Oh, there's a butterfly!
Oh there it is!
The Siuslaw National Forest has been working with the Oregon Silverspot butterfly for about 40 years,
it was listed in 1980.
Back then pretty much all we knew about it was that it was
dependent on the early blue violet for its host plant,
the caterpillars can only eat early blue violets,
and the early blue violets were being overtaken by invasive grasses,
they were being topped over, shaded out, dying off,
So our entire program consisted of trying to cut back those non-native grasses
and improve habitat for the viola adunca, or the early blue violet.
Unfortunately despite all kinds of efforts for years and years and years,
the overall population trend kept decreasing
until the point where of the five populations that were around when it was listed in 1980,
we only had one population left on Mt. Hebo that was able to sustain itself without help from us.
That was a pretty scary moment for us when we realized that
and one of the big things we realized was that everything we knew about the Silverspot was based on when it’s an adult
and we could only study the adults for a few weeks every summer
and their needs when they're an adult are way different than their needs from when they're a caterpillar.
So to me, I felt like the only way to try to turn around this downward trend
was to understand what was impacting the butterfly during 80% of its life,
when it's a caterpillar.
The problem was nobody had ever found a caterpillar in the wild,
and we didn’t know anything about what they needed in the wild.
Fortunately for me I was working with a group of detection dogs
on another very rare species,
and when I was out in the field working with them I just started talking with them,
they’re brilliant biologists in addition to being dog handlers,
and we sort of just talked through the problems.
Could we find caterpillars in the wild using detection dogs?
Their answer was as long as we have training material, we can find them.
Once we were finally able to train them on live caterpillars from the zoo program,
we were able to cover such a large area and the dogs would indicate,
and they were able to very quickly in just a few days tell us,
that yes there are caterpillars emerging from diapause,
they are surviving,
and they’re well distributed across the landscape
which again, at that point, we had no idea any of those answers.
In figuring out that there were a lot of answers to be had if we could study animals in the wild,
I started reaching out to research scientists like Cheryl Schultz at the Washington State University,
Michele Zwartjes with the U.S. Fish and Wildlife Service,
and Rich Van Buskirk from Pacific University.
As a kind of group we would go back to all of the questions that we had had over the years
and we tried to get it down to, if we are going to effect survival of Silverspot,
what do we need answers to?
So we picked a few questions.
There has been a lot of work out at these sites,
at the Forest Service sites, the State Park sites and others,
where there's been a lot of management on the ground
for the last twenty or thirty years or more,
at the same time as they have been bringing butterflies out from the zoos,
so doing captive rearing programs.
Very limited monitoring had been done,
and so we knew that there was management happening,
and we knew that there was captive rearing going on,
but we didn’t know what the effectiveness is,
we didn’t know like, is it working?
Cheryl, I think that’s your 160 over there!
So we reached out to Dr. Erica Henry.
Erica is an amazing butterfly ecologist,
she’s really one the leading butterfly ecologists working with rare butterflies.
She has incredible experience, diligence, creativity, and talent,
and was the perfect person to really lead this study in the field.
What we did is we went in and clipped the grasses, carefully,
and removed all the thatch around the violets in an area that we could monitor,
so we put in enclosures that are a meter and a half by a meter and a half,
so that’s about five feet by five feet—
I like to think of them as baby play gyms because when I first saw the picture it made me think of all the baby play gyms,
so it’s our Silverspot baby play gyms.
In a couple different places we had plots that were clipped,
plots that were not clipped,
and then we also put in loggers to measure temperature and humidity,
and put the caterpillars in, put the enclosures over them
and then waited to see how many butterflies would come out.
Those are just about done coming out,
when we started there were all these questions like would any butterflies come out?
Would they crawl under, would predators bite through the webbing,
would bears get them ‘cause bears have now gotten into some of the pupil enclosures,
all kinds of things, we just didn’t know.
We have seen lots and lots of butterflies come out of them,
Erica’s been pulling them out daily and she has started to pull some cursory analysis,
it looks like around twice as many butterflies are coming out of the areas that are clipped, versus the areas that aren’t.
And we think that makes a lot of sense because we know from studies that were done on larval biology that when caterpillars are crawling around on the ground,
they’ll finish eating a violet and then they’ve got to find their next violet plant.
If it’s bare ground they can crawl around
and they kind of wander for a while but they find more violets,
but if there’s a ton of thatch, it’s kind of like going through a maze:
up and down and up and down and around and over—
they can crawl a long time but it’s much harder to crawl through
ten inches of thick thatch than it is to crawl over bare ground and find what you’re looking for
because even if they don’t find it immediately, you know-
“Oh, I just bit the wrong thing I’m going to go find something else.”
You know that’s really informal, we haven’t formally analyzed the data,
but the gestalt is we’re getting higher survivorship in the plots that have been clipped, which is you know, that’s good!
It’s good information because it helps us think about
what’s the effect of potential management,
how do we manage habitat in the future.
That also couples with other pieces of interest which is,
these butterflies have been put in the field for years from this captive rearing program,
but because they’ve never been marked, we don’t know what they’re doing.
We don’t know whether they survive, we don’t know where they go,
we don’t know if they completely disperse offsite and never come back again,
we just don’t what the effect of putting all these individuals is in terms of does it actually help our wild populations.
So this summers’ projects is really two pieces:
one piece is funded by the Forest Service,
which is to look at the effectiveness of habitat management on the ability of caterpillars to grow and survive in these habitats,
and the second part funded by U.S. Fish and Wildlife Service,
is to look at the adult dispersal and look at where do the captive individuals go,
meaning not captive but raised in the zoo and then released,
versus what are the wild ones doing,
how much are they flying around between all these different pieces of habitats.
A very common way in butterfly ecology to estimate population size
is through mark recapture methods.
And basically the idea is every day you go out,
and you mark every butterfly you see that’s unmarked,
and you identify the mark,
so in this case the silver or the blue glitter on the wings,
to know that it’s been marked.
So by knowing the relative proportion of marked versus unmarked each day throughout the season,
you can statistically estimate both how many butterflies are out within the entire population over the season,
you can also find out how long individuals are living, so adult survival.
At first I was playing around with how I wanted to mark them,
so this one actually has silver gel pen on the underside of the wing too,
but I wasn’t certain if that would last long enough
so that’s why we switched to the sharpie,
‘cause I’ve done mark/recapture with sharpies before
and knew that that would last.
And then when you let them go you just open your fingers
and they flap around and they pretend like you’ve killed them…
and then they fly away just fine.
Every time we see a butterfly we take a GPS point and record the behavior—
that one was just basking in the grass—
whether it’s a new capture or re-capture,
if we catch females right now we’re noting whether they’re
like freshly emerged or old and tattered,
whether we use the net to re-sight a butterfly,
and if they’re nectaring, what species of flower they’re nectaring on.
And then we take a picture of the vegetation around where we saw the butterfly
so we can do some vegetation analysis later.
In order to do any sort of work with the species itself,
you do have to get permitted through the Fish and Wildlife Service,
so there’s a pretty large process where you submit your project plan,
and the Fish and Wildlife Service determines whether or not your project
aligns with the recovery of the species and will start to answer
some of those really important questions to lead towards recovery of the species,
and if it does then the second step is Fish and Wildlife Service determining the potential impact by doing this study that you’re going to have on the species
and that’s both in a negative and a positive light.
So that’s when I came into the picture,
and that’s when my office and
Michele Zwartjes with the
Newport Field Office came in.
The wonderful thing is the type of research that was being asked to be done,
that can answer so many questions about the life history of a butterfly,
and they’re not really questions that we have thoroughly explored in the past,
and every single answer will make giant steps towards recovery of the species.
The other piece that we want to understand is their dispersal behavior,
so we want to know, is a butterfly that comes out here found somewhere else,
how much is it traveling on a daily basis—
these guys live a long time, on a weekly basis—
and we’re finding out a lot!
We’re seeing marked individuals that are moving between parts of this
meadow system within a day—
192! We just marked this butterfly!
And sometimes finding them weeks later which is super exciting.
Oh my gosh! It’s number 16 again!
It’s the oldest female we marked!
Most of my work has been with blue butterflies that live a week to ten days
maybe, so the fact that we’re seeing individuals that were marked on like July 5th,
and now it’s August 19th, it’s really pretty impressive!
This species is doing things that I just, I don’t see a lot of species doing
personally and I think that’s just so neat.
There’s even stuff about adults that we thought we knew just about everything
about that we’re discovering for the first time,
and by having people out in the field and taking such a hard look at this stuff,
other things started popping into our awareness…
I mean the biggest surprise was that butterflies came out—
the first butterfly was seen on June 25th, which was really early,
and we marked probably 130 wild butterflies-ish in the next three weeks or so,
and only maybe a handful of them were females.
But then we just did not see them, we did not re-sight any of them,
every butterfly we caught and marked was a male,
and we were like what is happening?
You can’t have a population with no females!
And then really just like a week and a half ago maybe, so like, August 5th or so,
we started catching females,
and we started re-sighting females that we had marked,
you know like number 16 and 17 were the first two females I’d marked on
July 5th, no sign of females,
and then those first few days with females
we re-sighted both of those butterflies.
So females emerged here early and they must have,
they either left the site, or they—
I feel like they had to have left the site.
So now I have new questions about like, where do they go?
If they’re going to some interior meadows, there have to be flowers to keep them
alive for a month if they’re going to leave for a month
and then come back here and lay eggs,
but then there’s also fresh individuals emerging.
It's like multiple reproductive strategies?
You know if there are females going somewhere to interior meadows
then knowing where those are is really important for population persistence
because we have to have resources in the landscape to keep the females alive
before they lay eggs.
The other thing is that if butterflies are emerging earlier because it’s getting
warmer, but they’re still laying eggs at the same time,
that stretches out the amount of time that they have to stay alive,
and if both of those things aren’t shifting in the same way in a warmer year,
then that is really interesting and could have some sort of unique climate change impacts for population persistence too.
So now, all my text messages to Cheryl are like,
“I have new questions! I have so many questions!”
When we started this summer, when everyone involved,
all of these wonderful partners started this summer of
investigating these two big questions,
everyone had in their minds that this is called a “pilot year”—
so it’s a year where you’re doing something really different from what you’ve done in the past,
and you have no clue if it’s going to be successful or not.
And we clearly have seen ton of success,
in both Step 1 and Step 2 of this multi-year, multi-level project.
I think that’s a perfect segue into just continuing to expand
because the pilot year ended up actually being a true sample year for us,
which means we have great data for one of these locations
that meta population is at.
So the hopes and the dreams are to expand that project in future years
to all of our other locations where the Silverspot is
currently found or can been found or has been found in the past,
to start to make that bigger picture of what’s going on in each of these habitats,
is it different, is it the same?
Does it allow for maybe large weather events?
If climate change is directly impacting certain locations,
are there other locations that we can work on
that we can develop into a habitat for them to use in the future?
And all sorts of great questions like that.
This is a great example of different agencies working together,
and really coming together as partnerships saying we need to understand more
about the biology and its habitat in order to really design effective conservation.
It’s been a pretty exciting summer,
and we’re really looking forward to gathering up everything that we’ve observed,
everything that we’ve learned, and discussing some next steps,
what answers we need a little more depth on, and where we can go from here.
And what changes we might make to management on the Siuslaw that
we can then see if that’s going to help turn this around for the Silverspot.