a function of water temperature or day length? Many biological triggers are more a function of day length or night length than temperature but I have seen nothing about fish spawns.

Both

Both

Fast Foward too the 6:00 mark, unless you wanna watch the whole video. Just Hardcore crappie facts!

Yep !

function of fish clocks,....water temps and day length are only conveniences.

Both but water temp is the most important factor I use to pattern any fish spawning.

Agreed on both, but Water Temp is huge. Crappie will start moving into staging when the water is in the mid 50's and will start a spawn about 62 degrees. The spawn obviously does not all happen at once. This will take a couple of months as they take their turns based on mother nature. If you are wanting to catch big crappie, search close to the shallows but stay in 10-12 FOW on structure. This cold snap is going to put us back a few weeks, especially with rain and snow melting as the rivers will be full of cold water. Last week I was catching them in 10-12 FOW on trees, but I fear soon that will change. The surface temp on Palestine in the North Lake was 57 but I know that is going to change with a 6 degree low. I use4d to bank fish for crappie, but most of what you catch is only males which are smaller. The female will come up and spawn (lay her eggs) and is only there for about 2 hours according to biologist. Then she returns to the 10-12 FOW to feed. I usually do not keep any at this time of year to allow for maximum spawn but I sure have fun catching them. Check out this video I made on prespawn. This was early March of last year (2020).

In DFW they don't spawn till April according to some.

when the redbuds and dogwood bloom in oklahoma

I know in our little private lake in Bluff Dale, both the crappie and the bass spawn are earlier than other bodies of water near by. I think a lot of it there has to do with the massive amount of aquatic vegetation and the extremely clear water too.

I didn't see them spittng out eggs but I'll say it's a good idea to start checking your spawning areas as soon as the day light hours start to grow.....
With increasing daylight hours comes increasing water temps...... And I've seen good pockets of fish up shallow in as cold as low 40° surface water temps......
You can follow the crowd or you can be a leader and fill your live wells.....
Go fishn and go fishn often and give it a check..... You'll be surprised.....
It also depends on your lake water depth and also clarity.......

Did y'all see how the biologist got chocked up about the black crappie spawning times.....LOL.....I always watch Crappie Connection and seen this one when it was released, they have some good info...... Y'all will be really surprised on the use of a 27' crappie rod in one of there recent releases by a well known big time tourney fisherman.....27' yes a 27' rod.......LOL
I've been using long rods way before it was cool to do so but 27' even took me by surprise.......
Be humble and be humble often.....

I didn’t watch fhe 27’ rods segment but I can’t imagine holding it still! I picked up a 20’ at the crappie expo in 2019 and I bet I had to hold it still in the rack for 5 minutes just to put it down!!

Very interesting information on here. i've been listening to a number of podcasts lately. I've heard 2 or 3 biologists that have said that the length of day is the most important factor with water temp a distant second. I think that just goes to show that noone, biologists included, has a really good understanding of what really triggers the spawn.