Yes, it is definitely pollinated by Hummingbirds. Smaller Hummingbirds will be more efficient because they have lower costs for flight and so can consume smaller volumes of nectar.

See: Pollination Ecology of Castilleja in Mount Rainer National Park, Ohio Journal of Science: Volume 72, Issue 2 (March, 1972).

Thank you Andrew, very pertinent reference, very useful... Best, GA

Profe, talvez solo engaña a los colibríes. Respecto a la recolecta de nectar, ¿ha usado capilares de 0,5 ó 1 microlitros?

Hola Rafa, sí he usado esos capilares... con resultados negativos, incluso luego de encerrar flores de un día para otro. El paper que puso Andrew indica que la polinizan Selasphorus. Lo que he visto en Cerro es que los colibríes Selasphorus flammula la visitan probando varias flores a la vez y al menos dos arbustos vecinos seguidos. Entonces, si hubiera engaño no caerían en la trampa tan frecuentemente. Mario Blanco me contactó con David Tank pero todavía no responde... Auf Wiedersehen!

Dear Gerardo,

many red-flowering Castilejas are pollinated by hummingbirds further north. Maybe your species has a mixed strategies with bees and hummingbirds as pollinators. It may also be that bees are no effective pollinators. You have to observe.

For collecting nectar I would use a standard protocol: Cover several flowers with fleeze during night and early morning and water the plants in the evening to make sure they have enough water. In the morning you will probably be able to collect nectar using micro capillaries (0.5 or 1 microliter). There are some data in the literature for some North American species having high sucrose contents >60% and giving also sugar concentration.

Best regards

Stefan

Thank you for your observations Stefan... I will continue trying measuring the nectar of Castilleja.