What is it about bushtits??

I am often asked "what's so interesting about bushtits?"  The answer to that is "it would fill at least one long book."  And I am in the process of writing it.  In the meantime, I thought some of you may be interested in seeing a very brief list of some of the odd, uniquely bushtit, behaviors I have seen.  

First you need to know that bushtits live in tightly knit family flocks of from 10 to 15 birds that combine with other flocks as the breeding season winds down.  During the winter, flocks became hard to find because they travel over several flock home ranges. Combined winter flocks may be huge.....even this year after the heat event, we often ran into a flock on Reed campus that had at at least 50 birds, some of whom were old friends of ours.  

The family and extended family flocks are maintained throughout the breeding season.  And that's what makes bushtits truly unique.  Although pairs (or more than a pair) maintain a weakly defended area around the nest, flock members frequently visit each other's nests and hang out when not at their own nest. They all know exactly where all the flock nests are and who is where and what they are up to.  They even seem to have "best friends" or birds they are seen with frequently and nest near.   

That's the skeleton version as there's much more complexity to the story!  But it's enough for now.  Here's some of the fun stuff I have seen over the years.  Teasers, as you will.  BTW, none of these observations would be possible without color-banded birds.  

1. Musical nests (nest ownership exchanges -- and back):  One day XXXX and YYYY will be building at nest and the next day they are nowhere to be found.  Instead it's ZZZZ and WWWW.  Sometimes XXXX and YYYY may return, and ZZZZ and WWWW will be building a new nest elsewhere.  I'm not the first one to observe this.  Steve Ervin did as well in CA in the early 70s. But he wasn't focused on that aspect of bushtit behavior so he didn't follow up on it.  

2.  Bushtit cads:  Males who cavort with a neighboring female even while he has a nest elsewhere.  I've detailed one situation like this from last year.  There are more.  

3.  Deadbeat dads:  Males who not only cavort, but takeover a nest while their first mate handles incubation alone (both male and female usually take turns).  They then desert the 2nd female to return to being a dad at the first nest, leaving the 2nd female to fend for herself.  

4.  Extra birds ("helpers"):  These are usually males and usually there's only one.  But it varies; in AZ I did have one nest with 6 males and one female. There's a good story in that re how and why this happens!  Hint: is it really helping.....?

5.  More than one pair at a single nest:  two males and two females have been observed.  More on those complicated stories later.  

That's a smattering of the convoluted shenanigans bushtits can get up to.  They seem a cheery and cooperative little bunch, don't they?  But I believe it's actually competition that drives the system.  At least that's what I think as I learn more about them over the years.....stay tuned!