我需要供认。

Fleas were not my favorite parasites by far. When the phone was ringing some ten years ago and questions about fleas kept coming – I was not amused. Why?

这些问题很简单，只是问“这些天狗和猫的跳蚤是什么？”。在澳大利亚悉尼大学拥有兽医寄生虫学家的头衔，我感到有义务做出回应。所以我做了。这是猫跳蚤– was my answer.

十年前，有人想到，狗和猫的跳蚤被新的超级跳蚤取代。我们很快通过从澳大利亚各地收集2500种跳蚤来驳斥了这个想法，并确认我们所拥有的本质上是猫跳蚤。毫不奇怪，我感到有证明，跳蚤不会成为我最喜欢的寄生虫。

Little did I know, that I was so wrong.

Cat fleas in Australia follow our lead

Over the past 10 years we have established that Australia has three distinct variants of the cat flea. To keep it simple we call them Sydney, Cairns and Darwin. We borrowed the names from the cities we first came across these fleas.

澳大利亚人口为2500万，居住在更大的城市中，有66％的人口。如果您看一下澳大利亚的地理，您不应该惊讶地看到85％的海岸线以内的85％。Australian Bureau of Statistics。Most of the interior is arid. But why am I telling you that?

猫跳蚤不喜欢沙漠。猫跳蚤将是我们所在的地方，因为它们喜欢我们的狗和猫。猫跳蚤的变体 - 悉尼，凯恩斯和达尔文 - 由DNA签名确定。

The Sydney variant appeared to be pretty much everywhere we looked, except when we started screening fleas from Cairns – up in the far north tropical Queensland, 2000 km north of Sydney. At first this seemed an oddity, but research and second thoughts proved it otherwise.

跳蚤，Ctenocephalides felis,是狗和猫的外托石。一旦跳蚤找到了主人，它很少（如果有的话）离开。它没有理由，因为每当享用时就可以吃一顿血餐。大多数血液甚至都没有消化，因此排便。跳蚤便便以狗和猫的皮毛结束，最终在狗或猫睡觉，休息或只是花时间的地方下车。

您正确猜到了 - 沙发或房屋或后院最喜欢的地方。实际上，便便是在同一地方生活的跳蚤幼虫的食物。雌性跳蚤每天在狗的毛皮上产生40个鸡蛋，并与跳蚤的大便一起掉下来。卵孵化和幼虫以已经存在的跳蚤便便。

在宿主之外，卵和幼虫在干燥，干旱的环境中无法生存，它们只是干燥。因此，其分布的主要决定因素是湿度和温度 - 气候。The dog or cat is the same in Sydney and Cairns, so the climate is governing the distribution of cat fleas, but would this be true for the flea variants?

Climate change is happening and science has produced some groundbreaking prediction models showing how every square kilometer of our planet will look. According to the政府间气候变化面板（IPCC），气候变化方案既乐观又悲观。我们想探索气候变化模型是否会影响跳蚤的合适利基市场，以及任何预测因素是否可以解释未来的分布。

在最近发表的寄生虫和媒介上发表的文章中，我们使用来自澳大利亚各地的公共生物气候数据为澳大利亚的猫跳蚤建模。在某些地方，我们鉴定出并在遗传上打字，猫跳蚤，我们预测了其他合适的壁ni。可以预见的是，猫跳蚤是整个海岸，毫不奇怪。

澳大利亚的猫跳蚤已经为气候变化做好了准备，凯恩斯的变体可能是我十年前快乐地忽略的超级跳蚤。

Similarly, for the Sydney variant, its niche was predicted almost everywhere except the top end, where Cairns variant reins. The future is volatile for the cat flea in Australia. The size of the flea niche will contract. While the Sydney variant will be losing, the Cairns variant will have a free pass to expand south and overtake the niche that is no more suitable for the Sydney cat flea.

Regardless; the fleas aren’t going anywhere. It may not be the same flea, but it will still be the cat flea. It might not be the Sydney flea that will be ravaging our pets, but instead the one that will descent from the tropical north.

所有这些表明，澳大利亚的猫跳蚤已经为气候变化做好了准备，而凯恩斯的变体可能是我十年前快乐地忽略的超级跳蚤。

And last but not least, fleas are my favorite parasites. The invasive strategy of the pesky cat fleas in Australia illustrates how fragile the balance between the environment, host and fleas is.