Global changes are inducing migratory birds to advance their annual cycle. However, changes in the time of arrival at their breeding grounds have significant fitness implications. This study aims to identify factors affecting the variability in arrival time of migratory white storks (Ciconia ciconia L.) and to determine if their arrival at North African breeding grounds is occurring earlier. We monitored the arrival of ringed white storks at a breeding colony in Algeria between 2017 and 2021. The birds arrived at this breeding colony over an extended period spanning mid-December to mid-June each year. We found that stork arrival was negatively correlated with age and year of arrival, with older birds arriving first and stragglers consisting of first- and second-year birds arriving later. Notably, arrivals have been shifting toward earlier dates at this breeding ground. Furthermore, cluster analysis of arrival dates for each age-class revealed two distinct groups comprising early and late arrivals. Advancement of the annual cycle of the North African white stork population is consistent with phenological shifts induced by global changes and that have been recorded globally in a wide range of living organisms.

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<sec><title>Capsule</title>Age, arrival date and egg laying date are essentially closely related and determine reproductive performance in the White Stork Ciconia ciconia.</sec><sec><title>Aims</title>To describe the impact of age, arrival date and egg laying date on breeding success in the White Stork.</sec><sec><title>Methods</title>Ringing data from a White Stork breeding colony of 212 nests at Dréan, Algeria, were used to model the relationship between age, arrival date, laying date and reproductive performance. Seventy breeders that were individually colour-ringed as nestlings were monitored.</sec><sec><title>Results</title>Birds breeding on the periphery of the colony had significantly smaller nests and showed a tendency towards later laying dates, but they did not differ from centrally nesting birds in age or arrival date. First year birds did not breed and second year birds were significantly more likely than older age groups to occupy nests but fail to lay eggs. Older birds arrived earlier at the breeding colony and had a higher probability of initiating laying than younger birds. They also had a higher probability of nesting successfully and fledging a larger number of young.</sec><sec><title>Conclusion</title>Age determined arrival and laying dates and influenced breeding performance in the White Stork.</sec>

The diversity and spatial distribution of ectoparasites of a large colony of white stork Ciconia ciconia at Dréan, in north-eastern Algeria, were investigated during two consecutive breeding seasons. The results indicated that nestlings were infested by the following four louse species: Colpocephalum zebra (Burmeister, 1838), Neophilopterus incompletus (Denny, 1842), Ardeicola ciconiae (Linnaeus, 1758), and Ciconiphilus quadripustulatus (Burmeister, 1838). Overall, the distribution of chewing lice exhibited a clustered distribution, with C. zebra being the most frequent species, with a prevalence of 39.6% and 41.0% in 2011 and 2012, respectively. Our results also suggested niche partitioning among the four louse species within the host’s body parts. A generalized additive model indicated that size, sex, and year influenced the abundance of ectoparasites; the abundance of chewing lice increased with the size of the host and was greater in females, as well as in the first year of study. Further studies are needed to explore the spatio-temporal variability in white storks’ lice infestations.

We carried out a study on dynamics of the Common Moorhen, Gallinula chloropus, a synanthropic rallid (Aves, Gruiformes), to elucidate the adverse effects this species has possibly suffered from the markedly increased habitat degradation that has been taking place over the last decades at Boussedra Pond, north-eastern Algeria. During the period 2015–2018, this wetland-related species showed an annual 35.4% decrease in its numbers, and the number of breeding pairs, which was monitored between 2008 and 2018, experienced an annual drop of 4.9%. The clutch size, a key determinant of breeding performance, averaged 4.7 ± 1.0 eggs (N = 26 clutches) in 2018 and was significantly lower than those reported in previous studies. As a result of anthropogenic activities, the size of the marsh decreased by more than 50% over the 1984–2018 period. The long-lasting shrinkage of this relict wetland was accompanied by the expansion of built-up areas (>50%) and cultivated plots, and, also, by a marked reduction in natural both wet- and dry-land habitats in its vicinity. We suggest that the decrease in the population trend and the breeding performance of the Common Moorhen could be indicative of the species stress response to the long-lasting land conversion, pressuring the relict habitat of Boussedra Pond.