Each day since the unusual pairing of a female Yellow-throated Vireo with its mate, a male Plumbeous Vireo, was discovered on May 31, each parent has been seen sitting patiently on their cup-like nest, high in a cottonwood tree. Observers at the Chatfield State Park site have avoided terminal neck-cramping by lying on the ground, staring up at the nest high above them. The chore of (presumed) incubation of vireo eggs has been shared by the closely-related birds, while the other parent forages for food nearby. Male Plumbeous Vireos are known to develop a "partial brood patch," and to take turns warming the tiny eggs - usually 3 to 5 in number. (*Colorado Breeding* *Bird Atlas I;* High Kingery, editor).
Photos show that the nest has been perfected with cotton-wood tree "cotton," and RMBO volunteers eagerly await the next step in nesting cycle - carrying food to hatched youngsters. Plumbeous Vireo eggs require 14 days of incubation, and the young fledge about 14 days after hatching. If you want to help monitor the nest of this rare pairing of two species of vireos, please contact me at: jroll...@gmail.com Joe Roller, Denver -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to cobirds@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
