[MARMAM] Two PhD positions available on marine mammals and noise

[Peter Teglberg Madsen]

Applications are invited for a PhD fellowship/scholarship at Graduate School of 
Natural Sciences, Aarhus University, Denmark, within the Biology programme. The 
position is available from August 2024 or later.

Title:
A sound marine environment

Research area and project description:
What do human activities at sea do to marine soundscapes and how are marine 
mammals affected by such anthropogenic noise? To answer these questions, we are 
inviting strong candidates for two Ph.D. projects funded by Aage V. Jensen's 
Naturfond: 'A sound marine environment' to start in the autumn of 2024. The two 
PhD candidates are expected to work closely together on a common project that 
will measure and model the underwater soundscape in the Bay of Aarhus, Denmark, 
and quantify the effects of vessel noise on the distribution and behaviour of 
harbour porpoises. The candidates will use passive acoustic monitoring (PAM) of 
ship noise and harbour porpoises at a number of stations placed in Aarhus Bay 
in concert with soundscape modelling of ship noise. These studies will be 
complemented with investigations of how individual porpoises react to ships and 
boats using sound and movement recording tags. The work will be divided with 
one Ph.D. project focusing on large ships and one with focus on small 
recreational vessels. Dissemination of the research findings involves 
peer-reviewed publications firs-authored by the candidates and a strong 
outreach component, involving stakeholder engagement, information to the public 
and citizen science. The project has the ambition to deliver strong results 
that can support a science-based management of marine habitats in Bay of Aarhus 
and beyond.

General information about the project can be found at the project website 
www.oceannoise.dk<http://www.oceannoise.dk>

The PhD project on large vessels will be supervised by Professor Jakob Tougaard 
at the Department of Ecoscience and the PhD project on smaller vessels will be 
supervised by Professor Peter T. Madsen at the Department of Biology. The two 
research groups are physically co-located and completely integrated in the 
daily life, ensuring a close collaboration between the two PhD projects. For 
technical reasons, applicants are asked to apply to this call at both graduate 
schools (GSTS and GSNS). If you have a preference for one of the two PhD 
projects (larger vessels or recreational boats) you can indicate this in the 
application and elaborate on why in your cover letter.

For technical reasons, you must upload a project description. When - as here - 
you apply for a specific project, please simply copy the project description 
above, and upload it as a PDF in the application. If you wish to, you can 
indicate an URL where further information can be found.

Qualifications and specific competences:
Applicants must have a relevant Master's degree (120 ECTS) in Bioacoustics, 
Engineering, Physics or similar fields and a strong interest in acoustics and 
the effects of sound on marine organisms. It is an advantage to have documented 
experience with quantitative data analysis on large data sets with Matlab, R, 
Python or similar software.

Good collaborative skills are required and you are expected to contribute fully 
to the large, diverse and highly active bioacoustics research group that you 
will become part of.

We also expect you to be able to communicate eloquently in both written and 
oral English.

Place of employment and place of work:
The place of employment is Aarhus University, and the place of work is 
Department of Biology, Zoophysiology, Build. 1131, CF Møllers Alle 3, 8000 
Aarhus C, Denmark.

Contacts:
Applicants seeking further information for this project are invited to contact: 
Professor Peter Teglberg Madsen, 
peter.mad...@bio.au.dk<mailto:peter.mad...@bio.au.dk> or Professor Jakob 
Tougaard, j...@ecos.au.dk<mailto:j...@ecos.au.dk>

How to apply:

For information about application requirements and mandatory attachments, 
please see the Application 
guide<https://phd.nat.au.dk/for-applicants/application-guide/>. Please read the 
Application guide thoroughly before applying.

When ready to apply, go to https://phd.nat.au.dk/for-applicants/apply-here/ 
(Note, the online application system opens 1 March 2024)

  1.  Choose May 2024 Call with deadline 1 May 2024 at 23:59 CEST.
  2.  You will be directed to the call and must choose the programme "Biology".
  3.  In the boxed named "Study": In the dropdown menu, please choose: "A sound 
marine environment (somaen)"

Please note:

  *   The programme committee may request further information or invite the 
applicant to attend an interview.

At the Faculty of Natural Science at Aarhus University, we strive to support 
our scientific staff in their career development. We focus on competency 
development and career clarification and want to make your opportunities 
transparent. On our website<http

[MARMAM] New paper: How whales dive, feast and fast

[Peter Teglberg Madsen]

Dear All,
This recent review in Annual Review of Ecology, Evolution, and Systematics may 
be of interest to some of you:
How Whales Dive, Feast, and Fast: The Ecophysiological Drivers and Limits of 
Foraging in the Evolution of Cetaceans

Abstract
Whales are an extraordinary study group for questions about ecology 
and´evolution because their combinations of extreme body sizes and
unique foraging strategies are unparalleled among animals. From a terrestrial 
ancestry, whales evolved specialized oceanic foraging mechanisms that 
characterize
the two main groups of living cetaceans: echolocation by toothed whales and 
bulk filter feeding by baleen whales. In toothed whales, lineage-specific 
increases
in body size, enhanced diving capacity, and echolocation enable them to hunt 
the most abundant prey on the planet: deep-sea fish and cephalopods.
Even greater body size increases, along with filter feeding and fasting 
capacity, permit large baleen whales to migrate long distances and exploit 
epipelagic patches
of schooling prey, such as krill or fish, which are highly abundant but 
ephemeral. For both groups, prey abundance and distribution
limit foraging performance, yielding divergent energetic niches that have 
shaped their convergent evolution to gigantism.

The paper can be found here: 
https://www.annualreviews.org/doi/abs/10.1146/annurev-ecolsys-102220-025458

Alternatively, feel free to write me an email for a pdf copy.

Happy holidays,
Peter
___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] sperm whale slow clicks

[Peter Teglberg Madsen]

Dear All,
We are working on a project concerning sperm whale slow clicks (also called 
clangs), and we are therefore interested in good PAM recordings of these sounds.
If any of you have such data and are interested in a collaboration please reach 
out to: simone.vide...@bio.au.dk and 
peter.mad...@bio.au.dk

Best
Peter
___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Diving porpoises conserve more oxygen when they can’t see

[Peter Teglberg Madsen]

Dear All,
In a recent paper we show that porpoises conserve more oxygen when they can’t 
see.
The dive response of marine mammals allow them to undertake long breath-hold 
dives to access rich marine prey resources. It consists of a mixture of 
peripheral vasoconstriction and a lowering of heart rate, leading to lower 
metabolic rates in un-perfused tissues.
The dive response has been shown to vary with breath-hold duration, depth, 
exercise, and expectations during the dive. However, it is unknown to what 
extent sensory deprivation influences the dive response and oxygen management.
We show that acoustic masking causes very little change in heart rate of a 
trained harbor porpoise tasked with discriminating between two targets, whereas 
visual deprivation reduces heart rate by half of control values, suggesting a 
much larger importance of vision from these previously considered obligate 
echolocators. This indicates that such strong oxygen regulation in response to 
a change in sensory information could be a potential anti-predator response.

Check the paper out here: 
https://www.cell.com/.../fulltext/S2589-0042(23)00281-X...

On behalf of the authors,
Peter

___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Toothed whale sound production

[Peter Teglberg Madsen]

Dear All,
Our recent paper on toothed whale sound production may be of interest to some 
of you. We have sought to address the fundamental questions of 1) how 
echolocating toothed whales can make 500 clicks per second with air at a 1000 
meters depth where air volumes are compressed to less than 1%, and 2) how 
toothed whales with the same nasal sound source produce can both powerful, high 
frequency clicks for echolocation and softer, low frequency calls for complex 
communication?

We confirm that toothed whales possess a nasal sound production system driven 
by air. Loud clicks are made when phonic lips collide after having been forced 
apart by the airflow. This air-driven, self-sustained oscillation mechanism for 
sound production is functionally the same as laryngeal and syringeal sound 
production in other mammals and birds. Acoustic analysis of calls across 
different toothed whale species shows that vocalizations are produced at 
different frequency regimes, consistent with tissue vibrations at different 
registers: just like human vocal folds making the vocal fry, chest and falsetto 
registers. We conclude that the vocal fry register makes powerful, high 
frequency echolocation clicks in toothed whales, and the two other registers 
make softer, more low frequency social calls for mediating complex behavioral 
interactions via acoustic communication. For both sound types, air can be 
recycled, allowing for continued sound production during deep dives.

The vocal fry register for echolocation uses only very little air per click 
because the phonic lips only open for about 1 ms, explaining how these apex 
predators can make the loudest biological sound pressure levels in the animal 
kingdom at depths of more than 1000 meters. This trick opened the previously 
unexplored rich food niches of the deep ocean for exploitation by more than 20 
species of large toothed whales.

The paper can be found here
https://www.science.org/doi/10.1126/science.adc9570

If you don't have access, please feel free to write me an email for a pdf.

Best
peter
___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Call for applications for the graduate summer school “Acoustic Communication”, August 6-19, 2022 in Denmark

[Peter Teglberg Madsen]

Call for applications for the graduate summer school “Acoustic Communication”, 
August 6-19, 2022



Graduate course arranged by graduate school SNAK, University of Southern 
Denmark, Odense, Denmark



Application deadline April 15th, 2022

The course focuses on methods and techniques for studying animal sound 
communication in air (infra-, ultra- and sonic ranges), in water, and in solids 
(vibrations). It includes lectures, practicals, and excursions with time for 
discussion and student presentations. Introductory lectures aim at giving an 
overview of the subject of acoustic communication followed by special lectures 
on the fundamentals of acoustics, signal analysis, psychoacoustics, animal 
sound production, and noise. Practicals aim at giving the students hands-on 
experience of sound and vibration recording, sound analysis, and playback in 
air and water with emphasis on methodological limitations and pitfalls. MatLab 
will be used throughout the course but prior experience is not required. The 
applicants will be evaluated through group presentations of practicals.



Time: August 6-19, 2022



Location: The marine and terrestrial field stations of the Department of 
Biology, University of Southern Denmark. The stations are located in the town 
of Kerteminde (marine) on the east coast of Funen and in the south of the 
island Funen (terrestrial), respectively.



Teachers: Resident experts and invited experts from abroad.

Resident experts: Peter Teglberg Madsen, Mark Johnson, Jakob Tougaard (AU, DK) 
Magnus Wahlberg, Jakob Christensen-Dalsgaard, Coen P.H. Elemans, Lasse 
Jakobsen, Ole Næsbye Larsen, Iris Adam (SDU, DK)



Participants: Strict priority is given to students enrolled in a PhD-program at 
their home universities. MSc-students and post-docs may attend if space 
permits. The maximal number of participants is 24.



Fees: DKK 10,000 (approximately USD 1,400 and EUR 1,400) to cover tuition, 
transport during course, accommodation, and all meals.



Language: English



ECTS points: 10



Application procedure: To apply, please send the following documents in PDF 
format:

• Curriculum vitae (max. 2 pages), indicating level of English language 
proficiency.

• A statement of your reasons for wishing to attend the course and your 
potential benefits of participation including a description of your research 
interests, the title of your PhD-project (or MSc-project), and name(s) of your 
supervisor(s) (max. 1 page).



The application should be emailed to bioacoust...@biology.sdu.dk by April 15th. 
The 24 successful applicants will be notified of acceptance before May 1st.

Course directors: Jakob Christensen-Dalsgaard & Lasse Jakobsen, Department of 
Biology, University of Southern Denmark. j...@biology.sdu.dk 
la...@biology.sdu.dk
Course webpage: 
https://www.sdu.dk/en/forskning/sound-communication-behaviour/education/graduate-course-bioacoustics
___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] post doctoral position available to study the effects of vessel noise on marine mammals using Dtags

[Peter Teglberg Madsen]

Dear All,
The Marine bioacoustics lab at Aarhus university has a post-doctoral position 
available to study the effects of vessel noise on marine mammals using Dtags.

Please find the details here:
https://www.au.dk/om/stillinger/job/post-doctoral-position-in-vessel-noise-effects-on-marine-mammals/

Best,
Peter

Zoophysiology, Department of Biology
CF Mollers Alle 3, 8000 Aarhus C
Aarhus University, Denmark

www.marinebioacoustics.com
https://www.facebook.com/MarineBioacoustics/


___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Graphical reviews of marine mammal physiology

[Peter Teglberg Madsen]

Dear All,
To celebrate the centennial of August Kroghs Nobel Prize in physiology, a 
special volume of Comparative Physiology and Biochemistry has been put together 
with a series of graphical reviews on animal physiology, including several om 
marine mammals that may be of interest to some of you.

You can find them all here:
https://www.sciencedirect.com/journal/comparative-biochemistry-and-physiology-part-a-molecular-and-integrative-physiology/special-issue/10XD4F4R26W


Enjoy and best
Peter

Zoophysiology, Department of Biology
CF Mollers Alle 3, 8000 Aarhus C
Aarhus University, Denmark

www.marinebioacoustics.com
https://www.facebook.com/MarineBioacoustics/

___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Why are whales so big?

[Peter Teglberg Madsen]

Jeremy and I have given that question some thought in the paper below that may 
be of interest.
Pdf can be downloaded from link or by writing one of us an email.

best
Jeremy and Peter

jerg...@stanford.edu / 
peter.mad...@bios.au.dk

The evolution of foraging capacity and gigantism in cetaceans

J. A. Goldbogen, P. T. Madsen

Journal of Experimental Biology  2018  221:  jeb166033  doi: 10.1242/jeb.166033 
 Published 12 June 2018

ABSTRACT

The extant diversity and rich fossil record of cetaceans provides an 
extraordinary evolutionary context for investigating the relationship between 
form, function and ecology. The transition from terrestrial to marine 
ecosystems is associated with a complex suite of morphological and 
physiological adaptations that were required for a fully aquatic mammalian life 
history. Two specific functional innovations that characterize the two great 
clades of cetaceans, echolocation in toothed whales (Odontoceti) and filter 
feeding in baleen whales (Mysticeti), provide a powerful comparative framework 
for integrative studies. Both clades exhibit gigantism in multiple species, but 
we posit that large body size may have evolved for different reasons and in 
response to different ecosystem conditions. Although these foraging adaptations 
have been studied using a combination of experimental and tagging studies, the 
precise functional drivers and consequences of morphological change within and 
among these lineages remain less understood. Future studies that focus at the 
interface of physiology, ecology and paleontology will help elucidate how 
cetaceans became the largest predators in aquatic ecosystems worldwide.

http://jeb.biologists.org/lookup/doi/10.1242/jeb.166033.


___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Toothed whale biosonar beams: from flashlight to floodlight

[Peter Teglberg Madsen]

Dear All,
For those of you interested in echolocation, we have two recent papers out 
showing that toothed whales can change the width of their biosonar beams 
adaptively to the sonar task at hand. At close range they broaden their 
acoustic field of view likely to minimize the risk that prey escapes, while at 
longer ranges a narrow beam may reduce clutter problems.
Please find abstracts below. Requests for pdf's can be made to the first 
authors:

Danuta Wisniewska: 
danuta.wisniew...@bios.au.dkmailto:danuta.wisniew...@bios.au.dk

Frants Jensen: fjen...@princeton.edumailto:fjen...@princeton.edu

Best
Peter


Peter T. Madsen
Zoophysiology, Department of Bioscience
Aarhus University, Build. 1131, CF Mollers Alle
8000 Aarhus C, Denmark

Phone: 0045 8715 6501
email: peter.mad...@biology.au.dkmailto:peter.mad...@biology.au.dk
Web: www.marinebioacoustics.comhttp://www.marinebioacoustics.com/
Facebook: https://www.facebook.com/MarineBioacoustics

[sender_logo]

Range-dependent flexibility in the acoustic field of view of echolocating 
porpoises (Phocoena phocoena)

http://elifesciences.org/content/early/2015/03/20/eLife.05651

Toothed whales use sonar to detect, locate, and track prey. They adjust emitted 
sound
intensity, auditory sensitivity and click rate to target range, and terminate 
prey pursuits with high repetition-
rate, low-intensity buzzes. However, their narrow acoustic field of view (FOV) 
is
considered stable throughout target approach, which could facilitate prey 
escape at close-range.
Here, we show that, like some bats, harbour porpoises can broaden their 
biosonar beam during the
terminal phase of attack but, unlike bats, maintain the ability to change 
beamwidth within this phase.
Based on video, MRI, and acoustic-tag recordings, we propose this flexibility 
is modulated by the
melon and implemented to accommodate dynamic spatial relationships with prey 
and acoustic
complexity of surroundings. Despite independent evolution and different means 
of sound generation
and transmission, whales and bats adaptively change their FOV, suggesting that 
beamwidth
flexibility has been an important driver in the evolution of echolocation for 
prey tracking.


Single-click beam patterns suggest dynamic changes to the field of view of 
echolocating Atlantic spotted dolphins (Stenella frontalis) in the wild

http://jeb.biologists.org/content/early/2015/03/11/jeb.116285.abstract

Echolocating animals exercise an extensive control over the spectral and 
temporal properties of their biosonar signals to facilitate perception of their 
actively generated auditory scene when homing in on prey. The intensity and 
directionality of the biosonar beam defines the field of view of echolocating 
animals by affecting the acoustic detection range and angular coverage. 
However, the spatial relationship between an echolocating predator and its prey 
changes rapidly, resulting in different biosonar requirements throughout prey 
pursuit and capture. Here we measured single click beam patterns using a 
parametric fit procedure to test whether free-ranging Atlantic spotted dolphins 
(Stenella frontalis) modify their biosonar beamwidth. We recorded echolocation 
clicks using a linear array of receivers and estimated the beamwidth of 
individual clicks using a parametric spectral fit, cross-validated with 
well-established composite beam pattern estimates. The dolphins apparently 
increased the biosonar beamwidth, to a large degree without changing the signal 
frequency, when they approached the recording array. This is comparable to bats 
that also expand their field of view during prey capture, but achieve this by 
decreasing biosonar frequency. This behaviour may serve to decrease the risk 
that rapid escape movements of prey take them outside the biosonar beam of the 
predator. It is likely that shared sensory requirements have resulted in bats 
and toothed whales expanding their acoustic field of view at close range to 
increase the likelihood of successfully acquiring prey using echolocation, 
representing a case of convergent evolution of echolocation behaviour between 
these two taxa.
___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] mini-review on beaked whales

[Peter Teglberg Madsen]

Dear All,

For those interested, we have compiled information from the last decade of 
beaked whale field work in a mini-review of these elusive deep divers.



The paper can be found here:



http://www.cell.com/current-biology/abstract/S0960-9822(14)00757-X



Alternatively, pdfs can be requested by emailing 
peter.mad...@biology.au.dkmailto:peter.mad...@biology.au.dk



Best

Peter
___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Paper on dolphin sound production

[Peter Teglberg Madsen]

Dear All,
For those of you intrigued by how the nose of dolphins produce sound this paper 
may be interest to you:

Nasal sound production in echolocating delphinids (Tursiops truncatus and 
Pseudorca crassidens) is dynamic, but unilateral: clicking on the right side 
and whistling on the left side
1.   Peter T. 
Madsenhttp://jeb.biologists.org/search?author1=Peter+T.+Madsensortspec=datesubmit=Submit1http://jeb.biologists.org/content/216/21/4091.abstract#aff-1,*http://jeb.biologists.org/content/216/21/4091.abstract#corresp-1,
2.   Marc 
Lammershttp://jeb.biologists.org/search?author1=Marc+Lammerssortspec=datesubmit=Submit2http://jeb.biologists.org/content/216/21/4091.abstract#aff-2,
3.   Danuta 
Wisniewskahttp://jeb.biologists.org/search?author1=Danuta+Wisniewskasortspec=datesubmit=Submit1http://jeb.biologists.org/content/216/21/4091.abstract#aff-1
 and
4.   Kristian 
Beedholmhttp://jeb.biologists.org/search?author1=Kristian+Beedholmsortspec=datesubmit=Submit1http://jeb.biologists.org/content/216/21/4091.abstract#aff-1
+http://jeb.biologists.org/content/216/21/4091.abstract Author Affiliations
1.1Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus, 
Denmark
2.2Marine Mammal Research Program, Hawaii Institute of Marine Biology, 
Kailua, HI 96734, USA
1.
↵http://jeb.biologists.org/content/216/21/4091.abstract#xref-corresp-1-1*Author
 for correspondence 
(peter.mad...@biology.au.dkmailto:peter.mad...@biology.au.dk)
SUMMARY
Toothed whales produce sound in their nasal complex by pneumatic actuation of 
phonic lip pairs within the blowhole. It has been hypothesized that dual 
actuation of the phonic lip pairs can generate two pulses that merge to form a 
single echolocation click with a higher source level, broader bandwidth and 
larger potential for beam steering than if produced by a single pair of phonic 
lips. Here, we test that hypothesis by measuring the sound production of five 
echolocating delphinids using hydrophones around the animals and imbedded in 
on-animal suction cups. We show that the studied animals click with their right 
pair of phonic lips and whistle with their left pair. We demonstrate that, with 
just a single pair of phonic lips, they can change the click energy levels over 
five orders of magnitude, change the click centroid frequencies over more than 
two octaves, and modulate the sound radiation from the melon for beam steering. 
We conclude that all of the click dynamics ascribed to dual actuation of two 
phonic lip pairs can be achieved with actuation of just the right pair of 
phonic lips, and we propose that the large dynamic range of source outputs is 
achieved by highly controlled modulation of the pneumatic driving pressure, the 
tension of the phonic lip labia and the conformation of the fatty melon and 
associated air sacs.
doi: 10.1242/​jeb.091306 November 1, 2013 J Exp Biol216, 4091-4102.


The paper can be found here: 
http://jeb.biologists.org/content/216/21/4091.abstract

Or requests for reprints can be made to: 
peter.mad...@biology.au.dkmailto:peter.mad...@biology.au.dk

Best
Peter


Peter T. Madsen
Zoophysiology, Department of Bioscience
Aarhus University, Build. 1131, CF Mollers Alle
8000 Aarhus C, Denmark

Phone: 0045 8715 6501
email: peter.mad...@biology.au.dkmailto:peter.mad...@biology.au.dk
Web: www.marinebioacoustics.comhttp://www.marinebioacoustics.com

[sender_logo]

inline: image001.jpg___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] Clicking in killer country

[Peter Teglberg Madsen]

Dear Marmam,
Please post this.
Best and thanks
Peter


Dear All,
On behalf of Line Kyhn and coauthors, I hereby wish to draw the attention of 
interested readers to this recent paper in Plos One on echolocation of 
porpoises in a killer whale habitat:

Clicking in a Killer Whale Habitat: Narrow-Band, High-Frequency Biosonar Clicks 
of Harbour Porpoise(Phocoena phocoena) and Dall's Porpoise (Phocoenoides dalli)

Line A. Kyhn1*, Jakob Tougaard1, Kristian Beedholm2, Frants H. Jensen2, Erin 
Ashe3, Rob Williams3,
Peter T. Madsen2
1 Department of Bioscience, Aarhus University, Aarhus, Denmark, 2 
Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark, 3 
Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, 
St Andrews, United Kingdom

Abstract
Odontocetes produce a range of different echolocation clicks but four groups in 
different families have converged on
producing the same stereotyped narrow band high frequency (NBHF) click. In 
microchiropteran bats, sympatric species have evolved the use of different 
acoustic niches and subtly different echolocation signals to avoid competition 
among species. In this study, we examined whether similar adaptations are at 
play among sympatric porpoise species that use NBHF echolocation clicks. We 
used a six-element hydrophone array to record harbour and Dall's porpoises in 
British Columbia (BC), Canada, and harbour porpoises in Denmark. The click 
source properties of all porpoise groups were remarkably similar and had an 
average directivity index of 25 dB. Yet there was a small, but consistent and 
significant 4 kHz difference in centroid frequency between sympatric Dall's 
(13763 kHz) and Canadian harbour porpoises (14162 kHz). Danish harbor porpoise 
clicks (13663 kHz) were more similar to Dall's porpoise than to their 
conspecifics in Canada. We suggest that the spectral differences in 
echolocation clicks between the sympatric porpoises are consistent with 
evolution of a prezygotic isolating barrier (i.e., character displacement) to 
avoid hybridization of sympatric species. In practical terms, these spectral 
differences have immediate application to passive acoustic monitoring.

A popular account can be found here:
http://www.mysciencework.com/en/MyScienceNews/10193/killer-whales-porpoise-clicks

A pdf copy can be found here:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0063763


Or by emailing me: peter.mad...@biology.au.dkmailto:peter.mad...@biology.au.dk

On behalf of the authors
Peter


Peter T. Madsen
Zoophysiology, Department of Bioscience
Aarhus University, Build. 1131, CF Mollers Alle
8000 Aarhus C, Denmark

Phone: 0045 8715 6501
email: peter.mad...@biology.au.dkmailto:peter.mad...@biology.au.dk
Web: www.marinebioacoustics.comhttp://www.marinebioacoustics.com

[sender_logo]

inline: image001.jpg___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam

[MARMAM] phd course in bioacoustics

[Peter Teglberg Madsen]

Dear All,

The graduate school SNAK in Denmark is now again offering its international
ph.d. course Animal communication august 10-20 2009. The 10 day course has
special focus on how to design bioacoustic experiments, and on methodology
and analysis. Topics covered include hydrophonemicrophone calibration,
arrays, hearing and sound production, sound propagation, noise, ABR,
psychophysics, signal processing, biosonars and communication. The class
will be given by resident and international experts in underwater and
terrestrial bioacoustics. 

For more information see 

http://www.snak.biology.sdu.dk/Courses/Opslag-Summer%20School%202009.doc

To apply, please see 

http://www.snak.biology.sdu.dk/Courses/How%20to%20apply.pdf

Application deadline is April 1. 

On behalf of SNAK and the organizers
Peter T. Madsen



 

___
MARMAM mailing list
MARMAM@lists.uvic.ca
https://lists.uvic.ca/mailman/listinfo/marmam