Marshall University Marshall Digital Scholar Theses, Dissertations and Capstones 1-1-2012 The Effect of Auditory Call Playback on Anuran Detection and Capture Rates Derek Adam Bozzell bozzell@marshall.edu Follow this and additional works at: http://mds.edu/etd Part of the Aquaculture and Fisheries Commons, and the Population Biology Commons Recommended Citation Bozzell, Derek Adam, "The Effect of Auditory Call Playback on Anuran Detection and Capture Rates" (2012). Theses, Dissertations and Capstones. This Thesis is brought to you for free and open access by Marshall Digital Scholar. It has been accepted for inclusion in Theses, Dissertations and Capstones by an authorized administrator of Marshall Digital Scholar.
For more information, please contact zhangj@marshall. The Effect of Auditory Call Playback on Anuran Detection and Capture Rates A thesis submitted to the Graduate College of Marshall University In partial fulfillment of the requirements for the degree of Master of Science Biological Sciences by Derek Adam Bozzell Thomas K., Committee Chairperson Frank Gilliam, Ph. Michael Little, Ph. Marshall University May 2012 Key Words: Anuran, breeding calls, automated recording systems (ARS), protocol, visual encounter survey (VES), call monitoring, auditory surveys Copyright by Derek Adam Bozzell 2012 (ii) ii ACKNOWLEDGEMENTS I would first like to thank Dr.
Pauley, who gave me the freedom to pursue my own interests and project. The ability to develop my own ideas, conduct my own research, overcome my own mistakes and difficulties, and pursue my own passions made my experience at Marshall University one I have benefitted immensely from. I would also like to thank my other committee members for their time and expertise. While I generally operated on my own, both Dr.
Gilliam and Dr. Little were there whenever I had questions or ran into problems. Several members of the Herpetology Lab were crucial to the completion of my thesis. Specifically, Scott Jones was also extremely helpful in familiarizing me with the area and assisting me in selecting study sites.
Nathalie Aall served as a field assistant for the first year of my research. With her help, I did not have to try to both survey and record data. Ben Koester was integral in helping me determine what statistical analyses were appropriate for my data, and in helping format my data correctly. Also, even though I ended up not needing to use many of his suggestions due to changes in the project, Nathan Shepard was excellent for brainstorming and always had some useful statistical ideas.
I would especially like to thank Dr. He provided funds to purchase additional call monitors needed for my project. This, in addition to the $500 Summer Thesis Award from the Graduate College completely funded my project. iii TABLE OF CONTENTS ACKNOWLEDGEMENTS.
iii TABLE OF CONTENTS. iv LIST OF TABLES. v LIST OF FIGURES. 1 Order Anura and Amphibian Declines.
1 Overview of Current Anuran Survey Methods. 4 Project Objective and Hypotheses. 18 Survey Efficiency Analysis. 18 Detection Rate Data Analysis.
19 Capture Rate Data Analysis. 20 Interpretation of Results. 20 Issues with This Study. 45 iv LIST OF TABLES Table 1: Location information of study sites.
Table 2: Site boundary types and the transect style used to survey each site. Table 3: The Beaufort Wind Code scale used in NAAMP protocol to note categorical wind speed during survey. Table 4: The Sky Code scale used in NAAMP protocol to note sky cover and weather during survey. Table 5: The Massachusetts Noise Index, used by NAAMP to measure ambient noise categorically.
Table 6: The Calling Index used by NAAMP to provide a categorical abundance measurement of calling individuals during survey Table 7: Results of the detection rate data analysis. Table 8: Results of the capture rate data analysis. v LIST OF FIGURES Figure 1: A map of the study areas of this project, Beech Fork State Park and Green Bottom Wildlife Management Area. Figure 2: A map of the study site locations in Beech Fork State Park.
Figure 3: A map of the study site locations in Green Bottom Wildlife Management Area. Figure 4: A Google Earth aerial photo of Beech Fork State Park, contain labeled points for BFSP1-BFSP8. Figure 5: A Google Earth aerial photo of site BFSP1. Figure 6: A Google Earth aerial photo of site BFSP2.
Figure 7: A Google Earth aerial photo of site BFSP3. Figure 8: A Google Earth aerial photo of site BFSP4. Figure 9: A Google Earth aerial photo of site BFSP5. Figure 10: A Google Earth aerial photo of site BFSP6.
Figure 11: A Google Earth aerial photo of site BFSP7. Figure 12: A Google Earth aerial photo of site BFSP8. Figure 13: A Google Earth aerial photo of Green Bottom Wildlife Management Area, contain labeled points for GRNB1-GRNB6. Figure 14: A Google Earth aerial photo of site GRNB1, Figure 15: A Google Earth aerial photo of site GRNB2.
Figure 16: A Google Earth aerial photo of site GRNB3. Figure 17: A Google Earth aerial photo of site GRNB4. Figure 18: A Google Earth aerial photo of site GRNB5. Figure 19: A Google Earth aerial photo of site GRNB6.
vi Figure 20: A diagram of the two types of transects used in this experiment. Figure 21: A Song Meter SM2™ automated digital recording device, designed by Wildlife Acoustics, attached to a tree. Figure 22: The “callbox” used to play breeding calls during experimental surveys. vii ABSTRACT The Effect of Auditory Call Playback on Anuran Detection and Capture Rates Derek A.
Bozzell Calls of male anurans during breeding seasons are species-specific identification tools. However, males cease calling after any nearby disturbance, including those of researchers. I proposed a variation on current methods that attempts to reduce this lag in calling after researcher-created disturbance by utilizing the propensity for competition in male frogs. I surveyed 14 breeding sites in Cabell and Wayne counties during the 2010 and 2011 breeding seasons.
First, I used traditional visual encounter surveys (VESs). After using automated recording devices to gather site-specific recordings of calls of all species present, I conducted secondary VESs while playing these playlists over a loudspeaker. I expected this would increase anuran detection rates, capture rates, and survey efficiency. crucifer showed a significant increase in detection and capture rates when surveyed using callbacks, which is likely due to aggressive call behavior.
Survey efficiency comparison was dropped due to lack of calling activity. Word count: 150 viii INTRODUCTION Order Anura and Amphibian Declines Order Anura contains frogs and toads, which are collectively known as anurans. Anurans are amphibians and, as such, most species deposit gelatinous eggs in water or moist areas that hatch into aquatic larvae, whereas adults exhibit varying degrees of terrestrial living, depending on the species (Pauley, 2011). Like most amphibians, many anurans use cutaneous respiration; their skin is permeable and used in gas exchange, heat regulation and osmotic regulation (Zug et al.
Unlike other amphibians, most anurans do not possess tails as adults; the word “Anura” is derived from the Latin prefix an- (“not”) and the ancient Greek oura (“tail”) (Merrem, 1820). Anurans are also especially adapted to saltatory movement, or jumping. Physiological adaptations for this type of motility include a flexible vertebral column; reduced number and size of ribs; a highly ossified appendicular skeleton; large, muscular hind limbs; and extended metatarsals (Zug et al. One of the most striking adaptations of anurans, and the one that this project relies on, is the auditory calls that males use to attract mates, and defend territory from conspecific males, during the breeding season.
The ability of anurans to emit and detect these calls is highly derived and involves several adaptations in the larynx, lungs, vocal sacs, and middle ear (Zug et al., 2001; Vorobyeva and Smirnov, 1987). Because of their unique skin, and the fact that they are exposed to both terrestrial and aquatic environments during their lifecycle, amphibians are especially sensitive to changes in the environment and to pollution. Amphibian species will be adversely affected by negative impacts to their environment sooner than most organisms, and 1 because of this they are known as bioindicator species (Halliday, 2005a). In the late 1980s, it was discovered that amphibians have been experiencing drastic population declines globally since at least the 1970s (Heyer and Murphy, 2005).
Studies have since shown that over one-third of all amphibian species are threatened, and over 120 species are already likely extinct (Stuart et al. More recently, the extinction rate of amphibians globally has been calculated to be 211 times the normal, background extinction rate, and if all species currently considered threatened go extinct, that rate will increase to 25,000 - 45,000 times greater (McCallum, 2007). In 1990, several programs were dedicated to understanding and correcting the underlying causes (Heyer and Murphy, 2005). Since these developments, there have been considerable research and funding dedicated to this issue.
Currently, there are several different causes for amphibian decline being studied. Among the probable causes are infection diseases, including Chytridiomycosis (Daszak et al., 1999); parasitic infection (Sutherland, 2005); ultraviolet radiation (Blaustein et al., 1994); chemical pollutants (Berrill et al., 1997; Bridges and Semlitsch, 2005); introduced species (Henle, 2005); habitat destruction, fragmentation and degradation (Green, 2005); increased amounts of vehicular traffic (Henle, 2005); unsustainable harvest for the pet trade (Wilson, 2005); and climate change (Reaser and Blaustein, 2005). Many researchers believe a combination of these factors is leading to the continued population declines observed in amphibians (Halliday, 2005b; Green 2005). Research to refine our understanding of these issues, how they interact, and their effects on amphibians is still underway.
2 Overview of Current Anuran Survey Methods Traditionally, anuran breeding calls have been used to aid researchers in estimating population parameters (Weir and Mossman, 2005; Weir et al. The current anuran survey methods include intensive surveys, standardized (manual) call surveys, and the use of automated digital recording devices (Corn et al. Under ideal conditions in a simple system, as in a laboratory setting, these methods produce similar species richness values (Corn et al. However, when used in the field, each of these survey types has strengths and weaknesses.
Visual encounter surveys (VESs) are a type of intensive survey wherein the researcher systematically searches the habitat of focus for a known amount of time (Vonesh et al. This is a well-used and effective method for developing species lists rapidly (Crump and Scott, 1994). Intensive surveys can also be used to gather detailed population abundance or demographic information. However, as the name implies, these methods require a great amount of time; researchers must be on the ground, actively surveying sites in order to gather data.
This is exacerbated by the fact that the act of surveying creates disturbances that cause anurans to cease calling (pers. Standard, or manual, call surveys involve a researcher passively surveying a breeding site by simply listening and recording the calling species. Controlled by the U. These surveys can gather data over a wide area, but in order 3 to do so logistically, the surveys must be volunteer-based, as seen in NAAMP.
Even though the data are checked by experts, using volunteers potentially reduces the accuracy and credibility of the data. Also, the types of data collected are limited to presence/absence data and categorical abundance numbers. One definite strength of the NAAMP protocol is the standardization of environmental data collected. Within the last 20 years, automated recording devices, or call monitors, have risen in popularity in anuran surveying.
These recording devices can be left in the field and set to automatically record sounds, like the breeding calls of anurans, for a given period of time at given intervals. Song Meter TM call monitors, a type of automated digital recording device developed by Wildlife Acoustics, have become a common tool in anuran surveys. Automated recording devices, such as the Song Meter SM2, are an established method of monitoring breeding amphibians, especially for presence/absence and basic abundance data (Corn et al., 2000; Acevedo and Villanueva-Rivera, 2006). They are known to produce similar data to manual call surveys (Acevedo and Villanueva- Rivera, 2006).