Agonistic Interactions within a group of
California Sea Lions (Zalophus Californianus)
and their effect on training participation
Emma Myers, Research Assistant at Blackpool Zoo, University of Manchester
Introduction
The role of zoos has changed dramatically over time
but now can be condensed into 4 main roles:
Conservation, Research, Education and Recreation.
(Bertram, 2004).
Why do animals sometimes choose not to participate?
One possibility may be due to aggression within the group prior to the public displays.
Public animal displays in zoos fulfil up to three of
these roles at once and are becoming increasingly
popular in zoos, with public displays increasing
throughout the UK.
Animals in captivity are unable to avoid agonistic interactions as they would in the wild.
To take part in displays, animals are trained using
positive reinforcement methods – an animal is
rewarded for doing as asked but never punished for
refusing (Schapiro et al. 2003). There is always a choice.
The study will help the trainers know how much aggression happens between the large
breeding group of sea lions and whether it has a negative effect.
This study looked into whether these agonistic interactions that occur before a public
display has a negative effect on how well the sea lions participate during the display.
Methods
The breeding group of 10 California Sea Lions at
Blackpool Zoo were observed twice weekly from
October 2015 to June 2016.
A
B
3
The group consisted of 1 six year old male and 9
females, ranging in age from 4 months to 30 years
(at the start of the study). A male sea lion was born
at the start of June 2016.
e
Wat
Rock
4
Water
6
2
Holding
Pen
The sea lions were observed for 40 minutes prior to
public displays and any agonistic interactions
between the animals were noted.
As well as this, the sea lions were observed during
the public display and any non-participation or
agonistic interactions during the display were noted.
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Figure 1. Pictures showing the California sea lion enclosure at Blackpool Zoo.
A shows a bird’s eye view of the enclosure and B shows a drawing with the different zones used in the study.
Results
No significant difference was found for any of
the sea lions or the group as a whole meaning
there is no association between the two.
Mean aggression for all California sea lions each week
25
40
35
Mean aggression (seconds)
A Fisher’s Exact Test was used to determine if
there was an association between aggression
before the display and aggression/nonparticipation during the display for each
individual sea lion and the group as a whole.
Mean weekly aggression for each California Sea Lion
Mean aggression (seconds)
A Kruskal Wallis Test showed a highly significant
difference (P<0.0001) between the individual sea
lion and the mean weekly aggression they each
displayed. There was no significant difference
(P=0.3174) between the week of observation and
the mean aggression for all sea lions.
30
25
20
15
10
20
15
10
5
5
0
0
ANYA
ELMO
FILIPA
GALA
GINA ISABELLE
Sea lion
LO
LOTTIE
RUBI
XANNA
Figure 2. Mean weekly aggression for each of the ten
California sea lions observed for all 19 weeks of the study.
Error bars show the standard deviation of each value.
Discussion
Results indicate that the aggression within the group does not have an effect on the sea lions
during the public displays.
This is an ideal result as it is important that the animal’s welfare remains a priority and that they
are not being negatively affected by group tensions and dynamics.
However, this result does not give an explanation as to what does cause the sea lions to not
participate in the displays. Further work needs to be done to look into what factors influence this,
such as different trainers, sea lion’s health, and amount of food available.
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Figure 3. Mean aggression of all 10 of the observed
California sea lions for each week of the study.
Error bars show the standard deviation of each value.
References
Bertram, B. (2004). Misconceptions About Zoos. Biologist,
51(4),p.199–206.
Schapiro, S.J., Bloomsmith, M.A., Laule, G.E. (2003). Positive
Reinforcement Training As a Technique to Alter Nonhuman Primate
Behavior: Quantitative Assessments of Effectiveness. Journal of
Applied Animal Welfare Science, 6(3),p.175–187.
Acknowledgements
I would like to thank all of the Education Department and sea lion
trainers at Blackpool Zoo for all of their help during this project,
and a special thank you to Laura Salanki for her endless support.