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Effective Conservation Measures (effective + conservation_measure)
Selected AbstractsBreeding biology and success of the Bearded Vulture Gypaetus barbatus in the eastern PyreneesIBIS, Issue 2 2003Antoni Margalida We present data from an extensive study of Bearded Vulture Gypaetus barbatus breeding biology in the Pyrenees from 1992 to 1999. Average laying date was 6 January (range 11 December to 12 February, n = 69) with no significant differences between years. Eighty per cent of clutches were of two eggs (n = 20) and average incubation was 54 days (range 52,56, n = 14). Hatching occurred on average between 21 February and 3 March (range 5 February,7 April) and the first and last chicks fledged in 21,27 May and 20 July, respectively. The average chick age at fledging was 123 days (range 103,133, n = 20). Bearded Vulture density increased significantly during the study period. Breeding success and productivity declined apparently as a consequence of the increase in the percentage of breeding failures during incubation and chick rearing, most during the hatching period. The factors that may determine breeding failure and the decline in breeding performance are analysed and management recommendations for more effective conservation measures are discussed. [source] Combined effects of fisheries and climate on a migratory long-lived marine predatorJOURNAL OF APPLIED ECOLOGY, Issue 1 2008V. Rolland Summary 1The impact of climate on marine ecosystems is now well documented, but remains complex. Climate change may interact with human activities to effect population dynamics. In addition, in migratory species conditions are different between the breeding and wintering grounds, resulting in more complex dynamics. All these possible effects should be considered to predict the future of endangered species, but very few studies have investigated such combined interactions. 2As a case study, we assessed the relative impact of fisheries and of oceanographic conditions in breeding and wintering sites on adult survival and breeding success of a population of the endangered black-browed albatross Thalassarche melanophrys in the Kerguelen Islands, Southern Indian Ocean. This study was based on long-term monitoring of individually marked individuals (1979,2005) and identification by tracking studies and band recoveries of the oceanic feeding zones used during breeding and non-breeding seasons. 3Breeding success was variable until 1997 and then declined gradually, from 0·88 to 0·48 chicks per egg laid. It was favoured by positive sea-surface temperature anomalies (SSTA) and trawl fishery during the breeding period, whereas it was negatively affected by positive SSTA around Tasmania, where the species winters. Adult survival was 0·918 ± 0·004 on average and increased with SSTA during incubation, but decreased significantly with high tuna longlining effort in the wintering zone. 4Our analyses show that demographic parameters were influenced by both climate and fisheries in both breeding and wintering grounds, but with different effect size. Black-browed albatross breeding success was more favoured by trawlers' offal and discards than by any of the seasonally/spatially oceanographic conditions, whereas their survival was equally affected by tuna longline fishery through incidental by-catch and spring SSTA. 5Synthesis and applications. Our work underlines that a comprehensive knowledge of the life history of a species in all the habitats used is important to disentangle the respective roles of environmental conditions and human factors on population dynamics. Identification of these effects is required when proposing effective conservation measures, because the conservation of threatened species may depend on their wintering country's exclusive economic zones. [source] Conservation ecology of Primula sieboldii: Synthesis of information toward the prediction of the genetic/demographic fate of a populationPLANT SPECIES BIOLOGY, Issue 1 2005IZUMI WASHITANI Abstract In an age of deepening biodiversity crisis, plant species biological studies integrating ecological and genetic approaches, especially exhaustive studies with a model plant species, are urgently needed for both assessing the present status and implementing effective conservation measures, as a comprehensive understanding of demographic/genetic interactions involved in the vicious cycle of plant population extinction is a prerequisite for any precise prediction regarding plant conservation. In this article, we summarize the major contributions to conservation ecological studies on a heterostylous clonal herb Primula sieboldii, focusing on gene flow and reproductive success, which are dependent on the life-history traits of the species and biological interactions with its effective pollinators, long-tongued bumblebees. [source] Comparisons of age, growth, and maturity between male and female, and diploid and triploid individuals in Carassius auratus from Okinawa-jima Island, JapanAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 7 2009Mikumi Takada Abstract 1.Carassius auratus, a primary freshwater fish with bisexual diploid and unisexual gynogenetic triploid lineages, is distributed widely in and around the Eurasian continent and is especially common in East Asia. East Asian C. auratus diverged genetically to form local endemic populations in different regions, and those distributed in the Ryukyu Archipelago form a local endemic population that can be regarded as an evolutionarily significant unit because of its high phylogenetic independence and evolutionary distinctiveness. Although the evolutionary uniqueness of this population should be conserved, its distribution area and population size are decreasing rapidly, and some island populations are currently considered endangered or already extinct. 2.To develop effective conservation measures to stop the current decline of Ryukyuan C. auratus, ecological data need to be collected. In this study, life history data for a C. auratus population distributed in the Hiji River system were collected by estimating age, growth, and spawning season. 3.The spawning season of C. auratus in the Hiji River extended from March to September, peaking during March,May. Females became sexually mature in their second year, but males reached maturity and were able to spawn as early as in the late spawning season of their year of hatching. Once having reached sexual maturity, males probably continuously stay ripe throughout their life. 4.Sagittal otoliths of C. auratus proved to be useful ageing structures because one annual increment is formed on the sagittal otolith before the spawning season in each year. The oldest fish observed were a 10-year-old female and an 11-year-old male. Females showed faster somatic growth and higher final standard length than males, and a sexual size dimorphism was observed. 5.The standard length at each age class did not differ between diploid and triploid C. auratus, suggesting that triploid growth rates were almost equal to those of diploids. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||