What weather best explains butterflies?

Prioritize variables with the strongest, fast, behavioral effects:

1. Air temperature (°C) – key for thermoregulation; activity rises to an optimum then drops if.....

2. Solar radiation / cloud cover – sun exposure enables flight; heavy cloud cuts activity.

3. Wind speed (m/s) – moderate wind reduces flight and transect detectability; strong wind grounds butterflies.

4. Relative humidity (%) – interacts with temp; very dry or very humid can lower activity.

5. Rain (same day + previous 24–72h) – suppresses flight same day; recent rain can boost nectar/host plants.

(If you can add only one: temperature; two: temperature + wind; three: add solar/cloud.)

Clear objectives (pick 2–3)

Quantify how butterfly activity/abundance changes with temperature, wind and cloud cover.

Identify weather thresholds (e.g., °C or wind speed) where activity sharply rises/falls.

Compare microhabitats (sunny edge vs shaded interior) to test microclimate effects.

Provide practical survey “best conditions” for future monitoring.

Testable hypotheses

H1: Activity increases with temperature up to ~30–34 °C, then declines (hump-shaped).

H2: Activity decreases as wind speed increases above ~2–3 m/s.

H3: Activity is higher under sunny/partly cloudy vs overcast conditions.

H4: After rainfall in previous 48 h, nectar feeders show higher counts.

Study design (fast and robust)

Site(s): 1–2 accessible greenspaces with mixed habitat (edge, open, lightly wooded).

Transects: 3–5 fixed 200–500 m routes (“Pollard Walks”). Mark them on a map.

Frequency: Survey each transect 2 times/day (late morning & early afternoon), 3–4 days/week for 4 weeks. Avoid rain during active counts; note if it rained earlier.

Effort control: Walk each transect in ~15–20 min at constant pace; 5 m detection band.

Weather logging: At start & end of each transect (or every 10 min) record: air temp, wind (Beaufort or meter), RH, % cloud/solar (simple 0–8 oktas), and whether it rained in last 24–72 h. Use a handheld meter if possible; otherwise, combine a shaded thermometer + nearby weather-station data.

Species data: Count individuals by species where possible; if ID is tough, group into guilds (e.g., swallowtails, whites, nymphalids).

Covariates (quick): time of day, microhabitat (edge/open/shade), flowers in bloom (0–3 scale), observer.

Simple data sheet (columns)

date | site | transect | start_time | end_time | duration_min | temp_C | wind_ms | RH_% | cloud_oktas | rain_24h (0/1) | habitat | flower_score | species | count

Analysis (straightforward)

Exploration: scatterplots of counts vs temp; boxplots by cloud class; line of activity across time of day.

Model(s): counts are typically overdispersed → use Negative Binomial (or Poisson if variance≈mean).

Example formula:

Count ~ Temp + Temp² + Wind + Cloud + Rain24h + TimeOfDay + Habitat + offset(log(Duration))

If multiple transects/sites: add Transect (random effect) → GLMM.

Thresholds: Fit a quadratic (Temp + Temp²) or a segmented regression to estimate optimum temperature.

Outputs to report: effect sizes (β), 95% CIs, pseudo-R², and predicted activity vs temperature curve at low vs high wind.

Sampling schedule you can finish in a month

Week 1: pilot the routes, practice IDs, finalize datasheet.

Weeks 2–3: full sampling (aim for ≥18–24 transect walks total).

Week 4: data cleaning, plots, model, write-up.

Interpreting “expansion”

In one month you can’t track range expansion, but you can infer favorable expansion conditions by identifying weather windows with peak activity and movement (e.g., sunny, warm, low-wind afternoons). Discuss how these conditions enhance dispersal (warmer thoracic temps → longer flights; calm air → straighter movement; post-rain nectar → fueling flights).

Low-cost equipment & tips

Clipboard, printed datasheets, stopwatch/phone timer, simple thermometer, wind meter (or Beaufort scale chart), RH meter if available, camera for uncertain IDs.

Standardize clothing color and pace to reduce detection bias.

Avoid double counting (forward only; don’t chase individuals).

Ethical note: no capture needed; if doing mark-release-recapture for movement, use non-toxic fine marker on the wing margin—only if you’re trained and permitted.

Deliverables (what to hand in)

1–2 pages methods with a site map and transect GPS traces.

Figures: (i) temp vs predicted activity curve, (ii) bar/line showing wind or cloud effects, (iii) heat table of species × weather class.

Short discussion linking mechanisms (thermoregulation, nectar availability, flight costs) to your results and to practical survey guidance (e.g., “Survey between 10:30–14:30 when temp 28–33 °C, wind

Excellent answer! Butterflies can be warmed by solar radiation, so it's worth measuring the operative and ambient temperature in the sun, as well as the ambient temperature in the shade. The operative and ambient temperatures in the sun can be measured using a hair-fine thermocouple (so fine that it doesn't decrease its reading when you move it from full sun into the shade) - inserted into a dead butterfly in the basking position, for the operative temperature.