WOW

Thank you all for such a great response to my first-time query on this list serve.  I will answer each respondent by separate email.  Below is a quick description of what I am up to.  I am not affiliated with any organization. I am a retired technologist with some underwater measurement experience during my working life.  My wife and I support several NGOs in the Peruvian Amazon and are involved in environmental issues in that area.  Inia is a threatened species and is extremely hard to count thus my mission. 

Since 2007, I have made three trips to the Peruvian Amazon where I have collected underwater sounds from Inia geoffrensis.  I have made recordings on the Main Amazon, Nanay, Itaya, Napo, Maniti, Pacaya, Yarina, Tahuayo rivers  and numerous smaller tributaries and lakes.

My working hypothesis is that by using sufficiently high acoustic sample rates to resolve the spectral composition of individual dolphin clicks I can capture waveform combinations unique to an individual animal.  My reasoning is that these energetic pulses, formed in the animal’s melon and associated complex musculoskeletal structure, are unique to each individual much as a fingerprint is to a human.

My objective is to determine if it is feasible to capture acoustic characteristics that are unique to each individual (click print) with the long term goal of developing a mobile individual counting system.  So far I have recorded some interesting vocalizations and many click trains along with very high amplitude pulses (ultrasonic but not clicks) possibly associated with feeding behavior.  I have not found anything in the literature that describes these energetic pulses.  In short I have many gigabytes of acoustic data recorded in proximity to these animals.  I use a SQ 26-07/08 Hydrophone from Cetacean Research Tech (Joe Olsen) and a Microtrack  24/96 Digital Recorder set at a 96KHz sample rate.  This limits what frequencies I can analyze to about 46KHz.  Inia clicks have been measured in more controlled conditions to at least 105KHz and possibly much higher so I know I will need to expand my sampling and recording capabilities.  . I keep a log of GPS position, river conditions and visual observations during each recording.

I consider the last three years work to have been a reconnaissance and am now trying to decide what to do with the data and what the next step might be.  I believe there is a good chance that something can be built that will allow faster and more accurate counting of these incredible animals in the wild.

Thanks

David E Bonnett

2374 NW Mountain View Road

Silverdale, Wa 98383

Cell : 360 710 4963

Home: 360 779 3850

d-bonnett@wavecable.com