Arnaud Béchet

Effect of A spring hunt on nutrient storage by greater snow geese in southern Quebec

A spring conservation hunt (15 Apr-31 May) to control the exponential population growth of greater snow geese (Chen caerulescens atlantica) was introduced in 1999 during their staging in southern Quebec, Canada. We tested the hypothesis that disturbance by hunting negatively affected nutrient storage in spring. We compared the amount of fat and protein stored by staging geese during the hunt (1999 and 2000) to similar data obtained sporadically between 1979 and 1998 (no hunt). We collected adult females at 3 sites along the St. Lawrence River during years with (n = 235 geese) and without (n = 194) hunting. We used abdominal fat and dry breast muscle mass as corresponding indices of fat and protein reserves. The condition of geese arriving at the staging area did not differ between years with and without a hunt. Abdominal fat of geese at the end of the staging period was 29-48% lower (depending on site and year) during years with a hunt than in years without. Similarly, breast muscles of geese at the end of staging were 5-11% lighter in years with a spring hunt. Low stable-carbon isotope ratios (δ 13 C) in tissues of geese collected in spring 1999 suggested that they fed less on corn, a C4 plant and a major food source for geese, than in other years. This may have contributed to their reduced body condition that year. However, despite high δ 13 C values in 2000, indicative of a high proportion of corn in the diet, nutrient storage in geese was still reduced compared to years without a hunt. We conclude that hunting was the most important factor explaining the low fat and protein storage of geese in springs of 1999 and 2000. We suggest that hunting disturbance reduced nutrient storage of geese because of decreased feeding activity and increased flying time.

To leave or not to leave: survival trade‐offs between different migratory strategies in the greater flamingo

1. The balance between costs and benefits of migration under different environmental, density-dependent and individual conditions may promote a broad range of migratory behaviours. We studied the factors influencing first-year migration and subsequent fidelity or dispersal among wintering areas, and the survival costs of different wintering behaviours in the greater flamingo (Phoenicopterus roseus). 2. We analysed by multievent capture-recapture modelling among-site dispersal/fidelity and site-dependent survival probabilities from 22 671 flamingos ringed in the Camargue (France) between 1977 and 2010 and resighted subsequently in their wintering grounds classified as France, Iberian Peninsula, Italy and North Africa. 3. We found that first- and second-year birds either resident or wintering at medium distances from their birth place, survived better than those wintering further afield. However, under severe winter conditions (extremely cold winter 1984-1985), individuals with the sedentary strategy suffered the highest levels of mortality. From the third winter onwards, the pattern of survival reversed: the long-distance wintering individuals (i.e. North Africa) survived better. 4. The proportion of first-year birds migrating for wintering was highly variable among cohorts and increased with favourable environmental conditions (wet years). After the first winter, birds showed high fidelity (>90%) to their previous wintering area and wintered preferably near their natal colony when they became adults (>2 years). 5. Survival estimates suggest that long-distance migration was costly for young and inexperienced individuals. Nonetheless, for adults, the most southern wintering areas seem to offer the most favourable local conditions for overwinter survival. 6. The higher availability of intermediate stopover sites during wet years may facilitate first-year migration. Then, once they have some wintering experience, flamingos appear to favour the known wintering grounds. As they grow older, dispersing towards the vicinity of the natal colony may provide higher breeding prospects for individuals wintering closer to this high-quality and saturated breeding ground, as predicted by the arrival-time hypothesis.

From Adaptive Management to Adjustive Management: A Pragmatic Account of Biodiversity Values

The conservation of biodiversity poses an exceptionally difficult problem in that it needs to be effective in a context of double uncertainty: scientific (i.e., how to conserve biodiversity) and normative (i.e., which biodiversity to conserve and why). Although adaptive management offers a promising approach to overcome scientific uncertainty, normative uncertainty is seldom tackled by conservation science. We expanded on the approach proposed by adaptive-management theorists by devising an integrative and iterative approach to conservation that encompasses both types of uncertainty. Inspired by environmental pragmatism, we suggest that moral values at stake in biodiversity conservation are plastic and that a plurality of individual normative positions can coexist and evolve. Moral values should thus be explored through an experimental process as additional parameters to be incorporated in the traditional adaptive-management approach. As such, moral values should also be monitored by environmental ethicists working side by side with scientists and managers on conservation projects. Acknowledging the diversity of moral values and integrating them in a process of collective deliberation will help overcome the normative uncertainty. We used Deweys distinction between adaptation and adjustment to offer a new paradigm built around what we call adjustive management, which reflects both the uncertainty and the likely evolution of the moral values humans attribute to biodiversity. We illustrate how this paradigm relates to practical conservation decisions by exploring the case of the Sacred Ibis (Threskiornis aethiopicus), an alien species in France that is the target of an eradication plan undertaken with little regard for moral issues. We propose that a more satisfying result of efforts to control Sacred Ibis could have been reached by rerouting the traditional feedback loop of adaptive management to include a normative inquiry. This adjustive management approach now needs to be tested in real-case conservation programs.

An automatic counter for aerial images of aggregations of large birds

Capsule Counts with precision comparable to those of an expert observer can be achieved automatically. Aims To develop an open-source freeware program that automatically extracts and counts the number of birds in aerial images of dense aggregations. Methods Software was developed and validated using aerial photographs of Greater Flamingo colonies from France, Turkey and Mauritania. We used a stochastic approach based on object processes. The objects representing flamingos were defined as ellipses, and the software detected these and produced a count. Details of the procedure are provided in electronic supplementary material. The energy is extracted by a birth-and-death algorithm, leading to the total number of birds. Results This procedure gave counts with precision comparable to manual counts of the aerial photographs by an expert (<5% difference). The procedure does not need any supervision of the extraction by an operator, thus reducing the processing time required to get the estimate of bird numbers in the image from >4 h to 20 min on average. Conclusion This open-source freeware should be useful for ornithologists and wildlife managers.

Global economy interacts with climate change to jeopardize species conservation: The case of the greater flamingo in the Mediterranean and West Africa

The conservation of many species depends on sustainable economic activities that shape their habitats. The economic use of these anthropogenic habitats may change quickly owing to world trade globalization, market reorientations, price volatility or shifts in subsidy policies. The recent financial crisis has produced a global impact on the world economy. How this may have affected the use of habitats beneficial to biodiversity has not yet been documented. However, consequences could be particularly acute for species sensitive to climate change, jeopardizing long-term conservation efforts.

Experience‐dependent natal philopatry of breeding greater flamingos

1. Contrary to the generally high level of natal philopatry (i.e. likelihood that individuals breed at their natal colony) found in first-breeding colonial birds, little is known of natal philopatry later in life. Most hypotheses advanced to explain natal philopatry are valid at all ages. However, for young and inexperienced birds, the benefits of natal philopatry may be counterbalanced by the costs of intraspecific competition at the natal colony making dispersal temporarily advantageous. In turn, experience may increase competitive ability and make natal philopatry advantageous again. 2. We evaluated this hypothesis on the large-scale dispersal of greater flamingos Phoenicopterus roseus breeding among three colonies comprising >85% of the Western Mediterranean metapopulation. The Camargue (France) and Fuente de Piedra (Spain) are large and saturated colonies while Molentargius (Sardinia) is a recent and growing colony. 3. We used a 20-year capture-mark-resighting dataset of 4900 flamingos ringed as chicks in Camargue and Fuente de Piedra and breeding at the three colonies. We assessed the effects of natal colony and breeding experience (first-time observed breeders versus confirmed experienced breeders) on dispersal using multistate capture-recapture models. Dispersal to an unobservable state accounted for temporary emigration. 4. Fidelity was higher at the natal colony (>84%) than elsewhere. Fidelity increased with experience in the two large colonies (Camargue and Fuente de Piedra) suggesting a large-scale experience-related despotic distribution. Breeding dispersal was significant (up to 61% and 52% for first-time breeders and experienced breeders, respectively) so that colony dynamics is affected by exchanges with other colonies. Except for Fuente-born breeders leaving Molentargius, dispersal to the natal colony was higher than to any other colonies. 5. Survival was not higher at the natal colony. Inexperienced birds likely had lower breeding success at the Camargue and skipped reproduction after having emigrated to the other large colony but not to Molentargius. Breeding at Molentargius could allow avoiding queuing (and non-breeding) at the large colonies while gaining experience and competitive ability for future attempts. 6 Natal philopatry appears as an important driver of large-scale breeding dispersal in the Greater flamingo. The fitness advantage of natal philopatry is likely experience-dependent and mediated by the variations of intraspecific competition.

Automatic Flamingo detection using a multiple birth and death process

Here we present a new approach to automatically detect and count breeding greater flamingos (Phoenicopterus Roseus) on aerial photographs of their colonies. We consider a stochastic approach based on object processes also called marked point processes. The objects represent flamingos which are defined as ellipses. We formulate a Gibbs density, associated with the marked point process of ellipses, which is defined w.r.t a Poisson measure. Thus, the issue is reduced to an energy minimization, where the energy is composed of a regularization term (prior density), which introduces some constraints on the objects and their interactions, and a data term, which links the objects to the features to be extracted in the image. Then, we sample the process to extract the configuration of objects minimizing the energy by a new and fast birth-and-death dynamics, leading to the total number of birds. This approach gives counts with good precision compared to manual counts. Additionally, this approach does not need image pre-processing or supervision of the extraction by an operator thus considerably reducing the overall processing time required to get the estimate.

Nest predation, temporal and spatial breeding strategy in the woodchat shrike Lanius senator in Mediterranean France

Abstract A low breeding success (36.5%) due primarily to nest predation by mammals, birds and reptiles has been found in the Woodchat Shrike Lanius senator at three study sites in Mediterranean France. Data collected for 3 years on natural and artificial nests showed no year, time, season or spatial effect on nest predation rate in this species. No particular spatial breeding strategy is used, breeding success being no better at any nest site currently used along roadsides or far from roads. With respect to nest predation pressures, the best breeding strategy for Woodchat Shrike should be to breed as early as possible at any suitable site within its territory. Nevertheless, the impact of high predation on the viability of the studied populations of this species cannot be fully explained by the large impact of habitat transformations (closure of open, bushy grasslands) on current day populations.

Range of the Greater Flamingo, Phoenicopterus roseus, metapopulation in the Mediterranean: new insights from Turkey

Metapopulation conservation should rely on a flyway approach aiming at assessing the spatial range of metapopulations by estimating the level of exchanges among local populations. In the western Mediterranean, Greater Flamingos have been shown to constitute a metapopulation with natal and breeding dispersal among colonies. In this paper, we examine whether this metapopulation reaches Turkey using a band-resighting study. Our results are the first evidence of natal and breeding dispersal from the western Mediterranean to Turkey, and suggest that the Gediz Delta, one of the two Turkish breeding colonies, can play a significant role in the recruitment of flamingos from the western Mediterranean. In 2003 and 2004, breeders of western Mediterranean origin accounted for more than 1.2 and 1.9% of the estimated breeding population of the Gediz Delta, respectively. Our observations also indicate that the western Mediterranean and Southwest Asia may constitute two sets of populations, which overlap in Turkey. Finally, the resightings of flamingos banded in Turkey show that post-fledging dispersal from Turkey reaches both the eastern and western Mediterranean wetlands. Future data on the natal and breeding dispersal of flamingos born in Turkey could clarify further the connection between Turkey and the western Mediterranean metapopulation.

Breeding Experience Might Be a Major Determinant of Breeding Probability in Long-Lived Species: The Case of the Greater Flamingo

The probability of breeding is known to increase with age early in life in many long-lived species. This increase may be due to experience accumulated through past breeding attempts. Recent methodological advances allowing accounting for unobserved breeding episodes, we analyzed the encounter histories of 14716 greater flamingos over 25 years to get a detailed picture of the interactions of age and experience. Survival did not improve with experience, seemingly ruling out the selection hypothesis. Breeding probability varied within three levels of experience : no breeding experience, 1 experience, 2+ experiences. We fitted models with and without among-individual differences in breeding probabilities by including or not an additive individual random effect. Including the individual random effect improved the model fit less than including experience but the best model retained both. However, because modeling individual heterogeneity by means of an additive static individual random effect is currently criticized and may not be appropriate, we discuss the results with and without random effect. Without random effect, breeding probability of inexperienced birds was always times lower than that of same age experienced birds, and breeding probability increased more with one additional experience than with one additional year of age. With random effects, the advantage of experience was unequivocal only after age 9 while in young having experience was penalizing. Another pattern, that breeding probability of birds with experiences dropped after some age (8 without random effect; up to 11 with it), may point to differences in the timing of reproductive senescence or to the existence of a sensitive period for acquiring behavioral skills. Overall, the role of experience appears strong in this long-lived species. We argue that overlooking the role of experience may hamper detection of trade-offs and assessment of individual heterogeneity. However, manipulative experiments are desirable to confirm our finding.