Les articles d'Elie Gaget

Diet composition and diversity of the Peregrine Falcon Falco peregrinus over 30 years on coastal Mediterranean islands, France

Wed, 26 Aug 2026 11:40:10

de Yves Kayser, Marion Fiorentino, Elie Gaget, Patrick Bayle
In Avocetta, 50 (July, 2026)
En ligne : riviste.unimi.it[...]

Objectives
We aimed to provide a long-term, comprehensive description of Peregrine Falcon Falco peregrinus diet composition and diversity on coastal Mediterranean islands, near a major urban area, at breeding and non-breeding seasons.

Methods
We identified prey species from 87 remain samples of F. peregrinus preys year-round collected on 6 islands near Marseille, France (1995-2024). Prey relative abundance, biomass, and diversity indices were calculated. Seasonal, spatial, and temporal variations in diversity indices and prey taxa abundances were assessed using Kruskal–Wallis tests and generalized linear models.

Results
We identified 4,483 prey individuals across 180 species (i.e., species richness), with birds <200 g dominating the diet. Shannon diversity index indicated high diversity, while inverse Simpson index and Pielou’s evenness suggested moderate dominance by a few species. The most consumed taxa were small insectivorous passerines (19% abundance, 4% biomass), followed by Phasianidae (15%, 15%) (mainly Common Quail Coturnix coturnix), Apodidae (14%, 6%), Columbidae (11%, 25%), Turdidae (10%, 8%), and Sturnidae (8%, 6%) (Common Starling Sturnus vulgaris). During the breeding season, species richness and Shannon diversity were higher, while inverse Simpson and evenness were lower; Apodidae, Phasianidae and Columbidae were more consumed, and Turdidae and Sturnidae more abundant in the non-breeding season. Urban vicinity islands showed higher richness and Shannon index but lower evenness than remote and uninhabited islands, with Phasianidae and Columbidae more abundant and Apodidae and small insectivorous passerines less abundant. Temporal trends indicated declines in Common Quail remains over 30 years.

Conclusion
Our 30-year study provides insights into Peregrine Falcon feeding ecology and highlights the high dietary diversity and trophic flexibility of Peregrine Falcons on Mediterranean coastal islands. Temporal, seasonal, and small-scale variations in the contribution of prey species to the diet may reflect factors related to prey ecology, including long-term trends in prey populations and their localized availability at or near nesting sites, stopover areas, and along a coastal flyway.

Evidence for a relationship between bird body size and uncertainty in individual morphological measurements at ringing

Fri, 26 Jun 2026 10:30:15

de Yanaël Martinais, Elie Gaget, Matthieu Guillemain, Charlotte Francesiaz
In Bird Study, (en ligne) (June, 2026), 1-13
En ligne : doi.org[...]

Operator errors when taking morphometric measurements are more important for larger species and for mass measurements. To quantify operator effects on morphometric measurements during ringing sessions, depending on species size and morphometric characters. Three morphometric characters (wing length, body mass and body condition index) had been measured during ringing sessions on 17,818 individuals of 14 different species in southern France. The deviation from the mean and the variation, both absolute and by percentage, of measurements taken by operators were estimated for each bird species and age and sex categories. We detected operator effects on measurements. Wing length showed a deviation from the mean, reaching less than 1% of total measurement and a small variation. However, body mass showed a large deviation from the mean, and a large variation reaching up to 10% of total measurement. Body condition index showed broadly the same results as body mass, with the same proportion. Larger species were the most affected by measurement errors, both in absolute and in percentage terms. Errors in morphological measurements are common during ringing sessions and are related to the characteristics of the species, particularly their size, the tools used (such as dynamometers for body mass) and the characteristics of the operators.

Vegetation trajectories over 150 years of temporary ponds created in the Camargue delta (Southern France)

Wed, 18 Mar 2026 15:40:14

de Hugo Fontes, Patrick Grillas, Thierry Dutoit, Antoine Gazaix, Elie Gaget, François Mesléard
In Restoration Ecology, (en ligne) (March, 2026), e70372
En ligne : onlinelibrary.wiley.com[...]

Temporary ponds in the Mediterranean climate have a high conservation value, but many have been severely destroyed or degraded. Pond restoration and new pond creation have been engaged widely. Evaluations of the success of such operations are generally carried out over 10–15 years and show divergent results over this timeframe. In the Camargue (Rhône delta, South of France), several temporary ponds were created with various objectives since the second half of the 19th century.
Study the long-term trajectory of plant communities in created temporary ponds and compare them with those of reference temporary ponds.
We carried out vegetation surveys and measured environmental parameters in 25 ponds created in the 19th, 20th, and 21st centuries, as well as in 27 natural reference ponds (space-for-time substitution approach).
Submerged macrophyte communities (composition, abundance, and species-richness) converged toward the reference communities after one or several decades. Emergent plant communities (terrestrial plants and helophytes) converged more slowly toward the reference communities (composition and abundance). Even after 150 years, the emergent plant communities with the highest conservation interest (in particular Natura 2000 habitat) were not found in created ponds.
The creation of temporary ponds in the Camargue is of conservation interest but cannot compensate for the loss of natural temporary ponds.

Nouvelles données sur quatre espèces de Lépidoptères inventoriées en Camargue (France)(Lepidoptera, Blastobasidae, Gelechiidae, Sesiidae)

Fri, 25 Sep 2026 13:55:47

de Jacques Nel, Elie Gaget, Fany Jariod, Marc Thibault, Luc Belenguier
In Revue de l’Association Roussillonnaise d’Entomologie, 119 (2026), 50-53

De nouvelles données (répartition, biologie et genitalia) sont présentées pour quatre espèces de Lépidoptères observées en Camargue (France, Bouches-du-Rhône) : Xenopathia novaki (Rebel, 1891) [Blastobasidae], Monochroa moyses Uffen, 1991 [Gelechiidae, Anomologini], Synanthedon theryi Le Cerf, 1916 et Bembecia ichneumoniformis ([Denis & Schiffermüller], 1775) [Sesiidae].

Vulnerability and adaptations to climate change in EU protected areas: A Natura 2000 managers’ perspective

Fri, 22 May 2026 15:36:46

de Giorgio Zavattoni, Jon E. Brommer, Tyler Hallman, Ineta Kačergytė, Szabolcs Nagy, Tomas Part, Diego Pavon-Jordan, Alaaeldin Soultan, Yanjie Xu, Elie Gaget
In Conservation Letters, 19(3) (2026), e70047
En ligne : onlinelibrary.wiley.com[...]

The Natura 2000 (N2K)—Europe's network of protected areas—is a key conservation instrument, but its effectiveness is challenged by climate change. We surveyed 382 N2K managers to investigate their perceptions of climate change and related site adaptation strategies. Warming and precipitation shifts were frequently reported as threats, with perceived vulnerability of N2K sites highest in the Mediterranean and lowest in the Boreal region. Our results suggest that the official N2K site information stored in the Standard Data Forms greatly under-report managers' assessment of vulnerability. 58% of the surveyed managers implemented adaptation strategies, which, when characterized following a resist–accept–direct (RAD) framework, aimed not only at resisting, but also at directing and accepting the effects of climate change. Managers also highlighted several barriers to the implementation of adaptation strategies, such as lack of funding, time, stakeholders’ consensus, and lack of knowledge on local vulnerability.

Threats to and management of Natura 2000 protected areas relative to agricultural practices

Fri, 28 Nov 2025 10:56:16

de Giorgio Zavattoni, Elie Gaget, Tyler Hallman, Ineta Kačergytė, Tomas Part, Diego Pavon-Jordan, Thomas Sattler, Jon E. Brommer
In Conservation Biology, (en ligne) (November, 2025), e70172
En ligne : onlinelibrary.wiley.com[...]

The Natura 2000 (N2K) network combines biodiversity protection and socioeconomic targets. Human activities, such as agricultural practices, can affect biodiversity in N2K sites in diverse ways. Limiting activities with negative impacts while enforcing land management that supports biodiversity is crucial for effective conservation. Yet, site-level information on how this is addressed in N2K sites is lacking. To fill this knowledge gap, we conducted a European Union-wide survey among N2K site managers. We aimed to assess the implemented conservation measures, their funding sources, and the extent to which different threats are addressed. Of the 341 responses, 61.8% reported the implementation of conservation measures linked to agricultural practices, such as adapting mowing and grazing at levels suitable for the conservation of grassland habitats and species. Sites with management tied to agricultural practices relied more on EU funding, such as the Common Agricultural Policy (CAP), whereas other sites depended more on national funding. Threats not addressed by conservation measures were reported by 63.8% of respondents, suggesting that overall management funding may be insufficient or ineffectively allocated. Most of these unaddressed threats resulted from intensive agricultural practices, such as the use of agrochemicals (reported as a threat in 13% of sites). These findings provide insight into how traditional agricultural practices, mostly related to low-intensity grazing and mowing, are frequently used as conservation tools, whereas intensive agriculture is a prominent source of unmitigated threats. Thus, achieving N2K conservation goals requires avoiding intensive agricultural practices and strengthening effective conservation measures in protected areas.

Shifting the baseline for waterbird and seabird conservation in europe, risk assessment over one century

Mon, 6 Oct 2025 11:40:14

de Elie Gaget, Jon E. Brommer, Thomas Galewski
In Biodiversity and conservation, (en ligne) (September, 2025)
En ligne : doi.org[...]

European waterbird and seabird populations have been threatened by anthropogenic activities for decades. Effective strategies are needed to restore both populations and their habitats. However, the temporal period used to define the state of reference when setting restoration targets requires careful considerations to avoid the risk of shifting baseline. A risk of shifting baseline occurs if a population decreases before the time period used to set a baseline. In Europe, most bird monitoring schemes started after the 1970s, yet significant changes in population trends were already reported earlier in the 20th century. We assessed the risk of shifting baseline for 88 out of 170 waterbird and seabird species breeding in Europe. Building on historical ecology, we reconstructed population trends between 1900 and 2018 from information collected in both historical literature and monitoring scheme reports. Historical trends confirm variations in population trends for several waterbird and seabird species over the period 1900-1970, with 35 decreasing species, 38 fluctuating species, 15 increasing species and 82 species with unknown trends. A high risk of shifting baseline was identified for 28 species, for which restoration targets must consider historical trends spanning at least a century. The risk was low for 12 species, probably low for 41 species, probably high for 7 species and uncertain for 82 species. Our study highlights the crucial role of historical data collected prior to the large-scale implementation of standardized abundance monitoring, as it allows for the identification of appropriate baselines to guide the restoration of waterbird and seabird breeding populations.

Interactions between climate warming and management actions determining bird community change in protected areas

Tue, 10 Jun 2025 10:35:42

de Leonie Jonas, Jon E. Brommer, Martin Jung, Michal Balaz, John J. Borg, Luka Bozic, Preben Clausen, Antoine Derouaux, Koen Devos, Cristian Domşa, et al.
In Biological Conservation, 308 (August, 2025), 111213
En ligne : www.sciencedirect.com[...]

Biodiversity is increasingly negatively affected by climate warming, making this issue a major conservation concern. Many bird species respond to warming temperatures by shifting distribution ranges, but these shifts often lag behind temperature changes. Protected areas (PAs) can facilitate such shifts, but a growing body of literature suggests that not all PAs facilitate climate warming responses equally, as realized management actions can differ. Here, we study waterbird community change as a response to climate warming in relation to targets of conservation projects implemented in Natura 2000 protected areas across the EU. We combine long-term waterbird survey data (i.e. International Waterbird Census) with data on conservation funded by the EU LIFE program, the main EU instrument for conservation. We used the community temperature index to measure thermal community changes over 28 years. We found community adjustment to climate warming lagged behind temperature. However, community change was twice as fast in sites were conservation was targeting wetland habitats compared with sites without habitat conservation. Targeting waterbirds directly did not lead to variation in community change compared with other types of species conservation. Our results imply that on the management level conservation targeting a community's habitat (rather than targeting the species group directly) is more likely to provide benefits for community adjustment to climate warming. This study demonstrates that management actions currently not targeting climate warming impacts on biodiversity, have the potential to support species responding to climate warming. However, conservation strategies need to be adapted to the challenges arising with climate warming.

Reviewing and benchmarking ecological modelling practices in the context of land use

Fri, 4 Jul 2025 10:18:59

de Elie Gaget, Martin Jung, Matthew Lewis, Florian Hofhansl, Laura Jane Graham, Eleanor Warren-Thomas, Piero Visconti
In Ecography, (en ligne) (July, 2025), e07745
En ligne : onlinelibrary.wiley.com[...]

Despite habitat loss and degradation are the primary drivers of biodiversity loss, different conclusions have been drawn about the importance of land-use or land-cover (LULC) change for biodiversity. Differences may be due to the difficulty of framing a coherent model design to assess LULC effects. Recommendations have previously been identified for the design of statistical models and failing to follow them can risk misidentification of drivers, misinterpretation of predictions, overconfidence, high uncertainty, and incorrect management recommendations. We review modelling practices in statistical models assessing biodiversity responses to LULC, and investigated relationships between modelling practices and citations by scientific articles and policy documents. We benchmarked practices across model approaches, political extents, and objectives. From 346 model applications, we found that more than half of the model applications have justified ecologically-relevant predictors, have used 1 km² or lower LULC spatial resolution, have used fine LULC thematic resolutions, performed validation or communicated uncertainty. However, we found that the model approach and political extent were strong determinants of the misuse of modelling recommendations. Top–down models followed less frequently three recommendations out of six, compared to other model approaches. Global studies used coarser LULC thematic and spatial resolution than studies at other extents, and thus potentially underestimated the relationships between LULC and biodiversity. Global studies were however more frequently cited by both scientific studies and policy documents. Modelling recommendations are not universally applied, especially because of methodological tradeoff, technical difficulties in their applications and data requirements. However, the multiples risks associated with the misuse of modelling recommendations, particularly in large-scale modelling exercises, raise concerns on model interpretation and policy support from science, regarding the impacts of LULC on biodiversity.

Contrasting effects of agriculture and urbanisation on bird and reptile communities in a Mediterranean delta (Gediz Delta, Türkiye)

Wed, 4 Jun 2025 15:53:31

de Dilara Arslan, Elie Gaget, Kerim Cicek, Anthony Olivier, Thomas Galewski, Ömer Döndüren, Anis Guelmami, Lisa Ernoul, Arnaud Béchet
In BMC Ecology and Evolution, 25(1) (June, 2025), 58
En ligne : doi.org[...]

Wetlands have been some of the most destroyed ecosystems over the last century, with important land-use changes resulting from agricultural, industrial, and urban development. Gediz Delta is a large wetland on the Aegean coast of Western Türkiye with natural areas affected by conversion to agriculture and urban developments from the Izmir metropolis. We assessed the effects of landscape type (natural, agricultural, and urban) on the composition of breeding bird (90 species) and reptile (14 species) communities in the Gediz Delta between 2019 and 2021. We used generalized linear models to estimate the effect of landscape types on community indexes and joint species distribution models to assess how species-specific habitat preferences explained their responses to landscape type.

Changes in waterbird occurrence and abundance at their northern range boundaries in response to climate warming: importance of site area and protection status

Fri, 8 Nov 2024 16:33:51

de Elie Gaget, O. Ovaskainen, U. Bradter, F. Haas, L. Jonas, A. Johnston, T. Langendoen, A. S. Lehikoinen, T. Pärt, D. Pavón-Jordán, et al.
In Animal Conservation, (en ligne) (November, 2024)
En ligne : onlinelibrary.wiley.com[...]

Climate warming is driving changes in species distribution, but habitat characteristics can interact with warming temperatures to affect populations in unexpected ways. We investigated wintering waterbird responses to climate warming depending on habitat characteristics, with a focus on the northern boundary of their non-breeding distributions where winter climatic conditions are more extreme. At these Nordic latitudes, climate warming is expected to drive positive changes in species occurrence and abundance, with likely differences in species-specific responses. We analyzed the occurrence and abundance of 18 species of waterbirds monitored over 2,982 surveys at 245 inland wetlands over a 25-year period in Sweden. We used hierarchical modeling of species communities (HMSC) which enabled us to relate species-specific changes to both functional traits and phylogenetic relatedness. We investigated occurrence and abundance changes in response to average temperature, temperature anomalies, site area, site protection status (Natura 2000), and land use in agricultural and urban surfaces. Unsurprisingly, both average temperatures and temperature anomalies were the most important variables influencing positively waterbird occurrence and abundance. For 60% of the species, the effect of temperature anomalies was even stronger in large or protected wetlands. Geese and mallard occurred more often at sites surrounded by agricultural and urban surfaces, respectively, but their occurrence in these habitats was not affected by interactive effects with climate warming. Species abundance was greater inside protected areas only for 11% of the species, but occurrence probability was higher inside protected areas for 44% of the species. Overall, we observed that species thermal affinity was a strong predictor for positive species response to temperature anomalies, and that species sharing similar phylogenetic history had similar relationships with environmental variables. Protection of large wetlands and restoration of the surrounding habitats are two targets for climate change adaptation strategies to facilitate future responses of waterbirds to climate warming.

Exposure of wetlands important for nonbreeding waterbirds to sea-level rise in the Mediterranean

Fri, 17 May 2024 16:11:40

de Fabien Verniest, Thomas Galewski, Olivier Boutron, Laura Dami, Pierre Defos du Rau, Anis Guelmami, Romain Julliard, Nadège Popoff, Marie Suet, Loic Willm, et al.
In Conservation Biology, 2024 (May, 2024), e14288
En ligne : onlinelibrary.wiley.com[...]

Sea-level rise (SLR) is expected to cause major changes to coastal wetlands, which are among the world's most vulnerable ecosystems and are critical for nonbreeding waterbirds. Because strategies for adaptation to SLR, such as nature-based solutions and designation of protected areas, can locally reduce the negative effects of coastal flooding under SLR on coastal wetlands, it is crucial to prioritize adaptation efforts, especially for wetlands of international importance for biodiversity. We assessed the exposure of coastal wetlands important for nonbreeding waterbirds to projected SLR along the Mediterranean coasts of 8 countries by modeling future coastal flooding under 7 scenarios of SLR by 2100 (from 44- to 161-cm rise) with a static inundation approach. Exposure to coastal flooding under future SLR was assessed for 938 Mediterranean coastal sites (≤30 km from the coastline) where 145 species of nonbreeding birds were monitored as part of the International Waterbird Census and for which the monitoring area was delineated by a polygon (64.3% of the coastal sites monitored in the Mediterranean region). Thirty-four percent of sites were threatened by future SLR, even under the most optimistic scenarios. Protected study sites and study sites of international importance for waterbirds were, respectively, 1.5 and 2 times more exposed to SLR than the other sites under the most optimistic scenario. Accordingly, we advocate for the development of a prioritization scheme to be applied to these wetlands for the implementation of strategies for adaptation to SLR to anticipate the effects of coastal flooding. Our study provides major guidance for conservation planning under global change in several countries of the Mediterranean region.

On the need and difficulty of evaluating management strategies improving species persistence

Fri, 1 Mar 2024 15:22:39

de Elie Gaget, Thomas Galewski, Jon E. Brommer, Isabelle Le Viol, Frédéric Jiguet, Nicola Baccetti, Tom Langendoen, Blas Molina, Filipe Moniz, Caroline Moussy, et al.
In Animal Conservation, 27(1) (February, 2024), 21-22
En ligne : onlinelibrary.wiley.com[...]

Discussion élargie sur les besoins d'évaluer les mesures de gestion favorisant la persistance des espèces, mais aussi des difficultés à mettre en place de telles évaluations sur les canards.

Habitat management favouring hunted waterbird species prevents distribution changes in response to climate warming

Mon, 10 Apr 2023 18:04:06

de Elie Gaget, Thomas Galewski, J. E. Brommer, Isabelle Le Viol, F. Jiguet, N. Baccetti, T. Langendoen, B. Molina, F. Moniz, C. Moussy, et al.
In Animal Conservation, 27(1) (February, 2024), 5-16
En ligne : onlinelibrary.wiley.com[...]

Climate warming is driving species to shift their geographical distribution poleward to track suitable climatic conditions. Two strategies have been suggested to help species respond to climate warming: facilitating distribution change or improving persistence. We questioned whether habitat management in favour of duck hunting activities interacted with duck responses to climate warming. We studied non-breeding waterbird community changes (110 species) over 28 years at 851 sites in South-West Europe, where habitat management is a common practice to attract and hunt ducks. We hypothesized that duck species targeted by habitat management do not need to track temperature changes as much as non-hunted species, because of the availability of suitable habitats provided by hunting land managers. We used the community temperature index (CTI) to assess the temporal responses of communities and species to climate warming. We compared the effect of hunting status with other functional traits on species responses, controlling for phylogenetic relatedness. The CTI trend has increased over the study period, indicating a community adjustment to climate warming. However, hunted ducks contributed to almost 40% of the negative contributions to this community adjustment, suggesting that hunted ducks do not shift their distribution as much as the other waterbirds do. Winter fidelity associated with the provision of attractive feeding grounds might explain why ducks did not seem to shift their distribution in response to climate warming. This study suggests the broad impact of human activities on wildlife, including on large-scale distribution processes, and questions the long-term consequences on duck populations.

Evaluation of moth community changes and northward shifts in response to climate warming in Korea using both local and global occurrences

Mon, 11 Dec 2023 14:18:14

de Tae-Sung Kwon, Sung-Soo Kim, Elie Gaget, Won IL Choi, Dae-Seong Lee, Young-Seuk Park
In Global Ecology and Conservation, December (December, 2023), e02763
En ligne : www.sciencedirect.com[...]

Although climate warming arguably induces changes in species distribution, thereby causing poleward shifts in various taxa, comprehensive research on the response of moths to climate warming is lacking. This study compared the distribution of macro-moths between historical (1978–2002) and recent (2011–2016) periods in South Korea using the macro-moth data collected at 18 survey sites to elucidate the changes in community composition. We used the community temperature index (CTI) to quantify the effect of temperature change on moth community changes. The CTI represents the average value of the species temperature index (STI; mid-value of thermal range) calculated using our local observations and global occurrences reported in the online database of the Global Biodiversity Information Facility. Our analysis revealed no significant difference in species richness between historical and recent surveys. However, some taxa, such as Uraniidae, Nolidae, Sphingidae, and Lasiocampidae, exhibited high turnover rates, while the number of sphingid moths with large body sizes greatly decreased. The temperature changes at the survey sites became pronounced with an increase in the survey interval (year) between historical and recent surveys (temperature increase = 0.465 ℃ ∙ 10yr-1), while the CTI change exhibited a weak signal for northward shift of moth species. The CTI using the local data indicated 0.09km/year of northward shift of moths, which is considerably slower than the northward shift (9.6km/year) of the isothermal bands. However, the CTI using global occurrence data, expected to improve the estimation of species thermal niches, did not show any sign of northward shift. When observed, the northward shifts of moths were primarily identified in the cold-adapted species with low STI values, suggesting that cold-adapted species are more sensitive and vulnerable to climate warming than warm-adapted species. These results indicate that the current distribution changes of species were uneven, and the species adapted to cold regions are the ones primarily responding to the temperature increase by migrating northward and to high elevations.

Field margins as substitute habitat for the conservation of birds in agricultural wetlands

Mon, 21 Aug 2023 15:21:50

de Pierre Mallet, Arnaud Béchet, Clelia Sirami, François Mesléard, Thomas Blanchon, Francois Calatayud, Thomas Dagonet, Elie Gaget, Carole Leray, Thomas Galewski
In Peer Community Journal, 3 (August, 2023)
En ligne : peercommunityjournal.org[...]

Breeding birds in agricultural landscapes have declined considerably since the 1950s and the beginning of agricultural intensification in Europe. Given the increasing pressure on agricultural land, it is necessary to identify conservation measures that consume little productive land. We tested the compensation hypothesis which states that field margins may represent substitute habitats for bird species in agricultural wetlands. We monitored bird species in 86 crop fields in rice paddy landscapes of Camargue (southern France), a wetland of international importance for birds. We investigated whether the area of three types of field margins (reed strips, grass strips and hedgerows) within a 500 meter buffer around the centroid of each crop fields had an effect on the abundance of bird species from three groups defined based on their primary habitat (reedbeds, grasslands, and forest edge species). We controlled for the area of each type of semi-natural habitat (wetlands, grasslands, and woodlands), crop diversity (rice, wheat, alfalfa, rape, and market gardening) and mean crop field size. Results show partial support of the compensation hypothesis with species-dependent responses to primary and substitute habitat area. Some species within the reedbed and grassland bird guilds are favored by the area of their primary habitat as well as by the area of field margins, in line with the compensation hypothesis. Eurasian reed warbler is favored by the area of both wetlands and reed strips. Corn bunting is favored by grassland and grass strip areas. We could not confirm the compensation hypothesis for other species. However, this may be due to the fact that most of these species did not respond to their primary habitat. These results therefore suggest that field margins may represent substitute habitats for some species but further studies, in contexts where species are strongly associated with their primary habitat, would be needed to confirm the generality of this hypothesis. Our results also suggest that species response to increasing the area of a field margin type may vary among guilds and even within guilds. Therefore, it may be difficult to favor all species within a given landscape and management actions may need to be tailored to whichever species are locally associated with the highest conservation priority. To tackle this challenge, it may be necessary to design landscape management actions at different spatial scales.

Anticipating the effects of climate warming and natural habitat conversion on waterbird communities to address protection gaps

Tue, 7 Feb 2023 15:47:00

de Fabien Verniest, Isabelle Le Viol, Romain Julliard, Laura Dami, Anis Guelmami, Marie Suet, Wed Abdou, Hichem Azafzaf, Nadjiba Bendjedda, Taulant Bino, et al.
In Biological Conservation, 279 (March, 2023), 10
En ligne : www.sciencedirect.com[...]

Thermal adjustment of waterbird communities to climate warming is crucial but hampered by natural habitat conversion, increasing their climatic debt. As it is, in contrast, facilitated in protected areas, assessing the adequacy of the current protected areas network with respect to future climate and land-use changes and identifying priority sites to protect is of major importance. In this study, we assess the thermal adjustment limitations that non-breeding waterbird communities might experience by the end of the 21st century in the Mediterranean region to highlight priorities for wetland protection. Priorities were set by combining the exposure of waterbird communities to natural habitat conversion and climate warming with their thermal specialization. The latter was calculated using winter abundance data of 151 species from 2932 sites of the International Waterbird Census in 21 Mediterranean countries. Exposure was assessed using future projections of temperature and land-use under four CMIP6 scenarios (SSP1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5). We found that strictly protected areas are located in wetlands whose waterbird communities, without protection, would likely experience high limitations in thermal adjustment in the coming decades. This highlights that the location of existing protected areas may effectively support the thermal adjustment of waterbird communities to future climate warming. However, 490 sites considered at risk lack protection, including 32 sites of international importance for waterbirds, stressing the need to strengthen the protected areas network in these sites in priority. Our study provides important guidance for conservation planning in the Mediterranean region to support waterbird responses to climate change. /
Dans notre étude, nous avons évalué les difficultés potentielles des communautés d’oiseaux d’eau hivernants à ajuster leur composition aux futurs changements de température en combinant la spécialisation thermique de la communauté avec deux métriques d’exposition à l’augmentation future des températures hivernales et à la perte future d’habitats naturels à l’horizon 2090 selon quatre scénarios futurs différents. Nous avons ainsi constaté que les aires protégées, et notamment celles strictement protégées, sont situées dans des zones humides dont les communautés d'oiseaux d'eau, sans protection, auraient probablement connu de fortes difficultés d'ajustement thermique au cours des prochaines décennies. Cela met en évidence la pertinence de l'emplacement des aires protégées existantes qui pourront faciliter de manière efficace l'adaptation thermique des communautés d'oiseaux d'eau au réchauffement climatique futur. Cependant, nous avons également identifié 490 sites à risque et ne bénéficiant d'aucun statut de protection, dont 32 sites d'importance internationale pour les oiseaux d'eau, ce qui souligne la nécessité de renforcer le réseau d'aires protégées méditerranéen dans ces sites en priorité.

Gap analysis of the Ramsar site network at 50: over 150 important Mediterranean sites for wintering waterbirds omitted

Wed, 7 Jul 2021 14:08:13

de Nadège Popoff, Elie Gaget, Arnaud Béchet, Laura Dami, Pierre Defos Du Rau, Ilse Geijzendorffer, Anis Guelmami, Jean-Yves Mondain-Monval, Christian Perennou, Marie Suet, et al.
In Biodiversity and conservation, 30 (July, 2021), 19
En ligne : link.springer.com[...]

The Mediterranean Basin is a biodiversity hotspot. Wetlands make a key contribution to this status, but many of them remain outside the Ramsar network fifty years after the establishment of the Ramsar Convention. Here we evaluate the extent to which the Mediterranean Ramsar network covers wetlands of international importance for wintering waterbirds using the Ramsar Convention criteria 2 (species of conservation concern), 5 (> 20,000 waterbirds) and 6 (1% of a population). These criteria were applied to 4186 sites in 24 Mediterranean countries using counts of 145 wintering waterbird species from 1991 to 2017. We identified 161 sites of international importance for waterbirds that have not yet been declared as Ramsar sites, which could be added to the 180 current Mediterranean Ramsar sites established based on waterbird criteria (criteria 5 and/or 6). Among these sites, a subset of 32 very important sites reached double the required level for at least one criterion and 95 were not protected by any site conservation status. Coastal wetlands represented half of the Ramsar gap for waterbirds. We identified that an additional 1218 monitored sites could be provisionally considered as internationally important and thus require more survey efforts to assess their status. This study highlights a lack of participation of the Mediterranean countries to build the Ramsar network for wetland protection. Our results should help policymakers and managers to prioritize future Ramsar site designation, notably in the Middle East and Western European region where important gaps were identified.

Imputation of incomplete large-scale monitoring count data via penalized estimation

Fri, 9 Apr 2021 18:17:28

de Mohamed Dakki, Geneviève Robin, Marie Suet, Abdeljebbar Qninba, Mohammed A. El Agbani, Asmaâ Ouassou, Rhimou El Hamoumi, Hichem Azafzaf, Sami Rebah, Claudia Feltrup‐Azafzaf, et al.
In Methods in Ecology and Evolution, 12(6) (April, 2021)
En ligne : besjournals.onlinelibrary.wiley.com[...]

In biodiversity monitoring, large datasets are becoming more and more widely available and are increasingly used globally to estimate species trends and conservation status. These large-scale datasets challenge existing statistical analysis methods, many of which are not adapted to their size, incompleteness and heterogeneity. The development of scalable methods to impute missing data in incomplete large-scale monitoring datasets is crucial to balance sampling in time or space and thus better inform conservation policies. We developed a new method based on penalized Poisson models to impute and analyse incomplete monitoring data in a large-scale framework. The method allows parameterization of (a) space and time factors, (b) the main effects of predictor covariates, as well as (c) space–time interactions. It also benefits from robust statistical and computational capability in large-scale settings. The method was tested extensively on both simulated and real-life waterbird data, with the findings revealing that it outperforms six existing methods in terms of missing data imputation errors. Applying the method to 16 waterbird species, we estimated their long-term trends for the first time at the entire North African scale, a region where monitoring data suffer from many gaps in space and time series. This new approach opens promising perspectives to increase the accuracy of species-abundance trend estimations. We made it freely available in the r package ‘lori’ (https://CRAN.R-project.org/package=lori) and recommend its use for large-scale count data, particularly in citizen science monitoring programmes.

Disentangling the latitudinal and altitudinal shifts in community composition induced by climate change: The case of riparian birds

Mon, 7 Dec 2020 17:17:28

de Elie Gaget, Vincent Devictor, Bernard Frochot, Régis Desbrosses, Marie-Christine Eybert, Bruno Faivre
In Journal of Biogeography, Online (December, 2020)
En ligne : onlinelibrary.wiley.com[...]

This study investigates whether, and how, the composition of riparian bird communities has been affected by climate warming and habitat change. Although these two forces act separately, their respective contributions are rarely examined. Moreover, while the response of a given community may be a function of latitude and altitude, most studies have focused on these gradients separately. Riparian ecosystems are an opportunity to investigate community change along latitudinal and elevational gradients. Location France, three major rivers (the Doubs, the Allier and the Loire) Taxon Birds. Methods Drawing upon bird community monitoring data over a period of 31 years (1982–2013, n = 1,286 point counts), we assessed community adjustment to temperature increase with the Community Temperature Index (CTI), and the homogenization pattern following habitat conversion with the Community Specialization Index (CSI). We evaluated the spatial climatic debt accumulated by communities, and the interaction between CTI and CSI trends. Furthermore, we tested differences in trends for lowland and highland elevations. Results Over the study period, the temperature increased by 1.17°C, and the CTI by 0.12°C, which corresponds to a spatial climatic debt of 4.9 km/year. Lowland communities adjusted to warming but not highland communities, which have experienced a decline in species abundance. CSI trends revealed biotic homogenization in both lowland and highland communities. This finding was uncorrelated with the CTI increase, and is thought to be due to the pressure from land use change on community composition. Main conclusions Riparian breeding bird communities have been affected by a temperature increase and, potentially, habitat change. Highland communities are most vulnerable to climate warming. Both climate warming and habitat change appear to have rapidly affected the composition of local communities, with expectable concerns on their diversity and specificity in the long term.

Antagonistic effect of natural habitat conversion on community adjustment to climate warming in nonbreeding waterbirds

Tue, 28 Jan 2020 09:43:18

de Elie Gaget, Thomas Galewski, Frédéric Jiguet, Anis Guelmami, Christian Perennou, Coralie Beltrame, Isabelle Le Viol
In Conservation Biology, 34(4) (August, 2020)
En ligne : conbio.onlinelibrary.wiley.com[...]

While the impacts of climate and land use changes on biodiversity have been widely documented, their joint effects remain poorly understood. We evaluated how non-breeding waterbird communities adjust to climate warming along a gradient of land use change. Using mid-winter waterbird counts (132 species) at 164 major non-breeding sites in 22 Mediterranean countries, we assessed the changes in species composition during 1991–2010, regarding thermal niche position and breadth, in response to regional and local winter temperature anomalies and to natural habitat conversion. We showed that in response to the temperature increase, communities became relatively richer in warm-dwelling species, but less where natural habitat conversion occurred. At the sites affected by natural habitat conversion, the overall species richness decreased with time, while the abundance relatively increased for the species with a broader thermal niche, independently of their thermal affinities. The strong negative relationship between natural habitat conversion and community adjustment to temperature increases suggests an antagonistic interaction between climate warming and habitat change. Indeed, we found no evidence of community adjustment to climate warming when natural habitat conversion was higher than 5% over 15 years. These results underline the importance of habitat conservation in community adjustment to climate warming. Article impact statement: Waterbird communities do not adjustment to climate warming when natural habitat conversion is >5% over 15 years. This article is protected by copyright. All rights reserved

Solution locale contre menace globale ?

Thu, 30 Jul 2020 10:30:22

de Elie Gaget, Thomas Galewski
In Espaces naturels, 71 (Juillet-Septembre 2020), 46-47

Les oiseaux d'eau en Méditerranée. Mesurer leur réponse au changement climatique

Thu, 30 Jul 2020 10:30:14

de Elie Gaget, Thomas Galewski
In Courrier de la Nature (Le), 323 (Juillet-Août 2020), 34-39

Mediterranean wetland conservation in the context of climate and land cover change

Fri, 19 Jun 2020 11:35:18

de Roxanne Leberger, Ilse R. Geijzendorffer, Elie Gaget, Anis Guelmami, Thomas Galewski, Henrique M. Pereira, Carlos A. Guerra
In Regional Environmental Change, 20(2) (6/2020), 67
En ligne : link.springer.com[...]

Wetlands are known to support diverse and unique species assemblages. Globally, but particularly in the Mediterranean basin, they are threatened by climate change and natural habitat loss. Despite an alarming decline of wetlands over the last century, standardised and systematic site assessments at large scale do not exist. Here, we perform an integrated assessment of Mediterranean wetlands by evaluating the combination of wetland protection and anthropogenic pressures, namely climate and land cover change, and the subsequent impact on wintering waterbirds. We used a multivariate partial triadic analysis to quantify climate and land cover change for each site between 1990 and 2005. We found that wetland sites in the southeast of the Mediterranean basin combined low or no protection cover with the highest increases in temperature and losses in natural habitats. Despite these findings, these sites also lack observation data on biodiversity, which may underestimate the resulting impacts. However, there are examples where active conservation measurements contributed positively to slow down wetlands’ reduction. Biodiversity data coverage needs to be ensured, regularly updated, and extended across sites regardless of their protection level, to allow for the assessment of biodiversity trends. This should be further extended to include current investments in remote sensing approaches.

Assessing the effectiveness of the Ramsar Convention in preserving wintering waterbirds in the Mediterranean

Wed, 4 Mar 2020 16:52:13

de Elie Gaget, I. Le Viol, D. Pavón-Jordán, V. Cazalis, Christian Kerbiriou, Frédéric Jiguet, Nadège Popoff, Laura Dami, Jean-Yves Mondain-Monval, Pierre Defos du Rau, et al.
In Biological Conservation, 243 (March, 2020), 108485
En ligne : www.sciencedirect.com[...]

Although biological conservation is based on international agreements, its effectiveness depends on how countries implement such recommendations as effective conservation tools. The Ramsar Convention is the oldest international treaty for wetland and waterbird conservation, establishing the world's largest network of protected areas. However, since it does not constitute any binding measure, its effectiveness in protecting wintering waterbird populations at an international scale has been questioned. Here, we use long-term (1991–2012) count data to assess the effectiveness of the Ramsar Convention in the Mediterranean Basin. We compared abundance and temporal trends of 114 waterbird species between 251 Ramsar wetlands and 3486 non-Ramsar wetlands. We found that the Ramsar network is critical for wintering waterbirds, concentrating nearly half of all waterbirds counted in the Mediterranean Basin in only 7% of monitored wetlands. Waterbird trends followed a northwest-southeast gradient, with a population decrease in the East. A significant and positive Ramsar effect on population trends was only found for the species of higher conservation concern in the Maghreb, particularly when a management plan was implemented. The Ramsar Convention was previously used on very important wetlands for waterbirds in Southern Europe, but is now an underused conservation tool. Our study suggests weaknesses in the use of Ramsar as an effective conservation tool in most of the Mediterranean Basin. However, the Ramsar Convention effectiveness to enhance waterbird populations in the Maghreb should encourage strengthening the Ramsar Convention. It should be done particularly in countries with limited environmental agreements and by systematic implementation of management plans.
Article impact statement
Identification of the regional disparities in the Ramsar Convention effectiveness to enhance waterbird populations across the Mediterranean Basin.

Prey remains of brown skua is evidence of the long-term decline in burrow occupancy of blue petrels and thin-billed prions at Mayes Island, Kerguelen

Mon, 9 Dec 2019 10:31:18

de Nathan Pacoureau, Elie Gaget, Karine Delord, Christophe Barbraud
In Polar Biology, 42(10) (October, 2019), 1873-1879
En ligne : doi.org[...]

Skuas are top predator and scavenger seabirds in marine and terrestrial ecosystems and monitoring their diet can provide valuable insights on the abundance and distribution of prey. The diet of the brown skua was studied at Mayes Island, Kerguelen archipelago, by collection of prey remains during their breeding cycle in 2013. We investigated a potential diet shift by comparing our results to those obtained two decades ago at the same colony. Our results confirmed the high specialisation of this skua colony in active predation of two burrowing petrels: the blue petrel and the thin-billed prion. We observed a shift in the diet of the brown skua with the importance of the thin-billed prion dropping significantly by 15%. Concomitantly, we observed a decreasing trend of burrow occupancy of the two main preys, with a more severe decline for the thin-billed prion. We suspected a dietary shift of brown skuas at Mayes Island related to a change in the relative abundance of blue petrels and thin-billed prions. Diet of brown skuas appears to be a valuable indicator of the relative abundance of burrowing petrels when they constitute the main food resource during breeding.

Long-term decline despite conservation efforts questions Eurasian Stone-curlew population viability in intensive farmlands

Mon, 8 Apr 2019 10:30:07

de Elie Gaget, Remi Fay, Steve Augiron, Alexandre Villers, Vincent Bretagnolle
In Ibis, 161(2) (April, 2019), 359-371
En ligne : onlinelibrary.wiley.com[...]

Agricultural intensification over the past decades has led to a generalized decline in farmland biodiversity. Farmland birds are particularly exposed to rapid changes in habitat and reduced food resources or availability. Understanding how farmland specialists can be preserved and their populations enhanced are major challenges for this century. Based on a long-term (19-year) study of a Eurasian Stone-curlew Burhinus oedicnemus population, we estimated the demographic parameters, including clutch size, egg volume, hatching success, survival rate and apparent population size. Demographic rates found for this French population were, on average, comparable to those found elsewhere in Europe. However, all demographic parameters showed negative trends, including a dramatic decline in the local population (26% decline over 14 years) and a 10% decline in adult survival rate over 11 years. Such a long-term decline, despite on-going conservation efforts, calls into question the overall sustainability of arable Stone-curlew populations. We infer some of the possible causes of this decline, in particular food shortage, and discuss how this pattern could be reversed through conservation measures applicable at very large spatial scales.

A More Effective Ramsar Convention for the Conservation of Mediterranean Wetlands

Fri, 15 Feb 2019 10:48:59

de Ilse R. Geijzendorffer, Coralie Beltrame, Laurent Chazee, Elie Gaget, Thomas Galewski, Anis Guelmami, Christian Perennou, Nadège Popoff, Carlos A. Guerra, Roxanne Leberger, et al.
In Frontiers in Ecology and Evolution, 7 (February, 2019)
En ligne : www.frontiersin.org[...]

The Ramsar Convention is the multilateral agreement aimed at protecting wetlands globally. Wetlands are particularly recognized for their role in the Mediterranean biodiversity hotspot by providing key habitats for endemic and migratory species, directly contributing benefits to the lives of people and being an integral part of their culture. In response to this importance, the Mediterranean Wetlands Observatory publishes Mediterranean Wetland Outlooks on the state and trends of Mediterranean wetlands; the first edition in 2012 (MWO1) and the second edition in 2018 (MWO2). In this paper, we used the results of the two Mediterranean Wetland Outlooks to highlight ways to increase the impact of the Ramsar Convention by identifying the spatial dimensions of detected biodiversity trends as well as the societal developments and estimated impacts of global change and protection status.

Cartographie des forêts humides dans la région d’El Kala (algérie) à l’aide des outils d’observation de la terre

Thu, 10 Jan 2019 17:01:51

de Asma Kahli, Ghania Belhadj, Elie Gaget, Clément Merle, Anis Guelmami
In La Terre et la Vie, 73(4) (2018), 431-445
En ligne : hdl.handle.net[...]

Les forêts humides sont parmi les écosystèmes humides les plus dégradés et les plus menacés dans le monde. En Algérie, elles représentent un ensemble d’habitats forestiers singuliers, fragiles et rares. La région d’El Kala, à l’extrême nord-est du pays, abrite de nombreuses zones humides uniques (lacs, marais, prairies humides, lagunes, etc.), parmi lesquelles quelques-unes des plus importantes formations de forêts humides en Afrique du Nord. L’objectif de cette étude est de développer une nouvelle approche cartographique afin de localiser et de délimiter ces formations à l’aide des outils d’observation de la Terre. Elle se base sur une combinaison d’indices topographiques et hydro-géomorphologiques, issus des Modèles Numériques de Terrain (MNT), de variables spectrales calculées à partir des images Landsat-8 et de données collectées sur terrain.

Waterbird communities adjust to climate warming according to conservation policy and species protection status

Mon, 24 Sep 2018 10:46:09

de Elie Gaget, Thomas Galewski, Frédéric Jiguet, Isabelle Le Viol
In Biological Conservation, 227 (November, 2018), 205-212
En ligne : www.sciencedirect.com[...]

Climate change is one of the strongest biodiversity threats. Worse still, the impact of multiple anthropic stressors on species dynamics could complicate adaptation to temperature increase. International conservation policies aim to protect ecosystems against anthropic pressures, but their ability to facilitate adaptation to climate change has yet to be assessed. Using wetland bird monitoring surveys, we evaluated the differences at the country scale of community adjustment to temperature increase of wintering waterbird communities (145 species) according to the implementation of the two main western Palearctic international conservation policies (Bern Convention and Birds Directive) in the Mediterranean basin (2786 sites, 22 countries) over a 22-year period. We showed that thermic community composition increases over time in countries which have enforced conservation policies. We found that strictly protected species under the Birds Directive and the Bern Convention contributed more to this community adjustment than the not strictly protected species. The mechanism results from a population increase in protected warm-dwelling species but not from a decline in cold-dwelling species. This study supports the ability of international conservation policies to mitigate the effect of climate change on animal communities./
Nous avons observé que les politiques internationales de conservation jouent un rôle positif dans l’adaptation des oiseaux d’eau au réchauffement climatique. Plus les pays du bassin méditerranéen ont des mesures de conservation fortes, plus les changements au sein des communautés d’oiseaux reflètent un meilleur ajustement au réchauffement climatique. Dans le détail, les espèces strictement protégées par la Directive Oiseaux et la Convention de Berne ont un meilleur ajustement de leur distribution que les espèces non strictement protégées.

Importance des politiques de conservation pour faciliter l'ajustement des communautés d'oiseaux d'eau hivernants au réchauffement climatique en Méditerranée (2018)

Wed, 16 Jan 2019 16:30:12

de Elie Gaget
Paris : Muséum national d'histoire naturelle, 2018, 205
En ligne : www.theses.fr[...]

Les activités humaines menacent gravement la biodiversité. Sous le terme de changements globaux, la sur-exploitation des populations et la destruction/dégradation des habitats arrivent en tête de liste des facteurs responsables de l’érosion de la biodiversité. Le changement climatique gagne en magnitude et ajoute une pression supplémentaire sur les espèces. En réponse à l’augmentation des températures du globe, les communautés se réorganisent suite au déplacement de la distribution géographique des espèces vers les pôles. Mais l’accumulation des pressions anthropiques est susceptible de produire des effets d’interaction limitant l’ajustement des communautés au réchauffement climatique. Dans ce contexte critique, la biologie de la conservation a pour but de concilier les activités humaines avec la conservation de la biodiversité. Dans cette thèse j’ai cherché à comprendre comment l’accumulation des pressions anthropiques peut limiter l’ajustement des communautés au réchauffement climatique et à identifier les solutions qui pourraient être mises en place pour faciliter leur adaptation à ce réchauffement. J’ai pris pour modèle d’étude les espèces d’oiseaux d’eau hivernants dans les pays du bassin méditerranéen. Ces espèces emblématiques bénéficient d’un dénombrement international destiné à suivre leurs populations en réponse aux prélèvements par la chasse et à la dégradation des zones humides dont elles dépendent. La Méditerranée est une région fortement anthropisée où l’utilisation des ressources naturelles exerce d’importantes pressions sur les zones humides et leur biodiversité. En réponse, les pays ont différentes stratégies pour protéger ces écosystèmes, ce qui fait de cette région un plan expérimental intéressant pour mesurer l’impact dans changements globaux sur l’assemblage des espèces en fonction des mesures de conservation mises en oeuvre. En étudiant la réponse des communautés au réchauffement climatique sous un gradient de perte/dégradation d’habitat, je montre que l’ajustement des communautés est réduit, voire empêché, par la dégradation des zones humides. La Convention Ramsar vise justement à protéger les zones humides et leur biodiversité en maintenant une exploitation raisonnée des ressources naturelles. En évaluant l’effet de cette convention, je montre que son efficacité à conserver les populations d’oiseaux est dépendante de l’implémentation d’autres outils de protection, mais que son rôle est crucial dans les pays où la législation environnementale est faible. Enfin, j’évalue la capacité des conventions internationales à faciliter l’ajustement des communautés au réchauffement climatique grâce à la réduction des pressions qui s’exercent sur les populations. J’ai comparé la réponse des communautés entre les pays ayant ratifié la Convention de Berne, ceux ayant engagé son application strictement réglementaire sous la Directive Oiseaux (Union Européenne) et ceux n’ayant pas ratifié ces conventions. Le résultat est clair, plus la réglementation est précise et strictement réglementaire, plus les communautés et les espèces strictement protégées s’ajustent à l’augmentation des températures.
En conclusion, les activités humaines sont une menace pour la biodiversité, mais les mesures de conservation, en réduisant les pressions sur les populations facilitent leur adaptation au changement climatique. La conservation des oiseaux d’eau nécessite une collaboration internationale et l’établissement de lois strictement réglementaires protégeant les zones humides et les espèces, tout en assurant une utilisation durable des ressources.