WHITE STORK

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INTRODUCTION
WHITE STORK Ciconia ciconia Order
Ciconiformes Family Ciconiidae
by PASQUA ROSA PONZIANI
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General 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

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• 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

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• 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

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• 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.

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• Migration

• 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
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• 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)

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• 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
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OBJECTIVES 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

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METHOD

• 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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Number 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.

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Behaviours 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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Shading 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
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The 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
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General 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.
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Does the feeding effort change between the nests?


Total mean113.62mn Sdt error24.67
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Each 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.

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Does the feeding effort increase with the number
of chicks?
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• 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.

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Do some parents feed for a longer time than
others?
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• 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.

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Shading

• 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

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DAY ONE

• Relation between temperature and shading time

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DAY TWO

• As the temperature increases, shading 2
  increases and shading 1 decreases (total shading
  increases)

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DAY THREE

• No shading behaviour is exhibited when the
  temperature is low

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• 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.

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• 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

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• 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

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• 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.

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• 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.

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Shading 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.

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• 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.

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• 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.

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Factors 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.

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• 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

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• 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

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• 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.

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ACKNOWLEDGMENTS
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.
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THE ORNITHOLOGY GROUP
Clothilde PATOUX Pasqua Rosa PONZIANI Styliani
TZIMIRI Joan STEVENSON Jessica SVENSSON Kerstin
NORDSTRÖM Joan OUDRY
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Anovacomparison of the mean feeding effort
between the number of chick
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Anovacomparison of the mean interval time
between feeds between the nests
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Anovacomparison of the mean feeding time between
the nests
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Annex