trillmich 2011). Because of the small sample size, and use
of tests mostly conducted when individuals were isolated
from the other bears, we did not control for social status in
our analysis. While social structure may have existed within
this cohort, we believe it would not have influenced out-
comes. For instance, even in a carnivore with strong social
hierarchical structure, such as the spotted hyena (Crocuta
crocuta), personality dimensions were not explained by
dominance status (Gosling 1998). Instead, social interactions
may increase stability in individual traits used to measure
personality. For example, wolf (Canis lupus) pups housed
with other pups showed more stable responses to novel
objects than pups housed in isolation (MacDonald 1983).
Studies of personality may prove to be a valuable tool for
rehabilitated wildlife. The reasons for rehabilitation often
stem from variable and nontraditional early life experiences,
which are known to alter a variety of individual traits and
have lasting impacts on future fitness (Lindström 1999). For
instance, an individual’s exposure to predators (Bell and Sih
2007) and the availability of resources (Brydges etal. 2008;
Chapman etal. 2010) have been shown to influence per-
sonality. Maternal effects—one early life component that is
often shortened or altered for rehabilitated wildlife—impact
a variety of phenotypic expressions, with mammals being
most profoundly affected, given their extended gestation,
lactation, and other facets of maternal care (Reinhold 2002).
For rehabilitated bear cubs, in particular, and other ani-
mals with life histories that lend themselves to interaction
with humans, personality testing could be an invaluable
window to behavior after release. Administering bold-shy
tests allows researchers to quantify the level of fear elicited
by unfamiliar and potentially threatening objects and situ-
ations (Réale etal. 2007). Behavioral testing may be able
to provide predictive insights into an individual’s level of
fear toward novelty. This is precisely why behavioral traits
and personality have historically been referred to as “coping
styles” (Koolhaas etal. 1999); reactions along the bold-shy
axis may, in large part, demonstrate an organism’s abil-
ity to cope with environmental conditions. Understanding
an animal’s boldness may reflect upon its future potential
responses to anthropogenic activity and myriad other stress-
ors after release, including its propensity to engage in con-
flict situations (Linnell etal. 1999).
Results of this study allude to a possible relationship
between bold-shy object testing (i.e., novel and startle)
and captive activity level. Previous studies have reported
relationships between boldness and activity axes (Boyer
etal. 2010; Lantová etal. 2011; Dammhahn 2012; Herde
and Eccard 2013), while others have demonstrated links
between those traits and dispersal (Fraser etal. 2001;
Dingemanse etal. 2003) or space use (Boon etal. 2007;
Minderman etal. 2010). Although we did not relate tests
to behavior of bears after release, we believe our study
provides a framework for future rehabilitation and release
programs interested in assessing individual behavior and
correlates to post-release behavior and space use.
While behavioral phenotype may shift later in life due
to internal changes or environmental stressors (Stamps
and Groothuis 2010), the expressions exhibited by reha-
bilitated wildlife during personality assays shortly before
release may mean the difference between life and death in
a species with potentially lethal conspecific interactions
(Sih and Bell 2008), or in a world of immediate anthropo-
genic dangers (Wilcove etal. 1998). Previous research has
identified correlations between personality and the fitness
and behavior of animals after reintroduction (Cavigelli and
McClintock 2003; Bremner-Harrison etal. 2004; Smith
and Blumstein 2008). Identifying the mechanisms that
shape and are shaped by behavioral traits is fundamental
to understanding individual life history and population
dynamics (Stamps and Groothuis 2010).
Ultimately, understanding the mechanisms behind ani-
mal behavior and broadening our scope to include new
species in personality research will illuminate relation-
ships to fundamental components of life history and spe-
cies ecology. Through this, we hope to facilitate a better
understanding of black bears and their behavior, include
black bears in the ongoing pursuit of personality research,
and broaden the tools with which we approach wildlife
ecology, management, and conservation.
Acknowledgements We wish to thank the Utah Division of Wildlife
Resources for allowing us to conduct this study and for their technical
support. We thank S. Brummer, E. Stevenson, J. Schultz, N. Floyd,
and M. Davis at the USDA NWRC Predator Research Facility for their
assistance. Earlier drafts of this manuscript were reviewed by F. Howe,
K. Jordan, and two anonymous reviewers. Funding was provided by
the Utah Division of Wildlife Resources, the Department of Wildland
Resources at Utah State University, and the USDA National Wild-
life Resource Center. Any use of trade, firm, or product names is for
descriptive purposes only and does not imply endorsement by the U.S.
Government.
Compliance with ethical standards
Conflict of interest The authors declare that they have no conflict of
interest.
Human and animal rights statement All applicable international,
national, and/or institutional guidelines for the care and use of ani-
mals were followed. Captive care and handling was administered
through NWRC-SOP no.ACUT-006.00, with research permitted under
NWRC Institutional Animal Care and Use Committee (IACUC) permit
QA-2354 and Utah State University IACUC permit #2434. This article
does not contain any studies with human participants performed by
any of the authors.
123Journal of Ethology (2018) 36:117–124
1 3
References
Adriaenssens B, Johnsson JI (2010) Shy trout grow faster: exploring
links between personality and fitness-related traits in the wild.
Behav Ecol 22(1):135–143
Altmann J (1974) Observational study of behavior: sampling methods.
Behaviour 49(3):227–266
Bateman PW, Fleming PA (2012) Big city life: carnivores in urban
environments. J Zool 287(1):1–23
Beckmann JP, Berger J (2003) Rapid ecological and behavioural
changes in carnivores: the responses of black bears (Ursus ameri-
canus) to altered food. J Zool 261(2):207–212
Beecham JJ, Ramanathan A (2007) Proceedings, 2007 International
Workshop on the Rehabilitation Release and Monitoring of
Orphan Bear Cubs. Bubonitsy, Russia, pp 23–31
Bell AM, Sih A (2007) Exposure to predation generates personality
in three spined sticklebacks (Gasterosteus aculeatus). Ecol Lett
10(9):828–834
Bell AM, Hankison SJ, Laskowski KL (2009) The repeatability of
behaviour: a meta-analysis. Anim Behav 77(4):771–783
Benson-Amram S, Dantzer B, Stricker G, Swanson EM, Holekamp KE
(2016) Brain size predicts problem-solving ability in mammalian
carnivores. Proc Natl Acad Sci USA 113(9):2532–2537
Biro PA (2012) Do rapid assays predict repeatability in labile (behav-
ioural) traits? Anim Behav 83(5):1295–1300
Boon AK, Réale D, Boutin S (2007) The interaction between personal-
ity, offspring fitness and food abundance in North American red
squirrels. Ecol Lett 10(11):1094–1104
Boyer N, Réale D, Marmet J, Pisanu B, Chapuis JL (2010) Personality,
space use and tick load in an introduced population of Siberian
chipmunks Tamias sibiricus. J Anim Ecol 79(3):538–547
Bremner-Harrison S, Prodohl PA, Elwood RW (2004) Behavioural trait
assessment as a release criterion: boldness predicts early death
in a reintroduction programme of captive-bred swift fox (Vulpes
velox). Anim Conserv 7(03):313–320
Brydges NM, Colegrave N, Heathcote RJ, Braithwaite VA (2008)
Habitat stability and predation pressure affect temperament behav-
iours in populations of three-spined sticklebacks. J Anim Ecol
77(2):229–235
Burns JG (2008) The validity of three tests of temperament in guppies
(Poecilia reticulata). J Comp Psychol 122(4):344–356
Butler SJ, Whittingham MJ, Quinn JL, Cresswell W (2006) Time in
captivity, individual differences and foraging behaviour in wild-
caught chaffinches. Behaviour 143(4):535–548
Can ÖE, D’Cruze N, Garshelis DL, Beecham J, Macdonald DW (2014)
Resolving human-bear conflict: a global survey of countries,
experts, and key factors. Conserv Lett 7(6):501–513
Careau V, Thomas D, Humphries MM, Réale D (2008) Energy metabo-
lism and animal personality. Oikos 117(5):641–653
Caspi A, Roberts BW, Shiner RL (2005) Personality development: sta-
bility and change. Annu Rev Psychol 56:453–484
Cavigelli SA, McClintock MK (2003) Fear of novelty in infant rats
predicts adult corticosterone dynamics and an early death. Proc
Natl Acad Sci USA 100(26):16131–16136
Chapman BB, Morrell LJ, Krause J (2010) Unpredictability in food
supply during early life influences boldness in fish. Behav Ecol
21(3):501–506
Cole EF, Quinn JL (2014) Shy birds play it safe: personality in captivity
predicts risk responsiveness during reproduction in the wild. Biol
Lett 10(5):20140178
Coleman K, Wilson DS (1998) Shyness and boldness in pumpkinseed
sunfish: individual differences are context-specific. Anim Behav
56(4):927–936
Cote J, Clobert J (2007) Social personalities influence natal dispersal
in a lizard. Proc R Soc Lond B Biol 274(1608):383–390
Cote J, Clobert J, Brodin T, Fogarty S, Sih A (2010) Personality-
dependent dispersal: characterization, ontogeny and conse-
quences for spatially structured populations. Proc R Soc Lond
B Biol 365(1560):4065–4076
Dammhahn M (2012) Are personality differences in a small itero-
parous mammal maintained by a life-history trade-off? Proc R
Soc Lond B Biol (published online). https ://doi.org/10.1098/
rspb.2012.0212)
Darwin C (1861) On the origin of species, 3rd edn. Murray, London
Dingemanse NJ, Réale D (2005) Natural selection and animal per-
sonality. Behaviour 142(9–10):1159–1184
Dingemanse NJ, Both C, Van Noordwijk AJ, Rutten AL, Drent PJ
(2003) Natal dispersal and personalities in great tits (Parus
major). Proc R Soc Lond B Biol 270(1516):741–747
Dingemanse NJ, Kazem AJ, Réale D, Wright J (2010) Behavioural
reaction norms: animal personality meets individual plasticity.
Trend Ecol Evol 25(2):81–89
Fagen R, Fagen JM (1996) Individual distinctiveness in brown bears,
Ursus arctos L. Ethology 102(2):212–226
Fraser DF, Gilliam JF, Daley MJ, Le AN, Skalski GT (2001) Explain-
ing leptokurtic movement distributions: intrapopulation varia-
tion in boldness and exploration. Am Nat 158(2):124–135
Gamer M, Lemon J, Fellows I, Singh P (2012) irr: various coef-
ficients of interrater reliability and agreement. R package ver-
sion 0.84
Gosling SD (1998) Personality dimensions in spotted hyenas (Crocuta
crocuta). J Comp Psychol 112(2):107–118
Gosling SD (2001) From mice to men: what can we learn about person-
ality from animal research? Psychol Bull 127(1):45–86
Groothuis TG, Trillmich F (2011) Unfolding personalities: the impor-
tance of studying ontogeny. Dev Psychobiol 53(6):641–655
Herde A, Eccard JA (2013) Consistency in boldness, activity and
exploration at different stages of life. BMC Ecol 13(1):49
Hostetler JA, McCown JW, Garrison EP, Neils AM, Barrett MA, Sun-
quist ME, Simek SL, Oli MK (2009) Demographic consequences
of anthropogenic influences: Florida black bears in north-central
Florida. Biol Conserv 142(11):2456–2463
Huntingford FA (1976) The relationship between anti-predator behav-
iour and aggression among conspecifics in the three-spined stick-
leback, Gasterosteus aculeatus. Anim Behav 24(2):245–260
Johnson JC, Sih A (2005) Precopulatory sexual cannibalism in fish-
ing spiders (Dolomedes triton): a role for behavioral syndromes.
Behav Ecol Sociobiol 58(4):390–396
Johnson HE, Breck SW, Baruch-Mordo S, Lewis DL, Lackey CW,
Wilson KR, Broderick J, Mao JS, Beckmann JP (2015) Shift-
ing perceptions of risk and reward: dynamic selection for human
development by black bears in the western United States. Biol
Conserv 187:164–172
Johnson-Ulrich Z, Vonk J, Humbyrd M, Crowley M, Wojtkowski E,
Yates F, Allard S (2016) Picture object recognition in an Ameri-
can black bear (Ursus americanus). Anim Cogn 19(6):1237–1242
Kaiser HF (1991) Coefficient alpha for a principal component and the
Kaiser–Guttman rule. Psychol Rep 68:855–858
Kallai J, Makany T, Csatho A, Karadi K, Horvath D, Kovacs-Labadi
B, Jarai R, Nadel L, Jacobs JW (2007) Cognitive and affective
aspects of thigmotaxis strategy in humans. Behav Neurosci
121(1):21–30
Koolhaas JM, Korte SM, De Boer SF, Van Der Vegt BJ, Van Reenen
CG, Hopster H, De Jong IC, Ruis MAW, Blokhuis HJ (1999)
Coping styles in animals: current status in behavior and stress-
physiology. Neurosci Biobehav Rev 23(7):925–935
Kortet R, Hedrick ANN (2007) A behavioural syndrome in the field
cricket Gryllus integer: intrasexual aggression is correlated with
activity in a novel environment. Biol J Linn Soc 91(3):475–482
124 Journal of Ethology (2018) 36:117–124
1 3
Lantová P, Šíchová K, Sedláček F, Lanta V (2011) Determining behav-
ioural syndromes in voles—the effects of social environment.
Ethology 117(2):124–132
Larivière S (2001) Ursus americanus. Mamm Species 647:1–11
Lessells CM, Boag PT (1987) Unrepeatable repeatabilities: a common
mistake. Auk 104:116–121
Lindström J (1999) Early development and fitness in birds and mam-
mals. Trends Ecol Evol 14(9):343–348
Linnell JD, Odden J, Smith ME, Aanes R, Swenson JE (1999) Large
carnivores that kill livestock: do “problem individuals” really
exist? Wildl Soc Bull 27(3):698–705
MacDonald K (1983) Stability of individual differences in behavior in
a litter of wolf cubs (Canis lupus). J Comp Psychol 97(2):99–106
McCall RB, Lester ML, Corter CM (1969) Caretaker effect in rats. Dev
Psychol 1(6):750–762
McDougall PT, Réale D, Sol D, Reader SM (2006) Wildlife conserva-
tion and animal temperament: causes and consequences of evo-
lutionary change for captive, reintroduced, and wild populations.
Anim Conserv 9(1):39–48
Meehan CL, Mench JA (2002) Environmental enrichment affects the
fear and exploratory responses to novelty of young Amazon par-
rots. Appl Anim Behav Sci 79(1):75–88
Mettke-Hofmann C, Winkler H, Leisler B (2002) The significance of
ecological factors for exploration and neophobia in parrots. Ethol-
ogy 108(3):249–272
Minderman J, Reid JM, Hughes M, Denny MJ, Hogg S, Evans PG,
Whittingham MJ (2010) Novel environment exploration and
home range size in starlings Sturnus vulgaris. Behav Ecol
21(6):1321–1329
R Development Core Team (2016) R: a language and environment
for statistical computing. R Foundation for Statistical Computing,
Vienna. http://www.R-proje ct.org. Accessed Oct 2017
Réale D, Reader SM, Sol D, McDougall PT, Dingemanse NJ (2007)
Integrating animal temperament within ecology and evolution.
Biol Rev 82(2):291–318
Réale D, Martin J, Coltman DW, Poissant J, Festa-Bianchet M (2009)
Male personality, life-history strategies and reproductive success
in a promiscuous mammal. J Evol Biol 22(8):1599–1607
Réale D, Dingemanse NJ, Kazem AJ, Wright J (2010) Evolutionary and
ecological approaches to the study of personality. Philos Trans R
Soc B 365(1560):3937–3946
Reinhold K (2002) Maternal effects and the evolution of behavioral
and morphological characters: a literature review indicates the
importance of extended maternal care. J Hered 93(6):400–405
Renner MJ (1990) Neglected aspects of exploratory and investigatory
behavior. Psychobiology 18(1):16–22
Rieucau G, Blanchard P, Martin JG, Favreau FR, Goldizen AW, Pays
O (2012) Investigating differences in vigilance tactic use within
and between the sexes in eastern grey kangaroos. PLoS One
7(9):e44801
Seyfarth RM, Silk JB, Cheney DL (2012) Variation in personality
and fitness in wild female baboons. Proc Natl Acad Sci USA
109(42):16980–16985
Sharma S, Coombs S, Patton P, de Perera TB (2009) The function
of wall-following behaviors in the Mexican blind cavefish and a
sighted relative, the Mexican tetra (Astyanax). J Comp Physiol A
195(3):225–240
Sih A, Bell AM (2008) Insights for behavioral ecology from behavioral
syndromes. Adv Study Behav 38:227–281
Sih A, Bell A, Johnson JC (2004) Behavioral syndromes: an ecologi-
cal and evolutionary overview. Trends Ecol Evol 19(7):372–378
Smith BR, Blumstein DT (2008) Fitness consequences of personality:
a meta-analysis. Behav Ecol 19(2):448–455
Stamps J, Groothuis TG (2010) The development of animal personality:
relevance, concepts and perspectives. Biol Rev 85(2):301–325
Stirling I, Derocher AE (1990) Factors affecting the evolution and
behavioral ecology of the modern bears. Int C Bear 8:189–204
Stoinski TS, Beck BB, Bloomsmith MA, Maple TL (2003) A behavio-
ral comparison of captive-born, reintroduced golden lion tamarins
and their wild-born offspring. Behaviour 140(2):137–160
Treit D, Fundytus M (1988) Thigmotaxis as a test for anxiolytic activity
in rats. Pharmacol Biochem Behav 31(4):959–962
Treves A, Karanth KU (2003) Human-carnivore conflict and per-
spectives on carnivore management worldwide. Conserv Biol
17(6):1491–1499
Valle FP (1970) Effects of strain, sex, and illumination on open-field
behavior of rats. Am J Psychol 83(1):103–111
Van Oers K, Drent PJ, De Goede P, Van Noordwijk AJ (2004) Realized
heritability and repeatability of risk-taking behaviour in relation
to avian personalities. Proc R Soc Lond B Biol 271(1534):65–73
Vonk J, Jett SE, Mosteller KW (2012) Concept formation in American
black bears, Ursus americanus. Anim Behav 84(4):953–964
Walsh RN, Cummins RA (1976) The open-field test: a critical review.
Psychol Bull 83(3):482–504
Ward AJ, Webster MM, Hart PJ (2007) Social recognition in wild fish
populations. Proc Soc Lond B Biol 274(1613):1071–1077
West-Eberhard MJ (1989) Phenotypic plasticity and the origins of
diversity. Annu Rev Ecol Syst 20:249–278
Whittier JL, McReynolds P (1965) Persisting odors as a biasing factor
in open-field research with mice. Can J Psychol 19(3):224–230
Wilcove DS, Rothstein D, Dubow J, Phillips A, Losos E (1998) Quanti-
fying threats to imperiled species in the United States. Bioscience
48(8):607–615
Wilson DS, Clark AB, Coleman K, Dearstyne T (1994) Shyness
and boldness in humans and other animals. Trends Ecol Evol
9(11):442–446
Wolf M, Weissing FJ (2012) Animal personalities: consequences for
ecology and evolution. Trends Ecol Evol 27(8):452–461
