The well known Ephrata Wellspan hospital night-heron colony has existed for many years, for a long time hosting only black-crowns to my knowledge. In 2015 a single male yellow-crowned joined them and displayed frequently to the black-crowns, attempted nest-building, but largely was completely ignored. Last year he attracted female of his own species and raised at least two young. This year, however, he again remained alone, displaying but not nest-building that I saw. In a very interesting turn of events, he has now persuaded a young female black-crown to begin pair-bonding and nest-building. I'm not sure on her age, but she appears to be in a subadult plumage. Average age to sexual maturity is listed as 2-3 years, and they acquire definitive plumage in their 4th year. The two were observed on Saturday by me to be working on a partially constructed nest (yellow-crown doing the work, with female attending), and by Josh Schulz a bit later to be necking and actually copulating! Yesterday Emily Broich and Laura Kemmick took more photos which show a pretty complete nest and continued copulation. It remains to be seen whether they will lay eggs, or even successfully raise young. However, this hybridization event is so rare in the wild I thought it would be interesting to share. Successfully hatched wild hybrid BCNHxYCNH chicks have only been documented in North America three times from what I can tell: Arizona in 1951, California from 2007 to maybe 2010, and Colorado in 2011. They will hybridize in captivity when mates of the same species are not available. An inexperienced female black-crown and a lonely male yellow-crown are the perfect conditions for this to occur.
If you come check out these birds, please take photos of their progress and document any behavior you see to eBird. Enter the hospital parking lot from Martin Ave and take your first right. They are easily visible in the row of pines at the back of this lot bordering the houses.