Monday, March 7, 2022

The first nests of 2022!!

I've been back in Portland for about a week and have encountered only flocks -- foraging and behaving un-interested in nesting.  No chases.  No little wing-flutters of romantic interest.  Nothing but food, food, food albeit in smaller flocks than those found in the winter.  We've found some old banded friends hanging out together.  That's been rewarding, but no nests.   

This is typical of March in these wet and raw climes.  Who wants to build a soggy nest on a soggy day?  Better to wait for a nice sunny one.  Which is what we had this afternoon.   On a sunny day, even when it's cold, food is easy to find.  A nap can be taken in the warm rays.  I have found that sunny early afternoons are prime bushtit nest-building time during this unpredictable time of the year.  

And so it was no big surprise when my assistant, Amit, found the first nest of the year around 1PM.  It's a loose hanging sack -- somewhere between a Stage 2 and a Stage 3 -- entangled in the lower branches of a very large juniper and only about head high.  Nice!  The unbanded pair was building rapidly, but quit around tea-time when all good bushtits without completed nests return to their flocks to forage and prepare to find a cozy, safe place to huddle together for the evening.  It's one reason early bushtit nests take so long to build --- the work day is short.  

The next nest was only a Stage 1.  It was a thick and sloppy tangle of spiderweb fixed to the small fork of a branch hanging on the very lower branches of a hemlock.  If it survives, it will be an easy nest to watch and to band at.  If it survives.  Already the goldfinches were there pilfering spider web.  The bushtits were annoyed and tried to chase them off but, unfortunately, the goldfinches made off with about half the load.  Only time will tell if this means the nest-site will be abandoned. Even if it is, it's likely the pair (also unbanded) will build nearby.  

Fingers crossed!! 


 

Tuesday, February 22, 2022

Interlude......San Juan Island bushtit story (2014 and earlier)

 I thought it would be fun to insert a draft from the book I've been writing that chronicles my research (and parts of my life) on bushtits beginning in 1986.  I began my research in the Sky Islands region of southeastern Arizona, briefly tried to study long-tailed tits in Spain, and then finally settled in the Pacific NW, beginning with the San Juan Islands.  This excerpt is about my short time on Shaw Island.  Just for fun:


Many years ago, in 1997, when I was contemplating moving my bushtit study to the Pacific NW where I, as a redhead, wouldn’t have to deal with the heat and the sun, I explored the possibility of the San Juan Islands in Puget Sound near Seattle.

These islands are beautiful and have the advantage of having a far lower yearly rainfall than the coastal areas of Washington, which deserves its reputation for being wet.  The islands are also relatively undeveloped so that there was plenty of land for bushtit habitat and little “suburb” to negotiate.  And there was a field station, albeit primarily for fish researchers, conveniently situated on the largest island of San Juan. Having lived at SWRS for so many years, I recognized the advantages of having colleagues and meals provided, leaving the days free to follow bushtits.  

 

So my husband Drew and I, dragging our then 1 year old Ellie and 6 year old Hannah, across the country (again) settled into a modern and comfortable apt within Friday Harbor Lab of the University of Washington.  Unfortunately, it was too early for the fish folk and so the dining room was closed.  But we had our own full kitchen which also made for a convenient bathtub for the baby. 

 

One of the things I learned about bushtits in the San Juan’s is that they are relatively new immigrants to the area and that they inhabit only a few of the larger islands.   In fact, they were observed on San Juan for the very first time in 1935.  (Coincidently, the same year Alexander Skutch described them as having helpers at the nest in Guatemala.)  Before then….no bushtits.  In retrospect, that makes sense.  Bushtits are pretty bad fliers.  They certainly can’t make any kind of distance easily.  Flights are usually confined to kind of weak, wave-like movements from tree to tree.  During the nesting season, pairs collect nesting material and often fly a great distance (for a bushtit) in a beeline to the nest.  But I can’t imagine any bushtit thinking it was less than suicide to cross a large body of water.  

 

On the other hand, it’s relatively easy to imagine one being blown off-course in a violent storm.  But you need more than two birds to make a flock, or even a nest.  So one bird would be a dead end.  Literally.  (It’s even possible, I suppose, that early bushtits somehow clung to the ferries that made their way from island to island.  But that’s a little far-fetched.)  

 

Females, as I’ve mentioned elsewhere, are the primary dispersers and so I imagine the first group of bushtits making it to the islands were female bushtits in small groups.  They must have arrived with great hope, only to find no males.  So no nests. And they died lonely spinsters.

 

In any case, since 1935 some brave or unlucky or stupid bushtits did eventually make it to San Juan, Orca, and Lopez and established themselves as breeding flocks. 

 

But my greatest hope in the San Juan islands was an outpost of the University of Washington on the smaller Shaw Island.  It had a cottage specifically reserved for researchers and two full-time caretakers.  There were no facilities (shopping and such) on the island, so shopping trips had to be made to one of the larger islands every two weeks or so.  But it was university property and plenty big enough for my research, especially if I included the convent property next door.  And my understanding was that the sisters were quite bird-happy and would welcome a project on their farm.  

 

So we headed out to Shaw Island with great hopes for a new research site.  After all, the distance between Orca and Shaw was a miniscule 2000 feet so. Surely, since 1935, they must have made their way to Shaw!  

 

But they hadn’t.  What we found was perfect bushtit habitat everywhere (brambles, old farms, etc) …..but not a spit.  Not a feather.  No bushtits at all.  A call to the local Audubon confirmed my fears.  I had the perfect new study site without any study animals.  Very disappointing.  

 

So we looked over the other islands as well, mostly as hikers and tourists, and found the bushtit densities weren’t particularly high and there was enough private land to make things difficult.  So I scrapped the idea and planned to head back to hot and sunny Arizona for yet another year (which turned into thirteen).  Oh well.  

 

Fast forward to 2014.  A good eighteen years later.  Arizona is no longer viable for me or for bushtits.  Not only are there unpredictable and potentially dangerous drug-runners in the Chiricahua Mountains, the droughts have decimated the bushtit population in these already desert mountains and so, if I want to study bushtits in any numbers, I really have to go elsewhere.  

 

And so I remember the San Juan Islands….beautiful and cool and possibly, eighteen years later, swarming with bushtits. Or so I can hope. The 1935 invasion was just the beginning and perhaps they have managed a bigger foothold by now.  In fact, it’s possible Shaw now has bushtits. What a wonderful thing that would be! I make a few quick calls to local birders who think here are bushtits on Shaw now, but they aren’t entirely certain what the population looks like.      

 

So, in 2014, Ellie and I settle into the “cottage” on Shaw Island, navigating a narrow one-lane road along the edge of the island and then a rather harrowing muddy dirt road to get to the cabin which sits right on the water.  This “cottage” is nothing I ever expected.  It’s just one room, but that one room has a full wall of floor to ceiling windows attached to a wide mossy deck over-looking the sound.  From here we can watch fishing boats, sea otters, whales, and all the other watery goings-ons in Puget Sound.  

 

The rest of the cottage is pretty bare-bones and smells strongly of mice.  It hasn’t been inhabited in awhile. After our first night there, that is verified.  The kitchen counter, although cleaned the night before, is covered with mouse turds.  So….mouse wars begin.  I don’t like killing the little guys.  They aren’t just house mice.  They are Peromyscus (wild white-footed mice) and actually belong here more than we do. As happenstance would have it, we accidently find the perfect solution.  At the bottom of the plastic trashcan our second night there is a trembling wide-eyed little rodent.  He’s been able to get in, but not out. Perfect.  At night we store the trash in the refrigerator and turn the plastic trashcan into a mouse trap:  a bit of tempting peanut butter at the bottom with a paper towel for cover.  The first night, we catch 3.  The second night 2, then one,  then…..none.  We are mouse-free.  Each of the little creatures is gently released far from our home near a dumpter that looks to me like mouse heaven.  

 

Ok.  Back to the bushtits and the solution to the mystery I am sure you (all three of you) are dying to hear about.  Are there bushtits on Shaw Island? 

 

Well……the first foray Ellie and I take out “into the field” is a success.  We find a fairly large flock of bushtits foraging on the edge of the field near the main House where the caretakers live.  Very exciting!  We decide to follow them for as long as we can.  That turns out to be easy.  They stay ---- for the entire day --- foraging in the brambles on the edge of the field.  Ellie and I take turns napping.  Six solid hours of nothing.  But at least we have bushtits.  

 

The next day is the same.  And I should point out that this seems odd.  Most bushtit flocks move large distances each day.  This flock seems perfectly happy to stay in one spot.  At one point they stray into the brambles in the middle of a large field nearby.  But that’s it……..

 

………until the next day.  Full of optimism (but not looking forward to another day of naps alternating with boring foraging bushtit observations) we head over to the brambles and, lo and behold (or rather not behold), there are no bushtits.  So we search.  And search. And search. We search the entire university property.  We get in the car and search the entire island by road (discovering that there’s a rather ritzy section at the other end -- Bill Gates lives there.)  And we find nothing.  No bushtits .  That goes on for a couple of days during which we are alternately mystified and supremely frustrated.  Where the hell are they??  

 

Finally on day three we find them (although without banded birds we can’t be certain they are the same birds) on the university property, but at the other end and near an old bunkhouse that is infrequently used by university classes.  The setting is beautiful.  Lovely old gnarled and flowering trees.  The gorgeous blue sea with the other islands on the horizon.  Seals.  Grassy lawn-like open areas.  Sun.  A convenient and clean outhouse (!!) in the woods.  

 

It’s a change from both our bushtit-less existence over the last few days and the long, boring days watching the flock live a sedentary existence in the brambles near our cottage.  

 

I don’t want to dwell on Shaw Island for too long because, honestly, it wasn’t too exciting.  We frequently lost the birds for days on end and then they would mysteriously reappear in an unexpected place.  Over the weeks that we were there (which seemed much longer) it began to dawn on me that we were probably watching only one flock with a very, very large home range: the entire island.  That would explain why they were so hard to find. 

 

The other odd thing about this flock (if it was the same one) was the ratio of males to females. There were far more males than one would expect in the usual bushtit flock.  And, when they finally began to nest, we found only two nests. 

 

So it dawned on me:  what we were likely looking at was a founding flock.  Shaw Island, just 17 years before, had no bushtits.  Somehow bushtits had made their way here and successfully bred.  But bushtits have one major flaw that makes it difficult for them to successfully and rapidly colonize an island.   Only the males are philopatric and stay with the natal flock.  Females, on the other hand, migrate out at the beginning of the spring to find a new flock to join and find a mate in.  But…….these females had nowhere to go.  There were no other flocks to migrate into.  They likely searched and searched to no avail, eventually succumbing to the elements as lonely spinsters.  Sad. And not a good way to increase a population.   

 

In the meantime, speaking of sad, I was succumbing myself to a kind of melancholy lethargy.  I began to mutter things like “Maybe I should just stop studying bushtits.” and “This is discouraging.  Let’s go home.”  I began to loose my enthusiasm.  But Ellie, wise Ellie, wouldn’t have anything of that.  “Why are we staying here, Mommy? she said one day.  “You know there are bushtits in Discovery Park in Seattle.  Why don’t we go there?”  

 

I had dug my heels into Shaw because of the lovely living conditions and the large university property but I had to finally see the reason in Ellie’s words.  We should at least look at Discovery Park even though it was in the middle of a city and really wasn’t a very appealing place to work.  

 

So we went.  And we found bushtits.  We found lots of bushtits.  We were tripping over them (not quite literally, but certainly figuratively).  In a few short days we found and watched six active nests.  Six happy nests with spitting and active bushtits.  Every block in the developed areas had at least one breeding pair.  It was bushtit heaven!  And my sprits rose --- as Ellie had predicted.  Bushtit, ho!   I had found my new study area.  Whew.   



So that's bit of the Washington story.  But.....but.......I'm in Portland!  So, Discovery Park wasn't my new study area, was it?  To learn more about that story, you'll have to read the book.....   

 

               

 


     

 

 

 

Saturday, February 19, 2022

Valentine's Day.......

 ......and, I'm guessing, bushtit love was in the air.  At least I'm guessing nest-building was already under way in Portland.  I'll be there in a little over one week to see for myself.  

The bushtit nest is one of the most remarkable features of bushtits and is, as all nests are, a physical and permanent (sic) manifestation of a behavior.  If you haven't seen one, take a look at my entry on March 6, 2020.  That was a lovely nest. 

The bushtit nest is a major feat of engineering with a combination of lichen and spider web serving as the stretchy scaffolding.  You wouldn't know it just by looking at them, but the combination is magic.  Spiderweb and lichen both have velcro-like properties such that they stick together and become extremely malleable.  Together they are material of choice for many other species as well:  hummingbirds, vireos, goldfinches, etc.  

Although in the 1930s, Evelyn Addicott described two modes of nest-building in bushtits, I've only seen one.  I suspect she interpreted different states of completion during what I call "Stage 3" (see below) as different building methods.  In fact, "Stage 3" is a broad category and encompasses several substages. It's also possible she was observing nests that were also being pilfered by nest-material thieves.  These can appear very holey and thin and are often abandoned.  

So what are the nest building stages?  I'll describe them here.  I'll find pictures and post them here another day.  

Stage 1 is barely visible at first.  It consists of a hint of spider web and lichen on a branch or in a fork between two branches.  You'd never notice it on your own.  The only way to locate an early Stage 1 nest is to see the birds carrying material repeatedly to the same area in a tree.  If you see that and can't make out anything in the area they are going to, you have found one!   Sometimes you can see them placing the material and even stretching it and securing it with their beaks.  But it can certainly seems almost imaginary.  As the nest progresses, though, a late Stage 1 nest becomes a thin platform of lichen and spider web that stretches between two tiny branches or, sometimes, just a blob of spider web and lichen in, say, a clump of mistletoe.  BTW, this is often a "trial and error" stage.  At this point the bushtit builders are still gauging (in whatever mysterious method they are using) the suitability of a particular nest site.  Consequently, Stage 1 nests may appear and disappear....and even reappear.  It happens.  

Stage 2 is when you finally see something resembling a nest -- although not a bushtit nest.  A Stage 2 nest is a simple cup.  The birds have completed the platform (Stage 1) and are now bringing in more material and are sitting in it and moving about to stretch it downwards so that the cup hangs.  This is were the strength and flexibility of the spiderweb/lichen combo becomes so important!  As it stretches longer and longer is gradually morphs into a...

....Stage 3 nest which is a long hanging sack without a hood.  Stage 3 nests can vary a great deal.  They can look quite flimsy if the birds stretch more than they bring in new material.  If they are experienced breeders, they will be careful to bring in enough material so that holes never appear and the sack, although thin, seems pretty substantial.  During Stage 3 the nest reaches its full length and material is added to the bowl at the bottom of the sack to strengthen it as the "true nest."  

Once the sack area of the nest is substantial, the birds begin to fashion a hood and work primarily on that and the outer parts of the nest.  This is a Stage 4 nest.  It's not finished but it finally looks like a bushtit nest with its characteristic gourd-like shape and a hood near the top with a side-facing entrance.  But it looks rough and the entrance is barely complete.  Once the nest is at a Stage 4, the adults will sleep in it;  if there are more than 2 building, they will all crowd in.  

Stage 5 I reserve for that "perfect" finished bushtit nest.  It's tightly put together with a substantial hood and a clearly defined entrance that has been lined and tightened so that only a bushtit can enter.  Sometimes, the entrance even extends a bit out from the nest like a short tunnel.  It's festooned with moss, spider egg cases, and other material from the environment to camouflage it as mush as possible. At this point, there is little building activity.  Feathers are the primary material brought in now as they fill the nest with hundreds they find in the area.  I can never figure out how they find so many!!  

The final product is truly beautiful and a masterful structure that has taken up to 3 weeks to finish.  Which is all the more annoying when it's torn to shreds by a predator!   For me and for the bushtits.  

So that's the overall process.  This can vary in some interesting ways which I'll elaborate on in future posts.  In the meantime, that's a start.  




 


Saturday, February 12, 2022

Do helpers really help?

Bushtits have  the distinction of being one of the very first birds described as having "helpers at the nest." That was in a paper by Alexander Skutch in 1935 in which he described this unusual behavior in only three species.   And the bushtit was honored to be among them.  

A helper at the nest is a nonbreeding (so we think) feeder of the nestlings.  Sometimes they also defend the nest and, in the case of bushtits, also sleep in the nest at night.  The bushtit helpers Skutch described in Guatemala were young birds who were helping their parents raise another brood in the same season.  Since then, it's become abundantly clear that "helping behavior" is far more complex and confusing than Skutch had imagined.  I won't get into the details here.  

One of the most enduring questions about helping behavior is:  do helpers really help?  After all, more birds feeding at a nest may attract predators.  Young birds feeding nestlings may be bad at their job.  There are many reasons to believe "helpers" may be detrimental.  Or maybe their "help" is neutral.  Maybe they help but their help really doesn't do anything positive or negative.  Maybe they do it just for their own reasons too numerous to be listed here.  

This whole issue is very complicated, especially now that we have DNA to figure out if maybe there are even more complications to this interesting story.  So I'll stick to one interesting observation in April in Arizona that provided me with, I think, one possible answer for bushtits.  And I mean just one!   This is just the tip of a huge iceberg.  

One relatively cold day in Arizona, I had 4 nests that were ready for banding; the nestlings were all about 10 days old and the nests were easy to reach. We had been watching the nests almost every day and knew that one was attended by 3 birds (two adult males and one adult female).  The other three had only 2 birds:  one male and one female.  

The night before banding had been exceptionally cold for the season.  My recollection (without checking my notes which are buried in a box in my office) is that the evening low dipped well below 25 degrees.  That's very unusual for early April, even in the mountains.  Still, I expected nothing out of the ordinary.  Bushtit nests are nice, warm, down sleeping bags and the attendants sleep in the nest at night.  I fully expected all would be well. 

But it was not to be so.  The first nest contained a sad surprise:  5 cold, dead nestlings.  They were otherwise perfect.  They had obviously died overnight.  The parents were no longer in attendance, but that wasn't surprising as we were there mid-day and they must have had the morning to figure out that their kids were no longer hungry.  Very sad.  

We carried on and opened the next nest....with the same sad result.  A lovely brood of, you guessed it, 5 cold and dead nestlings -- all banding age and healthy-looking --- but dead.  And the same was true of the third nest.  

But the fourth nest was a different story.  This nest was the one nest with 3 birds attending.  At this nest, the nestlings were alive and well and we could carry on with our task of banding the little guys.  The attendants actively fed while we did this --- as I always remove only half the brood at a time to process so the attendants don't get upset by an empty nest.  (Fortunately, they can't count.)  

So why did this one brood survive the cold night?  I can think of some possibilities...all of which may be true and all of which involve the 3rd bird.  

The first possibility is that 3 adults sleeping in the nest during a cold night kept everyone warmer than in the nests with only two adults.  So these nestlings spent the night in relative warm and safe comfort. They weren't cold-stressed and that was due to the extra warmth provided by third bird.  

Another possibility is that 3 birds provisioned the nestlings the evening before and perhaps even in the early morning hours with more food --- and therefore energy --- giving them plenty of energy to deal with the unusual overnight cold.  

The final benefit the 3rd bird may have provided was extra food on a daily basis.  It may be that the surviving nestlings went into that cold night with greater reserves because they had been fed at a greater rate than the others with only 2 attendants.  (These are actually data I can look at once I extract those notebooks from the box!!)

Regardless of the mechanism and the small sample size, I am willing to suspect that this extra bird was indeed "helpful."  His actions may have saved the lives of the nestlings he was helping to feed.  And for him, sleeping in a warm nest most certainly saved his life as well.  

So, in this case, the helper was actually helping.  Chalk up one point for "helpers do help".......at least sometimes.   

  

 

Wednesday, February 9, 2022

Toilet paper bushtits



I am posting an amusing (and somewhat disgusting) video taken by Amit Gordon in 2020.  It's exactly what you think it is:  a pair of bushtits gathering toilet paper for their nest.  Ugh.

Bushtits build their large, pendulous nests using spider web and lichen as the brick and mortar.  But they do add other elements they find in their environment --- twigs, leaves, moss, etc.  Unfortunately, if toilet paper is available --- and it is in Oaks Bottom in some areas --- they will also gather that and incorporate it as well.  We call these nests "toilet paper nests" as it's pretty obvious when they add the stuff.  They look a bit white and fluffy.  

When I first saw one festooned in such a manner, I worried that it would dissolve when it rained.  I mean, that's what toilet paper is designed to do, right?  Eventually, anyway.  But the first TP nest surprisingly survived to fledging and was even reused in the same season.  

Not so the nest of this little pair.  I think they used so much toilet paper, the nest only progressed to a loose hanging sack.   And then it simply fell out of the tree.  There just wasn't enough of substance to keep it together.  

My guess is these were first year birds.  Maybe they learned their lesson.  Maybe not.  




 

Tuesday, February 8, 2022

Do bushtits grieve?

This is really part of a much larger, controversial, and more philosophical conversation that should be had at some point....but most certainly won't grace the pages of this blog.  Nonetheless I do think it's worth a brief mention here:  

There's a fine line between empathizing with your study species and out-and-out anthropomorphic interpretation of animal behaviors.  It's a line that's not easily drawn when you've spent as many years with one species as I have ---- even if that species is only a tiny drab-grey bird.  

But I do think it's important to point out that, as a behavioral scientist, I firmly believe that animals have emotions comparable to our own.  Why do I think so?  I do so for a variety of reasons.  First, we share the same functional responses internally to similar external stimuli.  Danger releases adrenaline, causing us to behave appropriately to that lion we've just encountered.  Run!  (or fight!) Prolactin is released at the sight of babies.....or nestlings.  It's why my hollering baby didn't get thrown out with the bath water.  And it's why birds feed their begging nestlings.  I could go on and on.  Suffice it to say that we all share the same chemicals causing us to behave appropriately -- thereby surviving and, eventually, reproducing. 

That's the functional angle.  But what about feelings?  I have always tried to convince my students that feelings are what we feel when we are flooded with those chemicals.  They are what cause us to react as we do.  If you get injected with adrenaline, you feel fear or anxiety.  If you are injected with prolactin, you feel a warm glow.....nurturing and patient.  I'm being simplistic, but I think you may get my point. There is no reason not to believe that a bushtit loves its nestlings any less than I love my own children.  Love causes us to put up with parenting.  And parenting passes on our genes.  

Which brings me to the subject of today's blog:  Do bushtits grieve?  

I believe they do.  And, of course, I have a story to illustrate my point. 

One of the nests in 2018 on Reed campus was found in March --- early in the season.  It was just on the water's edge deep in "The Canyon" and was found by Gary Granger.  By the time I saw it, it was almost finished and stood out starkly against the sky and water.  It was built well into some very tall grasses and reeds, but was not cryptic at all.  In fact, it was a very obvious nest.  

Being obvious doesn't seem to doom bushtit nests.  Many that I feel are fated for destruction because "how in the world could that jay over there not see that ridiculously obvious bushtit nest??" survive just fine.    Others that seem carefully hidden -- so much so that they are practically impossible for us to watch -- are torn to shreds within hours of hatching or even earlier.  So being out in the open couldn't predict this nest's final fate. 

The attendants were an unbanded female and a banded male (LGXL).  They seemed a happy couple, bringing feathers to the nest fairly frequently and not nearly as noisily as some.  I had fond hopes the nest would survive and produce a batch of healthy fledglings. 

Eventually it was clear that they were incubating eggs.  The unbanded female and LGXL had became furtive and silent around the nest, exchanging incubation duties with only a quick "spit" to alert the incubating bird to its replacement's arrival.  A quick, almost imperceptible, exchange and then silence.  (This is why watching incubating nests in positively maddening.....they switch so quickly, it's hard to read bands.) 

One day, however, I arrived for a watch only to find the nest in tatters.  Feathers were everywhere.  It had clearly been someone's lunch and the contents were now digesting in someone's belly.  In most cases, when I come across a destroyed nest, the parents are no longer in sight.  They have taken off to begin a new nest or to try to kick a neighbor out of theirs.  But that day was different.  LGXL was there alone --- there was no sign of the unbanded female. The sky was dull and the gentle wind ruffled the scattered feathers, sending them further from the now defunct nest site.  

LGXL seemed listless.  He was silent and hopped slowly around the area.  Several times he dropped to gather a small feather and bring it up to what remained of the nest. Once there, he hopped slowly about a bit and then discarded the feather only to try again a few minutes later.  His entire aspect can only be described as "dejected."  He spent some time perched on a nearby branch, puffed and silent, and then began his random and pointless feather-gathering once again. 

It was hard to watch, what can only be described as, this sad, little bird.  He seemed so lost and lonely.  Usually when a bushtit gathers feathers, they are quite animated and noisy.  I would  describe it as a "joyful" time.  Not so this quiet, listless gathering of lost feathers and bringing them to the lost nest.  

I thought at the time that LGXL was just there soon after the predation had occurred and that this might explain his unusual behavior.  I also wondered if he had lost his mate as well to the predators.  That does happen, although rarely.  I watched for awhile and then left him to continue in solitude.  I fully expected him to be gone the next day.  

But he wasn't.  He was still there.  He wasn't quite as focused on the nest as he was the day before, but he was still hopping about slowly and occasionally picking up a feather only to set it down almost immediately.  After awhile, he seemed to give up and fly across the canyon to join a known pair who were foraging on the other side and whose nest I hadn't located yet.  It was just the 3 of them, making me even more certain LGXL's mate had perished along with the nest.  

Over the next week, I saw him near the destroyed nest site a couple of times, but for only brief periods.  It was as if he returned once in awhile in the vain hope that the nest and his mate was still there.  

As far as I knew, he never found another mate.  For the rest of the season, I saw him rarely and only alone or in the company of a small flock.  The following year, he was gone -- presumably he had died over the winter.  

So that's the story.  Make what you will of it.  It's hard not to imagine LGXL wasn't grieving his loss -- and for more than a single day.  Imagine his plight.  One day he was incubating a clutch of eggs in his warm, safe nest, switching incubation duties with his mate, and cuddling up with her and the eggs every night.  Then suddenly it was all gone.  No eggs.  No nest.  No mate.  It makes sense to me that he would be grieving --- and his grieving behavior wasn't particularly productive.  It didn't help him.  It was depressive.  He didn't find a new mate.  He didn't rebuild his nest.  

For what it's worth, I think he really was a sad little bushtit.         

   

 

 

 


Friday, February 4, 2022

If at first you don't succeed......

 ......try, try again...and again, and again....ad nauseum

In Arizona, a nest failure often resulted in intense competition for neighboring nests within the same flock. Sometimes the interlopers were successful at booting out the residents.  Sometimes they weren't.  When they were, the original residents were faced with their own nest-less dilemma and went off in search of a handy nest nearby to try to takeover.  When competitors weren't successful, they tried elsewhere or finally built their own nest.  Sometimes they reached an uneasy truce with the residents and joined the nests as "helpers."  But in almost every situation in which a nest was lost, the homeless pair would at least try to take over someone else's nest first.  

Not so in Portland.  Although I do see competition for neighboring nests on occasion, most pairs who have had their nest torn to shreds by a predator and the contents devoured, seem to move right into building their own real estate.  

One, rather extreme example from 2021 immediately springs to mind.  It involves a female on the Reed campus banded as RREX (roar-ex) who now holds the record for number of nests built in a single season.  We suspect she was a SY female (hatched in 2020) based on her behaviors and choice of nest sites early on....none of which served her well!  A supremely inexperienced bird perhaps.  

RREX's first nest (RD-3) was in the same place as a 2020 nest in a pine over-hanging a busy walkway on campus.  It wasn't very cryptic.  Nonetheless, she and an unbanded male (UnbM) managed to hatch a brood of chicks....which were eaten and the nest destroyed only 4 days after hatching.  Ah well.  

Just a day later, RREX and UnbM were pilfering nesting material from the remains of a neighboring nest that had also met the same fate and were well on their way building a new nest (RD-29) just a few yards from the one supplying nesting material (thrifty birds!)  in the same tree high in the lofty branches if a huge pine.  Dumb move, RREX.  Um......maybe the destroyed nest should have been a clue???

Only a few days into that rapid build, RD-29 was destroyed, likely containing eggs given that it was almost complete and RREX and her mate were ready to go, so to speak.  

Score ----  RREX 0: Predators 2

But RREX was not deterred!   On the day we found RD-29 in tatters, RREX was again building yet another nest (RD-34).  This one was built in record time, reaching an almost ready state in just a day.  It was small and shoddily put-together, but seemed to suffice because -- you guessed it -- 3 days later it was also history.  

Score --- RREX 0: Predators 3

Was RREX done yet?  One would think so.  But, no, she was wasn't.  Her 4th nest nest was found that same day.  This time it was up against a building in a small deciduous tree and was very well-concealed.  Maybe she had learned a lesson?  Nope.  Four days later, it was nothing but a lump of spiderweb, feathers, and lichen on the ground.  

Score:  RREX 0; Predators 4

At this point we were in wonder at this plucky little bird.  She seemed determined to build a nest that would survive the season, no matter how many tries she had to make.  And so that same day.....

.......we found RD-40, which progressed very rapidly.  This time she had placed the nest in one of the most least cryptic places imaginable.   It was in the top of a bush right next to the entrance to the Psychology building.  It was extremely obvious but, perhaps somewhat protected by its people-heavy location.  Or so we (and she?) hoped.  But, alas, it was not to be.  After a few inactive, but hopeful, nestwatches, I discovered a hole near the top of the nest.  Apparently predators had come in and removed the contents without destroying the nest.  It happens.  

Score:  RREX 0: Predators 5

That's a record.  I have never seen so many rebuilds, and so rapidly begun, by the same bird (we assume the same pair even).  It not only emphasized the dramatic predation rates we were seeing in Portland in 2021, it also flew in the face of my early assertion, based on Arizona birds, that failed breeders attempt a takeover if they can.  RREX apparently never did.  

So what happened to her eventually?  Well, just a day or two after I ascertained that RD-40 was toast, I did see her in the vicinity being actively chased and courted by 2 males at the same time.  So she was still a hot commodity and still interested in nesting.  There even might have might have been a Nest#6 (or even #7) somewhere.  But we will never know.     

But I do know she was still around in the fall.  I found her in a massive flock one day among many other  banded birds on Reed campus.  The next day she was the only banded bird in a flock of about 10.  They were making a leisurely loop taking in some of the nesting areas RREX had used that spring.  Could it have been RREX and her (finally) kids?  

We'll never know.     


 




Thursday, February 3, 2022

TOTX

Sometimes someone sends me a photo so stunning, I can't help but share it.  Today I'd like to post this beautiful photo of TOTX (tots) taken by Tony Freixas.  Thank you, Tony!  


Since we have his picture, I'll tell you a bit about TOTX and his life this year.  It was a difficult one but also very interesting and intertwined with the lives of his neighbors.  

TOTX originally had a lovely nest (RD 2) in a backyard immediately adjacent to Reed campus.  It was found during the last week in March in a very early stage and was low-hanging fruit, nestled in a thick vine just a few feet off the ground.  Nonetheless, it was hard to watch because a tangle of thorny berry bushes grew up along the border of the garden and campus so that short people (me) had a very hard time seeing over and into the yard.  Fortunately, the owners of the yard generously allowed us in to watch the nest and all was well.  We even had a chair to sit in.  A nice perk.  

But TOTX was a bit of a pain.  He was a very noisy bird.  Not only was he noisy near the nest, he was noisy no matter what.  We could always tell he was in the area and exactly where he was with his mad spitting.  And he wasn't just spitting at us.  He was spitting at the world.  The female (who remained unbanded) was much more discrete when she arrived alone.  But TOTX was often found following her about noisily, during nest-building, egg-laying and even after the kids had hatched. I don't know how she put up with him.  

TOTX's loud personality eventually got him in trouble about 10 days after his eggs had hatched.  Predators finally got the hint and found his nest, ripping it to shreds and undoubtedly feasting on the contents.  End of RD 2.  But not the end of TOTX (and, we assume, the female he was with).  

Just 2 days later he was seen visiting at the nest of his closest neighbors (RD 24) only 50 meters south of his destroyed nest.  The residents, PXPW (female) and ERYX (male) had built their nest also unusually close to the ground...about 6 feet.  It was pretty obvious hanging in the dense shade between two very large pines.  Its saving grace, however, was the vines and low branches that also hung around the base of these trees so that the bird's comings and goings were not too obvious.  During this visit, TOTX just hopped about and peered in.  PXPW and ERYX seemed unperturbed.  No fuss.  Just a friendly and quick perusal of the neighbor's real estate.   

However, only two days after TOTX's first visit to the nest he was found visiting again.  This time things were very different.  ERYX was nowhere to be seen.  TOTX, an unbanded female, and an unbanded male were all there making a fuss around the nest where PXPW was incubating eggs.  The unbanded female was ripping nesting material from the nest and the unbanded male was trying to court poor PXPW.  It was all very puzzling.  Where was ERYX?

Well, it turns out that, unbeknownst to us at the time, ERYX had found an unbanded female (perhaps the nest-material thief at RD 24 and even perhaps the female at RD 2) and had been building a new second nest (RD 41) not far away.  In fact, it was almost complete by the time we found it that very day.  ERYX had apparently abandoned  PXPW to incubate on her own while he established a new nest with a new female.  Yet another bushtit cad!   

Important note:  We don't know who the female at RD 41 was as she was unbanded.  She may have been TOTX's mate from RD 2.  Or she may have been just another unbanded female.  We will never know in part because......

.......just 2 days later TOTX was visiting RD 41.  In fact, TOTX, PXPW, ERYX, and an unbanded female were all there together.  This time TOTX and ERYX were aggressively chasing each other and TOTX was observed entering the nest repeatedly.  Just two days after this TOTX and an unbanded female were clearly victorious and were the proud new owners of RD 41.  ERYX was now back at RD 24 with PXPW, vanquished and again a dutiful dad, helping her incubate and feed once the nestlings hatched.  

All seemed well for TOTX and the unbanded female at RD 41 as well.  They finished building the nest which was well-hidden in a hanging branch of a very high deciduous tree about 15 feet over a sidewalk.   Both birds were very careful in approaching it.  TOTX seemed to have learned his lesson and was not the noisy idiot he had been at his first nest.  The nestlings hatched and we were anticipating getting up to them soon for banding and blood for DNA until......

.......disaster struck in the form of the heat dome.  RD 41 was one of the casualties -- all the nestlings perished.  It was sad for us and undoubtedly sad for TOTX as well. 

But, happily, he survived.  The picture above that was taken in the winter attests to that.  Hopefully we will see him again this spring with a brand new nest.    


  

   

Monday, January 31, 2022

Thoughts on bushtit numbers after the heatwave

I've noticed quite a bit of conversation in OBOL re the heat dome and resulting bushtit numbers.  Rather than comment in OBOL, I thought I'd offer my thoughts here so that a larger audience can see them if they want.  These are just thoughts.  I have no answers! 

First, every single banded adult at the eight nests survived the event. So, at least from that small sample, there wasn't any adult mortality.  In addition, many other banded birds have been seen since.  I'll have a better idea of adult mortality when the breeding season begins next month.  But even then, I won't know the cause if the % survival is lower than usual.   

We have found about 100 nests/year over the last 4 years in Portland.  I have never had a nest with dead nestlings before.  The only other time was just once in Arizona after a freak cold spell: 3 out of 4 banding-age nests contained dead nestlings.  The only surviving brood had 3 adults feeding at (and sleeping in) the nest.  

On the other hand, predation rates were exceptionally high this year in Portland.  Personally, if there is a dip in bushtit numbers, I would expect that had a greater effect on the population than the heat dome, given that the heat came very late in the nesting season.  

Bushtit numbers in the winter are hard to come by.  As they are in large and mobile flocks, you either see them.....or you don't.  Many CBCs miss bushtits.  But that doesn't mean they aren't there!  I think the best way to get an indication of the robustness of a population is to count flock size.  Not estimate.  Count.  That means catching them as they cross a street or from tree to tree and counting them as they cross.  Big flocks in winter=healthy population.  

The problem is the occasional small flock doesn't mean much.  This November and December, I found the same bird in both a monster flock of >50 and messing around for over an hour in a smaller flock of 10.  So....she's was doing both.  I think if you go out often and see only small flocks of <15 birds, that may indicate a problem.  

The heavily-feathered bushtit nest is great at insulating against cold.  But it also serves to protect against heat.  I did a short study in AZ several years ago and found that the interior of a bushtit nest stays at a reasonable temperature even in full sun on a very hot day when the exterior nest surface temp rose above 120 degrees.  In Portland this year,  WT 12---the 3-bird nest that lost all 6 nestlings during the heatwave---was a small nest with very little insulation.  It was mostly in the shade, BTW.  The one nest with eggs during the heatwave was a pretty bizarre nest (the 3rd nest for the pair that year) with uncharacteristically thick sides and many feathers.  Perhaps that saved it?  Who knows.  It was also partly shaded as were most of the nests at that time.  

One more point:  Nests that survived were  significantly closer to water.  Water is essential to prevent dehydration which is the primary cause of death in the heat for birds.  We (Amit Gordon, Ian Connelly, and I) wrote all these observations up for publication and it is currently in press in The Wilson Journal of Ornithology.   

Hope all that is of some interest!  Comments and additional ideas welcome.  




Sunday, January 30, 2022

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!       

Saturday, January 29, 2022

The deadly heatwave of 2021

No recap of the 2021 bushtit field season can fail to omit the effects of the unprecedented heat wave on bushtit nestlings.  And it wasn't good news.  It was, in fact, quite sad.  And informative.  Unfortunately.  

In late June, a "heat dome" settled over the Pacific Northwest for 3 interminable days.  It was record-setting and completely out of the range of normal for the area.  Completely.  Each day the temperature climbed.  By the 28th of June it was 116 degrees in the shade.  Walking to the grocery store from my house -- only a 5 block trek -- felt risky.  My daughter, her partner, and their cat joined us in my 800 sf house which we tried to cool to barely acceptable with 2 ACs.  Even so, we had to partition the house into one small space, leaving the rest of the house to bake.  We all became vampires...avoiding the day and going out only at night for "fresh" 100 degree air and short strolls around the neighborhood.  

But what of the bushtits?  How were they faring?  It was the tail end of the field season and we had only 8 active nests.  One of them was close to fledging age.  One was still incubating.  The other 6 had nestlings....some very young, some older.   One of these was a nest (WT 12) we were particularly interested in as there were two males and one female.  All three birds had built and incubated and were now feeding.  We were, understandably, anxious to get blood samples from the nestlings once they were old enough.   Were both males co-dads??  It seemed highly probable.  So that was the only nest we kept tabs on for those 3 days.  One of us would head out at dawn, watch it for 30 minutes in the 90 plus heat, and then crawl back into whatever cool cave we had devised for ourselves to wait out the day. 

By the 29th the heat had abated somewhat so we set out to check the 8 nests we had.  I won't get into the all the sad details of what we found.  I'll just summarize:  

One nest had been torn apart by predators, the contents most certainly devoured.  That's not unusual.  Another had fledged prematurely and a grisly fledgling corpse was hanging from the entrance -- sans eyes and brain -- apparently entangled in the artificial poly the parents had used to line the entrance.  Ok.  Gross, weird........and huh???

Two others were silent and when we opened them, contained dead nestlings.  The adults were no longer even in attendance.  (We did, I might add, relocate every single adult with an active nest during the heatwave and could verify none of them had perished from the heat.)  

Happily, 3 nests had survived:  one still had eggs and the other 2 were feeding kids, although we were to later discover that only some of the nestlings had survived in each.  And only one egg hatched from the nest with eggs.  So even those nests had not survived unscathed.   

By far the saddest result of the heatwave was at WT 12 -- the nest we had such fond hopes for.  When I arrived to watch it at 6am on the 29th, all 3 adults were bringing food to the nest.  That was encouraging!  But it didn't take long for me to discover the sad reality.  Yes, they were bringing food in, but they were also bringing it out.  It was clear that whoever was in there was no longer capable of eating.  But could they still be alive?  I rushed home to get some sugar water thinking that a bit of that might revive the nestlings and save their lives.  (Bad science, but sometimes I just can't help it.) But, alas, when we opened the nest we found 6 tiny dead perfect nestlings....smaller than they should have been for their age.  They must have died not long before given the behavior of their parents.  So sad.  We collected the little bodies to take samples from the livers for DNA. 

As we encounter more of these catastrophic heating events, most certainly due to human-mediated global climate change, local birds and other animals will no doubt be affected as were the Portland bushtits.  In fact, it's highly likely that other breeding birds were impacted in a similar way during the 2021 heatwave.  It was only the fact that we were already closely monitoring bushtit nests, and have been for many years, that we were able to observe the effects of the heatwave on them and compare that to previous years.  

A sad end to the season and an ominous warning for the future.