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Assessing the sustainability of European Turtle dove hunting along the European western flyway

Assessing the sustainability of European Turtle dove hunting along the European western flyway. François Sabathé. Hervé LORMÉE 1 , Lara MORENO 2 , Carles CARBONERAS 3 , Will PEACH 3 , Christophe BARBRAUD 4 & Cyril ÉRAUD 1

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Assessing the sustainability of European Turtle dove hunting along the European western flyway

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  1. Assessing the sustainability of European Turtle dove hunting along the European western flyway François Sabathé Hervé LORMÉE1, Lara MORENO2, Carles CARBONERAS3, Will PEACH3, Christophe BARBRAUD4 &Cyril ÉRAUD1 1 Office National de la Chasse & de la Faune Sauvage - France2 Instituto de Investigacion en Recursos Cinegéticos - Spain3 Royal Society for Protection of Birds – United Kingdom4 Centre d’Etudes Biologiques de Chizé – Centre National de la Recherche Scientifique - France

  2. Main question: is mortality associated to hunt sustainable? are populations under concern overharvested? Hunting and population viability Legal hunting 11 European countries 4 in western flyway: France, Spain, Portugal and Italy (partly) Hunting pressure described as generally high (Boutin et al. 2001) but no attempt to quantify this pressure

  3. Carry out hunting of the European Turtle-dove at locally and internationally sustainable levels Objectives: 1 – Estimate a maximum harvestable fraction (P) of the turtle dove population using the western flyway: By using a relevant method for species where demographic data are incomplete Calculation of P according to a wide range of demographic scenario, from most pessimistic (for species) to most optimist 2 – Detect if overharvest occurs: By comparing harvest levels and assessment of theoretical maximum sustainable harvest level

  4. David Iliff Fishtechmarine.com HBW alive Graham Robertson How to detect overharvested bird populations when demographic information is incomplete? Step 1: Calculation of the maximum growth rate (λmax) that a population/speciescouldachieve, in the absence of any additive mortality Demographic Invariant Method (DIM) (Niel & Lebreton 2005) Estimate potential maximum annual growth rate (λmax)of a species from incomplete demographic information λmax= exp([a + So/(λmax – So)]-1) a average age at 1st reproduction So adult survival rate Niel, C., Lebreton, J.-D., 2005. Using demographic invariants to detect overharvested bird populations from incomplete data. Conservation Biology 19, 826–835.

  5. Wade, P.R., 1998. Calculating limits to the allowable human- How to detect overharvested bird populations when demographic information is incomplete? Step 2: Calculation of the maximum harvestable fraction (P) Tom Campbell P (Potential maximal harvestable population fraction)(Wade et al. 1998) caused mortality of cetaceans and pinnipeds. Marine Mammal P= Nb(λmax – 1) N total population size (before hunting starts) b correction factor (accounting for density effect on demographic performance) λmax Maximum growth rate Wade, P.R., 1998. Calculating limits to the allowable human- caused mortality of cetaceans and pinnipeds. Marine Mammal. Science 14, 1–37. Science 14, 1–37

  6. The turtle dove western flyway Two alternative scenarios: including/excluding Northern Italy Breeding populations under concern:Belgium Denmark France Germany Italy* Netherlands Portugal Spain Switzerland United kingdom European countries hunting turtle doves France Italy* Portugal Spain

  7. Luc Tison Three alternative estimates of So:: Low0.593 λmax= 2.03 medium 0.623λmax= 1.98 High 0.748λmax= 1.79 Calculation of λmax λmax = exp([a + So/(λmax – So)]-1) a: 100% of birds breeding at one year of age So: range of adult survival rate from low to high

  8. Calculation of Potential maximal harvestable population fraction P = Nb(λmax – 1) N = [ (number of breeding pairs  2) + number of juveniles ] in 2013 Number of breeding pairs: Most recent population sizes (lower & upper range) for each country, corrected by the yearly multiplicative trend slope to obtain a 2013 population size. Number of juveniles: fecundity(*)  nb of breeding pairs (low and high values) (*) fecundity = number of flying juveniles per pair per year b: safety factor set to 0.1 as recommended for threatened species (Dillingham & Fletcher 2008)

  9. Hunting bags over the western European flyway Most recent statistics available: COUNTRY Hunting bag Period & source France:91 704 2013-2014 hunting season – Aubry et al. 2016 Portugal: 109 815 2013-2014 hunting season – ICNF in Fisher et al 2017 Italy: 305 590 ~ 2004-2014 annual average – Sorrenti & tramontana 2016 Spain: 824 369 2013-2014 hunting season – Moreno et al.2017 TOTAL with northern Italy (18.6% of national hunting bag): 1 125 033 TOTAL without northern Italy:1 068 494 * Aubry, P., Anstett L., Ferrand, Y., Reitz, F., Ruette, S., Sarasa, M., Arnauduc, J.-P. & Migot, P. (2016). Enquête nationale sur les tableaux de chasse à tir. Saison 2013-2014 - Résultats nationaux. Faune Sauvage 310, supplément central. 8 p. * Fischer, I., Ashpole, J., Scallan, D., Carboneras, C. & Proud T. (in press). International Single Species Action Plan for the Conservation of the European Turtle-dove Streptopeliaturtur (2018 to 2028) * Sorrenti, M. & Tramontana, D. (2016) Estimate of turtle-dove Streptopeliaturtur harvest in Italy. FederazioneItalianadellaCaccia – Ufficio Avifauna Migratoria * Moreno, L., Peach, W. & Arroyo, B. (2017). Do hunting bag changes match the population trends of Turtle Dove? The case of Spain. Pp. xx-yy in E. Bro & M. Guillemain (eds.) 33rd IUGB Congress & 14th Perdix Symposium abstract book. ONCFS, Paris.

  10. Scenarios considered for Calculation of P P calculated for lower and upper range of turtle dove population size overharvest No overharvest  Hunting bags always exceed P for lower range values of population size  For upper range values of P, hunting bag is below P (no more than 15%) in only 4 scenario where both productivity and λmax are at maximum levels

  11. Conclusion  This approach:  Is still likely to underestimates total harvest as: - some hunting bag data are lacking - hunting bags realized in Africa during wintering are not known - Crippling losses are not taken into account  High uncertainty associated with demographic parameters so there is an urgent need to use more detailed and updated value of demographic paramaters (f, So), and more frequent and complete hunting bag statistics Should take into account age structure of hunting bag as additive mortality may depend upon the juvenile/ratio into harvest

  12. Updated abundance and hunting estimates in Spain Trebol-a Beatriz ARROYO1, Lara MORENO1 , Alba ESTRADA1 ,José JIMENEZ GARCIA-HERRERA1 &Will PEACH2 1 Instituto de Investigacion en Recursos Cinegéticos - Spain2 Royal Society for Protection of Birds – United Kingdom

  13. Importance of Spain in the western flyway 1 – Largest breeding population size 2 – Largest hunting bags Objectives: More precise estimation of abundance Complete and assess hunting bags Relationship between hunting bags and hunting policy

  14. A Turtle dove abundance Analyses of SACRE data Taking into account detectability through repeated visits and N-mix models Taking into account spatial variation in environmental favourability for the species 2013 population: 1 135 526 (1 014 658 – 1 322 037) (lower than Herve´s calculations)

  15. Turtle dove hunting bags Controlling for missing data and underreporting Contacting directly provincial representatives (and hunting state reports) 2013-14 hunting season: 888 306 (higher than Herve´s calculations)

  16. Hunting bags and policy Variation of annual bags in each region in relation to policy (implementation of quotas, total number of hunting days in the season, etc))

  17. Conclusion Results of previous approach conservative: - abundance data lower and hunting bags higher than values used  High uncertainty about which measure would lead to a strong-enough reduction of hunting bags in Spain.

  18. Thanks for your attention!

  19. A recent change in conservation status  WorlRed List 2015 : movedfrom « LEAST CONCERN » to « VULNERABLE » http://www.iucnredlist.org/details/22690419/0  EuropeanRed List 2015: « VULNERABLE » http://datazone.birdlife.org/userfiles/file/Species/erlob/summarypdfs/22690419_streptopelia_turtur.pdf « Declinemoderatelyrapid »  30% in 15.9 ans (3 generations)  Near Threatened « Rapid Decline »  30-49% in 15.9 ans (3 generations)  Vulnerable

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