Surinam toad, Pipa pipa While in Peru I had a chance to hand audition one Surinam toad on 20 July 2012 at approximately 11 pm. No sounds were detected.

Pink river dolphin, Inia geoffrensis While in the Pacaya–Samiria National Reserve in the Peruvian Amazon, I had the opportunity to record pink river dolphin on a number of occassions. Note, that the Tucuxi river dolphin (Sotalia fluviatis) were sometimes present. Usually a single pair or small pod. For more information go to the Amazon project page

Here is a short video clip of Pink River dolphin recorded about 3 pm on 21 July 2012. The audio includes aerial sounds and underwater sound played over a loudspeaker. Towards the end of the video you can hear and see bubbles that the dolphin blew under our drifting boat.

Spectrogram of underwater sounds recorded during the video sequence (not synched). Note that much of the dolphin's sounds are above the human hearing range, but you can hear it if you playback at a slower speed.

Listen to the underwater sounds recorded during the video (not synced exactly to the video).

Spectrogram of another example of pink river dolphin sounds, and bubble sounds recorded on 24 July 2012

Listen to the underwater sounds.

Spectrogram of sound attributed to the pink river dolphin as recorded at night on 24 July 2012 during a caiman survey. Note, gray river dolphin could have been in the area unobserved.

Listen to river dolphin at night.

Harbor seal, Phoca vitulina

Sounds recorded in the Gulf of Maine during the Fishing Grounds of New England PAM survey.

Spectrogram of a single call of Phoca vitulina recorded in Casco Bay off the coast of Maine on 22 June 2003 at approximately 2200 h.

Listen to a seal call

Spectrograms of a 15 minute series of repeating seal calls recorded in Casco Bay on 24 June 2003 about 1745 h

Spectacled Caiman, Caiman crocodilus An approximately 47 cm specimen auditioned during a caiman survey on 24 July 2012. Three 47-97 cm specimens examine were silent.

Black caiman, Melanosuchus niger An approximately 138 cm specimen auditioned during a caiman survey on 24 July 2012. Three 108-147 cm specimens examine were silent.

Black caiman, Melanosuchus niger An approximately 138 cm specimen being auditioned during a caiman survey on 24 July 2012.

Spider crab, Libinia emarginata

Specimen auditioned 24 July 2019 at the Cotuit, MA town dock. Several specimens auditioned over the years. No audible sounds detected.

Blue crab, Callinectes sapidus

Spectrogram of Blue crab, Callinectes sapidus sounds recorded in Popponesset Bay on Cape Cod, MA on 24 June 2020. The crab produced sounds only after being released into the water. Sounds may have been bubble release.

Listen to the blue crab

Lady crab, Ovalipes ocellatus

Spectrogram of Lady crab, Ovalipes ocellatus sounds recorded in Cotuit Bay on Cape Cod, MA on 8 June 2014. Sound recorded as swimming crab ran into hydrophone array. Attribution not certain. However, I have heard a similar sound when holding a lady crab on one occussion (not recorded)

Listen to the Lady crab

Amazonian Freshwater Crab, Sylviocarcinus pictus silent individual recorded on 23 July 2012.

American Beaver, Castor canadensis

Spectrogram of a Beaver tail slap recorded in the Connecticutt River on 1 June 2017 near sunset. The spectrogram shows the sound both underwater (top) and simultaneously in air (bottom).

Listen to a beaver tail slap. The sound of the slap underwater can be heard in your left ear, while the sound above water in your right ear. Note, sound levels are not comparable.

Amazonian manatee, Trichechus inunguis

Sounds recorded in the Peruvian Amazon. See the Amazon PAM survey for more information.

Spectrogram of a Trichechus inunguis call series recorded on July 7, 2012. This was the first published sound of the species in the wild.

Listen to the Amazonian manatee

Spectrogram of a single whistle from the call series

Yellow-spotted River Turtle, Podocnemis unifilis Three silent individuals approximately 18 cm carapace length were auditioned on 14, 16 and 23 July 2012.