ROLES OF SURVIVAL AND DISPERSAL IN REINTRODUCTION SUCCESS OF GRIFFON VULTURE (<i>GYPS FULVUS</i>)

Gouar, P. Le; Robert, Alexandre; Choisy, Jean-Pierre; Henriquet, Sylvain; Lécuyer, Philippe; Tessier, C.; Sarrazin, François

doi:10.1890/07-0854.1

Cited by 92 publications

(113 citation statements)

References 68 publications

Supporting

Mentioning

109

Contrasting

Order By: Relevance

“…In any case, our results provide no support for a simple behavioural origin of the difference in body condition, as neither activity patterns nor diet differed between released and wild birds. Whatever determined body condition in surviving released birds studied, the poor condition apparently translated into low survival rates: Just like in many other studies of captive-reared animals (Brown et al 2006;Le Gouar et al 2008;Parish and Sotherton 2007), we found that survival in Mallards was extremely low after release into the wild. Models fitting best with our data suggest that survival of released Mallards during their first year in the wild was less than 0.04.…”

Section: Discussionsupporting

confidence: 75%

Low survival after release into the wild: assessing “the burden of captivity” on Mallard physiology and behaviour

Guillemain

Elmberg

et al. 2011

Eur J Wildl Res

View full text Add to dashboard Cite

Captive-reared animals used in reinforcement programs are generally less likely to survive than wild conspecifics. Digestion efficiency and naive behaviour are two likely reasons for this pattern. The Mallard is a species with high adaptability to its environment and in which massive reinforcement programs are carried out. We studied physiological and behavioural factors potentially affecting body condition and survival of captive-reared Mallards after being released. Digestive system morphology and an index of body condition were compared among three groups: captive-reared birds remaining in a farm (control), captive-reared birds released into the wild as juveniles (released) and wild-born birds (wild). We also compared behaviour and diet of released vs. wild Mallards. Finally, we conducted a 1-year survival analysis of captive-reared birds after release in a hunting-free area. Gizzard weight was lower in control Mallards, but the size of other organs did not differ between controls and wild birds. The difference in gizzard weight between released and wild birds disappeared after some time in the wild. Diet analyses suggest that released Mallards show a greater preference than wild for anthropogenic food (waste grain, bait). Despite similar time-budgets, released Mallards never attained the body condition of wild birds. As a consequence, survival probability in released Mallards was low, especially when food provisioning was stopped and during harsh winter periods. We argue that the low survival of released Mallards likely has a physiological rather than a behavioural (foraging) origin. In any case, extremely few released birds live long enough to potentially enter the breeding population, even without hunting. In the context of massive releases presently carried out for hunting purposes, our study indicates a low likelihood for genetic introgression by captive-reared birds into the wild population.

show abstract

Section: Discussionsupporting

confidence: 75%

Low survival after release into the wild: assessing “the burden of captivity” on Mallard physiology and behaviour

Guillemain

Elmberg

et al. 2011

Eur J Wildl Res

View full text Add to dashboard Cite

show abstract

“…This can be particularly relevant for the long term success of reintroduction projects of social birds (e.g. Berthold et al, 2000;Gouar et al, 2008;Schaub et al, 2004) and these interactions can be studied and scenarios tested with an IBM like Simsoar (Seddon et al, 2007). For anyone interested, the model code is available as supplement to this paper (see Appendix A).…”

mentioning

confidence: 99%

Understanding soaring bird migration through interactions and decisions at the individual level

Loon

Shamoun‐Baranes

Bouten

et al. 2011

Journal of Theoretical Biology

View full text Add to dashboard Cite

Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel networks is still very limited. To start investigating these aspects we developed an individual-based simulation model that describes the local interactions between birds and their environment during their migratory flight, leading to emergent patterns at larger scales. The aim of our model is to identify likely decision rules with respect to thermal selection and navigation.After explaining the model, it is applied to analyse the migration of white storks (Ciconia ciconia) over part of its migration domain. A model base-run is accompanied by a sensitivity analysis. It appears that social interactions lead to the use of fewer thermals and slight increases in distance travelled. Possibilities for different model extensions and further model application are discussed.

show abstract

“…Interactive parameters for the bird-and cohort-level random effects allow demographic variability to change as a function of time since release. This might be reflected as a short-term period of high population loss immediately after release, as has been observed in other populations of released birds (Sarrazin and Legendre 2000;Le Gouar et al 2008).…”

Section: Survival Estimationmentioning

confidence: 61%

Evaluating release alternatives for a long-lived bird species under uncertainty about long-term demographic rates

Moore

Converse²,

Folk

et al. 2010

J Ornithol

View full text Add to dashboard Cite

The release of animals to reestablish an extirpated population is a decision problem that is often attended by considerable uncertainty about the probability of success. Annual releases of captive-reared juvenile Whooping Cranes (Grus americana) were begun in 1993 in central Florida, USA, to establish a breeding, non-migratory population. Over a 12-year period, 286 birds were released, but by 2004, the introduced flock had produced only four wildfledged birds. Consequently, releases were halted over managers' concerns about the performance of the released flock and uncertainty about the efficacy of further releases. We used data on marked, released birds to develop predictive models for addressing whether releases should be resumed, and if so, under what schedule. To examine the outcome of different release scenarios, we simulated the survival and productivity of individual female birds under a baseline model that recognized age and breeding-class structure and which incorporated empirically estimated stochastic elements. As data on wild-fledged birds from captive-reared parents were sparse, a key uncertainty that confronts release decision-making is whether captive-reared birds and their offspring share the same vital rates. Therefore, we used data on the only population of wild Whooping Cranes in existence to construct two alternatives to the baseline model. The probability of population persistence was highly sensitive to the choice of these three models. Under the baseline model, extirpation of the population was nearly certain under any scenario of resumed releases. In contrast, the model based on estimates from wild birds projected a high probability of persistence under any release scenario, including cessation of releases. Therefore, belief in either of these models suggests that further releases are an ineffective use of resources. In the third model, which simulated a population Allee effect, population persistence was sensitive to the release decision: high persistence probability was achieved only through the release of more birds, whereas extirpation was highly probable with cessation of releases. Despite substantial investment of time and effort in the release program, evidence collected to date does not favor one model over another; therefore, any decision about further releases must be made under considerable biological uncertainty. However, given an assignment of credibility weight to each model, a best, informed decision about releases can be made under uncertainty. Furthermore, if managers can periodically revisit the release decision and collect monitoring data to further inform the models, then managers have a basis for confronting uncertainty and adaptively managing releases through time.

show abstract

ROLES OF SURVIVAL AND DISPERSAL IN REINTRODUCTION SUCCESS OF GRIFFON VULTURE (GYPS FULVUS)

Cited by 92 publications

References 68 publications

Low survival after release into the wild: assessing “the burden of captivity” on Mallard physiology and behaviour

Low survival after release into the wild: assessing “the burden of captivity” on Mallard physiology and behaviour

Understanding soaring bird migration through interactions and decisions at the individual level

Evaluating release alternatives for a long-lived bird species under uncertainty about long-term demographic rates

Contact Info

Product

Resources

About