Can speed and tri-axial acceleration measured by biologgers be used to classify Oystercatcher behaviour?

MSc Thesis Roeland A. Bom

Supervision:Dr. Judy Shamoun-Baranes & Prof. Dr.ir. Willem Bouten

Dr. Bruno J. Ens & Drs. Kees Oosterbeek

Px Jeroen Onrust

Biologgers measuring tri-axial acceleration

• Static acceleration• Dynamic acceleration

Heave (z)

Sway (y)

Surge (x)

Shepard et al, 2008

•classify complex behaviours?• Energy and storage

Aim

• Can tri- axial acceleration be used to classify animal behaviour? - test case: the Oystercatcher Haematopus ostralegus.

• Can acceleration be used to make (spatial) time budgets over a long time period?

• Can instantaneous speed be an alternative for classifying behaviour?

Why Oystercatchers?

• Ideal shorebird to observe a range of distinct behaviours.• Fundamental ecology.• Conservation ecology.

• UvA biologggers measure: geolocation, instantaneaous speed and acceleration (20 Hz)

• Solar panel to charge the battery

• Logging interval up to 3 seconds

• Communicate with antennae, interactively change settings

The biologgers

Methods

• Observe logged bird in the breeding season while logging with10-20 seconds interval + 3 seconds accelerometer data.

• Link observation data to logger data and make classification model for acceleration- and speed data separately.

• Log throughout the year.

Study area: Schiermonnikoog

• Observations on three logged birds

• 702 labeled data belonging to 18 different behaviours

• Speed model

• Three groups of behaviours, misclassification-error 32%

• misclassification-error fly not fly 8%

Results

No movement

Fly Terrestrial locomotion

is the speed = > 0.19 m/s?

Is the speed > 3.5 m/s?

NO

NO

YES

YES

• Static acceleration Pitch & Roll

• Dynamic acceleration Maximum (g) Average absolute (g/s) Periodicity Frequency (Hz) Instantaneous speed (m/s)

classification model for acceleration data

0.0 0.5 1.0 1.5 2.0 2.5 3.0

-1.0

0.0

1.0

Forage_bs

166_20090703_10time (s)

dyn

am

ic a

cce

lera

tion

(g

)

Heave (Z)

Sway (Y)Surge (X)

Results

NOYES

is the average absolute dynamic acceleration in the sway = < 0.4 g/s?

Stand

Terrestrial locomotion

Preen

SitFly

is the average absolute dynamic acceleration in the surge = < 1.9 g/s?

is the heave pitch angle < 0.72°?

NO

NO

YES

YES

YES

NO

is the average absolute dynamic acceleration in the heave = < 10.4 g/s?

• Acceleration model

• Five groups of behaviours, misclassification-error 13%

Time (s)

Acceleration figures

Terrestrial locomotion

Fly

Preen

Dyna

mic

acce

lera

tion

(g)

0.0 0.5 1.0 1.5 2.0 2.5 3.0

-1.0

0.0

1.0

Wax

166_20090703_45time (s)

dyna

mic

acc

eler

atio

n (g

)

0.0 0.5 1.0 1.5 2.0 2.5 3.0

-1.0

0.0

1.0

Forage_bs

166_20090703_2time (s)

dyna

mic

acc

eler

atio

n (g

) 0.0 0.5 1.0 1.5 2.0 2.5 3.0

-1.0

0.0

1.0

Fly

166_20090707_51time (s)

dyna

mic

acc

eler

atio

n (g

) Heave (Z)

Sway (Y)Surge (X)

Complex behaviour?

Forage

Handling

0.0 0.5 1.0 1.5 2.0 2.5 3.0

-1.0

0.0

1.0

Handle_is

166_20090703_16time (s)

dyna

mic

acc

eler

atio

n (g

)

0.0 0.5 1.0 1.5 2.0 2.5 3.0

-1.0

0.0

1.0

Forage_bs

166_20090703_17time (s)

dyna

mic

acc

eler

atio

n (g

)Dy

nam

ic ac

cele

ratio

n (g

)

Time (s)

Heave (Z)

Sway (Y)Surge (X)

Results•Geolocations and accelerometer data throughout the year

2 km

Fly Terrestrial Locomotion Preen Stand Sit

Habitat vs Behaviour

Day night behaviour

Conclusion

• Biologging measuring acceleration can be used to distinguish several key behavioural classes in Oystercatchers.

• This information can be used to calculate time budgets in a spatial and temporal scale.

• Such quantitative analysis of behaviour can improve our understanding of how Oystercatchers organize their time.

Supervisors: Bruno Ens, Judy Shamoun-Baranes & Willem Bouten

Fieldsupervisor: Kees Oosterbeek

Fieldworkers: Jeroen Onrust, Hedwig Ens & Maaike Ebbinge

UvA team: Edwin Baaij & Emiel van Loon

thanks to