Variation of primary production during winter induces synchrony in survival rates in migratory white storks Ciconia ciconia

Summary 1. The environmental conditions that migratory birds experience during their stay at different locations throughout the year can have significant impact on the variation of annual survival rates. Because migrants often crowd during non-breeding, environmental conditions can affect survival rates of individuals originating from different breeding populations, thus also provoking spatial synchronisation of annual survival rates. The identification of critical environmental factors affecting survival is therefore crucial for understanding large-scale population dynamics of migrants. 2. We studied temporal and spatial variation of survival rates of migratory white stork Ciconia ciconia from eastern Germany and Poland and examine factors associated with this variation. We used resighting and dead-recovery data from more than 30 000 individuals sampled over 19 years to estimate survival. 3. Survival rates of juvenile and adult white storks originating from the two countries varied in parallel over time. Thus, variation in survival was caused by environmental variation to which individuals of both age classes from both countries were similarly sensitive. Variation in the primary production (as reflected by the normalized difference vegetation index) at one staging area in the eastern Sahel that is visited from October to November contributed up to 88% to the temporal variation in survival. Annual survival was reduced when primary production in the Sahel was low. 4. As the population growth rate of white storks is very sensitive to changes in survival, variation in primary production in the Sahelian staging area contributed significantly to population changes and is likely to be an important reason for population synchrony. 5. This study demonstrates that dynamics of migratory bird populations inhabiting large breeding areas can result from environmental variation encountered at a staging area that is visited for only a short period of time.

[1]  M. Schaub,et al.  Why you should use capture-recapture methods when estimating survival and breeding probabilities: on bias, temporary emigration, overdispersion, and common toads , 2002 .

[2]  G. Zink.  Populationsdynamik des Weissen Storchs, Ciconia ciconia, in Mitteleuropa , 1967 .

[3]  J. Lebreton,et al.  Marked Individuals in the Study of Bird Population , 1993 .

[4]  Robert A. Cheke,et al.  Brown locust outbreaks and climate variability in southern Africa , 2002 .

[5]  R. Pradel,et al.  Is the reintroduced white stork (Ciconia ciconia) population in Switzerland self-sustainable? , 2004 .

[6]  J. Marchant,et al.  The demography of the decline in the British willow warbler population , 1995 .

[7]  R. Jovani,et al.  Age‐related environmental sensitivity and weather mediated nestling mortality in white storks Ciconia ciconia , 2004 .

[8]  Per Lundberg,et al.  POPULATION EXTINCTIONS IN CORRELATED ENVIRONMENTS , 1998 .

[9]  A. Møller,et al.  Ecological conditions during winter predict arrival date at the breeding quarters in a trans‐Saharan migratory bird , 2004 .

[10]  J. Gaillard,et al.  Population dynamics of large herbivores: variable recruitment with constant adult survival. , 1998, Trends in ecology & evolution.

[11]  F. Bairlein,et al.  Comparison of survival rates between populations of the White Stork Ciconia ciconia in Central Europe , 1993 .

[12]  T. Szép.  Relationship between west African rainfall and the survival of central European sand martins Riparia riparia , 1995 .

[13]  Susan M. Haig,et al.  Links between worlds: unraveling migratory connectivity , 2002 .

[14]  Hobson,et al.  Linking winter and summer events in a migratory bird by using stable-carbon isotopes , 1998, Science.

[15]  S. Schoenmakers,et al.  REGIONAL DECREASE IN THE NUMBER OF WHITE STORKS (CICONIA C-CICONIA) IN RELATION TO FOOD RESOURCES , 1987 .

[16]  P. Busse,et al.  An analysis of the recovery distribution based on finding probablities , 1987 .

[17]  A. J. Noordwijk,et al.  The EURING exchange code 2000 , 2003, Journal für Ornithologie.

[18]  W. Fiedler,et al.  Detection of a new important staging and wintering area of the White Stork Ciconia ciconia by satellite tracking , 2001 .

[19]  David R. Anderson,et al.  Model selection and multimodel inference : a practical information-theoretic approach , 2003 .

[20]  T. Oatley,et al.  REVIEW OF RECOVERIES OF RINGED WHITE STORKS CICONZA CICONZA IN SOUTHERN AFRICA , 1988 .

[21]  David R. Anderson,et al.  Modeling Survival and Testing Biological Hypotheses Using Marked Animals: A Unified Approach with Case Studies , 1992 .

[22]  C. Tucker,et al.  Expansion and Contraction of the Sahara Desert from 1980 to 1990 , 1991, Science.

[23]  K. Burnham,et al.  Program MARK: survival estimation from populations of marked animals , 1999 .

[24]  Kenneth P. Burnham,et al.  Evaluation of some random effects methodology applicable to bird ringing data , 2002 .

[25]  B. Sæther,et al.  Disentangling the sources of variation in the survival of the European dipper , 2002 .

[26]  Roger Pradel,et al.  ASSESSING THE RELATIVE IMPORTANCE OF DIFFERENT SOURCES OF MORTALITY FROM RECOVERIES OF MARKED ANIMALS , 2004 .

[27]  I. Newton.  Relationship between breeding and wintering ranges in Palaearctic‐African migrants , 1995 .

[28]  Robert A. Cheke,et al.  Complex dynamics of desert locust plagues , 1993 .

[29]  E. K. Urban,et al.  The Birds of Africa , 1982 .

[30]  H. Caswell.  PROSPECTIVE AND RETROSPECTIVE PERTURBATION ANALYSES: THEIR ROLES IN CONSERVATION BIOLOGY , 2000 .

[31]  P. Berthold,et al.  Long-term satellite tracking sheds light upon variable migration strategies of White Storks (Ciconia ciconia) , 2002, Journal für Ornithologie.

[32]  I. Newton.  Population limitation in migrants , 2004 .