CicadaBroods #CicadaSinging #CicadaAggregation
Cicada Broods: Do They "Sing Where They Emerge" or Aggregate Elsewhere?
If you’ve been observing cicadas, especially the mesmerizing 17-year cicadas, you might wonder if they sing where they emerge or travel to join others in a cicada chorus. A concerned Chicago resident mentioned, “Four days ago, our trees were absolutely COVERED in cicada exuviae. We have none singing near our home at all. However, we can hear in the distance an absolute roar of them.” Let’s dive into this fascinating phenomenon. 🌲🦗
Cicada Emergence: A Local Event
😲 Cicada exuviae, or their shed exoskeletons, are a sure sign that these insects have emerged nearby. But their lack of singing near your home can be puzzling. Generally, cicadas do emerge and begin their life cycles in the same areas.
- Cicada nymphs spend most of their lives underground.
- Upon emergence, they climb nearby vegetation to shed their exoskeletons.
- Males start singing soon after emergence to attract females.
Aggregation: The Mystery of the Cicada Roar
Those in Chicago hearing cicadas far away might wonder, why are there no songs near them despite numerous exuviae?
- Aggregation Behavior: Male cicadas tend to aggregate or group together in areas to amplify their mating calls. This behavior makes their chorus more attractive to females.
- Optimal Conditions: Cicadas prefer specific conditions to sing, like sunlight and the right temperature. They might migrate short distances to find these ideal spots.
- Predator Avoidance: By singing in large groups, cicadas reduce the likelihood of individual predation, known as the "predator dilution effect."
Why the Distant Roar?
If you’re hearing cicadas from afar, here are some potential reasons:
- Microclimates: Differences in microclimates (sunlight, temperature) around your area might lead cicadas to aggregate in specific spots.
- Vegetation Density: Areas with denser vegetation might be more attractive for aggregations.
- Human Impact: Urban landscapes can alter cicada behavior, pushing them to less disturbed spots.
Interesting Cicada Facts
- The 17-year cicadas, or Magicicada, spend most of their lives (17 years!) underground before emerging.
- Upon emergence, they only live for a few weeks to mate and lay eggs.
- Their loud singing can reach up to 100 decibels!
Conclusion: Understanding Cicada Behavior
So, do cicadas sing where they emerge, or do they travel to aggregate? The answer is a combination of both. While they emerge and initially begin singing locally, various factors can lead them to aggregate in specific areas, creating those distant roars.
If you find your area covered in exuviae but quiet, be assured that the cicadas are close, just gathered in a spot that better suits their aggregative and survival instincts. 🌳✨
Feel free to share your experiences with cicadas in the comments below and let’s continue the conversation about these fascinating insects! 🗣️
Commenting to check back later, cause I wondered this too. Some trees are ridiculously loud – I imagine that’s where the alphas are – some have smaller crowds (betas?), and some have none. Maybe it’s the kind of tree they like best, or it could be a chance meetup kinda thing.