Question

For 23 years, the Xerces Society for Invertebrate Conservation has held an annual monarch butterfly count. Volunteers visit spots on the West Coast where monarchs are known to gather. They count the insects to learn about the health of the species.


Xerces started counting in 1997. That year, it found more than a million monarchs. By 2018, that number had dropped to fewer than 30,000. In 2020, Xerces counted just 1,914 monarchs.


A study was published in March in the journal Science. Researchers looked at decades’ worth of data on butterflies in the western United States. They found that butterfly populations are shrinking by almost 2% each year.


“It compounds each year,” Matt Forister, the study’s lead author, told TIME for Kids. “Over time, it’s really bad.”

Answer 1

Do you want a summary, a kid-friendly rewrite, a classroom activity, or a brief analysis of the numbers? I can do any of those. Meanwhile, here are a few useful things based on the passage:

Quick summary
- Xerces has run an annual West Coast monarch count since 1997. Counts fell from over 1,000,000 (1997) to under 30,000 (2018) and to 1,914 (2020).
- A March study in Science found western U.S. butterfly populations are declining about 2% per year. Lead author Matt Forister noted the effect compounds, producing large losses over time.

What “2% per year” compounding means
- If a population falls 2% each year, after n years the remaining fraction is (0.98)^n.
- After 10 years: (0.98)^10 ≈ 0.82 → about 82% remains (an 18% drop).
- After 50 years: (0.98)^50 ≈ 0.36 → about 36% remains (a 64% drop).
- Example: starting with 1,000,000 butterflies, a steady 2% annual decline for 23 years gives 1,000,000 × (0.98)^23 ≈ 628,000. That shows why compounding is important — but it’s far less severe than the actual monarch decline reported.

Why the monarch numbers are worse than 2% compounding
- The actual Xerces counts (from >1,000,000 to ~1,914) represent about a 99.8% decline from 1997 to 2020 (1,914 / 1,000,000 ≈ 0.0019). That magnitude is much larger than a steady 2% annual decline, which means monarchs have faced other severe, possibly episodic or multiple, pressures beyond a uniform yearly decline.

Likely causes and conservation steps
- Causes: habitat loss (especially milkweed loss), pesticides (including neonicotinoids and herbicide-driven loss of milkweed), climate change (storm and temperature effects on migration/overwintering), disease and parasites, illegal habitat disturbance at overwintering sites.
- What helps: plant native milkweed and nectar plants, avoid/reduce pesticides, protect overwintering groves, support and volunteer with conservation groups, participate in citizen science counts.

Tell me which of the following you want next:
- Short kid-friendly version
- One-page classroom activity or worksheet
- Graph-ready data/plots (I can show expected declines for given rates)
- A brief explainer of causes and what schools/communities can do