PubTalk - 7/2021: Invasives - Lizards, Treesnakes, and Burmese, Oh My!

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Title: Invasive Species - Lizards, Treesnakes, and Burmese Pythons, Oh My!

By Amy A. Yackel Adams and Andrea F. Currylow

  • Relocation of species from their home ecoregions can wreak havoc in novel habitats
  • Invasive reptiles around the world have negatively impacted many ecosystems and biodiversity
  • We look at examples of Brown Treesnakes, Veiled Chameleons, and Tegu Lizards
  • Learn what USGS scientists are doing about Burmese Pythons in Florida Everglades and the challenges they face


Date Taken:

Length: 00:56:10

Location Taken: Fort Collins, CO, US


Hello everyone and welcome to the

USGS Public lecture for this month.

Thank you everyone for

joining us this evening.

My name is Christy Ryan and I am with our

science Information Services office and

I will be your host and moderator today.

Before I introduce our speakers.

I have a few announcements to make a first a

heads up about our lecture for next month.

On August 26 we will have research

scientist Tom Edwards as our guest speaker.

Thomas with our USGS Utah Cooperative

Fish and Wildlife research.

Unit and is also a professor in the

Department of Wildland Resources

at Utah State University.

The tentative title of his lecture is

species modeling for endangered species,

so please be sure to join us next

month as well and now I have a couple

of tips on some of the features

of this virtual platform to turn

on closed captioning.

If you're watching on your desktop,

click on the screen and look towards the

bottom for the close caption symbol.

Also towards the end of the lecture.

We are going to open it up for

Q&A session with our speakers,

so if you have questions,

you can submit them through the

Q&A chat window to find it.

Look for the question Mark icon in the

upper right hand corner of your screen.

That will bring up the Q&A panel

where you can type in your questions.

Please understand we may not have time

to answer all the questions that we get,

but we'll do our best and appreciate

your understanding.

So now we want to begin our

lecture for tonight.

We have a great talk for you,

the title, invasive species, lizards,

tree snakes and Burmese pythons.

Oh my.

Tonight we actually have the

pleasure of welcoming 2 speakers.

Doctor Amy Yakel Adams and

Doctor Andrea Kirylo,

both research ecologists with the

USGS invasive Species science branch

of the Fort Collins Science Center.

Doctor Amy Yakel Adams leads the USGS

Florida Invasive Reptile Project,

based in Everglades National Park

and Big Cypress National Preserve

where her collaborative research

focuses on obtaining vital rates,

dispersal and movement.

And control of invasive Burmese pythons

and black and white tegu lizards.

Amy is also a principal investigator

on the USGS Brown Tree Snake

Project based in Guam and areas in

Memphis and detectability.

Control tool evaluation,

model validation and development,

and the optimization of monitoring,

management and early

detection and rapid response.

Our other speaker,

doctor Andrea Carrillo is stationed

in Everglades National Park and

locally leads the invasive reptile

research activities in the park.

Working closely with partner

organizations to develop science

based research aimed at informing

invasive species management,

doctor Kirylo has a broad research

background and it continued interest

in collaborations on topics including

ecophysiology anthropogenic effects

on populations, conservation biology.

Behavioral ecology and invasive

species dynamics.

So with all that said,

I don't want to take up any more time.

Without further ado,

let's all give a warm virtual welcome

to Amy and Andrea. The floor is all yours.

Thank you for inviting myself and my

colleague today and we're really excited

to share with you our work on invasive

reptiles to keep with the theme of the

cartoon and the title of our talk,

I want to highlight the yellow brick road.

The yellow brick road in the fictional

land of Oz is a reference to the path

that leads to success or adventure

in working with invasive reptiles.

It has been a path mixed with

successes and adventure,

and today we will share our yellow

brick road with you.

First, let's put our work in

the context of the larger body.

On invasive species, there is one

week a year that is designated as the

National Invasive Species Awareness Week.

Notice it is not today,

but a full week why, well,

maybe because invasive species

are such a big problem. In fact,

invasive species aren't enormous issue,

and it involves invasive plants, insects,

birds, vertebrates, and invertebrates.

It is also an expensive issue,

costing the US about $120 billion a year.

So what are invasive species?

Well. It is an alien species,

also called the non native whose

introduction does or is likely to

cause economic or environmental

harm or harm to human health.

This definition is associated with

the presidential executive order,

signed by Fred,

former President Bill Clinton.

Back in 1993.


managers and biologists thought

reptile biology would limit

its invasion 10 potential.

Because reptiles are ectotherms.

Because they have a slow

metabolism metabolism,

they're also slow moving

and had limited dispersal.

But this is not the case indeed,

and there's an entire book on invasive

reptile and antigens by Fred Kraus.

Time and time again reptile invasions

have demonstrated that reptilian

predators have substantial impacts

on native species and ecosystem.

USGS and its collaborators

have documented these impacts.

This slide depicts the several species

that are that the Fort Collins Science

Center has worked on for years,

and in some instances decades,

the brown tree snake,

the veiled chameleon, Burmese pythons,

and black and white tegus.

Today we will look at each invasive reptile.

I will present the brown

tree snake and veiled.

Chameleon and Andrea will

present on the Brown, Burmese,

Python And the black and white tegu

These reptile UM represent introductions

that have occurred across the globe.

Some have been accidentally translocated,

such as the brown tree snake,

the others, the veil, chameleon,

Burmese, Python And black and white.

Tegu have been introduced into Florida,

primarily through the Prep pet trade.

Not all introductions are successful.

It's about 10 to 20% of non native species.

Introductions eventually become invasive.

And again,

that's causing harm to environment,

economy or public health.

So let's start off with the accidentally

introduced brown tree snake.

This is an iconic invasive species.

It is a slender snake.

And its venomous and it can

get up to about 6 feet,

but it rarely does so on Guam

because it's now pray limited.

Brown tree snakes are native to

Indonesia in the Solomon Islands

and beginning in Australia on

Guam it has caused the extinction

of most native forest birds.

It is posed a threat to humans

to infants via bites,

and has caused power outages.

It also on has see potential

for accidental transport to

other islands in the area,

and that remains an ongoing threat.

Let's take a closer look at

the impacts of this snake.

A USGS colleague Doctor Julie Savage

is responsible for finding the link

that the brown tree snakes suppressed

and can eliminate bird species.

This red line separates the species

that still persists on long.

Versus those that are now extinct

were extricated from Guam.

In a predator exclusion study,

we showed that excluding brown

tree sinks from plants which

occurred during monitoring period.

Two, that's depicted here by the Brown line.

The number of Carly lizards

dramatically increased.

See the open squares for each

of the monitoring periods.

So by removing the snakes,

the lizard rebounded.

Mammals are also affected by

the brown tree sing presence.

We conducted small mammal trapping

on Guam and the neighboring islands

of Rhoda site Pan and Tinny,

and to better understand that

effect and to no surprise.

We see that rodent density on

Guam is very low compared to

adjacent snake pre islands.

This illustrates the suppressive effect

that snakes have on their road and

praying it also is illustrates that

the neighboring islands have a previous.

They could support a brown tree snake

if it were introduced to those islands,

so this is highly problematic.

So how does one control brown tree snakes?

First, it has an interdiction program in

place to prevent snakes from leading Guam,

and we have the USGS LED rapid

response team to respond to snake

sightings in the region.

This form of control is referred

to as containment.

Keep snakes on the island because

we cannot eradicate them right now.

On however,

we are trying to suppress or

eradicate them in small areas.

On Guam this is done via host

of control tools.

USGS has a role in evaluating these

control tools with consist of live lure,


toxicant via bait tubes or

aerial drops from helicopter.

Detector dogs and nocturnal visual searching.

We have extensive research on

all of these control tools,

but I'm only going to present

information on two traps and

nocturnal visual searching.

All the control pools are evaluated

on bomb in a 12 acre area.

This is surrounded by a snake proof barrier.

This fence, with its double bulges,

keep snakes inside and prevents a snake

from outside entering into the area.

Snakes cannot breach the bulges.

They're not able to move on

to camera vivir backwards.

In this 12 acre area we marked every

individual with the tiny pit tag.

This gives us a known population of

snakes in order to evaluate control tools.

Simply put, we know who is in the

population and whether we detect

them with their control tool.

We will now look at snake traps

and then visual searching.

This is a modified minnow trap and

it's considered to be one of the most

effective snake traps in the world.

It has two funnel entrances with

handcrafted flat doors that

allow snake entries on the ends.

Inside is a protective chamber

where a live mouse.

On is situated with the food.

This lowers the snake to the trap.

Snakes find their way in through the

flat doors and we check the traps in

the morning we recorded the identity

of the sink and take measurements

such as weight has not been like.

Using Mark recapture methodology,

I estimated trap capture for snakes

based on several covariates,

but the size of the snake was

one of the strongest predictors

for determining capture.

Note that we had size along the X axis

and capture probability along the Y axis.

Here's how to think about

capture probability.

If you have a value of 0.14,

this means that on a given night with

100 snakes available for capture,

you would likely capture 14 of them.

Given optimal conditions.

There's two things to note on this graph.

Rough capture probability is overall

low even with optimal conditions.

Also, crapping fails to

target small snakes reliably.

This was critical for managers to

know as they work on containment

of brown cheese. Snakes on Guam.

With this research we found that

given enough time and traps,

spaced every 52 feet all meant

a large snakes can be captured

and removed from the population.

However, this trap is not a reliable

tool for capturing the small snakes.

Let's look at another tool,

visual searching for brown tree snake.

This involves searching at night

with the headlamp to secure the

snake and obtain its identity.

The snake is then immediately

released as point of capture.

Again, using a 12 acre enclosure,

we search along transects,

their space 26 feet apart,

and we scanned the vegetation

in the ground for snakes.

When we find the snake,

we capture it,

read it,

spit tag and take various measurements

such as weight is not that plank.

Again, using Mark recapture analysis,

I estimated visual capture for

snakes based on several covariates,

and size was again strong

predictor for determining capture.

The sex of the snake also matters.

Two things to know. First,

emails have a lower detectability than nails.

That's not ideal.

Second, visual searching can

detect snakes of all sizes.

That is good news,

but the detection is still really low.

This means it will take a lot of visual

searches to detect and remove snakes.

Right now this is our primary

tool for rapid response on other

islands because it is the only tool

that detects snakes of all sizes.

So two evaluate the effect of a large meal.

On brown tree snakes we divided

snakes into two groups.

There is a treatment group and

that's depicted at the top here.

That is the group that got a large

rat with a transmitter inside in.

On the second group was the control group.

They only got the transmitters.

These transmitters allow us to track

the snake and to assess how much

of the snake was moving and given

night defined as tips per hour.

And that's here on the right

hand side of the graph.

It's the tips per hour,

ranging from .4324 point 8.

On this is a heat map.

That's what you're looking at,

and it shows the hourly mean tipping rates.

If we look at the top heat map,

we readily see that those snakes they

got a meal with their transmitter

moved less for this several days after

the meal to take depicted by the

lighter colors of yellows and Blues.

The reverse is true for those

that only ingested a transmitter.

They kept moving in search of food,

and this is clearly shown.

With the heat map,

because it is very dark over

the course of the week.

So how does this translate

to detection of snakes?

We found that the snakes that

recently fed on the large meal I'd

greatly suppressed visual untrapped

detection versus those that were unfed.

You can see that by the red

lines this is not good news,

and it drives home the importance

of prevention because tree snakes

on a prayer a child will be more

difficult to detect, period.

There is so much more to share

about brown tree snakes,

but I want to move on to another invader

and this is the veiled chameleon.

Here is a success story.

This is a fairly large lizard

and can get up to two feet long,

eats vegetation and small

invertebrates as well as vertebrates.

It is originally found in

Saudi Arabia and Yemen area.

We do not know when it arrived tunaley,

but removal started in 2002.

Impacts were not documented,

but Maui was deeply concerned

about the potential of biodiversity

loss in plants and wildlife.

The veil chameleon is a habitat

generalist of dry and wet areas.

It matures quickly in just four months.

It can start reproducing and

does so several times a year,

with about an average clutch size at 35.

With that kind of profile,

you can understand why the Maui

Invasive Species Committee responded

immediately when a dead veiled

chameleon was reported on island,

and that's depicted here on this map

by a Black Star when that communion was

found in media campaign was launched,

asking all Islanders to report

any additional sightings.

This led to chameleons being found

in the other part of the island

marked by the Red plus signs.

Let's zoom.

In to that area and see what's going on.

OK, we can readily see it's a

neighborhood suggesting a pepper lease.

The yellow dots represent veiled

chameleon captures by the Maui

Invasive Species Committee.

I'm going to start calling it miss,

so if I go back and forth,

know that I'm talking about the

same entity misconducted nighttime

surveys for the chameleon with

staff and Bonnie volunteers.

It was a serious time investment

to get these individuals removed

from the environment.

In fact,

they took the invasion so

seriously that they responded with

both research radio tracking to

understand movements of the animal,

as well as the night time.

Removal of billions.

But it even works hold on.

There we go.

They even went so far as to remove

the favored dense vegetation of

this species did so between homes.

The old wood chipper to ensure

chameleon removal.

Here I'm showing a Dale chameleon

removal per search hour.

Overtime we can see that

their effort in 2002 to 2004.

Removed, they'll chameleons and

then the numbers were reduced to

zero starting about 2007 miss.

Continue to get no chameleons year after

year despite sustained search effort.

This is where I came into the picture.

Miss wanted to know when

they could stop searching.

Colleagues and I produced a new removal

model to address their question.

It correlate selected confidence interval

and a remaining population estimate,

and So what? That looks like.

Is by the time 2012 they come around,

they had another year with zero,

but our model was estimating that the

remaining population was somewhere

between 0 and 11 and were 95% sure.

In fact, our model showed an 87%

chance that some chameleons remained,

so miss kept searching and it's good they

did because the next year in 2013 they

captured five more Canadians after 2013.

No more chameleons were found

in the following years.

This same model can be used to look

at the initial removal data and then

project into the future for veiled

chameleons on Maui we can see on the

left hand side the estimated initial

population size and on the right

side the scenario of doing nothing.

We can readily see that without masks

actions they would have had a much

larger population to contend with,

and this highlights the importance of

early detection. And when I fed response.

In order to eradicate an invasive species.

This schematic underscores my point.

Control costs quickly increase

once a reptile population begins

to establish and spread.

As time elapsed without responding,

the area infected increases.



prevention is the least expensive

place to be on the schematic,

and the best way to protect ecosystems.

But if prevention fails,

then eradication is the least expensive

and most protective response in the mallee

case they had a localized population

and they aggressively began eradicating.

Hold on and go back.

On they succeeded if they had failed,

containment would have

been the next approach.

This is where we are with

the brown tree snake.

Land Management agencies are containing

it from spreading to other islands.

Also, land managers go back.

I'm not sure it looks like we

have a timer on what he slides.


land managers are suppressing it as

a long term strategy for protecting

resources for the veiled chameleon on Maui.

The last two stages were adverted.

That was the good news.

About the day of communion.

The bad news is that it's also in Florida,

with over 600 having been removed this

year alone by doctor Melissa Miller.

Florida is a hot spot for Rep foundations,

and Andrea will tell you more about that.

Great, can you hear me?

We can OK great.

Thanks Amy, UM, so is the chameleon.

The reason why USGS invasive species science

branch has a field station in Florida?

Well, not exactly.

There are actually more non

natives in Florida than anywhere

else in the entire world.

It's invasion central which is a

bummer because the entire southern

portion of Florida is covered by

a protected area that you might

have heard of the Everglades.

In fact, he Everglades comprises one and

a half million acres of South Florida.

It's the largest subtropical.

Wetland ecosystem remaining

in the in North America.

So it used to be more than devices LG with

its warm and humid Equatorial climate.

It's known as a biodiversity hotspot,

loaded with wildlife all

located just outside of Miami.

For Myers and West Palm Beach,

it also contains one of the

highest numbers of federally

listed species in in the US.

So having so many unique habitats and

species with a highly in habitable climate,

the Everglades is particularly

vulnerable to invaders invaders.

Here's just a small subset of such

hurtful invaders from a top right.

There's the infamous Burmese Python

And a tiny blind snake and brown

basilisk and red haired slider cycled

Cayman Nile monitor, cane toad,

green iguana, red tailed boa Peters,

ragama curly tailed lizard,

keeping treefrog,

Mexican spiny tailed iguana.

Brown and old outlets.

Chameleon night in Old Green ameiva

green trout frog and in the lower right.

Though black, I might take you

that's just 19 out of the 180 plus.

Non native herbs or final species

introduced to Florida of just the

reptiles and amphibians and the

Greater Everglades ecosystem.

There are dozens of introduced species,

63 of which have become established and

establish means that the individuals

of the species are finding each other,

reproducing and sustaining a

population with sorry, but that many.

It means that one in three of any

introduced reptile or amphibian

will become established in Florida.

Looking at the lists by taxonomic group,

you can see that for example there

are 48 lizards.


only 16 of those species are

native to Florida,

meaning that 75% extent of this state

lizard species in Florida are non native.

It's mind boggling.


the Florida Fish and Wildlife

Conservation Commission just released,

updated and new regulations that seek

to prevent additional interactions

and help curb their releases of

pets into existing invasions.

The first and last species I

listed here on the collage,

or the two that we study the most

intensively and so Flo Southern Florida.

It's the Burmese Python And the black

and white Paper Science Center in vases.

Invasive reptile research is done in

close partnership with National Park Service.

The majority of our research is in,

so Flo is done in these two Everglades

National Park and Special Preserve.

The reason we focus on the Burmese Python

And black and white tegu in particular,

it's because they have both spread

widely in southern Florida and

they've demonstrated to have

negative ecological impacts on the

native species and ecosystems,

and they're at the very top or the very

top of the invasion curve that Amy explained,

so removing them completely would

be astronomically expensive if not

impossible given the current technologies.

So our focus is on research to

improve removal techniques while

also studying the impacts that

these species are having on Florida.


So the third species that will

talk about is the Burmese Python.

It's a large,

constricting snake species that

can reach 19 feet or more if diet,

dietary generalists, generalists,

and let me tell you they will eat

anything that fits in their mouths,

milit anything from EDB, little screws,

all the way up to entire adult

raccoons and deer their native to

Southeast Asia and how did they make

their way to Florida while they were

right here through the live at trade.

In fact,

over 180,000 were imported to

the US since 1975.

Mostly from Thailand and Vietnam.

With that many pets of such

a large animal that

readily breed in captivity,

it's easy to understand how they were able

to establish populations when released,

which happened in the 1980s in Florida,

pythons have been implicated,

and in the declines of native species,

many native species.

They're extremely difficult to find,

leading to seemingly

uncapped controlled costs,

and they've even been documented

bringing along parasite from Asia

that they've passed a native snakes

that further spread the infection even

beyond the current range of pythons.


Data from before and after Python

population explosion suggests that

they consume so many measle mammals.

Mammal species such as raccoons,


marsh rabbits that it led to

98% loss of mammals in the

Everglades National Park that.

Is very it's now.

It's very unusual to see a rabbit or

raccoon in the park where it used to

be pretty common before pythons or

diet also includes some threatened

and endangered species such as the

Key Largo woodrat and the wood stork.

In fact,

from the data that we are,

we are collecting with partners.

Pythons have been documented to now

consume more than 60 different price species.


this is including birds mammals after why,

there's a here's a visual representation

of the magnitude of the impact that

just one Python may have as it grows.


you can imagine that if up to 100

pythons hatched from a single nest,

that their communal communal ative impacts

on the Everglades wildlife could be immense.

OK, so how many are?

Are there?

Well, we don't really know.

We don't have data reliably estimate how

big the population maybe because pythons.

Are so difficult to find well.

What are the ways that we can find pythons?

There's several removal techniques,

each has their own utility,

but also amount many challenges.

There's currently one.

No one tool that can work in more than

very specific situations or time of year.

Similar to detection efforts

for nearly every species,

we can employ visual surveys

in the Everglades.

Certain to find pythons.


I keep telling you that they're

really hard to find.

So let me just show you what I mean by this.

When people think about finding

pythons in the Everglades region,

they'll picture something like

this photo or the role that

pythons relatively easy to.


what we actually see when we do surveys

is better represented by this photo

where the Python maybe not so obvious.

Where now I know that a lot

of you are probably really

great at spotting wildlife,

and you've probably already seen

this large animal in the photo,

so it's easy for you to imagine

detecting it as you breeze by

this spot during your Python,

but I'll just give the rest of

you a little more time to find

it in case you haven't yet.

You get. Oh

we all know they must be greatly

middle to photograph, right?

OK, well. Have y'all found it?

I'm sure you have.

Congratulations, you accomplish

a successful Python survey.

However, we needed a little

more help in order to find it.

So we use video telemetry and

just to show you where it is.

In case you haven't seen it,

it's right here, outlined in yellow,

but I know that some of you might

still be a little bit newbie is that

there's actually a snake there,

so I'm going to go ahead and just zoom

in on this one little portion of the

photo where you can see the Python skin.

Andrea, I'm not sure if we're

seeing what you're seeing right now.

Oh no, yeah, we're we're seeing

detectability slide with UM.

In the background.

OK, now maybe your slides are updating.

It looks like here,

oh bummer.

We see it now.

Alright, well there you go. You probably.

So it it is right there,

there are difficult to find,

but I hope the point is obvious that

these animals are are incredible.

Having credible crypsis abilities.

So what are some other ways

that we can use to find pythons?

Well, Amy mentioned one that she didn't

go over for the grand tree snakes,

but you might have heard

about wildlife detector.

There are several groups in Florida that

have trained dogs to detect pythons,

and they do sometimes seem better

at finding pythons in humans,

but only in certain circumstances.

Using dogs has limitations.

Like high water implement,

wetter weather, difficult terrain.

Longfield hours far in the back

country and heat dogs are.

It's hard for dogs to smell

when they're planting.

It also is worth noting that the

detector dog could tell us that a Python

was in that last photo that I showed you,

but a human would still have to actually

locate it to capture it and remove it.

So how else might we find pythons?


many herpetologists know that at

night reptiles near roads often

move onto the roads to soak up the

residual heat from the pavement.

If you slow,

if you slowly drive roads at night,

you'll likely see some sample of

her fan from the surrounding area,

and sometimes this includes pythons,

so this must method,

though it takes hours and hours and

days and days to find pythons it can work.

But come on, there must be another way right?

Like a trap.

Right, yes, there is.

Well, sort of.


unlike brown tree snakes like blam,

Bernice Pythons will not

readily enter translated traps

have been designed and trials,

but none yet have been terribly effective,

probably due to the abundance of

surrounding wildlife that serves as pie.

Python pray.

So why would they need to enter a trap?


the habitat is so vast and inaccessible,

many other species could also

be inadvertently captured.

Though these challenges haven't

completely stopped researchers

from trying there aren't many.

There are several more trapped

attractants being developed and

tested currently in conjunction

conjunction with surveillance

and shows more promise.

Other ways that make tracks more

effective might be to exploit

trailing behaviors and pythons.

We wanted to know a pheromones that

pythons used to try trail and find

each other during the breeding season,

could I?

Be identified and manipulated

so that managers could use them

to lure in pythons like a Python

perfume where they could be trapped.

So to test this,

we and partners use what's known

as a Y maze and we use them to

test binary sent choice.

AY maze is a has a couple internal

partitions that can help direct

the scenting animal down a path

that you wanted to go,

and then you remove that sensing

animal and the partitions,

and send another sneak down to

see if that snake preferentially

chooses the scented arm or the

non scented arm and over multiple

trials and multiple individuals

we can statistically

determine whether or not

there's just random chance.

Or if there is preference for pythons and

we're currently analyzing those results,

but if you're wondering about

the details of how to use large

reptiles and I made studies,

that's a great question.

We actually just published the

methods only paper in the Journal

of Visualized Experiments that

also has a demonstration video.

OK, now you might be thinking

wait a second Doctor Carrillo.

I thought people were paid to remove

pythons in the Everglades and that those

programs are really successful, right?

Well, you're not wrong.

People are certainly trained

and paid to like pythons.

In fact, we've helped the National

Park Service develop a program to

train people in identifying and safely

handling Python so that they can capture

them to state agencies followed suit

and pay their Python contractors.

But the problem is that despite

swamp buggies and air boats and

kayaks and off road vehicles,

the great majority of Wildlands and

the Greater Everglades ecosystem

is still inaccessible.

Not only our Python is difficult

to find in these habitats.

But so our whole interns.

It may take an entire 10 hour

field data traverse just a few

miles of habitat coupled with the

crypsis of these pythons are able

to achieve the only viable option

if you want to make any money.

Stumbling upon and removing pythons.

Is by Rd cruising.

In fact,

the vast majority of pythons removed

were found on roads and levees,

so we have to admit that we must

only be scratching the surface.

It would be so much more effective

if we could just find locations

where pythons congregate,

like in breeding aggregations.

This is where we could not only

remove several pythons at one time,

but we'd also be targeting and removing

the most important subset of individuals.

The large breeding adults.

How do we find these breeding aggregations?


using radio telemetry.

We can plan adult pythons with radio

transmitters known as Scout Snakes.

We tracked them deep into the Everglades

during the breeding season where we hope

to discover breeding aggregations and

associated states that we can remove.

When we do this, UM with many

partners in that scout collaboration,

we are,

we're partnering with National Park

Service in Big Cypress National Preserve,

the Conservancy of Southwest Florida,

US Fish and Wildlife Service across

Lake National Wildlife Refuge,

and this collaboration puts our

resources and expertise together to

collect data on scout pythons across the

region in a systematic and standardized way.

This collaboration has promoted,

in expansion of layered research

and keeps key players moving

forward faster together using.

Our collective knowledge.

Though we're learning a lot from our

work and over the past couple decades,

we still don't know some

of the pipe Python basics.

So the only part of the picture

we've begun to buckle down with

partners to design and address the

knowledge gaps in a systematic

and directed fashion targeted by

this collaborative research or the

missing life history information

commonly referred to as vital rates,

and includes status such as

survival rates across ontogeny,

sex ratios and sex.

Specific maturity and reproduction,

information dispersal and population


Altogether fundamental information

needs to address management actions.

And finally,

all of the removed pythons

contribute to various other

research projects that involve more,

more committed the morphometric

measurements and sampling so that other

collaborators can gain the most

ecological data that we can out

of every single thing we want to

determine their dietary preferences.

Look for any introduced diseases or parasites

that could be harmful for our species.

And here in Florida

investigate Mercury content,

add to genetic data sets,

monitor stress and reproductive

hormone cycles, etc.

We also do this work with tag lizards,

so I'll jump into talking about them.

The black and white tag.

It was a larger Neverwas lizard that

are dietary and habitat generalists.

It's native to several

countries across South America,

but it was first observed being

established in Florida in 2008,

just outside of Everglades

National Park boat.

A goose hardiness allows them

to live across the landscape.

They appeared to do well in

habitats that are our agricultural

or near human habitation,

which is plentiful in so Flo,

Southern Florida.

They probably like these areas because

of the prevalence of food sources,

but they are now.

Established in multiple populations in

several areas in the state not only in so.

Flo pages have great potential for

devastating ecological impacts because

they're both dietary and habitat generalists,

meaning that they eat just about anything

and they live just about anywhere,

even in areas where it snows a little bit.

In fact, in one that you investigate

term habits of tigers in South

Florida over the winter months,

we conducted the work on free

ranging wild haggis just outside

of every place National Park.

We were able to characterize biologically

significant thermal periods.

Fertagus described the environmental

conditions generally triggering

hibernation and found that eggs can

maintain stable temperatures throughout

the winter despite external conditions.

While some don't hibernate at all,

so the Pegasus apparent ability for

thermal stability expands and underscores.

The invasion threat of air

to areas outside of Florida.

In fact, we modeled it using

five different approaches.

We built species distribution

models based on data from tag use,

native ranges,

and then we projected these

models to North America to map

potential teddy distributions.

Our results suggest that much of

the southern United States and

northern Mexico probably contains

suitable habitats to Fertagus,

indicated here in the maps and

darker colors and that study,

we propose that Florida was

not the only state where tags

could become established.

And unfortunately we were right.


Tigers have been detected in Georgia,

but fortunately we were also right

in suggesting that early detection

and rapid response programs or EDR

are targeting tattoos and potentially

suitable habitat could prevent

establishment or abate negative

impacts on the native ecosystems.

So in Georgia,

the early detection rapid response

efforts were originally reported

by locals who haunted in the area

and we work with Georgia State and

Georgia Southern University to

document that I go establishment

and began efforts to eradicate

them before they could reach the

point on the invasion.

Prove that they have in so Flo.

In another study of tag is over winter.

Like I mentioned,

sometimes they're in areas or

they can survive in areas that

are cooler than South Florida.

They're even, oh sorry,

so you can see in this background

photo that it showed of the slide.

It shows some of the enclosures

that Aggies hibernated in in these

man-made underground Refugio,

so we moved Wildcat tags from Florida to

Auburn University campus in Alabama where

the study was conducted in these enclosures.

Most of the Tagus survive the

winter in the enclosures,

again justifying the Tigers have

the potential to spread despite

non ideal climatic conditions.

But can they find other resources

that they need to live in those areas?

Well, because pigs are dietary generalists,

they're kind of the lizard version

of a raccoon.

They eat insects, fruits, plants, snails,

crayfish, carrion birds, small mammals,

turtles, snakes, lizards, and frogs.

They're also affected.

Nest predators,

eating the eggs of ground,

nesting birds, alligators and turtles.


the document in the ecological

impacts are still being researched,

since much of the activity information

that we have on wild tags in

Florida is anecdotal or in Ferd.

We are working with National Park

Service and University of Florida

to conduct and analyze data,

diet samples and habitat data

to acquire these samples we're

turning to to techniques including.

Surveillance and trapping.

Luckily, since tigers love eggs,

we can exploit.

This chicken eggs are relatively

inexpensive and readily available and

take his love them so we are able

to effectively track these voracious

lizards and to monitor and slow

the tegu invasion front encroaching

into the Everglades National Park.

We're currently operating surveillance

systems of game cameras in close

partnership with National Park Service.

Wanna take his detected?

Will immediately report the

sighting to NPS so that they can

jump into action with live traps

and remove tattoos in this way.

Our collaboration functions as a

long term monitoring study and

an early detection rapid response

surveillance system using the

specimens collected during attracting.

We work with partners to understand

those dietary preferences and

those that may change overtime,

reproductive timing, output,

population demography and activity.

One last example of the work

that we do in in.

If you look at this photo in the bottom left,

it's a picture of a non native milk sink

that a visitor to the Everglades reported.

We were able to respond and

impressively our crew founded.

It happened to be a female so

it could have had eggs which

would have been disastrous.

So we we've seen how important

early detection and rapid response

efforts can be and this is because

we're we're working at the very

leading edge of that invasion curve.

So going back to that invasion curve,

here's the the populations of

Florida pythons and tag use.

But here's where we see

the population in Georgia.

And I just go ahead and overlay

with veiled chameleon and

brown tree snake populations.

You can see that depending on

where you are in the world,

invasive species science can follow a

path to success through adventures.

It's its own yellow brick road.

Thank you for your attention everyone.

Oh my goodness,

thank you to both of you that was.

That was an amazing **** was fascinating.

And I know our viewers enjoyed it too.

'cause we do have quite a

few questions that came in.

If you guys are open for a little Q&A here.

Uh-huh alright,

so let's start with the first.

Here, UM, Amy,

I believe this one is for you.

This came in around the

time you were speaking.

Why are brown tree snakes

responsible for some power outages?

That's a great question.

So brown tree snakes are amazing

climbers and I'm going to recommend

that you watch some video footage that

Doctor Julie Savage and her husband,

Tom Siebert had secured where the

brown tree snake is shown creating a

lasso and able to climb up structures

in this undulating pattern. And so.

That allows them to basically climb any

round structure, such as the cement.

Lines on Guam.

They would touch both parts of the

electrical system and short it,

and that would cause power outages.

There are some early images.

Where the snake would an actually end

up electrocuted and stuck high up on

the wires so they're touching on the

two pieces that need to be touched.

Very much like Raptors when they

land on electrical lines,

they send the current through

their body and short the system.

Oh uh, OK. Another one that came in here.

And Andrea, I believe you spoke to this.

Is it true that people are paid to

hunt pythons in the Everglades?

Yes, yes. So there are a couple of

programs in in South Florida with

other agencies that contract people.

They train them on how to handle it.

The animals identify them and then pay them

either hourly or by the foot of the snake.

And so yeah, we work in partnership

with them, but we're not part

of those programs particularly.

OK great, another one here.

Probably also for you Andrea up.

What should someone do if they encounter

a Python or one of these invasives?

Do we call the USGS?

Who would they call?


I'm sort of. I mean,

there's so there's an app called.

I've got one and so that's

that's where you can report,

you know on your right on your phone

you can take a photo of the animal.

It has a GPS location and it'll go right

to the people that need to hear about it,

and so they can respond immediately,

and then it can also be identified.

So if you're not sure and you just want to,

you know, check to see if it might be

and and you're concerned about the area,

then go ahead and take a photo

and send it in and they can.

They're great biologists,

so they will go ahead and identify

it for you and let you know.

Awesome, uhm, here's another one.

Are there any reports of

pythons attacking humans?

Uh, well so not no, not really.

Come in in the US there's, I mean there's

there's rumors all over the Internet,

but the only documented case of a

Python sort of going after humanism

is during a survey for, you know,

the biologists were walking,

looking for them, and they,

you know, approached them,

possibly stepped on the animal.

And then you know, so it's stuck in response.

But no, they don't readily attack humans.

OK, good to know. Ah.

Here's another one about pythons.

Can drones be used to locate pythons?

No, they're good question.

Uhm, you know, that's.

I, I think that there's a there

might be some application for that,


you know if you have a a broad open

area and it's maybe just after sunset

because you gotta remember that

pythons are like every other reptile

are what we know as cold blooded or

ectotherms or ectotherms so they get

their heat from the environment.

So if you want to use a drone

for like the infrared,

you're going to have to to to do it at

a specific time of day and the Python

have to be on the surface and ready.

You know readily seen.

And you could see why.

Maybe you couldn't.

'cause the the delay in

our in our presentation,

but you can see that you often

can't see these animals.

And even when we're tracking them,

you know to the location where we can spend,

you know 1020 minutes knowing that

it's right in front of us or right

under us and we're trying to to see it.

So it has to be in a very specific

situation with Canopy cover

and grasses and stuff.

It's probably not likely

useful and in many situations.

OK, here's another one.

What about using dogs,


monitor lizards,

etc to detect Python nests and

inhibit recruitment?

Alright yeah, so I talked a little bit about

using detector dogs and again, there's,

you know, limited utility with them.

But you know, targeting this is a great

idea that there's also some issues

with detecting reptiles that don't

move much if they don't move much,

they won't have a scent trail,

so dogs don't have anything to follow,

so there's a Python just sitting on her

nest which they will do for, you know,

a month or two or couple months.

While she's basically protecting her eggs.

There's no scent trail for a dog defined.

I can't remember what the other

part of that question was.

Uh, let's see let me scroll back up here.

I think that's yeah.

Rat picture rents.

Yeah, go ahead and.

Uhm, I know that rats are

amazing for tracking and picking

up and following sense again,

that has not been evaluated for pythons.

You know, Andrea is already

eluded the difficult terrain

that we have in the Everglades,

making it difficult to navigate,

even for for humans.

So that is one of our greatest limitations.

Understood. Uhm, OK, here's a

question that came in from a Rachel.

How do you think it would go if you

used a method similar to the Scout

snake method to use telemetry on

animals that prey on Python eggs?

I I see the images on me, but uhm I.

I'm not sure what targets Python eggs,

so there's there's probably

limit limitations with that.

If you have, you know you can think

of an animal that targets them. Uhm?

That's yeah, yeah, I think right now. I mean,

that's this is part of some of the work,

especially that Andrea is heading off

is better understanding this this part.

The reproductive time of you know where

females are on their clutches of eggs and and

the interactions that happen at those nests.

So that work right now

is just really starting.

For us in the Everglades,

and I think we'll have a better sense

of what? Would target I mean?

Right now I think it would be you know,

potentially bears Bobcats on.

But at this point, you know I don't

think it would be necessarily feasible

to track those animals to get it nests.

Gotcha, uhm OK. One more here.

And just so folks know I

do have a couple links,

I'm going to be putting in to the Q&A

just kind of a for your information.

Things that Amy and Andrea have

provided that might give you some more

information on some of these topics,

but as far as I can tell,

this may be the last question

we have from anonymous.

Could Gene drive technologies genetic

engineering to alter sex ratios

and reduce reproductive rates?

Be used on invasive reptiles.

Let me take that one.

Uhm, it's great timing on that question.

So Andrew and I are part of a

larger collaborative with USGS,

so we have additional colleagues.

And really this is being spearheaded

by Maggie Hunter at work in a

USGS Science Center in in Florida,

in the Gainesville area,

and they're looking at synthetic biology.

And could that be used?

To eventually control round

pythons in in the Florida area,

the thing that's.

That's hard with that is that it requires

a lot of knowledge and a lot of that

knowledge we don't have from now.

So USGS has embarked on what's

called a vital rates initiative,

and we have two USGS science centers

that have come together to begin to look

at the vital rates and by vital rates I mean,

you know female reproduction,

survival of juveniles,

survival of adults.


those kinds of parameters we need to

know that information because that's

the information that would help inform

any kind of genetic manipulation.

And I do know that.

Doctor Maggie Hunter is really

researching this with some others and

that this is a long term horizon.

This is not something that we would see.

For me it's going to be years

over well over a decade.

On Andrew,

do you want to add anything to that?

No, I just yeah, yeah,

I think it's it's a ways out,

but it's definitely something

you know to consider.

OK, well I'm not seeing anything

new come in at the moment so.

Thank you both so much.

You covered so much great material

here and we really appreciate you

guys taking the time to to give

this public lecture tonight, Ann.

I also want to send a huge thank you

out to our audience as well for joining

us tonight and just in case you want to

watch this again or share with others,

this lecture will be available in about

a week for on demand viewing on our

website which is shown on the screen

now and also if you go to that website.

We have about 200 other archived public

lectures there spanning the last 20

years so please be sure to check it out.

Again, thank you Amy Andrea,

please all of you out there in virtual world.

Join us next month, August 26.

Seven PM Pacific Time for Tom Edwards

talk on species modeling and until then,

thank you again and have a great evening.

Bye for now.

Thank you, thank you.