What's up Chicago? I'm Erin Allen, and this is Curiosity.
So I've spent the vast majority of my life living in an urban city,
mostly in Detroit and Chicago.
And I'm sure you know what I mean when I say concrete jungle.
But also I grew up going camping, hiking, going skiing.
My family was in the city, but we was also outside.
And the same is true for Dr. Allison, Saucer Dottay-Vallet.
She grew up in Brooklyn, New York, but despite growing up in the city,
my parents made sure we spent time in nature.
They would take us to the parks within the city
and we'd find salamanders under logs and we'd look for frogs.
Dr. Allison is the curator of biology and herpetology
and vice president of conservation research at Chicago Academy of Sciences
and the Peggy Notabart Nature Museum.
And speaking of frogs, you might remember her from our last episode
about the declining frog population in Chicago.
She said that frogs are some of the animals we call indicator species.
So an indicator species could be any organism
that shows some degree of sensitivity or vulnerability to environmental change.
So if you were to look at population size or distribution of a particular species
or its growth rate or its reproductive output,
these are kind of metrics that can inform us
about how a species is responding to different changes in the environment.
And how they respond indicates how that environment is doing,
which affects everything in and around it, including us humans.
They are a good way to pay attention to the quality of the environment
that we're living in and clean water is necessary for all of us to live.
Paying attention to frogs is informing us about the changes in our environment.
You can check out our last episode for more on what happened
to all the frogs that used to hop around Chicago
and what that tells us about changes in the city's environment over time.
Today, I'm talking to Dr. Allison about indicator species in general
in the Chicago area and how we should be thinking about them
as vital contributors to our own well-being and vice versa.
Dr. Allison, Cesar Dote Vallette, welcome to Curious City.
Thank you so much.
I'm so happy to be here.
So, first of all, this concept of an indicator species,
it really got me thinking about Chicago and surrounding areas
and some of the most important indicator species in the area.
And I know in a conversation that we had before this, you mentioned that
there's so many things that are important and it's kind of hard to narrow that down.
But if we could frame it in the context of the environmental
quality questions that we ask ourselves a lot in this area,
how do you think about some of those top environmental quality questions
and then which indicator species really speak to those?
Yeah, it's a great question.
If you think about environmental quality as it affects human health,
you can think about air quality, certainly, or water quality.
And for many plants, we see noticeable visible damage to leaves
when there are conditions that produce a lot of ozone.
So if we think about like air quality action days that we have during the summer,
where they tell people, hey, don't drive during these conditions,
it's very hot, there are a lot of pollutants in the air.
Those are conditions that would produce more ozone.
And so ozone sensitive plant species like common milkweed, for example,
would show visible damage on the leaf under those types of conditions.
OK. And an indicator species can be an animal or it could be a plant.
I wonder if you could give an example of another quality issue
that involves animals. Yeah, for animals,
many of the indicator species are going to be species with shorter
generation times and species that are abundant enough
so that we can notice a change in their population.
So you don't want to necessarily focus on something that's super rare already.
It's going to be hard to find.
It's going to be harder to assess kind of qualitatively.
Is there a difference under current conditions versus historic
conditions with a rare species?
But for some common species, we could think about different types
of amphibians and amphibians rely on the presence of wetlands.
And different amphibians have different habitat needs.
So some will only breed in fishless wetlands.
And these tend to be temporary pools that get drained
or under drought conditions that are going to dry early.
That's going to affect the reproduction of those species.
So blue spotted salamanders would be a great indicator
species for kind of drought frequency and wetland quality in our area.
And other species like wood frogs are very sensitive to road salt.
So we could think about where our wetlands are in proximity
to some of the busiest roads that have a lot of that kind of winter.
Deicers. This is this is stuff that like I just would never think about.
And I wonder if there are any surprising species,
plants or animals that you're like that you've come across in your researcher
that maybe the average person would be like, wow,
I had no idea that maybe I should be thinking about that more.
Oh, sure. I mean, if you think about butterflies generally,
and I know a lot of people do think about butterflies and it's good that they do.
They're critical pollinators.
They're important indicators of prairie plants in many cases,
especially in our region.
You know, we were considered the prairie state and we have less than one percent
of our prairie habitat, our pre colonization habitat remaining.
And so with that, we've lost a lot of particular plant species
that certain butterflies rely on.
So, for example, we have an imperiled butterfly called the Baltimore checker
spot in the region, and it needs a host plant called white turtle head.
And if we don't have enough of those individual plants,
it can't support a population.
So if you see decline in Baltimore checker spots,
you know, there's probably decline in that host plant.
And that may have to do with how the land is being managed
or how much habitat there actually is.
Yeah, all these all these woo, woo, woo terms are coming to my mind.
I'm just like, we are a product of our environment and we're all connected.
And I mean, it's, you know, it's it's cliche to say, but it's so true.
And absolutely, you know, as you were talking about
how we affect the environment in negative ways and how we can kind of make up
for that with intention, it made me think about kind of evolution as a whole.
And this is kind of another big picture question.
I don't know. I mean, I have this inclination to be sad, right?
When you say, oh, we don't have the habitat for butterflies
that we used to at the prairies, you know, that we used to have.
But should should I be sad about that?
Is that just a natural way that things go?
I mean, we are all here together.
We are all interacting and things evolve because of that.
I wonder what your take is on that.
Well, you know, things you change in ecosystems
are not static and biodiversity is dynamic.
We have, you know, ecological succession.
So, yeah, an environment is not going to be static through time.
But I think there is sadness in thinking about what we have lost
and how that is a product of both our past and our current actions.
So can we be more thoughtful in, you know, the actions that we do every day?
To make sure that we're preserving all of the biodiversity that we still have.
You know, we're never going to know everything about the role of a given species.
And so, yes, there's change.
We have invasive species that come in with, you know, trade and commerce.
Things that are introduced into the Great Lakes.
They may have sometimes positive effects, sometimes negative effects.
Typically, they're out competing species that were here for, you know, precious resources,
whether it's food or nesting habitat or light in the case of the plant environment.
And when we lose some of these species from the environment,
we're losing function and we're losing quality.
And the more biodiverse an ecosystem is, it is typically more resilient to change.
So if you only have, let's say, two invasive species that start to dominate a wetland,
if some, you know, invasive pest species comes in that feeds on those
and we just have a monoculture, what do you have left?
Yeah.
And we generally want to keep common species common.
So there is a lot of attention for rare species, because once a species is rare,
it's already kind of started down a kind of spiral of decline.
There's already a number of environmental stressors in the environment that that may be affecting it.
And in some cases, it could just be that the habitat that it needs has always been limited.
But paying attention to the trends in the species that are more common is really important,
because these are the species that are somewhat able to tolerate land use change.
So, you know, if you're seeing suddenly a decline in a species like a green frog or a bullfrog,
that can take advantage of, you know, human created habitats like park lagoons and golf courses
and stormwater basins.
If we start seeing that they're declining, that's an abundant species that can disperse,
that tends to be a little bit more salt tolerant than some of the other frogs.
And so we can use that as kind of a set sentinel of something larger at work.
OK, that's a helpful way to think about it.
It's like all about resilience and biodiversity.
And if there is a big change, you know, how can how can the habitat and the species deal with that?
We heard in the future that the situation with the frog population in Chicago
is not necessarily good or as it has been over the past few decades, but it's also not dire.
No frogs are currently headed toward extinction, as far as we know here.
But are there any vital indicator species that are in dire straits in the area?
Well, I would say with the frogs, while some are not necessarily headed toward full scale
extinction, we still have other populations in the state.
We can have regional loss and so we can lose populations from the Chicago region.
And that loss can then affect overall, you know, robustness of the species at its geographic scale.
But in terms of, you know, other kind of Chicago regional species that are becoming
more and more critically imperiled, it tends to be the species that have limited ability to disperse.
They're bad at crossing roads, they're bad at flying, or they just do limited distance movements.
And so smaller bodied species, species that are ectotherms, that their activity is closely tied
to ambient temperature are going to be more sensitive to environmental change.
You know, we have urban heat island effects that most cities have, but Chicago's is unique.
And I can talk more about what that is.
It's basically a pattern where we see generally hotter temperatures in places where there's more pavement.
But in Chicago, we have this interesting situation because of our proximity to the lake, where the
heat island is not centered in downtown.
It's actually centered, you know, on the west side and the south side.
And so in those places, there could be species that lay eggs that have to be out in the environment,
where the soil temperature is fluctuating, and maybe it gets too hot for them.
So those are the types of things we can start to think about in these kind of urban frameworks.
OK. You know, I love hearing the story of, you know, the fact that despite you growing up in a very
urban, citified environment, you were exposed to so much nature.
And that's true for me as well.
But I think it's just not the case for a lot of people who grew up in urban cities.
I feel like a lot of people just don't see themselves as a part of nature.
They don't see the changes in their natural surroundings as indicators of their own well
being or their own their own situation.
And as a person whose job it is, in part, to think about this, how do you reckon with
that as a person who's sort of a rarity in an urban city?
Well, I think in part, I work at the right place.
So at the Nature Museum, we are trying to to build those positive connections between
people and nature and increase people's awareness of the resources around us and the natural
areas around us and how even in a city, we are a part of nature, we can affect change
through small actions, whether it's, you know, not keeping lights on all night to help reduce
light pollution or, you know, being mindful about noise pollution that we produce.
These are things that affect the wildlife around us.
It affects migratory birds.
It affects dragonflies.
It affects frogs ability to hear each other call.
And these are all things we can think about, you know, on our household level and our
personal level, but we can also, you know, try to educate each other about like, hey,
maybe shut those lights off at night because it's impacting migratory birds.
It's a simple action.
But if enough people do it, then we can have a measurable effect.
Yeah.
Dr. Allison, Cesar Dote, Vellette is Vice President of Conservation Research and Curator
of Biology and Herpetology at the Peggy Notepart Nature Museum.
Dr. Allison, thank you so much.
Thank you so much.
This episode of Curious City was produced by me, Erin Allen.
Suzy On is our editor.
Curious City is a production of WBEZ Chicago and is a part of the NPR network.
If you have questions about Chicago and the region, you can send them our way
at
[email protected] or visit us at wbez.org/curiouscity.
Thanks for listening.
I'll talk to you next week.
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