Tarantula season is over for 2023 :(

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

YearNumber of trips
(people participating)
Total milesTotal tarantulas
2020*25 (2)71535
202138 (3)103434
202275 (11)2018196
202362 (6)2063110
* 2020 was a pilot year
Male tarantula on Lake Mary Road, Flagstaff, AZ

NPR article on tarantulas


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).

Tarantula season is here!

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!

Tarantula season is almost here

Greetings all. Tarantula seasons is almost here. I am still running the Lake Mary Tarantula Project: Cycle for Science! We usually see our first male tarantula in September! Steve saw one last week – but I am not sure if it was a male or perhaps a female escaping from a flooded burrow. Females are a lot more robust (chunky) than the males, and males have a little hook on leg 1 (see images).

You can start sending me your files beginning in September – unless we start seeing males earlier. Remember I need 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.

Feel free to contact me if you have any questions.

Tarantulas –  fuzzy megacharismatic fauna

Greetings all,

It has been awhile since I posted an update. I was able to run some preliminary analyses on the tarantula data that you collected (thank you). I presented the preliminary results at the Joint Annual Meeting of the Arizona and New Mexico meeting of the American Fisheries Society and The Wildlife Society in Farmington New Mexico in 2-4 February 2023. I’ll add some of the results to the web site. I got some interesting findings that I did not expect 🙂 Stay tuned. Below is an image of the title slide for the talk I presented at the conference.

I presented some of the results on a separate page: Tarantula research results

Tarantulas are still out and about

I saw two tarantulas today during my run! They were small and were not moving very fast, but they were out. Thanks to Eric L. and Steve H. who are still out biking and sending in files. Eric saw two tarantulas on Saturday (12 Nov 2022). Steve went out a little later in the day and unfortunately didn’t see any. I’ll be out of town starting tomorrow – so I welcome any data you can send.

Thank you

Updates to webpage: new maps and the desert tarantula

I have just updated the tarantula location map and added a heat map – which shows where we have seen the most tarantulas. Keep on sending in files and don’t give up before the tarantulas do – they are still out looking for love, I just saw two today (10/30/2022)!

I was out of town in Las Vegas this past week and went on a couple of mountain bike rides 20 mi west of Las Vegas on the Blue Diamond trails (Late Night Trailhead) and saw a couple desert tarantulas Aphonopelma iodius. These are related to the hairy red tarantula Aphomopelma marxi that we see in Flagstaff. The males of the desert tarantula also go out looking for love in the fall. Both images in this post are desert tarantulas.

Desert tarantula
Desert Tarantula Aphonopelma iodius

Keep sending in Tarantula Data

Although we just had a cold spell, tarantulas are still out and about. Last year the last tarantula of the season was in mid November! So keep looking for tarantulas on your bike rides and continue sending me the files. Thanks to everyone who sent in data over the past week, Bill S. , Eric L. and Steve H . It is much appreciated! Keep up the good work, and have a good week.

Keep sending in data!

Thanks to everyone who have sent in their cycling data. Remember, even if you don’t see any tarantulas please send me your data file. Check out the webpage or contact me if you have any questions.

I will be out of town and will not be able to get my usual midweek ride in on Wednesday. So, I would really appreciate any weekday rides that you might go on this week as well as the next couple of weeks as I will be traveling for work and will not be able to bike as much as I usually do.

Thanks everyone and happy cycling!

Holy Tarantulas batman!

Holy tarantulas Batman! A new record was set yesterday. I saw 38 live tarantulas crossing the road yesterday. I rode from my house around Mormon Lake and back (56 mi). Can you beat my record? Get out there and keep your eyes peeled to the road – don’t forget to scan both sides of the road. Happy hunting.

I would also like to thank Bryce B. for a fun ride – and for his first submission of data to the tarantula project. I am looking forward to more data from Bryce and others, keep up the good work everyone.


Thank you tarantula spotters

Thanks and a shout out to Bob P. and Steve H. for sending in data, and to Camille B. for her second year of participating in the Cycle for Science – Lake Mary Tarantula Project.

Don’t forget to send in your ride data even if you didn’t see a tarantula. To know why tarantulas are out and about, I also need to know when they are not out and about. This helps in determining if their appearance is related to weather factors, such as temperature, humidity, wind, etc…

Thanks to all that have sent me data, I am still awaiting ride data from some of you that I met and talked to October 1.

Tarantula season is here

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!

New publication available

I am happy to report that my manuscript “Aquatic mollusc control through desiccation: it is not the amount of time out of water, it is the amount of water out of the mollusc” has be published in Hydrobiologia. You can view the paper here: https://rdcu.be/dhKyG

Red rimmed melania and quilted melania snails
The invasive red-rimmed melania Melanoides tuberculata and quilted melaniaTarebia granifera (smaller ones)
Quilted melania snails in desiccation vials
Quilted melania in desiccation vials