Another spring migration is upon us! Once again, I will be writing weekly reports of migration happenings and the impact of weather on migration.
Please take a moment to review my Weather Map Primer. This primer covers how to read a weather map and details how the weather affects migration.
Progress has picked up since last week's update. Within the central flyway, the northern edge of monarch migration has held near Oklahoma City, Oklahoma. Along the Atlantic seaboard, monarchs are making their way northward to South Carolina. Texas remains a hot spot for monarch first sightings.
Anna in Hugo, OK: "First sighting. In my backyard on a mix of dead nettle, hen bit, and other assorted wildflowers." (03/26/2023)
A record atmospheric river battered the California coast again last week but finally, five days of dry and sunny weather slowly warmed the land. Nights were still chilly and the forecast for most of the West for the next ten days is for below-normal temperatures and above-normal chances of precipitation. How will the monarchs fare in these unusually challenging conditions?
La migración de invierno ha concluido su fase final en los bosques de Oyamel en el centro de México.
Ha sido durante el fin de semana cuando el área donde estuvo la última colonia que muchos pudieron admirar hasta el pasado Viernes, quedara totalmente vacía. Un puñado volando y algunas muy maltratadas y deshidratadas aún luchando por aparearse, intentan su milagroso viaje al norte.
The overwintering season has ended here at the Monarch Butterfly Biosphere Reserve.
Over the weekend, there was a small, remaining colony. Today this spot and throughout the Oyamel fir forests of the MBBR in Central México is empty of monarchs. Only a handful of monarchs can still be seen flying as they try to mate. These last few monarchs have tattered wings and some appear incredibly dehydrated. Most likely these monarchs will not migrate north.
Los 3-4 días de lluvia fueron milagrosamente refrescantes para la población restante en Sierra Chincua y El Rosario, motivando la floración, la humedad en la tierra y el agua en los arroyos. La baja de temperatura, retuvo a las Monarcas por algunos días más en sus colonias.
Alrededor de 60-80 árboles aún muestran racimos pequeños a medianos en ambos Santuarios!
Last week’s 3-4 day rain at the overwintering sites was refreshing for the remaining population at Sierra Chincua and El Rosario Sanctuaries. The rains prompted blooming. And the rain provided moisture for the soil and water for streams.
Cooler temperatures held-up monarchs for a few more days at their colonies.
Around 60-80 trees are still showing small to medium clusters at both sanctuaries.
Last week the California coast was once again pummeled by another atmospheric river with battering sheets of rain and high winds. Rivers overflowed their banks, floods surged throughout the region and trees fell. Yet, despite the storm's intensity, when sunny clear days appeared, monarchs were on the move in an extraordinary fashion. Read about their mass dispersal, a rare event in California.