In #sympatry, as in Finland, the 🐜🐜🐜 #hybridise extensively and form a mosaic #hybrid #zone: #admixed populations (♦️) alternate in space with non-admixed pops (🟢&🟠) with different climatic adaptations. The ♦️ occupy warmer nest sites than their cold-adapted parent (🟢)! 2/5