When are ticks active in the forest? - briefly
«Ticks» reach peak activity from April to June when daytime temperatures stay between 7 °C and 25 °C and relative humidity exceeds 80 %. Activity drops sharply during hot, dry periods and again in winter when temperatures fall below 5 °C.
When are ticks active in the forest? - in detail
Ticks in forest ecosystems display activity that depends on environmental conditions rather than calendar dates alone. Temperature, relative humidity, and photoperiod together determine the likelihood of questing behavior.
Spring emergence occurs as temperatures rise above the lower threshold of approximately 7 °C, provided that relative humidity stays near or above 80 %. Early summer sees the highest density of active stages, especially nymphs of Ixodes ricinus and Dermacentor variabilis. Late summer brings a secondary peak, primarily of adult females seeking hosts for oviposition. Early autumn may retain limited activity if moisture levels remain sufficient; activity declines sharply once temperatures drop below 5 °C or humidity falls under 70 %.
Daily cycles show a preference for the cooler, more humid periods of the day. Peak questing often aligns with early morning and late afternoon, when leaf litter retains moisture. Midday heat and low humidity suppress movement, causing ticks to retreat into the soil or leaf litter.
Microhabitat characteristics further refine activity patterns. Areas with dense leaf litter, shaded ground cover, and proximity to water sources maintain the moisture required for questing. Open, sun‑exposed patches dry quickly, limiting tick presence.
Key environmental thresholds:
- Temperature ≥ 7 °C
- Relative humidity ≥ 80 %
- Saturation deficit ≤ 5 mm Hg
«Ticks become questing when temperature exceeds 7 °C and humidity remains above 80 %», a finding confirmed across multiple European studies.
Risk periods correspond to the described seasonal and diurnal peaks. Human and animal exposure increases during spring and early summer mornings, especially in shaded, humid understory. Preventive measures should focus on these times and habitats.