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Summer in September

Community Science Manager, Richard Smart looks at how squirrels escape the summer heat.

Fox squirrel, laying on ground by a tree.

“OMG, it’s hot. Why is it so hot? I’m sweating from just walking. I moved from Texas to get away from this heat. Ugh. I hate this.”

This was the conversation I had in my head, and likely expressed in my posture and face, as I walked back to work after my lunch break. It was Tuesday, September 3rd, and as I walked back in the office, I apologized to everyone for my appearance and smell. Luckily they laughed, and said I was fine, but I felt like I had run 6 miles. After drinking some water, basking in the air conditioning, and taking deep breaths, I began to cool down and relax.

It never fails to surprise me that summer heat in Los Angeles extends into September. I mean, I expect it to still be hot in September when I am in Dallas, but not in L.A. Here. I always expect high temps to be in the mid 70s. My first summer in L.A. was very mild. And even when temperatures reached into the 90s it seemed to only last for 1-2 hours, then start dropping. This contrasted to my experience in Dallas, when temps reached into the 100s by 9 a.m., and stayed that way until 9 p.m. That mild first L.A. summer was back in 2013, and I swear every summer since has felt very hot, particularly in August and September.

Fox squirrel, laying on ground by a tree.
"Here is a squirrel heat dumping at Travel Town in Griffith Park. Los Angeles, Ca."
photo and quote: Anthony Gates

Have you seen squirrels laying on the ground, arms and legs stretched out so wide that their stomach, neck, and limbs are all touching the ground? The first time I saw a squirrel laying like that, I pointed at it and laughed. Now when I see a squirrel in that pose I think, “You look how I feel.” And that, my friends, is the feeling of defeat. In September I cannot even pretend to be unbothered by the hot summer. I try to look calm, cool and collected in the heat during June, July, and August, but come September I can no longer battle. It's too hot. I want to lay with the squirrels, body on the dirt, and refuse to move one more inch until the air temperature cools down.

Fox squirrel heat dumping on a rock.
"Adulting is hard...even for squirrels."
photo and quote: Elyse Villa

When squirrels exhibit this behavior it's called “heat dumping.” When humans do it it's called “now, that’s just sad.” Heat dumping refers to squirrels using the ground to cool their body temperatures. It is a rather clever way to cool down. Not unlike a person slumping on their couch wishing and waiting for their AC or ceiling fan to cool them down.

Fox squirrel heating dumping at El Camino College.
"...location is west parking deck, 2nd level of El Camino College. It was really hot that day."
photo and quote: Annette Abelin

I sometimes wonder how did the first squirrel to heat dump come upon this behavior? Did it trip, fall on its stomach? As other squirrels pointed and laughed, did the clumsy squirrel realize “Hey, I'm actually cooling down while laying on the ground.” How much convincing did it take for the other squirrels to try out this behavior? And when did this behavior move from something people point out and say, “Hey, look at that squirrel” to a behavior that scientists learn about, and even study?

Fox squirrel heating dumping at Pasadena City College.
"I took this picture on September 30 in Pasadena City College campus. That day was very hot, so this squirrel laid down on the ground. It was so cute."
photo and quote: Na Ma

I will say, the best part about September in Los Angeles is swimming in the ocean. Most times the water temperature in the ocean is in the low 60s. That’s cold for this Texas-born person. In September ocean temps can reach the high 60s and even low 70s. Those temps are warm enough that I can go into the water without feeling like I’m freezing, while still providing a refreshing respite from the summer heat.

Squirrels partake in heat dumping, I enjoy body surfing. Either way we are doing our best to escape the September heat. How do you cool down?