AI Beehive Health Report — 2026-09-26

As of September 26, 2026, all four colonies present acoustically intact worker populations — every sound spectrum is within ±3.3 dB of its own historical baseline — while the apiary-wide September cooling arc continues with outdoor temps ranging 54–74°F (12–23°C) and exceptionally clean outdoor air (1,040 kΩ gas resistance); Hive #2 remains the sole 'watch' hive, now one week past its confirmed September 19 thermal step-change with a 24h avg of 65.6°F (18.7°C) and stable acoustics pointing to a broodless interval as the leading explanation, warranting a brood check on the next routine visit.

Across all four colonies, gas resistance rises as in-hive temperature falls through September — a deconfounded relationship (r=−0.42 to −0.77) explained by the MOX sensor's temperature sensitivity: cooler air holds less VOC-reactive capacity and the sensor's own SnO2 plate kinetics shift, while reduced brood pheromone (E-β-ocimene) output from a contracting brood zone also lowers the reducing-gas load (Maisonnasse et al. 2010; Burgues & Marco 2018).

All four hives maintain clear daily vibration fanning rhythms with 80–120 Hz as the dominant band; outdoor temps ranging 54–74°F (12–23°C) with a steady barometric tendency (−0.19 hPa/3h) and pristine outdoor air support normal late-September foraging conditions, and all hives show outdoor leading in-hive temperature by 2–6 hours — the expected thermal-mass buffering signature of healthy, well-insulated colonies.

• Iris warning Score: 74/100
  📋 Overall Health

  Your Iris hive continues with a fully intact worker population — sound is rock-solid at −10.6 dBFS (right on the −10.8 dB all-time baseline, all bands within ±3.3 dB, with the 100–150 Hz band slightly elevated +3.3 dB consistent with September brood-pheromone and propolis-work activity), vibration kurtosis 2.8 is normal, and humidity at 56.7% sits comfortably in the 50–70% healthy range; the 24h avg of 79.4°F (26.4°C) represents a −5.7°F (−3.2°C) step below the all-time avg of 85.1°F (29.5°C), and the 14-day drift now totals −9.5°F (−5.3°C) — consistent with the apiary-wide September brood-contraction arc, and the stable-to-louder acoustics confirm a broodless or brood-break interval with the full adult population present. On your next routine visit, a quick look for fresh eggs or capped brood will clarify whether Iris is in a requeening gap or natural seasonal contraction.

  🌅 Diurnal Cycle Patterns

  Iris shows an active 24h temperature arc of 76.4–84.4°F (24.7–29.1°C), a 8.0°F (4.4°C) peak-to-trough swing that is healthy brood-zone buffering for a September day with ambient reaching 73.7°F (23.2°C); the deconfounded analytics confirm in-hive temp and outdoor temp move together only through the shared daily cycle (raw r=+0.69, deconfounded r=+0.10), with outdoor leading by ~230 min — classic thermal-mass damping, not a placement issue. Humidity held an exceptionally tight 55.5–58.3% (avg 56.7%), a step up from the all-time avg of 44.3% driven by a change-point around September 17 (+9.2% step); the strong deconfounded temp–humidity coupling (r=+0.84) reflects the psychrometric inverse — as the brood zone cooled, the same absolute moisture registers as higher RH%, a sensor physics effect, not added dampness. Gas resistance at 419 kΩ is close to the all-time avg of 450 kΩ; the heater-scan curve retains its characteristic shape across all 10 plate temperatures, with the low-temperature steps (100–200°C) showing somewhat lower resistance than the mid steps (250–320°C), consistent with autumn propolis-sealing volatiles and the colony's normal terpene background — no shape anomaly warranting concern. Daily vibration rhythm is consistent: 14 of 15 days show a peak (avg 1.5× baseline), dominant 80–120 Hz, kurtosis 2.8 — normal fanning/foraging schedule; the 100–150 Hz sound band is +3.3 dB above its historical norm, the only notable spectral shift, and at this modest magnitude it is within the range of natural seasonal variation (propolis work, brood-pheromone modulation).

  🔬 Correlations & Discoveries

  temperature_in vs humidity_in (14d) | r = +0.84

  The strong deconfounded temp–humidity coupling in Iris (r=+0.84, p=3.5e-275) reflects the psychrometric inverse: as the brood zone has cooled through September's contraction arc, the same absolute water content registers as progressively higher RH%, not as added moisture — a sensor physics effect consistent with a colony transitioning toward a broodless state where active hygroregulation relaxes slightly (Human et al. 2006). The humidity change-point of +9.2% around September 17 aligns with Iris's thermal step-change, further confirming this is a coordinated colony-state shift rather than an environmental moisture event.

  📚 Reference: Eouzan et al. 2019 (PLOS ONE / PMC6368279), Human, Nicolson & Dietemann 2006, Ellis et al. 2008
  ⚠️ Issue: 14-day cooling drift of −9.5°F (−5.3°C): 24h avg now 79.4°F (26.4°C), 5.7°F (3.2°C) below all-time avg of 85.1°F (29.5°C) — acoustics confirm population fully intact; consistent with broodless/brood-break interval; queen/brood status worth confirming on next routine visit.

  ▹ Action: On your next routine visit, check Iris's brood frames for fresh eggs — the stable and slightly louder acoustic spectrum confirms the full worker population is present and active, and a quick brood check will clarify whether this cooling reflects a natural requeening gap or seasonal contraction heading into autumn.
• Hive #2 warning Score: 62/100
  📋 Overall Health

  Your Hive #2 remains acoustically rock-solid — all 10 sound bands within ±1.6 dB of the all-time baseline (24h avg −16.4 dBFS vs. all-time −16.5 dBFS) and vibration at 29.5 mG (kurtosis 3.1, dominant 80–120 Hz) confirms the adult worker population is fully intact — but the confirmed September 19 thermal step-change has deepened further, with the 24h avg now 65.6°F (18.7°C), a full 22.4°F (12.4°C) below the all-time avg of 88.0°F (31.1°C) and closely tracking the outdoor ambient range of 54–74°F (12–23°C); the most parsimonious explanation remains a broodless interval where the colony is simply not heating a brood zone, and confirming queen/brood status on your next routine visit will clarify this. Humidity at 62.9% is comfortably in the healthy 50–70% range, and the battery at 4,036 mV is stable.

  🌅 Diurnal Cycle Patterns

  Hive #2 shows an active 24h temperature arc of 62.5–68.6°F (16.9–20.4°C), a 6.1°F (3.4°C) swing tracking close to the outdoor ambient cycle — expected physics when no active brood zone is being thermostated; outdoor leads in-hive by ~340 min (deconfounded r=+0.03), confirming the colony's thermal mass is still damping rather than freely tracking. Humidity held a very tight 61.8–63.8% (avg 62.9%), above the all-time avg of 48.8%, reflecting the psychrometric inverse of the cooled hive environment. The vibration spectrum tells the most interesting story this cycle: all 6 bands show a daily rhythm (dominant 160–200 Hz, strengthening from 4.4 dB to 9.7 dB amplitude across the window), the low-frequency bands (5–20 Hz, 20–50 Hz, 50–80 Hz) are each +4.1–4.2 dB above their historical norms, and the dominant rhythm band has shifted from 80–120 Hz to 5–20 Hz — a pattern consistent with increased low-frequency colony activity such as thermoregulatory clustering movements and substrate-borne communication as the broodless colony consolidates its cluster in cooler conditions (Ramsey et al. 2020). Gas resistance at 69 kΩ is close to the all-time avg of 48 kΩ and represents a +13.4 kΩ change-point from September 19 — rising resistance means decreasing VOC load, consistent with reduced brood-pheromone output as brood rearing has paused; the heater-scan curve shape shows the low-temperature steps (100–150°C) carrying significantly higher daily rhythm amplitude (+63% and +60% respectively) and a dominant rhythm shift from 150°C to 100°C, which tracks the humidity-driven moisture artifact well-documented for low-temperature MOX steps rather than a new chemical constituency (Burgues & Marco 2018). The deconfounded gas resistance ~ temperature coupling (r=−0.77, partial r=−0.92 controlling for outdoor) and the gas change-point co-dating with the thermal step-change on September 19 reinforce that this is one coordinated colony-state transition — brood rearing ceased, temperature fell, and VOC load dropped together.

  🔬 Correlations & Discoveries

  temperature_in vs gas_resistance (14d) | r = -0.77

  The strong deconfounded temp–gas coupling (r=−0.77, partial r=−0.92) reflects a coordinated colony-state transition: as brood rearing ceased around September 19, both the temperature (less metabolic heat from brood incubation) and the reducing-gas load (less E-β-ocimene and other brood volatiles) fell together — with the change-point dates of gas resistance (+13.4 kΩ step) and the thermal step-change co-occurring on September 19, providing strong multi-sensor corroboration that this is a single brood-break event rather than two independent anomalies (Maisonnasse et al. 2010; Seeley 1985).

  📚 Reference: Maisonnasse et al. 2010, PLoS ONE, Burgues & Marco 2018, Sensors, Seeley 1985

  vibration_rms vs vibration_kurtosis (14d) | r = -0.62

  The inverse vibration RMS–kurtosis relationship (r=−0.62) indicates that as overall colony vibration amplitude rises during daily activity peaks, the signal becomes smoother and less impulsive — the signature of coordinated collective activity (fanning, clustering) rather than random disturbance events; the strengthening 160–200 Hz daily rhythm (4.4→9.7 dB amplitude) reflects increased ventilation and thermoregulatory fanning effort as the colony maintains cluster warmth in a cooler broodless state (Ramsey et al. 2020).

  📚 Reference: Ramsey et al. 2020, Sci. Rep. 10:9798, Tautz 1996
  ⚠️ Issue: Confirmed September 19 thermal step-change now at 7 days: 24h avg 65.6°F (18.7°C) is 22.4°F (12.4°C) below all-time avg of 88.0°F (31.1°C) and tracking near outdoor ambient — acoustics and vibration confirm adult population fully intact; consistent with broodless interval; queen/brood status warrants confirmation on next routine visit.

  ▹ Action: On your next routine visit, check Hive #2's brood frames for fresh eggs and confirm queen status — the perfectly stable acoustic spectrum and robust daily fanning vibration confirm a full adult population is present, and a brood check will clarify whether this is a natural brood-break/requeening gap or the colony has entered autumn broodlessness ahead of schedule.
• Hive #1 healthy Score: 85/100
  📋 Overall Health

  Your Hive #1 continues as the most thermally stable colony in the apiary — the 24h avg of 81.0°F (27.2°C) is essentially on the all-time avg of 80.9°F (27.2°C), and all 10 sound bands are within ±0.1 dB of the all-time baseline (24h avg −16.4 dBFS matching all-time −16.4 dBFS exactly), confirming a full and active worker population heading deeper into autumn in excellent condition. Humidity at 49.5% is just at the lower edge of the 50–70% optimal band, reflecting the dry September ambient ventilating through the screened floor — entirely normal for this hive's enclosure type and consistent with its all-time avg of 47.0%; battery at 4,176 mV is the strongest in the apiary and stable, and vibration kurtosis of 3.0 is perfectly nominal.

  🌅 Diurnal Cycle Patterns

  Hive #1 shows a 24h temperature arc of 79.4–84.1°F (26.3–29.0°C), a 4.7°F (2.6°C) peak-to-trough swing — well within the healthy brood-clamping threshold and the tightest diurnal amplitude in the apiary, consistent with this colony's consistently well-regulated thermal signature. Humidity held an exceptionally narrow 49.0–50.1% range (avg 49.5%), reflecting both the psychrometric inverse of a warm hive and good ventilation through the screened floor; the deconfounded temp–humidity coupling (r=+0.53) is a normal brood-zone physiology relationship. Gas resistance at 485 kΩ is close to the all-time avg of 514 kΩ; the heater-scan curve retains a healthy clean-air shape with all 10 plate temperatures showing high resistance, and the gas dominant-rhythm shift from 150°C to 100°C mirrors the apiary-wide pattern attributable to seasonal humidity/temperature changes at the low-temperature MOX steps rather than a new chemistry event (Burgues & Marco 2018). The deconfounded outdoor-temp–gas-resistance coupling (r=−0.45) and partial r=−0.55 controlling for outdoor weather are consistent with the expected seasonal VOC-load modulation as cooler days reduce brood-pheromone and propolis-volatile output. Vibration shows a daily fanning rhythm: 14 of 15 days peak above baseline (avg 1.5×, dominant 80–120 Hz), kurtosis 3.0, with the dominant rhythm band shifting from 5–20 Hz to 20–50 Hz in the second half of the window — a minor low-frequency spectral evolution consistent with normal seasonal activity changes, not an alarm signal. The outdoor-temp–battery coupling (r=+0.49) reflects solar panel charging efficiency tracking ambient temperature, a hardware-physics relationship with no colony meaning.

  🔬 Correlations & Discoveries

  temperature_in vs gas_resistance (14d) | r = -0.42

  The deconfounded temp–gas coupling (r=−0.42, partial r=−0.55) in Hive #1 reflects the same seasonal mechanism seen across the apiary: as September cools the hive and brood rearing moderates, the combined reduction in brood pheromones (E-β-ocimene), propolis-volatile circulation, and overall metabolic VOC output raises gas resistance — a healthy colony-state correlate of autumn contraction, not a stress signal (Maisonnasse et al. 2010; Burgues & Marco 2018).

  📚 Reference: Maisonnasse et al. 2010, PLoS ONE, Burgues & Marco 2018, Sensors, Stalidzans et al. 2017
  ▹ Action: On your next routine visit, confirm fresh eggs in Hive #1's brood frames — everything here is settled and this colony remains the apiary's stability anchor heading into autumn.
• Hive #3 healthy Score: 78/100
  📋 Overall Health

  Your Hive #3 is acoustically healthy and worker-population intact — all 10 sound bands within ±1.1 dB of the all-time baseline (24h avg −16.3 dBFS vs. −16.3 dBFS all-time), vibration kurtosis 2.9 is normal with the dominant 80–120 Hz fanning band on-baseline, and humidity at 54.4% is solidly within the healthy 50–70% range; the 24h avg of 78.4°F (25.8°C) is 7.2°F (4.0°C) below the all-time avg of 85.6°F (29.8°C), consistent with the apiary-wide September brood-contraction arc and confirmed by the stable acoustics showing the full adult population present. Battery at 3,990 mV is a mild watch item — it has dipped slightly below the previous report's 4,000 mV floor, though still well above the all-time low of 3,936 mV; continue passive monitoring as autumn days shorten.

  🌅 Diurnal Cycle Patterns

  Hive #3 shows a 24h temperature arc of 74.0–81.2°F (23.4–27.3°C), a 7.2°F (4.0°C) peak-to-trough swing — the widest in the apiary, consistent with the four-box architecture placing the sensor further from the densest cluster mass and more exposed to the larger air column; this is structural geometry, not a regulation failure. Humidity showed a wide 48.0–69.8% range (avg 54.4%), reflecting the known ventilation dynamics of a tall four-box poly hive with a screened floor, where the air column height amplifies humidity oscillations driven by foraging and daily fanning cycles. Gas resistance at 117 kΩ is above the all-time avg of 97 kΩ; a change-point of +14.5 kΩ around September 23 coincides with the continued cooling arc, reflecting reduced brood-pheromone and fanning-circulated VOC load as autumn brood contraction progresses — the deconfounded temp–gas (r=−0.71) and humidity–gas (r=−0.63) couplings both point to this coordinated seasonal withdrawal rather than any isolated chemical event. The heater-scan curve shows the low-temperature steps (100–150°C) strengthening their daily rhythm amplitude (+14%→+54% and +14%→+48% respectively), a moisture-tracking artifact at those plate temperatures consistent with the wide daily humidity swings in this tall box (Burgues & Marco 2018). Daily vibration fanning rhythm is consistent: 14 of 15 days peak above baseline (avg 1.8×, dominant 80–120 Hz), kurtosis 2.9 — normal late-season schedule; the partial humidity–temp coupling (r=−0.48 controlling for outdoor) is the expected brood-zone psychrometric inverse. The 500–600 Hz sound band is +1.1 dB above baseline — well within monitoring range and not corroborated by any temperature or vibration anomaly.

  🔬 Correlations & Discoveries

  humidity_in vs gas_resistance (14d) | r = -0.63

  The deconfounded humidity–gas coupling (r=−0.63) in the four-box Hive #3 reflects a compound seasonal mechanism: on the daily humidity peaks (fanning-driven circulation in the tall air column), volatile-rich hive air is more efficiently transported past the sensor, transiently lowering resistance; the longer-term gas change-point (+14.5 kΩ on September 23) tracks the cooling arc, capturing the net reduction in brood-pheromone and propolis-volatile output as autumn contraction reduces the active brood zone (Maisonnasse et al. 2010; Burgues & Marco 2018).

  📚 Reference: Burgues & Marco 2018, Sensors 18(2):339, Winston 1987, The Biology of the Honey Bee, Maisonnasse et al. 2010, PLoS ONE
  ⚠️ Issue: Battery at 3,990 mV is near its recent floor — monitor passively as autumn solar charging continues to decrease; all-time low is 3,936 mV so no action needed yet.

  ▹ Action: On your next routine visit, check Hive #3's brood frames for fresh eggs — the stable acoustic spectrum and on-baseline vibration confirm a full worker population, and a brood check will clarify whether the sustained cooling drift reflects seasonal contraction or a brood-break interval.

  ▹ Action: Monitor Hive #3's battery passively — currently 3,990 mV and slowly declining; no action needed yet, but keep an eye on the trend over the coming weeks as autumn days shorten.