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.