1. As the proportion of threatened species increases, so too does the need for effective conservation strategies. In response, captive breed-and-release and habitat mitigation programmes are two conservation actions that are increasing in use and effectiveness.
2. Success of these programmes is frequently hampered by the continued presence of threatening processes. In the case of amphibian reintroductions, a key threatening process that is difficult to eliminate is the deadly fungal pathogen, Batrachochytrium dendrobatidis (Bd). This pathogen is the proximate cause of decline for the threatened green and golden bell frog, Litoria aurea, and has contributed to the failure of previous breed-and-release programmes of this amphibian.
3. To investigate whether is it possible to establish a captive-bred population of L. aurea that could persist in the presence of Bd, a breed-and-release programme was conducted in a created habitat that included increased salinity to inhibit fungal growth rates, exclusion of potential reservoir hosts and source animals bred from parents ‘experienced’ with the strain of Bd present in the release environment.
4. The population persisted in the created habitat for more than 4 years (the timescale of monitoring) but suffered higher infection levels compared with nearby extant populations of L. aurea. These infections significantly reduced apparent survival. Infection dynamics were linked to temperature, host density in the previous season, and size and age of the host, and these factors differed from those in extant populations and are likely to have contributed to the high levels of Bd infection at the created site.
5. This article discusses how it may be possible to manipulate these factors to improve the success of future breed-and-release programmes, and recommends the construction of warm water bodies and a strategy of prioritizing the release of fewer, large propagules of high body condition and mixed-age class, over large numbers of younger, smaller animals.

中文翻译：

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面对威胁性病原体 Batrachochytrium dendrobatidis 改进繁殖和释放计划

1. 随着受威胁物种比例的增加，对有效保护策略的需求也在增加。作为回应，圈养繁殖和释放和栖息地缓解计划是两种使用和有效性不断提高的保护行动。
2. 这些计划的成功经常受到威胁进程的持续存在的阻碍。在两栖动物重新引入的情况下，一个难以消除的关键威胁过程是致命的真菌病原体Batrachochytrium dendrobatidis (Bd)。这种病原体是濒临灭绝的绿色和金铃蛙Litoria aurea数量减少的直接原因，也是导致这种两栖动物先前繁殖和释放计划失败的原因。
3. 为了调查是否有可能建立一个可以在 Bd 存在下持续存在的L. aurea人工繁殖种群，在创造的栖息地中进行了繁殖和释放计划，该计划包括增加盐度以抑制真菌生长速度，排除潜在的宿主和来源动物的父母“经历”了释放环境中存在的 Bd 菌株。
4. 种群在创造的栖息地中持续了 4 年以上（监测的时间尺度），但与附近现存的金黄色葡萄球菌种群相比，其感染水平更高。这些感染显着降低了表观存活率。感染动态与温度、上一季的宿主密度以及宿主的大小和年龄有关，这些因素与现存种群中的因素不同，可能是造成创建地点高水平 Bd 感染的原因。
5. 本文讨论了如何可能操纵这些因素以提高未来繁殖和释放计划的成功率，并建议建造温水体和优先释放数量较少、体型高的大型繁殖体和混合年龄类，在大量更年轻、更小的动物上。