Tarantula season is starting to slow down. However, it is not over yet. as of October 26 we have had 77 sightings of tarantulas on 36 trips. The latest in the season that a tarantula was observed was 7 Dec 2024 (since 2020). So keep your eyes open! October is the peak season but there are a few stragglers in November.

Thanks to those of you that have submitted data.

It is that time of year when male tarantula are out looking for love. I haven’t seen a tarantula yet this season – but I expect to see them pretty soon. They are already on the move in Colorado (different species). Have you seen or heard the story on NPR? https://www.npr.org/2025/09/11/nx-s1-5534462/tarantulas-colorado-mating-season The article mentions a few things that are not known about tarantulas , and I hope to answer some of those questions, such as when and why they start moving when they do.?

So please start sending me your bike ride files (kml) even if you do not see a tarantula. I have already received a couple of files, thank you Camille! My webpage “Cycle for science” provides an overview of the citizen science project. Let me know if you have any questions.

Now that the temperature is cold and it is December, it looks like tarantula mating season is over. However, don’t be surprised if the weather warms up for a day or two and you see a tarantula. If you do, let me know location, and time! Thanks to everyone who participated in the tarantula project this year. We had six volunteers, and completed 65 trips covering 1918 mi and observed 118 tarantulas. Thank you!

Here is an interesting article on tarantulas from the BBC.

https://www.bbc.com/future/article/20241029-why-the-illegal-trade-of-tarantula-spiders-is-booming

Greetings,

It is prime time tarantula season. I saw seven tarantula this morning (2024-10-06) on a 40 mi ride, including this gorgeous male below! October is usually the best month for seeing tarantulas. Keep sending me your files, I appreciate it and will be in need of everyone’s data as I will be out of town for two weeks this month (October) for work.

It is that time of year when male tarantulas start heading out looking for love. Usually this begins sometime in September and ends around the middle of November. So, keep your eyes open for those wandering love seeking Lotharios while you are out and about. This will be the 5th year of tracking male tarantulas in the fall and any data that you can contribute is very much appreciated. I will be out of town for a good chunk of September and October, so I will be in need of other’s peoples data. Keep up the good work.

Who will be the first person to spot a male tarantula this fall?

Contact me if you have any questions.

Thank you

I think it is safe to say that tarantula season is over. Thank to everyone that contributed data this year, Steven H., Eric L., Bryce B., Karen L., and Richard S. Below is a summary table of the number of trips, miles covered, and tarantulas documented. 2020 was a pilot year where I and my partner were the only ones participating, in subsequent years I had a number of volunteers participate. I was hoping to retain a few more people from 2022 for 2023, but we covered more miles. Suggesting that we had more dedicated bicyclists this year. Let’s see if we can beat those numbers in 2024! We also had fewer tarantulas per mile compared to last year. I don’t have enough data to suggest if it was due to weather, or some other factor. It might be just normal oscillations in populations over time. I’ll analyze the data and update the results page, preliminary results suggest that the analyses I did last year still hold, but stay tuned.

Yearly summary of Cycle for Science – The Lake Mary Tarantula Project

Year	Number of trips (people participating)	Total miles	Total tarantulas
2020*	25 (2)	715	35
2021	38 (3)	1034	34
2022	75 (11)	2018	196
2023	62 (6)	2063	110

https://www.npr.org/2023/10/03/1203321429/tarantulas-in-colorado-are-on-the-move-and-theyre-looking-for-love

NPR Colorado did a story on male tarantulas out looking for love in La Junta Colorado. They are talking about the brown tarantula (Aphonopelma hentzi) which is a different species than what we have here in Flagstaff. The one we have in Flagstaff is the hairy red also known as the Grand Canyon black tarantula (Aphonopelma marxi).

We had our first sighting of a tarantula this season. It was observed by Eric L. this past Sunday (24 Sept 2023) while he was fixing a flat tire during his ride! I would also like to thank Bryce B. for sending in data for six bike rides while I was out of town for two weeks.

Thanks for sending in data Eric and Bryce!

Greetings all,

Tarantula season is here, well… almost. September is when they first start showing up, and when I start collecting bike ride data. So please start sending me your bike ride files. Remember I would like all bike trips even if you did not see a tarantula. By comparing trips with tarantulas to those without, we can tease out what environmental, and temporal factors are related to movement associated with mating. Preliminary data analysis indicates that humidity is pretty important to the appearance of male tarantulas.

I found a small poem to get you in the mood for “Tarantula Season“

Thank you for participating!