Title: WHITE STORK
1INTRODUCTION
WHITE STORK Ciconia ciconia Order
Ciconiformes Family Ciconiidae
by PASQUA ROSA PONZIANI
2General information
- The age of first-breeding varies between 3 and 6
years (rarely 2 or 7) - Europe is their breeding area
- Males arrive about one week before females,
take up possession of a nest and defend it - The first female to arrive at the nest is usually
accepted and a monogamous relationship is formed - The same pair may nest together over more than
one season
3- Nests are constructed in sunny and elevated
positions, like the top of electricity poles,
church towers and roofs - Clutch size varies from 2 to 6 eggs, with 4 eggs
being the most usual number - Incubation period is 33-34 days, with sitting
shared by both sexes - Eggs hatch asynchronuously and both parents care
for and feed the young
4- The number of young successfully fledged is
usually between 2 and 3 - Sometimes an adult may kill and eat a nestling or
throw it out of the nest, if it appears weak - The young leave the nest at 58-64 days of age and
become independent 7-20 days thereafter, when
they leave the nesting area
5- Diet of White Stork
- The White Stork feeds exclusively on animal
matter. It takes a very wide variety of food,
including small mammals, eggs, fledglings and
small birds, reptiles, amphibians, fish and
invertebrates
- Diet of White Storks in lake Kerkini (Goutner V.,
Furness W., 1997) Examination of pellets showed
that diet was mainly composed of Orthoptera
(61.9), then Coleoptera (30.5), Hemiptera
(5.6), Insect larvae partly aquatic (1.0) - Fish was not found in pellets, but scales were
found on the bill of chicks, probably because the
fish bones are entirely digested.
6- White Stork is a migratory bird
- Most White Storks spend the winter season in
Africa and the breeding season in Europe - To reach Europe they follow two routes. To the
West, birds cross between the continents at the
straits of Gibraltar and to the east they pass
over the Bosporus and Dardanelles of Turkey - The White Storks breeding in Greece use the east
route
PAUL GORIUP AND HOLGER SCHULZ
Migration routes of the White Stork
7- THE WHITE STORK IN GREECE
- Greece is considered to be one of the most
important breeding areas of the White Stork in
the Balkan peninsula - The White Stork in Greece, until 1950 had a wide
geographical distribution in the whole country
(Martens 1966). - In recent decades the species has been restricted
only to the central and northern parts of the
country and to the island of Lesvos - The majority of the population of the White Stork
in Greece arrives between 20 of March and the
beginning of April. - Departure to the wintering ground begins around
the middle of August and continues until early
September - In 1993 the total population of White Storks in
Greece was found to be 4774 individuals - The higher portion is located in central and
northern districts. Macedonia was found to have
the highest number of nests, about 1382.(all data
from Tsacalidis and Papageorgiou)
8- The area of behaviour observation was Kerkini
- Wetland seems to be the most important ecological
factor affecting the distribution and population
abundance of the White Storks. Macedonia
districts where the most wetland - areas in Greece are located showed the highest
population density. - Wetland is a particular environment where the
predominant element is water, and it is
permanently or periodically covered by water.
http//students.ceid.upatras.gr/pirot/serres/3p_n
ofr.html
9OBJECTIVES OF BEHAVIOUR STUDY
- FEEDING BEHAVIOUR
- General activity of feeding behaviour
- Mean feeding time per feed for each nest
- Mean feeding effort in relation to the number of
chicks in nest - Mean time between two feeding
- SHADING BEHAVIOUR
- How shading behaviour changes throughout the day
influenced by the change of temperature - If shading behaviour is influenced by number of
chicks - How much time both parents are absent from the
nest
10METHOD
- Sampling area
- The observations were carried out on 9 nests
(numbered 1 to 9) in the village of Kerkini
(Macedonia region). - Nests no.1 to 5 are build on artificial platforms
set on electricity poles along a road. - Nests no. 6, 7 and 8 are build on the towers of
the church, away from the road. They are in close
proximity and nest no.8 was shadowed by nest
number 7 from approximately 12.30 to 19.00 - Nest no.9 is build on the roof of an elementary
school.
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12Number of chicks per nest 2 chicks in nests
no.1,3,6,and 9. 3 chicks in nests no.2,4 and 8. 4
chicks in nests no. 5 and 7. These numbers were
checked using a mirror on the top of a long pole.
- Sampling time
- We observed the nests from the 30/05 to the
01/06/2000. - Day 1 from 13.00 to 17.00 4 hours
- The weather was sunny, except from 16.00 to 17.00
approximately, when there was a cloud cover. - Sunrise at 5.05, sunset at 19.41.
- - Day 2 from 9.00 to 19.00 10 hours
- Broken cloud cover until approximately 12.30 and
then sunny. - Sunrise at 5.05, sunset at 19.41.
- Day 3 from 9.00 to 12.00 3 hours
- Clouds and storm until approximately 11.00, then
sunny. - Sunrise at 5.04, sunset at 19.42.
13Behaviours observed
Feeding behaviour When parents regurgitate food
in their nest to feed their young. The
regurgitation of water was not counted as feeding
behaviour since it is both to water and wet the
chicks.
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15Shading behaviour When parents shade their young
with their back oriented to the sun. On the first
day, no gradation was defined in the shading
behaviour. From the second day we defined 2
grades
16The interactions with other individuals were also
taken into account (e.g. Intruders disturbing
nests,).
Observation method Observations were made with
binoculars. Start and finish times are recorded
for each behaviour. The times given in the
results are Central European Times, they are one
hour behind the sun time.
Other parameters The temperature was taken in
the sun each hour from 14.30 the 1st day. The
presence of clouds was also noted
17General activity of feeding
RESULTS
There is no peak of feeding at any particular
period of the day the storks do not seem to feed
their chicks at a preferential time. The
standard errors show the variation in feeding
effort between the 3 days.
18Does the feeding effort change between the nests?
Total mean113.62mn Sdt error24.67
19Each nest is influenced by some ecological
particularities (age of the parents, competition,n
umber of chicks).
- Hypothesis The feeding effort varies between
nests - Conclusion Generally, the interval between 2
feeds does not vary between the nests the
storks feed their chicks approximately every 2
hours.Thus the majority of parents exert the same
feeding effort. - Anova test shows no significant difference
(p0.0623) between means for all the nests - However, the p value is borderline therefore we
can consider the differences between means for
the nests - No.4 differs from the groups 1,3,6,8,9 nest 4 is
disturbed by the presence of an intruder,which
feed the chicks.Thus the chicks are feed by 3
birds instead of 2. - No.7 differs from No. 9 nest 7 has 4 chicks,
this may increase the feeding effort, and
decrease the interval between 2 feeding.
20Does the feeding effort increase with the number
of chicks?
21- HypothesisMore chicks in the nest increase the
stimulation for parents to get food. Thus the
feeding effort should increase with the number of
chicks. - ConclusionThe nests with 4 chicks are
significantly different from the nests with 2 and
3 chicks (p0.0128) thus parents with 2 or 3
chicks feed their chicks less than parents with 4
chicks . - The feeding effort seems to increase with the
number of chicks but the lack of data prevents us
from drawing conclusions. - Nest 4 has a specific feeding behaviour 3 birds
feed 3 chicks whereas usually the chicks have
only 2 parents.Thus we decided to exclude it from
the test.
22Do some parents feed for a longer time than
others?
23 -
- HypothesisThe feeding time varies between nests
- Conclusion
- With the Anova test (p0.1373) we have made the
comparison of the mean feeding time between the
nests.This shows that either the data is
unreliable or there is no significant difference
between the means and therefore all the birds
regurgitate for approximately the same duration. - The time of feeding ranges between 4 and 7
minutes. - There is no relationship between the feeding time
and the number of chicks. - The poor number of data prevent us drawing
conclusion and - the statistic tests are at the limit to be
acceptable. -
24Shading
- Observation hours were unequally divided among
the three days - Problems with the data collection
- No statistical analysis
- Separate treatment for each day
- Exclusion of nest number 8 from the results
25DAY ONE
- Relation between temperature and shading time
26DAY TWO
- As the temperature increases, shading 2
increases and shading 1 decreases (total shading
increases)
27DAY THREE
- No shading behaviour is exhibited when the
temperature is low
28- Groups of nest with 2, 3 and 4 chicks
Table . Mean shading time for nests with 2,3 and
4 chicks per hour for each day
- When more chicks are present the amount of
shading time decreases.
29- Duration of parents absence
Table 2. Absence Time (min) of both parents from
nests for each day. In bold are the nests with 4
chicks.
- When more chicks are present parents seem to
leave the nest for longer periods
30- DISCUSSION
- Our data, although very limited, illustrates
some general parental behaviour of storks. - Feeding activity
- Our observations show no change of feeding
activity throughout the day. - Past studies have shown two peaks in feeding
activity 4 5 hours after sunrise
and 3 4 hours before sunset. Pedro de Barros
Daniel Moura
31- The mean interval between feeds.
- The mean interval between feeds was
approximately 2 hours. - It has been mentioned that chicks of less than
15 days are fed every one hour. And chicks of
more than 15 days are fed every 2 hours. Oxford
University Press, 1977 - Differences that were observed between nest 4
and the other nests may be attributed to the
presence of an intruder in this nest.
32- Mean feeding time
- The mean feeding time per feed was between 4 and
7 minutes.
- Feeding effort
- From the results feeding effort is greater for
larger brood size. This result contradicts
previous studies. - Schadd and Ritchison (1998) found that, in
Yellow-Breasted Chats (Icteria virens) the
feeding rate does not increase with more chicks
in the nest. - In fact chicks in larger broods receive less
food.
33Shading behaviour
- Shading behaviour is commonly exhibited by the
order Cicconiformes, for e.g. the Spoonbills
(Platalea leucorodia) and the Storks.
- Shading behaviour (exhibited by the storks in
this study) is closely related to the weather
conditions. Generally the pattern of shading
follows the changes of the temperature over the
day. - Also the type of shading behaviour ( posture
change from wings closed to wings partially open
) changes through out the day, as the temperature
changes. This suggests that open wings is more
efficient for shading.
34- Also the position of the sun in the sky, may
influence the shading posture. Shading 2 posture
increases and the shading 1 posture decreases as
the sun moves higher in the sky. - No observation was carried out on a nest without
chicks and therefore we do not know if the
shading behaviour was originally a behaviour for
the birds to cool themselves and secondarily
developed for shading to protect the chicks from
the sun.
35- The results suggest that shading behaviour
decreases with larger brood size. - However, the differences in shading behaviour may
also in fact be due to the size of the chicks and
not only the number present in the nest. - The parents may instinctively change their
behaviour, with less shading and more absence
from the nest and they may invest more time in
feeding, when the chicks increase in size. - The two nests with the greatest number of chicks
were also visually much lager than chicks in the
other nests. Parents of these two nests were also
both absent at the same time for a longer
duration throughout the day than the parents in
any other nest. The time spent on shading is
therefore reduced.
36Factors Affecting Data
- It is important to note that although an attempt
has been made to interpret the data and to
suggest reasons to explain the results, in fact
the study provides no concrete evidence to
support our conclusions. There are several
reasons for this - - Total observation time is only 17 hrs and total
sample size is only 9 nests. - Observations did not include the earliest part
of the morning from sunrise and the latest part
of evening to sunset. - Duration of observations was not consistent for
each day. - It is therefore very difficult to carry out
statistical analysis on such limited data and to
have confidence in the results obtained.
37- Furthermore,
- identifying each behaviour during observations
without prior experience was subjective,
especially in relation to shading behaviour. - no measurements were taken to determine the age
of the chicks
38- The study group feel that we have benefited in
several ways from this exercise. Not only did we
learn about, and stimulate our interest in the
behaviour of the white stork, but also we have
been made more aware of the problems and
complexities associated with behavioural study. - Familarity with bibliography and observation
prior to recording data are essential for
identifying, understanding and defining the
behaviour being examined. - Sample size and observation duration must be
sufficient to allow accurate and dependable
statistical analysis of representative data. - We also recognize the benefits of working in a
group. Communication is fundamental and every
person in the group contributes his/her ideas to
support and improve our understanding of the
subject
39- BIBLIOGRAPHY
- De Barros, P Moura D. 1985 Breeding, feeding
and mortality factors in white stork Ciconia
ciconia populations nesting in Portugal in 1985. - Goutner, V Furness, R. 1997 Feathers of white
stork ciconia ciconia chicks in north-eastern
Greece, as indicators of geographical variation
in mercury contamination. - Tsachalidis, E Papageorgiou, N. 1996
Distribution status and breeding of the white
stork. - Goriup, P Schulz H. 1990 Conservation
management of the white stork an international
opportunity. - Muzinic, J Rasajsk J. 1992 On Food and Feeding
habitats of The White Stork Ciconia Ciconia in
The Central Balkan. - Oxford University Press 1977
- Schadd, C Ritchison G. 1998 Provisioning of
nestlings by male and female yellow-breasted
chats.
40ACKNOWLEDGMENTS
The ornithology group is grateful to V. Goutner
and A. Pålsson for their help in collecting and
interpreting the data. Also, we would like to
thank E. Lekka for her help with the statistical
analysis.
41THE ORNITHOLOGY GROUP
Clothilde PATOUX Pasqua Rosa PONZIANI Styliani
TZIMIRI Joan STEVENSON Jessica SVENSSON Kerstin
NORDSTRÖM Joan OUDRY
42Anovacomparison of the mean feeding effort
between the number of chick
43Anovacomparison of the mean interval time
between feeds between the nests
44Anovacomparison of the mean feeding time between
the nests
45Annex