Hey, Janet! Have a wonderful trip - I hope you’re going somewhere with lots of birds!
Another vote for merino! I wear my lightweight merino tees in the hottest part of the summer - I find them more comfortable than synthetics or cotton. We just got back from 11 days in Peru - combo hiking and sightseeing trip. My 4 merino tees, 2 long sleeve and 2 short sleeve were the mainstay of my wardrobe. My new favs are from Outdoor Voices. A little less form-fitting than Smartwool and Icebreaker. Also took two pairs of midweight Smartwool hiking socks for our 7 days of hiking - hung them to air out between wearing and never needed to wash.
I love merino sports bras and bralettes. Thanks to karen13’s recommendation, I’m going to give the Icebreaker hipkini a try.

Late to this but yes, ditto everyone who's recommended merino. Stays un-gross so much longer than cotton or synthetic (I've not been impressed with most of the anti-microbial treatments for synthetic sports gear). For outdoor travel, I take merino tees, undies, bralettes, and socks. I only do synthetic for pants/shorts. Then I add a puffy, fleece, or wool sweater for insulation, depending on circumstances, and a Goretex shell.

For plain old city travel, I have no qualms about re-wearing tees once or twice, regardless of fabrication. I don't sweat much unless it's super humid or I'm really exerting myself.

And how fun to have an unplanned YLF meetup at REI!!

Karen, merino definitely sounds promising. I’ll look into it. Unfortunately REI’s sale is over.

Ryce, thanks for the merino recommendations, and yes, there will a lot of birds. In fact, my husband made me a list of birds to study - 4 1/2 pages long. I said what kind of vacation is it anyway, if I have homework! My MO is to look at the list on the plane.

LaP, thanks for the merino recommendations, too. An REI meetup was unexpected and fun. Karen and I met before, after we realized we lived pretty close. Karen looked really fab in wide leg jeans.

Janet, sounds like you're sorted. Have a safe and wonderful trip.

Angie, thank you.

Have a great trip! Since we are all sharing, I wear the same merino wool socks many times before washing. They do not stink. T-shirts I re-wear too. But I don't sweat.

I'm really late here but wishing you a wonderful trip, and also, how fun you met up with Karen!!

Have a wonderful trip. This should be a time of year to see lots of birds. Have fun.

Style Fan, I’ve had wool socks in the past, for skiing. I really liked them, but couldn’t find them anymore.

Suz, thank you. It was great to see Karen.

Joy, thank you. The list my husband gave me had a lot of birds, including many that would be lifers. So fingers crossed!

Hmm... The last time I went on a camping trip, Jimmy Carter was US President !!

So, here's what I took ( as far as my aging memory will do ) for a weeks wear.

Undies: 7 pair
Socks: 10 pair
Jeans: 2 pair
Boots: 1 pair
T-shirts: 4
Turtleneck skivvies: 2
Wool jumpers: 2 ( one was a ribbed high t'neck and the other was a shetland V-neck ) for layering
Waterproof insulated jacket: 1
Gloves: 2 pair
Knit hat: 1
Boonie style army hat: 1
Scarf: 1

I managed to stay mostly clean apart from getting bogged in quicksandy mud up past my knees alongside a creek we were hiking along that took what seemed like ages to get free from with my friends' help.

Cer, you have an excellent memory! Your packing list looks excellent. I shook Jimmy Carter’s hand several years ago. His son was running for office and he came to an event. I went, hoping he would speak, which he didn’t. I really admire his work with Habitat for Humanity.

...and now I am SPENT !!