Pathogens pose a major risk to wild host populations, especially in the face of ongoing biodiversity declines. Beak and feather disease virus (BFDV) can affect most if not all members of one of the largest and most threatened bird orders world-wide, the Psittaciformes. Signs of disease can be severe and mortality rates high. Its broad host range makes it a risk to threatened species in particular, because infection can occur via spill-over from abundant hosts. Despite these risks, surveillance of BFDV in locally abundant wild host species has been lacking. We used qPCR and haemagglutination assays to investigate BFDV prevalence, load and shedding in seven abundant host species in the wild in south-east Australia: Crimson Rosellas (Platycercus elegans), Eastern Rosellas (Platycercus eximius), Galahs (Eolophus roseicapillus), Sulphur-crested Cockatoos (Cacatua galerita), Blue-winged Parrots (Neophema chrysostoma), Rainbow Lorikeets (Trichoglossus moluccanus) and Red-rumped Parrots (Psephotus haematonotus). We found BFDV infection in clinically normal birds in six of the seven species sampled. We focused our analysis on the four most commonly caught species, namely Crimson Rosellas (BFDV prevalence in blood samples: 41.8%), Sulphur-crested Cockatoos (20.0%), Blue-winged Parrots (11.8%) and Galahs (8.8%). Species, but not sex, was a significant predictor for BFDV prevalence and load. 56.1% of BFDV positive individuals were excreting BFDV antigen into their feathers, indicative of active viral replication with shedding. Being BFDV positive in blood samples predicted shedding in Crimson Rosellas. Our study confirms that BFDV is endemic in our study region, and can inform targeted disease management by providing comparative data on interspecies variation in virus prevalence, load and shedding.

病原体对野生寄主种群构成重大风险，尤其是在生物多样性持续下降的情况下。喙和羽毛病病毒（BFDV）可以影响全世界最大和最受威胁的鸟类之一Psittaciformes的大多数成员，即使不是所有成员。疾病迹象可能很严重，死亡率很高。它的寄主范围广，尤其是对濒临灭绝物种的威胁，因为感染可能通过大量寄主的溢出而发生。尽管存在这些风险，但仍缺乏对本地丰富的野生寄主物种中BFDV的监测。我们使用qPCR和血凝试验检测了澳大利亚东南部野生地区的7种丰富寄主物种中BFDV的流行，负载和脱落情况：深红Rosellas（Platetycuscus elegans），Eastern Rosellas（Platycercus eximius）），加拉（Eolophus roseicapillus），有硫的美冠鹦鹉（Cacatua galerita），蓝翅​​鹦鹉（Neophema chrysostoma），彩虹鹦鹉（Trichoglossus moluccanus）和红腰鹦鹉（Psephotus haematonotus）。我们在采样的七个物种中的六个物种中，在临床正常鸟类中发现了BFDV感染。我们将分析重点放在四种最常见的物种上，即深红Rosellas（血样中BFDV的患病率：41.8％），有硫的凤头鹦鹉（20.0％），蓝翅鹦鹉（11.8％）和Galahs（8.8％）。物种而非性别是BFDV患病率和负荷的重要预测指标。BFDV阳性个体中有56.1％正在将BFDV抗原排泄到他们的羽毛中，表明病毒活跃复制并脱落。血液样本中BFDV呈阳性可预测绯红色Rosellas脱落。我们的研究证实了BFDV在我们的研究区域是地方性的，并且可以通过提供有关病毒流行率，负荷和脱落的种间差异的比较数据来为目标疾病管理提供信息。