Short Wave: Climate Change Could Alter Spidey Love
Hosted by Emily Kwong and Regina Barber
Release Date: August 6, 2025

Introduction to the Tarantula Migration

In the episode titled “Climate Change Could Alter Spidey Love,” NPR’s Short Wave takes listeners on a captivating journey to the Comanche National Grasslands in southeastern Colorado. Host Emily Kwong introduces the phenomenon of tarantula migrations, a yearly event where thousands of male Colorado brown tarantulas emerge from their burrows in search of mates.

Emily Kwong sets the scene:
"You're listening to Short Wave from npr. Hey shortwavers. Emily Kwong here. And today we're going on a road trip to the Comanche National Grasslands of southeastern Colorado near Lahon..." [00:17]

The Spectacle of Migrating Tarantulas

As drivers traverse dusty roads during early fall, shadows resembling rocks begin to traverse the asphalt. These shadows are, in fact, tarantulas making their slow journey across highways. Ecologist Dallas Haselhun elaborates on this mesmerizing display:

"They are tarantulas, slowly meandering their way across the asphalt as you're driving at highway speeds, trying your best, hopefully to avoid them." [00:51]

Tarantulas, though intimidating to some, are described by Haselhun as fascinating creatures. Each year, from mid-September to mid-October, sexually mature male tarantulas undertake this perilous quest to find a mate, often facing dangers from speeding cars and predators.

Personal Encounters and Community Impact

Dallas Haselhun shares a personal anecdote from their time as a tarantula researcher:

"And I was like a kid in the candy shop. The second I saw one, I pulled over immediately and I jumped out and I just ran straight to it." [01:37]

This passion for tarantulas extends beyond research. The local community in La Junta celebrates the migration with Tarantula Fest, a beloved annual event where Haselhun serves as a parade judge:

"It was hard not to continually get choked up given the reputations of tarantulas and seeing a whole community come around to celebrate them." [02:21]

The Mystery Behind the Migration

Despite the public fascination, the triggers for this massive tarantula migration remain largely unknown. Haselhun discusses the challenges in understanding what incites thousands of males to leave their burrows simultaneously:

"We lack such basic knowledge of their life history. No one had gotten out and done the gritty dirty fieldwork to actually see. Is there something that's triggering these males to go and mate seek?" [02:32]

Investigating the Triggers

To uncover the mysteries of tarantula behavior, Haselhun conducted extensive fieldwork. They monitored tarantula activity by counting spiders at various times of the day. A significant observation was the correlation between sudden cold snaps and increased tarantula activity:

"There was this cold snap where the temperature dropped significantly. And then all of a sudden, I saw 20 to 30 tarantulas after seeing none for weeks." [06:38]

Haselhun hypothesizes that abrupt temperature changes may compel the tarantulas to emerge:

"They're sitting in there in the sweltering heat... then it gets really cold very quickly. And it's making them go, oh no, I gotta go find a mate." [08:00]

Life Cycle and Challenges of Male Tarantulas

The episode delves into the life cycle of male tarantulas, highlighting their brief adult phase and the perilous quest for mating:

"Male tarantulas actually die after they've sexually matured within about a year. So this is quite literally their last hurrah." [08:39]

After mating, males often face the risk of being eaten by females, a behavior observed through tracking with radio transmitters:

"We quickly found that it was pretty hard to track them down because they would be half eaten inside the female's burrow." [09:48]

Ecological Importance and Knowledge Gaps

Haselhun emphasizes the gaps in our understanding of tarantulas’ ecological roles:

"These tarantulas could be contributing quite a lot to their ecosystems, but we don't even know what's triggering their mating season." [10:12]

Referencing a 1950s book titled The Tarantula, Haselhun points out that over six decades later, many fundamental aspects of tarantula biology remain unexplored.

Changing Perceptions and the Impact of Climate Change

The cultural perception of tarantulas is shifting, influenced by increased scientific interest and public education:

"It’s this push a lot more recently, I think, where people are starting to love... the creepy crawlies, the outcasts... are getting a lot more popular." [11:10]

Addressing the implications of climate change, Haselhun discusses how rising temperatures and altered weather patterns could affect tarantula populations, particularly those at the northern edge of their range:

"As climate change starts warming these areas up, or we start just seeing much different climactic variation, I would expect that this group of tarantulas actually ends up being able to be that stronghold for the species because they're used to such swings in temperature." [12:35]

Conclusion: The Future of Tarantulas

As the episode concludes, Haselhun reflects on the importance of understanding tarantulas not just for scientific knowledge, but also for appreciating their role in the ecosystem and the broader implications of environmental changes.

Emily Kwong wraps up by highlighting the dedication of scientists like Haselhun in unraveling the complexities of these elusive spiders, leaving listeners with a deeper appreciation for tarantulas and the mysteries they present.

Notable Quotes

• Dallas Haselhun on first encountering wild tarantulas:
  "And I was like a kid in the candy shop. The second I saw one, I pulled over immediately and I jumped out and I just ran straight to it." [01:37]

• Dallas Haselhun on tarantulas’ survival strategies:
  "Male tarantulas actually die after they've sexually matured within about a year. So this is quite literally their last hurrah." [08:39]

• Dallas Haselhun on climate change impact:
  "I would expect that this group of tarantulas actually ends up being able to be that stronghold for the species because they're used to such swings in temperature." [12:35]

Key Takeaways

• Tarantula Migration: An annual event where male tarantulas emerge to mate, a behavior influenced by environmental triggers like temperature changes.

• Research Gaps: Despite their prominence, fundamental aspects of tarantula biology and ecology remain underexplored.

• Cultural Shift: Perceptions of tarantulas are improving, fostering greater public interest and appreciation.

• Climate Change Concerns: Altered climatic conditions could significantly impact tarantula populations and their migratory behaviors.

This episode of Short Wave not only sheds light on the intricate lives of tarantulas but also underscores the broader implications of environmental changes on lesser-known species. Through engaging storytelling and expert insights, listeners gain a comprehensive understanding of the delicate balance within ecosystems and the factors that influence it.