Papers by Jean-Dominique Lebreton
Euro courses, 1991
Empirical studies of Structure - Activity Relationships (SAR, see, e.g., Dore and Miquel, 1981, D... more Empirical studies of Structure - Activity Relationships (SAR, see, e.g., Dore and Miquel, 1981, Devillers and Karcher, 1990) and of Species - Environment Relationships (SER, see, e.g., Lebreton and Yoccoz, 1987, Jongman et al., 1987) share several striking characteristics. In both cases, one wishes to link the information in a first table X1 (Activity data, Species data) to the information in a second table X2 (Structure, Environment) obtained on the same statistical units as X1. X2 is supposed to influence X1. As a consequence any statistical approach should take account of this fundamental dissymmetry and should attempt to predict features in X1 from features in X2.
Les etudes de la biodiversite, qui recoupent l’ensemble de l’ecologie scientifique, font largemen... more Les etudes de la biodiversite, qui recoupent l’ensemble de l’ecologie scientifique, font largement appel a des approches quantitatives tres variees, souvent completement integrees aux problematiques de recherche, tant fondamentale qu’appliquee. La bioinformatique et la biomathematique de la biodiversite s’inserent donc dans une ingenierie de l’ecologie en plein developpement. Cet article propose un tour d’horizon de ces approches quantitatives a l’intention des ingenieurs, en s’appuyant sur les niveaux traditionnels d’organisation des systemes ecologiques: populations, communautes, ecosystemes.
The Black-headed Gull population of the Forez (central France), under study since 1976, is remark... more The Black-headed Gull population of the Forez (central France), under study since 1976, is remarkably stable. This stability, or slow growth at the very most, implies a change in some demographic parameters of the population. Indeed, large differences in breeding success were found between colonies established on traditional sites, successfully occupied year after year (where breeding success is high), and those established on sites that are occupied discontinuously (where breeding success is low). Such differences suggest that the gull population has reached saturation at the best sites. Most of our work was carried out in one of the traditional colonies (with more than 2 000 breeding pairs). Here, the saturation hypothesis is supported by the strong competition taking place for nest sites, which leads the younger breeders to make use of nest sites low over water, therefore highly vulnerable to wave action, and to variations of water level. A study of mortality and recruitment, using a capture-resighting technique, provided a more direct evidence of population saturation on this colony : full breeding was only reached at five years of age. But the strongest evidence of density-dependence in recruitment is brought forward by the estimation of the proportion of birds locally recruited is each cohort : this proportion varies inversely with the initial fecundity of the cohort. Only a limited number of breeders can therefore be recruited each year in this colony. A density-dependent population model confirms that density-dependence is strong enough to induce a stabilization in numbers of the colony members. Theoretical and practical consequences of this mode of population regulation are discussed.
HAL (Le Centre pour la Communication Scientifique Directe), 2013
International audienc
HAL (Le Centre pour la Communication Scientifique Directe), 1987
David Lack soulignait en 1954 la remarquable stabilité des populations d'oiseaux en comparant les... more David Lack soulignait en 1954 la remarquable stabilité des populations d'oiseaux en comparant les fluctuations de leurs effectifs à la houle sur la sur face de l'océan. Cette stabilité suppose que des régulations viennent déprimer certains paramètres démographiques lorsque les effectifs augmentent (« Dépen dances de la densité »). Si l'existence de telles régulations n'est plus guère mise en doute (voir par exemple Royama, 1977, pour une discussion complète), leur nature reste mal connue : quels sont les paramètres démographiques sur les quels les variations d'effectifs vont faire sentir leurs effets ? par quels mécanis mes biologiques (raréfaction de la nourriture hivernale, raréfaction des sites de nid ... ) ? Ces questions , très largement discutées dans les années soixante .. ) restent d'actualité et constituent un problème central en écologie fonctionnelle. On attachera un intérêt tout particulier à la résistance à des perturbations, permanentes (rési lience) ou temporaires (stabilité) , d'une population dont la régulation s'effectue par l'intermédiaire de tel ou tel paramètre. Alors qu'on a cru dans le passé pouvoir comprendre les phénomènes de fluctuation et de régulation par de simples analyses des recensements successifs (voir un ex . dans Krebs, 1970), la faillite de ces méthodes Ebe rhardt , 1970 ; lto, 1972 ... ) amène à privilégier l'analyse des paramètres démographiques par rapport à celle des effectifs . L'étude de la dynamique de la population forézienne de Mouette rieuse Larus ridibundus s'efforce ainsi, parallèlement à un constat de stabilité ou de faible croissance des effectifs , de comprendre par une analyse des paramètres démographiques, comment s'effectue la régulation des effectifs. Le présent article vise à dresser un deuxième tableau d'ensemble de nos résultats, après dix ans d'étude, en affinant ou en éprouvant les hypothèses d'un précédent bilan . L'accent sera mis en conclusion sur les conséquences de la régulation sur la résilience des effectifs . Des résultats plus classiques de biologie de population ont été publiés par ailleurs . Le Forez, bassin d'effondrement traversé par la Loire, à 60 km à l'Ouest de Lyon (France), abrite la nidification de la Mouette rieuse depuis le XIX• siè cle au moins (Le breton, 1981, p. 89). Une description générale de la région est donnée par ) (voir également Lebreton, 1981). Cette population de Mouette rieuse est tout à fait représentative des populations de Rev. Eco!. (Terre Vie), Suppl. 4, 1987 .
Revue D Ecologie-la Terre Et La Vie, 1980
L'évaluation quantitative des populations animales dans la nature est une diffi culté réelle, que... more L'évaluation quantitative des populations animales dans la nature est une diffi culté réelle, quelles que soient les espèces concernées. Le problème a souvent été résolu partiellement par des méthodes de capture-recapture ou par des dénombrements relatifs qui permettent au moins de mesurer les fluctuations d'abondance (Blondel, 1969 ; Seber, 1972). Les dénombrements absolus (exhaustifs) sont beaucoup plus rares et portent générale ment sur des espèces grégaires : oiseaux coloniaux pendant la période de reproduction, canards en période hivernale, etc. Ils offrent l'avantage de mesurer l'importance réelle des effectifs présents sur un milieu donné (donc de définir sa capacité d'accueil) et permettent de suivre dans le temps l'évolution de ces effectifs. Ces dénombrements, qui portent sur des rassemblements pouvant aller jusqu'à plusieurs dizaines de milliers d'individus, sont effec tués soit par des procédés photographiques (Grzymeck et Grzy meck, 1960 ; Boyd, 1961 ; Goethe, 1961), soit par des estimations visuelles de la taille des groupes (observations au sol, en bateau, en avion, etc.), soit le plus souvent par une combinaison de ces moyens. Dans tous les cas, les risques d'erreur sont grands : cou verture photographique incomplète (\Vatson, 1969) , erreur de lecture sur la photo (Sinclair, 1973 ; Harris et Lloyd, 1977) , erreur dans l'estimation visuelle (Matthews, 1960 ; Joensen, 1974). La précision de la mesure n'a été recherchée de manière élaborée que dans très peu de cas : essentiellement par Jolly (1969) pour répondre à des problèmes théoriques d'échantillonnage, par Cau ghley et Goddard (1972) pour évaluer des effectifs totaux à partir de plusieurs dénombrements successifs et sous-estimés, et par
Ecological Modelling, Oct 1, 2005
The earliest matrix models, proposed in the 1940s, consider age classes, and were later proved to... more The earliest matrix models, proposed in the 1940s, consider age classes, and were later proved to be equivalent to the discrete time version of the stable population theory. In this theory and models, besides the asymptotic growth rate, a very important characteristic is the turnover of individuals, measured in various ways by generation time. Models considering stages, on the contrary, do not take into account the age of individuals and seem largely preferable to age-structured models for many populations in which demographic characteristics are related to biological stages (such a seed, rosette, flowering plant, etc.) rather than to age per itself. These two kinds of models can be embedded as particular cases of stage by age models or multistate models. Theses general models can be used to develop a multistate stable population theory with many advantages. This general theory is reviewed with emphasis on general rules for sensitivity analyses in which generation time plays a central role.
Oikos, Jul 1, 1981
... Breeding avifauna of a Mediterranean succes-sion: the holm oak and cork oak series in the eas... more ... Breeding avifauna of a Mediterranean succes-sion: the holm oak and cork oak series in the eastern Pyrenees, 1. Analysis ... pastoral secondary successions (Ken-deigh 1948, Odum 1950, Johnston and Odum 1956), secondary regeneration successions after fire (Haapa-nen ...
La Terre et La Vie, Revue d'Histoire naturelle, 1976
HAL (Le Centre pour la Communication Scientifique Directe), Oct 18, 2018
Blog RO7 de la SFE
When population mortality outweighs fertility rates, the long-term survival of the population is ... more When population mortality outweighs fertility rates, the long-term survival of the population is not sustainable, resulting in species extinction. Given the current extinction crisis there is an urgent need to maximize the effectiveness of conservation management programs. For many such strategies, well-informed demographic models provide rigorous predictions of population fate, which can be critical for successful conservation. However, the accuracy of these models hinges on the availability of demographic data. Despite the importance of demographic data to inform management of threatened species, there has been no global assessment of demographic information available. We standardized the taxonomy and terms describing traits across 24 databases on demography and/or with demographic life history traits. We developed a Demographic Index of Species Knowledge (DISKo) that shows data availability for fertility and survival, which are the essential data to understand population dynamics...
Population models for Greater Snow Geese: a comparison of different approaches to assess potentia... more Population models for Greater Snow Geese: a comparison of different approaches to assess potential impacts of harvest.-Demographic models, which are a natural extension of capture-recapture (CR) methodology, are a powerful tool to guide decisions when managing wildlife populations. We compare three different modelling approaches to evaluate the effect of increased harvest on the population growth of Greater Snow Geese (Chen caerulescens atlantica). Our first approach is a traditional matrix model where survival was reduced to simulate increased harvest. We included environmental stochasticity in the matrix projection model by simulating good, average, and bad years to account for the large inter-annual variation in fecundity and first-year survival, a common feature of birds nesting in the Arctic. Our second approach is based on the elasticity (or relative sensitivity) of population growth rate (lambda) to changes in survival as simple functions of generation time. Generation time was obtained from the mean transition matrix based on the observed proportion of good, average and bad years between 1985 and 1998. If we assume that hunting mortality is additive to natural mortality, then a simple formula predicts changes in lambda as a function of changes in harvest rate. This second approach can be viewed as a simplification of the matrix model because it uses formal sensitivity results derived from population projection. Our third, and potentially more powerful approach, uses the Kalman Filter to combine information on demographic parameters, i.e. the population mechanisms summarized in a transition matrix model, and the census information (i.e. annual survey) within an overall Gaussian likelihood. The advantage of this approach is that it minimizes process and measured uncertainties associated with both the census and demographic parameters based on the variance of each estimate. This third approach, in contrast to the second, can be viewed as an extension of the matrix model, by combining its results with the independent census information.
Wildlife Research, 2011
Context Monitoring the status of albatross populations and identifying the factors driving observ... more Context Monitoring the status of albatross populations and identifying the factors driving observed trends remain international conservation and management priorities. The shy albatross is endemic to Australia and breeds only on three Tasmanian islands. Aims To provide a reliable total population estimate for shy albatross, including an assessment of demographic trends for each of the three populations where possible. We consider also key drivers of population trends for each population, particularly the potential role of fisheries by-catch, with an overall aim of determining the status of the species. Methods Aerial photography and ground surveys were used to estimate the number of annual breeding pairs and trends in adult and juvenile survival rates were calculated using mark–recapture methods. At-sea distribution data was used to identify population specific trends in the overlap of shy albatross and fisheries to evaluate the potential influence of fisheries by-catch on the popul...
Theoretical Population Biology, 1996
, in two neglected papers, have generalized to the multisite case the Euler Lotka renewal equatio... more , in two neglected papers, have generalized to the multisite case the Euler Lotka renewal equation and demographic characteristics such as age structure and reproductive value. The purpose of this paper is twofold: first, to restate the multisite renewal equation in the matrix context; second, to derive results on age structure, net reproduction rate, generation time, and sensitivities, as generalizations of the one site case. The potential of this approach for population biology is illustrated using a model of a black-headed gull Larus ridibundus population.
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Papers by Jean-Dominique Lebreton