Hamline University Graduate School

St. Paul, Minnesota

http://cgee.hamline.edu/frogs

Scientists in MN and elsewhere had found malformed frogs in the early 1990s. Then the issue hit the national media in 1995. Why?

Students in Henderson, MN, found hundreds of malformed frogs at a site.

A Thousand Friends of Frogs was formed in the wake of this media coverage

What are we being told by:

Amphibian (frog and toad) malformities

Amphibian populations locally and globally

But first……a few questions!!

smooth or slimy skin warty and dry skin strong, long legs and stubby bodies with short

webbed hind feet hind legs two bulging eyes parotid glands behind eyes

lay eggs in clusters lay eggs in long chains

Both are considered ectothermic (often called cold blooded) because their body temperature adjusts with the outside environment.

Vs.

Frogs have: Toads have:

A group of frogs is A group of toads is called called

an ARMY of frogs a KNOT of toads

Vs.

Frogs Toads

Anuran Diversity

14 species in MN

Frogs and Toads

92 species in USA

3,300 species in the world

Red-eyed Treefrog

glass Frog

poison dart frog

White’s Treefrog

Horned ToadFire-bellied Toad

Ornate Horned Frog poison dart frog

Strawberry Poison Dart FrogAfrican Dwarf Frog

MN Frogs and Toads

Habitats for frogs and toads

rivers and streams

lakes, ponds, marshes

grasslands

forests

Why We Care

1. Frogs and toads are a part of the planet’s bio-diversity.

2. Frogs and toads interact in interesting ways with each other and the environment, i.e. both prey and predators

Why We Care

3. Frogs and toads provide benefits to humans i.e. Gastric Brooding Frog of Australia might have provided answers for people suffering from gastric ulcers

(Case of the Vanishing Frogs, T. Halliday and W. R. Heyer).

4. Frogs As Bio-indicators

1) double life--amphibious2) permeable skin 3) absorb and concentrate toxins--

biomagnification

4. Frogs As Bio-indicators

Biomagnification: a process in which retained substances become more concentrated with each link in the food chain

Malformed Frogs & Toads

External Malformations

• extra or missing limbs• branching limbs• spikes or protuberances• missing eyes• abnormal webbing

Internal Malformations

• reproductive• digestive• urinary

Malformed Frog Pictures

Dr. David Hoppe, University of Minnesota-Morris

Dr. David Hoppe, University of Minnesota-Morris

Dr. David Hoppe, University of Minnesota-Morris

Dr. David Hoppe, University of Minnesota-Morris

Causes of Malformations

• genetic origins• parasite disruption of limb formation• chemical contamination• viruses• ultraviolet radiation• physical trauma (predation, people)

Trematode (flatworm) cysts have been demonstrated to cause problems in limb bud development in tadpoles

Dr. Stanley K. Sessions, Hartwick College

Dr. Stanley K. Sessions, Hartwick College

Possible Chemical Contaminants

• agrochemicals• heavy metals• acid rain• chlorofluorocarbons (CFCs)

Types of Agrochemicals

• herbicidesManeb-

fungicide

• pesticides propylthiourea

• fertilizersDr. Stanley K. Sessions, Hartwick College

Types of Agrochemicals

applications of the herbicide atrazine have led to egg mortality and tadpole deformities (Hazelwood 1970)

Dr. Stanley K. Sessions, Hartwick College

Correlations to Human Health Concerns

• high nitrate levels (from fertilizers) in human drinking water and frog breeding ponds are hazardous

• human birth defects result from pesticide application

• UV radiation results in blindness and skin cancer in humans and other animals; DNA damage in developing frog eggs

Where have all the frogs gone?

Global Population Decline

• a concern during the past decade• frog declines widespread and well-

documented• possible causes include habitat

destruction, increased UV radiation, and chemical contamination

Global Population Declines

•Loss of habitat from filling in wetlands to

create more farmland for crops, and to build more houses and roads

(Case of the Vanishing Frogs, T. Halliday and W. R. Heyer).

Global Population Declines

• Increasing ultraviolet radiation• Pollution by chemicals• Acid rain• Pathogens• Parasites• Introduction of non-native species

Global Population Declines

Amphibian declines occurring in locations where habitats relatively undisturbed.

Australia:

Gastric Brooding Froglast seen in wild in 1980s

Global Population Declines

Monteverde, Costa Rica:

Golden Toad last seen 1988

Global Population Declines

Other places experiencing declines include: Puerto Rico Ecuador Venezuela Brazil U.S. Rocky Mountains Cascade Mountain Range in Washington, Oregon, and California

What You and Your Students Can Do to Help!

Care

Adopt

Look

Listen

Answer the

Malformity and Calling Surveys

Various types of surveys depending on your objectives

Malformity surveys: deal specifically with malformities in amphibians

Calling surveys: need to know the calls of anurans

terrestrial salamander monitoring

aquatic surveys

Malformity and Calling Surveys

A Thousand Friends of Frogs has two surveys—

Malformity and Calling

http://cgee.hamline.edu/frogs/students/involved.html

Malformity and Calling SurveysMalformity surveyProtocols for collecting and reporting data.

Data collected and transferred to scientists

Results on web site

http://cgee.hamline.edu/frogs/science/datasht.html

Calling survey: Minnesota Frog WatchOver 100 volunteers surveying in the state

Working with MN Dept. Natural Resources

http://cgee.hamline.edu/frogs/science/wach2000.html

Malformity and Calling SurveysNorth American Reporting Center for Amphibian Malformities (NARCAM)

http://www.npwrc.usgs.gov/narcam

Report data on the web

Malformity and Calling SurveysNorth American Amphibian

Monitoring Project (NAAMP)

http://www.im.nbs.gov/amphibs.html

Protocols for reporting data

State coordinators

Malformity and Calling Surveys

What you need to know to survey?

Depends on type of survey conducted

ID of frogs, toads and salamanders—color, shape, etc.

Calls of frogs and toads

Let’s learn a few calls!!

Bullfrog

Spring Peepers

Student Activities

Other student activities

Student Reports on Project Web Site

Student Poetry

Student Writing

Student Art

Celebrating

amphibians

Australia

Finland

Minnesota

Scotland