The effects of oil and gas infrastructure noise on alarm communication in Savannah sparrows

88 Pages·2016·1.08 MB·English

by  Bridget Antze

The effects of oil and gas infrastructure noise on alarm communication in Savannah
sparrows (Passerculus sandwichensis)

By
Bridget Antze

A Thesis
Submitted to the Faculty of Graduate Studies of
The University of Manitoba
In Partial Fulfillment of the Requirements of the Degree of
Master of Natural Resource Management

The Natural Resources Institute
Clayton H. Riddell Faculty of Environment, Earth and Resources
University of Manitoba
Winnipeg, MB

Copyright © Bridget Antze
ABSTRACT
Anthropogenic noise may interfere with avian acoustic communication, however some
species alter the structure of vocalizations, to improve transmission in noise. Here, I
conducted playback experiments to determine whether compressor stations, generator or
grid-powered screw pump oil wells, and overall ambient noise levels affected responses
of Savannah sparrows (Passerculus sandwichensis) to conspecific alarm calls at their
nests. I also measured the structure of alarm calls, to determine whether Savannah
sparrows altered vocalizations in noise. On control sites, Savannah sparrows responded to
alarm calls by delaying provisioning visits. At compressor station sites, the loudest
infrastructure treatment, they showed less of a delay. Close to compressor stations,
Savannah sparrows lowered the frequency and increased the bandwidth of alarm calls.
These findings suggest the compressor stations may interfere with anti-predator
communication, but that Savannah sparrows can alter the structure of alarm calls at these
sites, perhaps mitigating some effects of noise.

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ACKNOWLEGEMENTS
First and foremost, I thank my supervisor, Dr. Nicola Koper, for her guidance,
encouragement and words of wisdom and advice throughout the thesis process. To my
committee members Dr. James Hare, Dr. Marty Leonard and Dr. Miya Warrington, I feel very
fortunate to have had the guidance of such an intelligent and positive group. Your comments,
recommendations, and enthusiasm were greatly appreciated.
I thank the funding agencies that supported this research: Cenovus Energy Inc. and the
Natural Sciences and Engineering Research Council of Canada (NSERC). I also thank the
Eastern Irrigation District and all other land owners that allowed me to conduct research on their
properties.
This project would not have been possible without the hard work and dedication of my
field assistants: Ariel Lenske, Kathryn Flemming, Celina Willis, and Dr. Claire Curry. Your
humour, patience, hard work, and Savannah sparrow spotting skills were instrumental in
collecting the data for this thesis. Thank you.
Finally, I thank my family, friends and my partner for their support throughout this
process. To my parents, thank you for encouraging me to follow my dreams, and for providing a
sympathetic ear when I needed it the most. To my friends and lab mates, in particular Jessica
Lockhart, Samantha Fischer and Heather Nenninger, I do not know what I would do without you
to share ideas, laugh, and commiserate with. Trevor, thank you for your love, care, patience, and
most of all for believing in me. Tonight when you ask if I finished my thesis today I can finally
answer, “yes!”

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TABLE OF CONTENTS
ABSTRACT .............................................................................................................................. ii
ACKNOWLEGEMENTS....................................................................................................... iii
TABLE OF CONTENTS ........................................................................................................ iv
LIST OF TABLES .................................................................................................................. vi
LIST OF FIGURES ............................................................................................................... vii
CHAPTER 1: INTRODUCTION ............................................................................................1
1.1 Background ..................................................................................................................1
1.2 Objectives .....................................................................................................................2
1.3 Literature Cited ............................................................................................................4

CHAPTER 2: LITERATURE REVIEW ................................................................................6
2.1 Decline of grassland songbirds .....................................................................................6
2.2 Oil and gas development and grassland songbirds .......................................................6
2.3 Anthropogenic noise and songbird communication .....................................................8
2.4 Alarm communication ................................................................................................10
2.5 Savannah sparrows .....................................................................................................11
2.5.1 Breeding behavior ...................................................................................................11
2.5.2 Nest defense behavior ..............................................................................................12
2.6 Literature Cited ...........................................................................................................13
CHAPTER 3: DOES OIL AND GAS INFRASTRUCTRE NOISE AFFECT
RESPONSES OF SAVANNAH SPRARROWS (PASSERCULUS SANDWICHENSIS)
TO CONSPECIFIC ALARM CALLS?.....................................................................................18
Abstract ............................................................................................................................18
3.1 Introduction................................................................................................................19
3.2 Methods .....................................................................................................................23
3.2.1 Study area ...............................................................................................................23
3.2.2 Response to alarm calls under natural conditions .................................................24
3.2.3 Effects of oil and gas infrastructure on alarm responses .......................................27
3.2.4 Ambient noise..........................................................................................................28
3.2.5Statistical Analyses ..................................................................................................29
3.3 Results .......................................................................................................................31
3.3.1 Response to alarm calls under natural conditions .................................................31
3.3.2 Effects of oil and gas infrastructure .......................................................................31
3.2.3 Effect of ambient noise............................................................................................36
3.2.4 Effects of wind speed ..............................................................................................37
3.4 Discussion ..................................................................................................................38
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3.4.1 Response to alarm calls under natural conditions .................................................38
3.4.2 Effects of oil and gas infrastructure and ambient noise .........................................39
3.5 Literature Cited ..........................................................................................................45
CHAPTER 4: DO SAVANNAH SPARROWS ALTER THE STRUCTURE OF
ALARM CALLS WHEN EXPOSED TO OIL AND GAS INFRASTRUCTURE
NOISE?.........................................................................................................................................49
Abstract ............................................................................................................................49
4.1 Introduction................................................................................................................49
4.2 Methods .....................................................................................................................55
4.2.1 Study area ...............................................................................................................55
4.2.2 Alarm call recordings .............................................................................................56
4.2.3 Acoustic Analysis ....................................................................................................57
4.2.4 Statistical Analysis ..................................................................................................60
4.3 Results .......................................................................................................................61
4.3.1 Effects of oil and gas infrastructure .......................................................................62
4.3.2 Effects of ambient noise ..........................................................................................60
4.4 Discussion ..................................................................................................................65
4.5 Literature Cited ..........................................................................................................71
CHAPTER 5: GENERAL DISCUSSION AND MANAGEMENT IMPLICATIONS…….76
5.1 Literature Cited ..........................................................................................................79

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LIST OF TABLES
Table 4.1. Call features that Savannah sparrows may alter to overcome acoustic
interference………………………………………………………………………………………58
Table 4.2 The effects of predicted SPL (calculated using ISO protocol 9613-2, 1996) and
wind speed on the ambient noise in the environment (extracted from calibrated recordings
in Raven 1.5)…………………………………………………………………………………….64

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LIST OF FIGURES
Figure 2.1. Sound profiles for ambient noise recorded 10 m from compressor stations
(n = 5) grid-powered screw pumps (n = 5) and generator-powered screw pumps (n = 5).
Measurements were made between April – August of 2013 and 2014 at representative
infrastructure sites located within the mixed-grass prairie surrounding Brooks, Alberta
(50.5642° N, 111.898° W). Measurements were taken at each 1/3 octave frequency band
using a Bruel and Kjaer 2250 SPL meter and frequency analyzer (dB(Z)), and averaged
across all replicates for each infrastructure type…………………...……………………………...8
Figure 3.1. Excerpt from a representative Savannah sparrow alarm call playback. Recording
was made from a field site within the vicinity of Brooks Alberta (50.5642° N, 111.898° W)
during June of 2013. The spectrogram was produced in RavenPro 1.4 using a Hann Window
Function with a Fast Fourier transformation length of 512 samples, 3 dB Bandwidth set at
135 Hz, and overlap of 50%..........................................................................................................26
Figure 3.2. Excerpt from a representative Western meadowlark song control playback.
Recording was made from a field site within the vicinity of Brooks Alberta (50.5642° N,
111.898° W) during July of 2013. The spectrogram was produced in RavenPro 1.4 using
a Hann Window Function with a Fast Fourier transformation length of 512 samples, 3 dB
Bandwidth set at 135 Hz, and overlap of 50%...............................................................................27
Figure 3.3 Average feeding latency of Savannah sparrows (Passerculus sandichensis) in
southern Alberta during May – July 2013 and 2014, following the playback of conspecific
alarm calls (alarm), western meadowlark songs (WEME), and on baseline feeding visits
when no stimuli were played (no playback), at control sites (n=21), compressor station sites
(n=15), grid-powered screw pump site (n=12) and generator-powered screw pump sites
(n=11)………………………………………………………………………………………….…33
Figure 3.4 The effects of distance from compressor stations on feeding latency in Savannah
sparrow (Passerculus sandichensis) in southern Alberta during May – July 2013 and 2014
during baseline feeding visits when no stimuli were played, n= 15 nests at compressor
stations, 8 of which had 2 observations of baseline feeding latency, while 7 had only one
observation……………………………………………………………………………………….35
Figure 3.5 The effects of (a) broadband (0 – 24000 Hz) and (b) low frequency (0 – 3000 Hz)
ambient noise on feeding latency in Savannah sparrow (Passerculus sandichensis) in
southern Alberta during May – July 2013 and 2014, following the playback of western
meadowlark songs, n = 41 nests…………………………………………………………………37

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Figure 4.1. A representative sample of Savannah sparrow (Passerculus sandwichensis)
alarm calls, recorded from a field site near Brooks Alberta (50.5642° N, 111.898° W)
during June of 2013. The spectrogram was produced in RavenPro 1.4 using a Hann Window
Function with a Fast Fourier transformation length of 512 samples, 3 dB Bandwidth set at
135 Hz, and overlap of 50%..........................................................................................................54

Figure 4.2. The effects of distance from compressor stations on a) peak frequency, b) 90%
bandwidth, c) First quartile frequency and d) third quartile frequency of Savannah sparrow
alarm calls. Recordings were made from 11 individuals at compressor station sites in
southern Alberta during May – July of 2013 and 2014………………………………………….63

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CHAPTER 1: INTRODUCTION
1.1 Background
Grassland songbirds are declining at a faster rate than songbirds of any other ecosystem
in North America (Herkert 1995; Sauer et al. 2012). In southern Alberta, increasing development
from the oil and gas industry may negatively affect grassland songbird populations. One way that
development may impact songbirds is if ambient noise produced by infrastructure prevents birds
from detecting and responding to acoustic signals. Previous research has shown that
anthropogenic noise has the potential to prevent female birds from detecting male songs (Habib
et al. 2007), and nestlings from detecting parental feeding (Leonard and Horn 2012) and alarm
signals (McIntyre et al. 2014). However, many species are also able to adapt to noise by shifting
the frequency (Slabberkoon and Peet 2003), amplitude (Brumm 2004), rate (Brumm and Slater
2006), or tonality (Hanna et al. 2011) of vocalizations, so they can be detected over background
interference.
Many birds respond to potential threats close to their nests by emitting alarm calls. These
calls can function to solicit help in fending off a predator (Gill and Sealy 2003), warning others
of approaching danger (Bernath-Plaisted and Yasukawa 2011), or signaling to predators that they
have been detected (Bergstrom and Lachmann 2001). When nests are particularly exposed (e.g.
cup nesting and ground nesting species) birds may respond to alarm calls close to their nests by
delaying provisioning visits, so as to avoid revealing their nest’s location to predators (Bernath-
Plaisted and Yasukawa 2011). Responding appropriately to these calls may determine whether or
not an individual or their nest survives, so if anthropogenic noise masks these signals (McIntyre
et al. 2014), the fitness consequences for birds living in noisy areas could be significant.
However, if birds are able to adapt to noise by altering the structure of alarm calls, so they can be
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heard over background interference, anthropogenic noise may present less of a problem.
Despite the importance of anti-predator signaling to survival and reproductive success,
much of the research on the effects of anthropogenic noise on acoustic communication has
focused on territorial singing (e.g. Slabbekoorn and Peet 2003, Brumm 2004, Wood and
Yezerinac 2006, Habib et al. 2007, Hanna et al. 2011, Lenske and La 2014, Gough et al. 2014)
while the body of research on the effects of noise on alarm communication is comparatively
much smaller (Lowry et al. 2012, McIntyre et al. 2014, Potvin et al. 2014).
This thesis aimed to determine whether ambient noise produced by gas compressor
stations and grid-powered and generator-powered screw pump oil wells compromises the ability
of Savannah sparrows (Passerculus sandwichensis), a common grassland generalist, to detect
and respond to alarm calls, and to determine whether they are able to adapt to noise by changing
the structure of vocalizations to improve transmission in noise. As a ground nesting bird,
Savannah sparrows may be particularly dependent on effective anti-predator behaviours to
adequately protect their nests from predators, so if anthropogenic noise interferes with anti-
predator communication, the consequences for reproductive success could be significant.
However, Savannah sparrows have also been shown to exhibit high levels of vocal adaptability
(Williams et al. 2013) so may be able to alter calls to overcome interference.
1.2 Objectives
1. Determine whether oil infrastructure noise prevents adult Savannah sparrows from
responding appropriately to alarm signals close to their nests
a. Determine whether Savannah sparrows respond to alarm calls by delaying feeding
visits
b. Determine whether that delay is altered in the presence of oil and gas
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