How to get presence/absence summary by month for each taxa to create ggplot bar plot?

I have fish stomach contents/diet data and I would like to get presence/absence information for each taxa in my df by month. Each observation (row) has information on the taxa absent (== 0) or present (== 1) in each fish's stomach. I have already transformed my original data to presence/absence values, however, I am not sure how to obtain a summary of what taxa was present or absent by month.

    structure(list(id = c("607_6", "808_4", "801_3", "807_11", "801_16", 
"724_13", "1030_40", "723_78", "701_4", "634_2", "1023_2", "1031_2", 
"643_4", "606_3", "723_79", "801_4", "629_4", "642_10", "801_10", 
"801_11", "1001_35", "616_4", "701_9", "627_2", "601_5"), Daphnia = c(0, 
0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0), Byths = c(0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 
1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1), Chiro.Pupae = c(0, 1, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0
), Empty = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L), Chiro.Larvae = c(0, 
0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 0, 0), Amphipod = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0), Isopod = c(0, 0, 0, 0, 0, 
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), 
    Chironomidae = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), Hemimysis = c(0, 0, 0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0), Copepoda = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0), Sphaeriidae = c(0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0), Chiro.Adult = c(0, 0, 0, 0, 0, 0, 0, 1, 0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), Trichopteran = c(0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 1, 0, 0, 0), UID.Fish = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), Chydoridae = c(0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0), Cyclopoid = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), Fish.Eggs = c(0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0), EggMass = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), Dreissena = c(0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0), Goby = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), Eurycercidae = c(0, 
    0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0), Hirudinea = c(0, 0, 0, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), totalnumPrey = c(0, 
    5, 0, 0, 102, 7, 220, 45, 0, 0, 0, 25, 116, 49, 119, 0, 7, 
    5, 0, 0, 0, 595, 105, 58, 20), MONTH = c(6L, 8L, 8L, 8L, 
    8L, 7L, 11L, 7L, 7L, 6L, 11L, 11L, 6L, 6L, 7L, 8L, 6L, 6L, 
    8L, 8L, 11L, 6L, 7L, 6L, 6L), empty = c("Empty", "Not_empty", 
    "Empty", "Empty", "Not_empty", "Not_empty", "Not_empty", 
    "Not_empty", "Empty", "Empty", "Empty", "Not_empty", "Not_empty", 
    "Not_empty", "Not_empty", "Empty", "Not_empty", "Not_empty", 
    "Empty", "Empty", "Empty", "Not_empty", "Not_empty", "Not_empty", 
    "Not_empty")), row.names = c(NA, -25L), class = c("data.table", 
"data.frame"))

I looked online and various SO posts like this one, but I am not getting exactly what I need.

I would like to end up with something like this (or similar) for each month for all taxa in my df (the values here are made up, might not reflect the real data):

Month	Daphnia	Byths	Chiro.Pupae	Isopod	Goby
11	1	1	0	1	0

My ultimate goal is to make a bar plot in ggplot that looks like this:

Originally, the data was in long format but this results in multiple rows per fish. I changed to wide format to end up with one observation(row) per fish.

How can I achieve this to ultimately plot presence/absence by month? Thank you!

Solution

Maybe you want something like with your selected column converted to a longer format. After that to show the zeros bars, you can say that there is a bar by giving it a small negative number (if you want to show zero bars). At last, the y-axis has a binary format. You can use the following code:

library(dplyr)
library(ggplot2)
library(tidyr)
library(lubridate)

df %>%
  select(MONTH, Daphnia, Byths, Chiro.Pupae, Isopod, Goby) %>%
  mutate(MONTH = month.name[MONTH]) %>%
  pivot_longer(cols = -c(MONTH), values_transform = as.numeric) %>%
  ggplot(aes(x = MONTH, y = sapply(value, FUN=function(x) ifelse(x==0,-0.1,x)), fill = name)) +
  geom_bar(position = "dodge", stat = "identity") +
  scale_y_continuous(breaks = c(0,1)) +
  labs(y = "Absence", x = "Month")

^{Created on 2022-07-30 by the reprex package (v2.0.1)}