The effects of different abiotic factors on
the Common Chaffinch song
Authors:
Andersen Daniel, Kantonsschule Beromünster,
Beromünster, Switzerland
Danielson Evelina, Katedralskolan, Lund, Sweden
Pavia Francesco , De La Salle Sixth Form,
Birgu, Malta
Pizzuto Martina- Marie, De La Salle Sixth Form,
Birgu, Malta
Tutor:
Schlüchter Beat
1. Summary
In this report the various relationships between the chaffinch and its environment is shown.
The area of Val Müstair and the Ofenpass was used to investigate bird songs of chaffinch
males during a time span of two days. It is observed that the birdsong sung by the Chaffinch
relies to a certain extent on the abiotic factors such as weather conditions (temperature,
cloud cover and wind speed), the altitude and the time of day. All these factors may contribute to the variations in the birdsongs.The strongest correlation could be observed between
the altitude (which is the abiotic factor which affected the birdsongs most) and ending frequency. However the altitude does most likely not have a causal effect on the song, instead it
will affect the desirability of the area as a possible territory. From qualitative observations we
could namely see that high end frequency sounds could be used in competition for resources.
2. Introduction
Every bird species has its own specific song. Only the male birds have the capability to sing,
mainly for find mates and for marking their territory. For example many species of serine
birds project different variants of their song. Some variants or types of songs are individually
different and shared between individuals of a population [1]. The Chaffinch Fringilla coelebs
shows the same characteristics.
The Chaffinch is 15 cm in length and is one of the most common birds found in Europe, in
fact 1.5 million pairs of Chaffinch can be found in Switzerland alone.it lives in dense coniferous woodland to parks and gardens, therefore it is found all over Europe. The Chaffinch is
found living at altitudes varying from 400 to a maximum altitude of 2400 meters above sea
level [1].
The song of a Chaffinch, has a characteristic ringing followed by a “descending cascade,
ending in flourish” [2]. The normal duration of one song or one strophe of a chaffinch bird
song is 1.5 to 3 seconds long. The song is divided into 3 syllables: the first, which consists of
a row of whistle sounds of high tone, the second (a trill) which includes sounds which are
quickly poured on each other and usually the tone is lower than the third, which is a sharp
short stroke at the end. The first and second syllables may vary in number of repetitions and
the end of the third syllable at which the ending frequency is found may also vary. Songs
also vary according to age since young chaffinch (up to 1 year of life) produce homogeneous
elements of the song pattern but curtain elements become differentiated [3]. This is the reason, why the songs of different individuals may vary within the same species.
It could be shown that chaffinch males may produce up to 6 varied songs [3]. These songs
are evidente in difference when they are in the form of sonograms. Therefore by using a
sonogram the 3 different syllables can be visualized. By using the sonogram various readings may be recorded to evaluate the differences in the songs according to different conditions such as weather, altitude and time of day.
This topic was chosen because it combines biological knowledge to another form of natural
science, which is physics. The question we wanted to answer is: Does the birdsong change
according to changing abiotic conditions including altitude, weather conditions (wind speed,
cloud cover and temperature) and time of day? The Hypothesis is that as abiotic factors such
as weather conditions and the altitude vary, so does the bird song.
We expect that in the morning and evening the duration of the song will be longer than during
the day since at those hours: insects are less likely to appear and there would be more light .
Both cloud cover and amplitude will have a reducing effect on the duration of the song since
less light would be present and due to less atmospheric pressure. The temperature will not
have any effect on the duration of the song. The wind will have an increasing effect on the
duration since birds would need to amplify their song to compensate for background noises.
In relation to the frequency, the time of day and cloud cover will have no effect; however the
wind speed and altitude will have an increasing effect and the temperature decreasing effect.
3. Materials and Methods
The common chaffinch was selected as the species of research. We recorded 45 chaffinch
songs under changing conditions. The values and conditions included: time, altitude, cloud
cover, wind speed and temperature.
The time was recorded by checking the time at which the birdsong was heard using a clock;
the altitude was calculated by using a hand-held GPS and maps; Scales were devised to
determine the amount of cloud cover and the wind speed respectively:
 0 indicates no cloud cover, 1 indicates moderate cloud cover and 2
indicates complete cloud cover
 0 indicates no wind, 1 indicates a breeze, 2 indicates a moderate wind speed and 3
indicates high wind speed.
The recordings were made in Switzerland in the area of Val Müstair and the Ofenpass.
Figure 1: Shows the areas which were investigated. The Yellow circle indicate the areas researched on the 22nd of June 2015 and the red circles indicate the areas investigated on the
23rd of June 2015.
One recorded birdsongs of every individual was then further analyzed using sound analyzing
software [Audacity]by first the view was changed into a sonogram. Then the stereo soundtrack was converted into a mono, then applying a high pass filter at 1.5 KHz and if necessary
normalized the soundtrack. The duration of the song, number of syllables (in all different
parts observed), highest and lowest frequencies were identified, refer to figure2.
Highest
Frequency
Duration
st
1 syllable
nd
2 syllable
Ending
frequency
Figure 2: Typical sonogram of a chaffinch produced by “Audacity”. The different characteristics analysed are indicated directly in the figure.
Excel was used to register all the data and to do the data analysis. . A linear regression was
performed and p-values to test for significance were calculated.
4. Results
The results of the statistic analyses are given in table 1. . Due to the low p-value the altitude
has the biggest effect on the song characteristics (ending frequency). The higher the altitude,
the lower the end frequency (fig. 3). The temperature shows a significant effect on the song
as well (fig. 4). and the time of day.
P-Values Table
Time of Day
Altitude
Cloud Cover
Wind Speed
Temperature
Total song
duration in
seconds
Number of
repetitions in
first syllable
0.272
0.935
0.075
0.656
0.277
0.758
0.242
0.983
0.637
0.723
Number of
repetitions in
second syllable
0.343
0.540
0.076
0.587
0.027
Highest
frequency in
kHz
Ending
frequency in
kHz
Change in
Frequency in
KHz
0.181
0.990
0.389
0.195
0.871
0.035
0.000
0.055
0.080
0.017
0.414
0.000
0.039
0.562
0.050
Figure 3: Results of the statistical analyses (p values) showing the relationship between
the abiotic factors and song characteristics. Significant (p<0.05) or nearly significant
outcomes are highlighted.
Figure 4: Effect of the temperature to the ending frequency
Also the time of day has an influence on the ending frequency namely, the frequency increase in a course of a day. Even the wind speed and the cloud cover differenciate the
ending frequency. Though their p-values are slightly higher than 0.05 they were still
analyized since the results would still be fairly significant. The results also show that a high
cloud cover has a negative corroletion with frequency while wind speed has a positive
corroletion with frequency.
5. Discussion
It can clearly be seen in the results that the variables: temperature, time of day and altitude
had a significant effect upon the ending frequency of the song of F. coelebs. The time of day,
temperature and wind speed had an increasing effect upon the frequency while altitude had
a decreasing effect. However these four variables do most likely not have a causal relationship but they rather act as indicators on environmental conditions that can explain why the
song of the F. coelebs varies. For example both time of day and altitude will have an effect
on temperature and wind speed, and thus this explains why the p-value was low for all variables considering end frequency.
In order to explain why the F. coelebs uses different end frequencies in different environments we can take use of some qualitative observations made during the data collection.
The highest frequencies were recorded in areas where many individuals of F. coelebs were
observed relatively close to each other. One place that is especially worth mentioning is in
the area of a pasture with cows (found on the second day, on the south facing mountain in
Valchava). Due to the cows the number of insects available was high, which made it a desirable place for F. coelebs whose nourishments partially consists of insects. From this observation we can conclude that high frequency sounds are used in the competition for resources.
This information can be used in order to explain the effect of our independent variables.
Since the most desirable territory for the F. coelebs will be in the forest on low altitudes
where they get cover and where insects and other food are plenty, this explains why the high
frequency ending is more common on low altitudes than on higher ones where trees and
bushes are more scattered and food is scarcer. Also insects will be more active during the
afternoon than in the morning which explains the increased use of high frequency sound in
this period of the day. This in turn will explain why the sound also is more common in increasing temperatures since the low altitudes will have higher temperatures.
Even though the correlation is significant the result could become even more reliable by recording a larger sample size. Also, as stated in the introduction, different songs of individuals
have a specific characteristic, this means that different individuals will have different average
frequencies even though they follow the same pattern when it comes to the different variables. The different characteristics could therefore have affected the final result. In order to
minimize this error repeated recordings of the same individuals could be made.
In order to determine cloud cover and wind speed estimations was done by the researchers,
thus the data will have been influenced by personal experience. To eliminate this errors
proper equipment could have been used such as wind speed meters.
Sometimes, in order to record the altitude a map was used which only allowed for rough estimations to be made. However the error might have occurred when using the GPS as well
as the altitude was recorded from a distance. On the other hand these errors are not significant enough to invalidate the conclusion about the variation of the song of F. coelebs.
Further research on the topic may include studies on how the song is effected by competition
between individuals of the same species which could be explained in further detail the results
of this study.
6. Acknowledgements
Acknowledgements go to SJf (Swiss Youth in Science), NSTF (National Student Travel
Foundation), MSSF (Malta Student Science Forum), Francis Stivala, Rebecca Abela, our
guides at IWRW (International Wildlife Research Week) Claudia Baumberger, Beat
Schlüchter, Hans Shmocker and Salome Steiner, our respective families and all our fellow
IWRW participants.
7. Literature / References
[1]. Tiere der Alpen /Die Wirbeltiere, Jacques Gilliéron /Claude Morerod
[2].Jim Flegg and David Hosking 1993
[3].Degree of prevalence of different song types of chaffinch (Fringilla coelebs L.) in populations of the European Russia Olesya Anatolyevna Astakhova
[Audacity].
8. Appendix
Data Analysis Graphs
Effect of Wind Speed
Effect of temperature in °C
Effect of Time of Day
Effect of Altitude
Effect of cloud cover