Monday, June 23, 2014

Treefrogs in trees

Gray treefrogs (Hyla versicolor) are often heard calling from trees near and over wetlands.

Recording of the gray treefrog (from the Amphibian Research and Monitoring Initiative)

These frogs are often mistaken for birds because of their musical trill and calling location.
I recently found one calling from a branch in a small tree near a wetland.
Gray treefrog (circled in red) in small tree at edge of wetland
Zoomed in to see gray treefrog sitting on branch

The gray treefrog is found throughout much of Minnesota and can change from mottled gray to mottled green. (Link to MN DNR gray treefrog page).

Gray treefrog in 'gray' phase

Gray treefrog in 'green' phase

Thursday, June 19, 2014

Vernal Pool - Identification and Verification

Vernal pools are small seasonally flooded wetlands that provide vital habitat for many native amphibians and aquatic insects that require fish-free wetlands to survive. (Photos to right show a few examples of vernal pools in northern Minnesota)
Vernal Pool Workshops: History, Identification, and Monitoring in the MN Coastal Zone
 Join researchers from the Natural Resources Research Institute and participate in hands-on workshops investigating 'Vernal Pools' in the region. Workshops are free and open to the public. Participants will be introduced to methods for locating and identifying vernal pools. These workshops will help raise awareness about the value and importance of vernal pools.

Hartley Nature Center - April 26, 2014 10 am - 1 pm (Save the Frogs Day!)
Jay Cooke State Park – May 17, 2014 10 am - 1 pm
Tettagouche State Park – June 7, 2014 12 - 4 pm
Boulder Lake ELC - June 13, 2014 12 - 4 pm
Sugarloaf Nature Center - June 14, 2014 10 am - 1 pm
Grand Marais – June 28, 2014 12 - 4 pm

For more information:

Interested in Vernal Pool Workshops and Volunteering?

Submit vernal pool locations and data

Saturday, May 10, 2014

Finally spring in Duluth!

Spring has finally arrived in Duluth!

Vernal pools (small, temporary wetlands) are almost ice free and wood frogs and spring peepers are starting to breed. Get out and hear the chorus of the early spring breeding frogs - it only lasts a few weeks.

Video of spring peeper calling 
(another spring peeper and chorus of wood frogs in the background)

Spring peeper - with characteristic X on back
Wood frogs in amplexus
Newly laid wood frog eggs

Thursday, April 17, 2014

Citizen Science Frog Monitoring at Hartley Nature Center - April 26

DULUTH, Minn. – Outdoor enthusiasts of all ages are invited to learn about two research opportunities taking place at Hartley Nature Center, April 26 from 10 a.m. to 1 p.m. The Saturday workshop will provide information and hands-on activities for frog monitoring and vernal pool identification and assessment. Presentations and guided walks to vernal pools starting at 10 a.m., 11 a.m. and noon.

“Anyone who is looking for an excuse to hike in beautiful Hartley Park is welcome to join us to learn about data collection for our long-term frog monitoring project and vernal pool status in northeastern Minnesota,” explained Jennifer Olker, scientist at UMD’s Natural Resources Research Institute. Vernal pools are temporary ponds that are vital breeding habitat for many forest creatures. They are not currently protected in Minnesota and scientists lack critical information about them.
Vernal Pool in Early Spring
Workshop participants will learn about Minnesota’s frogs and toads, the current state of amphibians, importance of small wetlands, and how they can help, including two volunteer opportunities: 

Western Chorus Frog and Wood Frog
helping collect data

1) Frog Monitoring Project: conducting surveys at Hartley Park during three periods: April 25 – May 15, May 30 – June 15 and July 5 – July 20

2) Vernal Pool Identification and Field Verification: in Hartley Park and other locations across northeast Minnesota from snowmelt through July. 

Pre-registration is recommended by contacting Jennifer Olker at,, 720-4344 or Ryan Hueffmeier,, 720-4379.

April 26 is also national Save The Frogs Day, the world’s largest day of amphibian education and conservation action. Poetry and art contests are being held as part of the celebration. Learn more at

The Natural Resources Research Institute’s mission is to foster the economic development of Minnesota’s natural resources in an environmentally sound manner to promote private sector employment.