Saturday, August 12, 2023

 Ok....I'm on a roll!  Let's see if I can can keep it up....

Today I'm going to post a short excerpt from my book which is a natural history narrative about all my years studying bushtits.  It has plenty of science in it, but fun stuff as well.  I've already shared some other excerpts in earlier posts.  The following belongs more or less to the "fun" category.  Enjoy!  

Caging bushtits 1989

I have several plans for the season this year that will give me information beyond what I have already collected in the field.  One of these plans involves mist-netting bushtits and studying them in captivity.  I have heard that bushtits are exceptionally difficult to keep in aviaries as they require live food and do not take kindly to cages.  

This year I have two completely different plans in place to safely provide me with caged bushtits.  The first is to capture adults relatively early in the day and late in the season -– adults unassociated with a nest -- and to provide them with an abundance of live waxworm larvae as soon as I have them safely in cages.  These larvae best mimic the soft-bodied caterpillars that bushtits adore.  Instead of holding the birds overnight no matter what, I plan to release the adults before dark if they don’t eat in the cage so that they can forage and survive on their own.  I don’t want to be responsible for the deaths any captive bushtits.   I really care way too much for them to see that happen. 

To temporarily house the bushtits that I catch I fashion three 1m x 1m x 1m cages out of hardware cloth. I‘m not concerned about the size of the cages because bushtits are not strong fliers and I reason that they will be perfectly happy in these temporary digs while we build a larger aviary.  And I expect I’ll only be housing perhaps four in each cage anyway.  

One morning, on a lark and feeling a bit lazy in my pregnant state, I string a mistnet right outside our little stone cottage where I have been seeing fairly predictably a small flock of bushtits foraging on most mornings.  Because the speakers and the begging fledgling tapes are being used in the field to colorband on the main study site as usual, I don’t have access to them.  Consequently if bushtits do end up in the net at all, it will be a bit of a surprise.  But I give it a try anyway….. 

…..and catch the entire flock of eleven birds on the first day around 4 PM.   After carefully removing each bird from the net, I place them all in the same cage.....so they will be together and happy....with a little vegetation  for perching and masses and masses of waxworms for eating – I hope.  In fact, there are so many waxworms in the cage, there is no way they can move without stumbling over one.  And I wait.  I stay a respectable distance from the cage at first so as not to disturb the birds, but I can see that they are frantic.  Being in the enclosure is not making them happy and, instead of settling down and eating the abundance placed so conveniently there for them, they are flying about and smashing into the hardware cloth walls, clinging to the sides, spitting loudly, and attempting to force their little heads through the holes in the hardware cloth which are thankfully way too small to cause any damage to the little birds.  

I let them struggle like this for about 2 hours, feeling quite sorry for them, and beginning to think that it will soon be time to release them.  I can’t imagine they are ever going to settle down and eat and I know that their metabolism is too high for them to survive this much energy expenditure and loss overnight without eating.  Releasing them is clearly the kindest thing to do. 

It seems unlikely that my presence will change anything so I move to sit next to the cage.  They don’t seem to notice me – that’s not really a surprise – and their behavior doesn’t change.  I watch for awhile as they continue their frantic attempts to get out of the cage.  Finally I’m feeling frustrated and ready to do anything.  I really want this to work.  Without any expectation that a wild bird will take food from my hand,  I pick up a wiggling waxworm and hold it out near a perch through the wire.  Remarkably and quite magically one of the birds notices, hops over, looks quizzically at the larvae I am holding in my fingers, and then grabs it and hops off with his prize.  It takes him a bit of time to process it before he can eat it.  But in that time the others notice his fortune and (hallalujah!) suddenly become aware that the cage is full of delectable and delightful and delicious waxworms.  Now all the activity changes dramatically.  Now everyone is single-minded as they gorge themselves on waxworms.  After 15 minutes, they are all stuffed and sated and very happy little bushtits.  As the sun goes down they huddle together in row, quietly spitting and chirruping, and dramatically fall asleep – every single one of them with one or two waxworms still hanging from their beaks.  It’s as if they couldn’t quite believe their luck and couldn’t eat more, but gave it a valiant try.  I wish I had a camera!    And so I leave them to sleep it off and to see what the morning brings, happy in the knowledge that they will at least survive the night.  

Dawn comes and I open my eyes with some trepidation to a relatively quiet room.  To my great surprise, I see no frantic activity in the cage just on the other side of our room.  I hear no frantic spitting.  Instead all 11 bushtits are either hopping about the cage quietly spit-spitting their contact calls and foraging or perched and preening.  In other words, they seem perfectly happy.  Not a single one is trying to go elsewhere.  I move slowly as I dress, but I needn’t.  Just as bushtits are nonchalant about our presence in the field, so they seem to be even so in this unnatural situation.  I can approach the cage, reach in and clean it, and move around the room perfectly naturally and the little flock simply goes about its business.  They seem to have adapted overnight to their caged existence and don’t even mind the large primates in the room. They even happily perch on my hand to eat.  This couldn’t be better.  Bushtits are born cage birds as long as they have food.  The little darlings.  

Monday, August 7, 2023

 I promised more about 2023 and so I will deliver.  We'll see how long that lasts.  

This year the bushtits made a liar out of me.  I am convinced it was a plot.  In Arizona, young females, as far as I could tell because finding them was hard, left their natal flocks in small groups and then settled in different flocks nearby.  They didn't move far.  But they did move out and to new areas.  

This year in Portland, I had the good fortune of finding all the nestlings from one of the nests that fledged late last summer -- now, of course, full grown and breeding age. BTW, both the parents of these guys nested successfully together again this year...sweet.....but that's another story in itself.  

Anyway.  We found all 5 kids on Reed campus near where they hatched and could identify the sex of them all -- keeping in mind that bushtits all hatch with dark down eyes and only after a few weeks morph into the striking yellow/cream eye that distinguishes females.  Lo and behold, there were 3 males and 2 females.  The females were still not far from where they had hatched when I recaptured them early in the season.  Within weeks two of the males and one female built nests not far from where they hatched.  That was a surprise. At least the female was.  I expected her to be long gone given what I thought I knew about bushtits.  That'll teach me.   

And then there was another female hatched last year who nested -- twice -- just 25 yards or so from the nest she hatched out from.  That was even a bigger surprise.   

Honestly?  Annoying.  So now I need to rewrite that part of the bushtit story.  Females may not be leaving their natal flocks in Portland.  At least some females seem to be hanging out with their bros.  Sigh.  

I do wish they'd be consistent!!  But, alas, that appears not to be in the cards.  Once the DNA gets analyzed, things may become much clearer.  At least one can hope.      

Thursday, August 3, 2023

2023 in a nutshell

I've said all this before, and I'll say it again:  I am a bad blogger.  I admit that.  The problem is during the bushtit breeding season I am (surprise!) busy out in the field finding nests, banding birds, and watching birds all day long.  I come home ready to eat dinner, relax, plan the next day -- not an easy task if there are competing priorities.  Which nests desperately need watching because we haven't watched them in a long time?  Which nests desperately need watching because there's something odd and interesting happening there?  Which nests have birds that need banding -- now?  Which nests have babies that need banding -- yesterday?  Where are we certain there is a nest but we haven't found it yet?  Ad nauseam.

You get my drift.  It's a job in itself just figuring out what takes priority the next day.  And then, of course, I need to organize the various assistants and myself around that plan for tomorrow.  And, finally, sleep. 

Repeat.  Day after day from March and at least through June.  In fact, I have the reputation of thinking a day off involves strolling around and looking for new nests or banded birds.  Obviously, I like what I do. But that does mean I have little time to blog during the most exciting part of the year and so......I am a bad blogger.  Apologies to those who have dipped into my blog, found it interesting, and been disappointed with the rarity of my posts.  

But now I am back in Maine and trying to find a publisher or agent for my book about my 37 years of bushtit research.  It's a frustrating and odd process.  I somehow have to convince an agent (preferred) that this tiny, boring-gray bird is actually interesting and, even more important, there are people out there who would buy a book devoted to this tiny, boring-gray bird.  I have no doubts, given what I know about bushtits and the interest I see in the public about them.  But convincing an agent or publisher is another story.  

So I am going to try to step up my blogging both because I would like to prove there is an audience and because there are parts of the bushtit story, especially the Oregon story, that haven't been written and this seems to be a good place to do that.  Rather than write into the certain void that is my computer, I'll write into this uncertain void that at least has the potential to reach some curious readers.  

I'l start with a brief recap of 2023 and move onto some fun stories in future blogs.  

Recap:  Well, it was an odd year in some ways.  The bushtit built their nests at about the same time of year that they usually do, beginning in March and "finishing" sometime in early April.  But what stood out this year was the lateness of egg-laying. First egg dates were about 3 weeks later than in most previous years.  It's easy to assume that was the result of a cold and wet spring.  But last year was a cold and wet spring as well and egg dates were as expected.  So...a mystery to be solved.  How do bushtits decide when to lay their eggs?  I have no idea.  Moving on......

Because eggs were laid so late, there were no fledglings at all until almost the end of the season.  I verified that this was weird by looking at past year's field notes.  In June we usually see fledgling flocks all over the place.  This June we saw very few.  And these few were "accounted for" fledglings.  In other words, they were fledglings from known nests.  That verified that we hadn't missed a bunch of earlier nests.  They just didn't exist.  

Late nesting also meant that no nests were reused for a second brood.  Which means only one brood of kids was added to the population.  But all was not lost!  Maybe because they nested so late, predation on nests was relatively (relatively) low and those kids that did hatch fledged successfully at a higher rate.  So a trade-off.  

Ok.  That was the boring update.  As in previous seasons, there are some fun stories to tell about the little guys and I will (try!) to post those over the next few weeks.  

So, stay tuned!!