Both species spawn multiple times per year. Redear cease spawning earlier. The pattern holds in both pond and tank settings. Apparent spawning frequency based on cohorts is not something I put much wei9ght in after seeing how some cohorts can outright fail from things like weather events. Larval Redear are a little easier in my setting to rear on formulated feeds. They appear slightly more robust at first feeding even though total length similar. I have made the F1 Redear(female) x Northern Bluegill (male) many times with thousands of fry produced each time where breeding is done in tank setting (1,200 to 2,000 gallons) where everything can be seen. Pond spawning I have done easy giving similar results to what is reported in the literature. The reciprocal Northern Bluegill (female) x Redear(male) has also leaked through when female Bluegill are given choice between male Bluegill and male Redear, but has not been produced in large numbers despite many situations where hybridization was possible in a more confined setting (75-gallon aquariums). Hybridization was not a function of female choice, rather cuckoldery on the part of male Redear.
About a decade back, a student and I affixed some red(stuff from Hobby Lobby) to opercular tabs of a couple male Bluegill. Those males were known studs to female Bluegill until the red was added. Mating success resumed when red fell off. Males flashed a lot in effort to dislodge the irritating red adornments.
