To Flee or Not to Flee: How Age, Reproductive Phase, and Mate Presence Affect White Stork Flight Decisions.

Recognizing, assessing, and responding to threats is critical for survival in the wild. Birds, especially in their role as parents, must decide whether to flee or delay flight when threatened. This study examines how age, reproductive stage, and the presence of a mate influence flight initiation distance (FID) and nest recess duration in white storks. Analyzing the data with a generalized additive mixed model (GAMM), we found significant correlations between FID and age, reproductive stage, and presence of a mate. These results suggest that the trade-off between current and future reproduction shifts during critical breeding periods, such as incubation and nestling care. To increase breeding success, White Storks appear willing to take risks and extend their stay in the nest when offspring are most valuable and vulnerable. In the presence of a mate, individuals leave the nest earlier, suggesting possible sexual conflict over parental care. The duration of nest abandonment is consistent with FID, except for age. These results illustrate how parental age, brood value, vulnerability, and sexual dynamics influence white stork flight decisions in complex ways. Understanding these dynamics enriches our knowledge of bird behavior and adaptations to environmental challenges and highlights the complexity of parental decision making.

Blowin' in the wind: Dispersal of Glossy Ibis Plegadis falcinellus in the West Mediterranean basin.

The movement of organisms is a central process in ecology and evolution, and understanding the selective forces shaping the spatial structure of populations is essential to conservation. Known as a trans-Saharan migrant capable of long-distance flights, the Glossy Ibis Plegadis falcinellus' dispersal remains poorly known. We started a ringing scheme in 2008, the first of its kind in North Africa, and ringed 1121 fledglings over 10 years, of which 265 (23.6%) were resighted. Circular statistics and finite mixture models of natal dispersal indicated: (1) a strong West/Northwest-East/Southeast flight orientation; (2) Glossy Ibis colonies from North Africa and Southern Europe (particularly on the Iberian Peninsula) are closely linked through partial exchanges of juvenile and immature birds; (3) unlike birds from Eastern Europe, North African Glossy Ibis disperse to but do not seem to undergo regular round-trip migration to the Sahel; (4) young adults (>2-years-old) have a higher probability of dispersing further than individuals in their first calendar year (<1-year-old); and (5) dispersal distance is not influenced by sex or morphometric traits. Together, these results enhance our knowledge of the dispersal and metapopulation dynamics of Glossy Ibis, revealing large-scale connectivity between the Iberian Peninsula and Algeria, likely driven by the spatial heterogeneity of the landscape in these two regions and the prevailing winds in the Western Mediterranean.

Diet of breeding Eleonora's falcon Falco eleonorae in Algeria: Insights for the autumn trans-Mediterranean avian migration.

How environmental changes are affecting bird population dynamics is one of the most challenging conservation issues. Dietary studies of top avian predators could offer scope to monitor anthropogenic drivers of ecosystem changes. We investigated the diet of breeding Eleonora's falcon in an area of Northeastern Algeria in the years 2010-2012. Feathers and insect remains originating from prey plucking behavior were analyzed, providing insights into the seasonally changing diet of this raptor, as well as the trans-Mediterranean avian migration. A total of 77 species of birds (16 Sylviidae, 11 Turdidae, and 4 Emberizidae), 3 species of insects, and 1 lizard were identified among prey remains, reflecting a diverse diet. Diet composition and prey abundance varied seasonally, faithfully correlating with the passage of migrant birds as recorded from bird ring recoveries. Our findings suggest that dietary studies of predators might be deployed to investigate changes in bird migration. We discuss our results in the context of trans-Mediterranean migration, with early-season prey mainly comprising trans-Saharan migrants (Apus apus and Merops apiaster) and late-season prey being dominated by Mediterranean winter migrants (Erithacus rubecula, Turdus philomelos, Sylvia atricapilla, and Sturnus vulgaris). Notably, we observed a significant reduction in species richness of passerine remains in 2012, potentially highlighting a decline in the diversity of avian migrants.

The future for Mediterranean wetlands: 50 key issues and 50 important conservation research questions.

Wetlands are critically important for biodiversity and human wellbeing, but face a range of challenges. This is especially true in the Mediterranean region, where wetlands support endemic and threatened species and remain integral to human societies, but have been severely degraded in recent decades. Here, in order to raise awareness of future challenges and opportunities for Mediterranean wetlands, and to inform proactive research and management, we identified (a) 50 key issues that might affect Mediterranean wetlands between 2020 and 2050, and (b) 50 important research questions that, if answered, would have the greatest impact on the conservation of Mediterranean wetlands between 2020 and 2050. We gathered ideas through an online survey and review of recent literature. A diverse assessment panel prioritised ideas through an iterative, anonymised, Delphi-like process of scoring, voting and discussion. The prioritised issues included some that are already well known but likely to have a large impact on Mediterranean wetlands in the next 30 years (e.g. the accumulation of dams and reservoirs, plastic pollution and weak governance), and some that are currently overlooked in the context of Mediterranean wetlands (e.g. increasing desalination capacity and development of antimicrobial resistance). Questions largely focused on how best to carry out conservation interventions, or understanding the impacts of threats to inform conservation decision-making. This analysis will support research, policy and practice related to environmental conservation and sustainable development in the Mediterranean, and provides a model for similar analyses elsewhere in the world. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10113-020-01743-1.

Contribution to the knowledge of the caddisfly fauna of Algeria: An updated checklist of Algerian Trichoptera with new records from the Aures region.

The caddisfly fauna of Algeria is poorly known and the few sporadic studies available were carried out decades ago. In this study, caddisfly larvae, pupae, and adults were collected in 11 stream localities from the Aures region, northeastern Algeria. Caddisflies were regularly sampled between April 2018 and February 2020. Two genera are new records to Algeria: Plectrocnemia and Setodes. In addition, four Trichoptera species are new to the Algerian fauna: Tinodes dives, Hydropsyche modesta, Plectrocnemia conspersa and Setodes acutus. Future caddisfly surveys in the region will doubtlessly contribute significantly to the incompletely known Trichoptera fauna of Algeria.

Trichoptera and Plecoptera of the Seybouse River, northeast Algeria: Distribution, phenology and new records.

The stoneflies and caddisflies of North Africa are still poorly known as vast areas of Algeria have yet to be investigated. A survey of the macroinvertebrates of the Seybouse River, northeast Algeria, was carried out from July 2014 to December 2016. Three species of stoneflies (Capnopsis schilleri, Capnioneura petitpierreae, and Tyrrhenoleuctra tangerina) and five taxa of caddisflies (Mesophylax aspersus, Hydropsyche maroccana, H. resmineda, H. artax/lobata, and H. gr. pellucidula) were identified. All taxa are new records to the Seybouse River and seven of them are new to northeastern Algeria. A multivariate analysis indicated that the Hydropsychidae exhibited a clear longitudinal gradient along the Seybouse River while Mesophylax aspersus seemed adapted to species-poor, intermittent streams. Further investigations of the stoneflies and caddisflies may inform conservation efforts and will prove useful to monitor the Seybouse River and similarly threatened North African rivers and streams.

Patterns of resource partitioning by nesting herons and ibis: how are odonata exploited?

Herons and ibis are colonially nesting waders which, owing to their number, mobility and trophic role as top predators, play a key role in aquatic ecosystems. They are also good biological models to investigate interspecific competition between sympatric species and predation; two processes which structure ecological communities. Odonata are also numerous, diverse, mobile and can play an important role in aquatic ecosystems by serving as prey for herons and ibis. A relationship between prey size and bird predator has been observed in Numidia wetlands (NE Algeria) after analyzing food boluses regurgitated by six species of birds (Purple Heron, Black-crowned Night Heron, Glossy Ibis, Little Egret, Squacco Heron and Cattle Egret) during the breeding period, which also shows a temporal gradient for the six species. Both the Levins index and preliminary multivariate analysis of the Odonata as prey fed to nestling herons and ibis, indicated a high degree of resource overlap. However, a distinction of prey based on taxonomy (suborder and family) and developmental stage (larvae or adults) reveals a clear size dichotomy with large-sized predators (Purple Heron, Black-crowned Night Heron and Glossy Ibis) preying on large preys like Aeshnids and Libellulids and small-sized predators feeding mainly on small prey like Zygoptera. Overall, the resource utilization suggests a pattern of resource segregation by coexisting nesting herons and ibis based on the timing of reproduction, prey types, prey size and foraging microhabitats.