keane animal behavior final paper

8/10/2019 Keane Animal Behavior Final Paper

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Sex-Specific Differences in Tufted Puffins (Fratercula cirrhata)

Shannon Keane

Abstract

Tufted puffins are aquatic birds belonging to the family of Alcidae that feed on fish,squid, and crustaceans. Although research on swimming behaviors has been done on otherAlcids, few studies exist on tufted puffins. This research on Alcids, specifically thick-billed

murres (Uria lomvia) and razorbills (Alca torda), found differences between the sexes in diving

depth, timing, and trajectory, in foraging behavior, and in the feeding of offspring. Based onthese studies, we expected to find sex-specific differences in the duration and temporal pattern of

swimming in the tufted puffin. We performed six 30-minute scanning observations on six

different dates at various time points on a population of 15 puffins, 13 males and 2 females, and

recorded the duration of swimming behaviors for all birds. Using a students t-test, we found nosignificant differences in duration (p=0.1491) or temporal patterns (Morning p=0.3939,

Afternoon p=0.2079) of swimming behaviors between males and females. In addition, we used

an outlier test to ensure all observations should be included in our statistical analyses. Thesedata suggest there is no difference between male and female foraging behavior in the wild.

Therefore, these birds cannot be treated like other Alcids. Future studies should focus on wild

populations to determine if the same patterns apply. Another potential study could explore

whether sex-specific differences exist in other behavior, such as diving depth or parental care.

Introduction

Research on members of the Alcid family, specifically on thick-billed murres (Uria

lomvia) and razorbills (Alca torda), found sex-specific differences in diving depth, timing, and

trajectory, in foraging behavior, and in the feeding of offspring. (Paredes, 2008) However, no

studies focus on sex-specific differences in tufted puffin (Fratercula cirrhata) swimming

patterns during the nonbreeding season. Tufted puffins (Fratercula cirrhata) are small, sexually

monomorphic birds and feed mostly on fish in their juvenile years and on squid and euphausiids

in their adult years. (Piatt, 2002) The study was designed to determine whether sex-specific

differences exist in the duration and temporal patterns of swimming behavior in the tufted puffin

during the nonbreeding season. Based on previous research on Alcids, we hypothesized that

differences in the duration and temporal patterns of swimming behaviors exist in the tufted

puffin. By studying this question, we hoped to determine whether tufted puffins could be treated


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like other members of the Alcid family. In addition, this study will give researchers insight into

the time budget of tufted puffins, which will enable them to better understand how the birds

spend their time and the risks to which they are exposed.

Methods and Materials

We observed the collection of tufted puffins, thirteen males and two females, in the

Aquatic Bird House at the Bronx Zoo from September 2014 to November 2014. The exhibit was

made up of rocky cliffs with ledges at variable heights and holes for their burrows, a waterfall in

the corner, and a swimming pool that spanned the length of the exhibit but was half the width

and had multiple places for the birds to enter and exit the water. They fed from a dish placed

behind a rocky ledge by the edge of the water. We conducted six 30-minute observations at

different times of the day, which were broken down into 5-min intervals.

The number of individuals swimming was counted throughout the observations. No

individual was counted twice by using the colored bands wrapped around the birds legs, which

were visible while the bird was both standing and swimming. Individuals were sexed according

to band colors given to us by zookeepers. The birds with light purple and blue bands and with

pink and black bands were female, and the other thirteen birds were male. We recorded the

duration of the swimming behaviors by noting when individuals entered and exited the water.

We determined sex-specific differences in duration of swimming by averaging the total

time each individual spent swimming in each of the six observation periods, grouping the

averages by sex, and then averaging the duration of each sexs swimming behaviorin each

period. We determined significance using an unpaired, two-tailed students T-test with an alpha

value of 0.05. In addition, the observations were split into two groups: observations before noon

and observations after noon. The average time spent swimming by each sex was recalculated


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according to the time of the observation such that both sexes had an average in both groups.

Paired, two-tailed students t-tests with an alpha value of 0.05 were then performed on both

groups to determine the significance of sex-specific differences observed. Finally, Grubbs

outlier test was used to ensure that all points could be used for our calculations.

Results

We recorded the number of puffins swimming during each observation (Fig. 1), the sex

of the individuals swimming (Fig. 2), and the total time spent swimming by each individual (Fig.

3). Males spent an average time of 16.25 minutes swimming (standard deviation = 9.388,

standard error = 3.832) over the six observations periods while females swam an average of

14.17 minutes (standard deviation = 9.704, standard error = 3.962). This difference was not

significant (unpaired t-test, two-tailed, alpha = 0.05, p = 0.6270). We then averaged the time

spent swimming during each observation group by sex and plotted it along the date and time of

the observation (Fig. 4). These averages were then separated into two groups: observations

before noon and observations after noon. The average time spent swimming in the morning was

15 minutes (standard deviation = 8.660, standard error = 5.000) for females and was 22.5

minutes (standard deviation = 3.750, standard error = 2.165) for males. In the afternoon, females

spent an average of 13.33 minutes swimming (standard deviation = 12.583, standard error =

7.265) while males spent an average of 10 minutes (standard deviation = 9.437, standard error =

5.449). The differences observed between the sexes in both groups were determined to be non-

significant (paired t-test, two-tail, alpha = 0.05, morning p = 0.3939, afternoon p = 0.2079).

Discussion

The results from all t-tests performed suggested no significant difference exists between

males and females in the duration and temporal pattern of swimming behavior in tufted puffins.


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Slight differences can be seen in Fig. 4, which suggest that females tend to be more active in the

afternoon and males tend to be more active during the morning; however, the differences were

insignificant according to the t-test performed. Therefore, our hypothesis was not supported by

these data. However, these results may be skewed by the small female population, small spatial

area of the exhibit, the low number of observations, and the limited time frame in which

observations were possible. Another possible source of error was the birds were fed from a food

bowl behind a rock. In other words, the birds did not have much room to move around and did

not have to enter the water for foraging purposes, which may have altered the results.

These findings suggest that tufted puffins do not follow swimming patterns similar to

other birds within their family. Because tufted puffins do not have the same patterns as other

members of their family, they should be treated differently when attempting to solve problems

related to their swimming behaviors. In order to support this claim, future studies should explore

whether these results are applicable to tufted puffins found in nature. In addition, future studies

could also focus whether sex-specific differences exist in other aspects of tufted puffin

swimming, foraging, or parental care or whether other differences exist between tufted puffins

and members of the Alcid family.

Acknowledgements

I would like to thank Kristen Stuart and Christopher Pedro for their assistance with data

collection. I would also like to thank Drs. J. Alan Clark and Evon Hekkala for their assistance in

the development of the project and the Bronx Zoo for allowing us to conduct our study.

Literature Cited

Paredes, R. I. (2008). Sex-specific differences in diving behaviour of two sympatric Alcini

species: thick-billed murres and razorbills. Canadian Journal of Zoology.

Piatt, J. F. (2002). Tufted Puffin: Fratercula cirrhata. The Birds of North America.


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Figure 1: Number of swimmers and non-swimmers by date

Figure 2: Number of males and females swimming by date

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Sept. 21 Oct. 15 Oct. 16 Oct. 20 Oct 23. Nov. 12

Numberofindividuals

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Swimmers

Non-swimmers

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Sept. 21 Oct. 15 Oct. 16 Oct. 20 Oct 23. Nov. 12

Numberofindiviudals

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Females


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Figure 3: Duration of swimming behavior by individual during each observation period

Figure 4: Average time spent swimming by each sex during each observation period

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29-Sep 15-Oct 16-Oct 20-Oct 23-Oct 12-Nov

AverageTimeSpentSwimming(min

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lp/b F p/b F p/s M yel M red M g/b M

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150015-Oct

110016-Oct140020-Oct

103023-Oct

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1400

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