Hello again, Caters!
Your pieces always seem so well-planned, and this one is no exception. As an avid ornithologist when I was a kid, I appreciate incorporating the authentic birdcalls into this! I can tell you're developing your own style and you appear to be pretty familiar with music theory. Kudos to you for putting in that kind of work!
Here are some things that have helped me as a composer. First, I have to remember that music is primarily an art, not a science (although it is definitely both). When I focus too heavily on the form and not the art of music, I tend to create pieces that my head likes but my heart doesn't. Ideally, both head and heart should be happy with the music I write. But striking that balance is very tricky, and only the greatest composers do that bit well! When I use music to paint how something makes me feel (spring, for instance), I'm generally much happier with the result because my head, with all its music theory, can very easily whip the melodies into shape. In other words, I lead with my heart and correct with my head.
Also, I've found that it helps to envision people actually playing my music as I write it. There's almost always a way to construct a melody so that it's enjoyable for the instrumentalist to play. I try to minimize bland repitition, and treat each line of music as if I were the one playing it.
All in all, my head really liked your Spring Trio but my heart wanted more emotion out of it. You have a lot of good ideas, though, and I'm confident you'll only get better over time!