Climate change will increase the recurrence of extreme weather events such as drought and heavy rainfall. Evidence suggests that modifications in extreme weather events pose stronger threats to ecosystem functioning than global trends and shifts in average conditions. As ecosystem functioning is connected with ecological services, this has far-reaching effects on societies in the 21st century. Here, we: (i) present the rationale for the increasing frequency and magnitude of extreme weather events in the near future; (ii) discuss recent findings on meteorological extremes and summarize their effects on ecosystems and (iii) identify gaps in current ecological climate change research.

Iconographies supplémentaires de l'article : Research frontiers in climate change: Effects of extreme meteorological events on ecosystems

Linking land cover satellite data with dietary variation and reproductive output in an opportunistic forager: Arable land use can boost an ontogenetic trophic bottleneck in the White Stork Ciconia ciconia.

Mettre en place des mesures de protection efficaces contre la degradation et la fragmentation de l'habitat d'une espece necessite d'etre capable de comprendre l'impact de l'environnement sur sa dynamique de population ainsi que sa sensibilite a la perte de connectivite entre les populations. Obtenir ces informations est deja un defi en soi, qui se complique encore pour les especes trop sensibles au derangement pour etre suivies de maniere classique. Lors de ce travail, nous avons etudie la dynamique et la genetique des populations d'une chauve-souris forestiere qui a subi un tres fort declin dans le nord de l'Europe, le Petit rhinolophe (Rhinolophus hipposideros), a l'aide de methodes non-invasives (comptages, genetique non-invasive).Nos resultats ont montre que le climat et le paysage autour des colonies de maternites influence la taille et la dynamique des populations du Petit rhinolophe. Nous avons egalement confirme un impact direct du paysage sur la survie des juveniles. Enfin, nous avons observe que la diversite genetique des populations pouvait etre fortement diminuee par leurs histoires demographiques et par un manque de connectivite entre les populations. Ces resultats ont des implications directes pour la conservation du Petit rhinolophe mais aussi pour le developpement des analyses integrant des donnees de genetique non-invasive pour la biologie de la conservation.

https://tel.archives-ouvertes.fr/tel-01944103/document

Etude non invasive de la dynamique et de la génétique des populations chez une chauve-souris forestière : impact de la qualité de l'habitat et de la connectivité

Age, arrival date and egg laying date are essentially closely related and determine reproductive performance in the White Stork Ciconia ciconia.To describe the impact of age, arrival date and egg l...

The early bird catches the worm: age-specific arrival time influences reproductive performance in the White Stork Ciconia ciconia

Globally, migratory behaviour is changing in response to climatic and anthropogenic change In recent decades, previously wholly migratory species started forming resident populations in the breeding area Partially migratory species with resident and migratory individuals in the same population provide an opportunity to understand the causes and consequences of changing migratory behaviour This study focuses on the influence of climate and food availability in determining movement and behaviour patterns of birds in populations that have recently become resident The white stork Ciconia ciconia recently established a resident population in Iberia, likely facilitated by the availability of abundant anthropogenic food resources including landfill and the invasive red swamp crayfish Procambarus clarkii Movement data from individual white storks fitted with GPS data loggers showed that year-round nest use by resident individuals dictates many aspects of foraging behaviour, including frequency of landfill use and foraging range Storks visited landfill from nests further away than previously expected (~48 km) High productivity near landfills has likely influenced the rapid population increase observed in recent decades, however breeding success in colonies far from landfill, particularly those located near rice fields, is low This suggest that the imminent closure of landfills, due to EU directives, will have significant impact on white stork numbers
 Many species are still too small to be tracked with GPS tags, so stable isotopes can be used to identify breeding and wintering quarters of migratory birds Stable isotopes were used to separate residents from migrants in a partially migratory population of lesser kestrels Falco naumanni Carbon isotopic composition of feather samples indicated that birds completing their moult in Africa could be identified However, resident birds could not be separated from birds that moulted in Iberia prior to migration This emphasises the need to understand moult timing and sequence to correctly interpret stable isotope data

Movement and foraging ecology of partially migrant birds in a changing world

Numerous studies have explored the relationship between environmental factors and White Stork Ciconia ciconia reproduction, mainly expressing breeding success as the number of fledglings. Nonetheless, one of the most critical life-history stages in birds falls between egg-laying and fledging, and identifying the factors causing offspring mortality during this period provides valuable knowledge. We quantified the number of laid White Stork eggs and the proportion of eggs that turned into fledglings in an agriculture-dominated region in Eastern Germany. Moreover, we identified the factors among land cover, weather and arrival dates, which influenced these two reproductive measures the most, and analysed the monitored mortality causes. On average, four eggs were laid per nest, and 57.8 % of the eggs turned into fledglings. The number of eggs laid was best explained by the negative effect of the arrival date of the second stork, while the percentage of eggs that turned into fledglings was more dependent on weather: most important parameters were mean temperature in the fifth and seventh weeks after the assumed breeding start (i.e. around the assumed hatching date), and the number of consecutive days with precipitation when nestlings are assumed to be approximately 3 weeks old. In an agricultural environment, weather effects that potentially disturb food availability might be more important than effects directly affecting the survival of White Stork offspring. The most frequent observed mortality cause, nest fights, furthermore revealed the relevance of intraspecific competition in the study population.

To fledge or not to fledge: factors influencing the number of eggs and the eggs-to-fledglings rate in White Storks Ciconia ciconia in an agricultural environment

Michael Arens

Papers

To fledge or not to fledge: factors influencing the number of eggs and the eggs-to-fledglings rate in White Storks Ciconia ciconia in an agricultural environment