Figure 1: Variety of Aggressive Behaviors Exhibited

ClosestApproach(meters)

Time within 5 meters

Number of Songs

Number of Flights

Puffing Bill Swipes Attacks

2.76 5.13 22.0 28.33 3.27 1.18 8.92

3.98 2.16 46.36 28.27 2.42 0.55 0.33

Fragmented

Non-Fragmented

METHODS:Capturing Decoys:•Decoys were caught the day of each STI.

•A decoy was caught by setting up mist nets and using an iPodand speaker playback combination set directly underneath themist nets.

•Captured Individuals were banded and morphologicalmeasurements were taken.

•All decoys were released back onto their territories at end ofday.

STI’s (Simulated Territorial Intrusions):•When necessary (if individual couldn’t be sited or heard),playback was used to determine focal individuals territory.

•A net was set up (raised) within the focal bird’s territory in anarea with the best chance of viewing the bird’s reaction to theaddition of the decoy.

•The speaker and iPod were placed next to the decoy and theplayback sequence was turned on.

•For ten minutes, the playback was played, with 10 differentsongs, each grouped into 4 sequences, divided by 30 secondsof silence.

•A variety of behaviors were observed & recorded (details,Figure 1)

•After the duration of the STI, the net was lowered to catch thefocal bird in order to band and measure the individual.

Determination of density:•Point counts/response to playback throughout 50 m segmentsof habitat types were done for 5 minutes each (Hamel et al.,1996), or

• Counting number of banded birds in habitat

BACKGROUND:Avian aggression:•Avian aggression has been well-studied in regard to differentbehavioral and physiological changes (Wingfield, 1985).

• Testosterone (T) and luteinizing hormones (LH) have beenmeasured in non-migratory birds both during breeding andnon-breeding season in response aggressive encounters, andmore specifically simulated territorial intrusions (STI) (Meddleet al., 2001).

•It has been noted that the increases in these two specifichormones can cause physiological changes in birds, includinginfluencing certain behaviors. Increased testoserone levels havebeen previously linked to increased territorial aggression(Wingfield et al., 1990; Hirschenhauser and Oliviera, 2006;Goymann et al., 2007)

•Territorial aggressive behaviors can be affected by certainenvironmental factors, such as food source or possible breedinghabitat (Busch, et al., 2004). Non-migratory birds are expectedto defend their territory year-round from both conspecifics andnon-conspecifics (Strutchbury and Morton, 2001).

Song sparrows as a model organism:•M. melodia is used as a model for this experiment due to itsabundance and well-studied physiology and well-definedbehavioral displays (Wingfield and Hahn, 1992).

•Individuals weigh 18-24 grams and responds to conspecificplayback.

•M. melodia is a non-migratory, seasonal breeder that defendsits territory year round, especially during breeding season.

ABSTRACT:Fragmentation of habitat is currently a major issue in

wildlife sustainability & management. Fragmented habitat canmanifest in numerous ways such as loss of amount of habitat,decreases in connectedness of habitat, and/or increase in edgeeffects due to the change in shape of remaining habitat. Avianspecies are highly subject to the effects of human disturbancessuch as fragmentation because they need to defend territoriesto maintain effective breeding and foraging home ranges. Tounderstand the pressure human disturbance puts on a localavian species of songbird, we examined the effects offragmentation on territorial aggression of the song sparrow(Melospiza melodia). Specifically, our study compared not onlythe degree of territorial aggression displayed betweenindividuals living in fragmented and non-fragmented habitats,but also the suite of types of aggressive behaviors. Additionallywe sought to understand the relationship betweenfragmentation and density of individuals in each habitat type.Overall this study demonstrates that fragmented areas contain agreater density of individuals maintaining territories and theseincreases in density influence certain aggression scores as wellas the types of aggressive behaviors displayed.

Habitat Fragmentation Changes and the Influence on Diversity of Song Sparrow (Melospiza melodia) Behavioral Aggression

Andrew Schroeder1, Lauren Steele1, Kyle McFerran1, and Sara O’Brien1

1Marian University, Department of Biology, Indianapolis, IN

RESULTS:

Figure 1: Comparison of different aggressive behaviors exhibited through STI data collection in both fragmented and non-fragmented areas.

Figures 3-6: Density of three experiment habitats with outline of habitat (in red) covered from June 14, 2010-July 20, 2010 and June 23, 2011-July 21, 2011.

Figure 2: Four Main Aggressive Behavior Comparison from STI’s

Figure 2: Data collected from 23 STI’s both fragmented (n=12) and non-fragmented (n=11). Significant differences were found in the average time spent within 5 meters of decoy cage *(5.16

min vs. 2.16 min.), and average number of songs **(22.0 vs. 46.36).

1. Behavioral Aggression:

2. Density Determination

Figure 3: Lake Sullivan & surrounding area Figure 4: MU Ecolab

Figure 5: Broad Ripple Canal at Butler University

Table 3: Bird densities per square meter

Table 3: Bird densities found per square meter of area studied

CONCLUSIONS:•Fragmentation influences specific aggressive behaviors such as proximity to decoy and number of songs(Figure 2).

•Fragmented areas generally displayed more aggressive behaviors than Non-Fagmented areas (See Table 1).

•Density was found to be higher in fragmented areas than non-fragmented areas (See Table 3)

•Overall these data demonstrate that the complexity of effects fragmentation can have on subtle behavioral changes which possibly paramount implications such as decreased fitness.

FUTURE RESEARCH:•Exploring into greater detail the effect of density on territorial aggression, such as monitoring how far fledglings have to go in order to find sustainable habitat.

•Measuring testosterone levels in both fragmented and non-fragmented areas to determine levels in response to behavioral changes we see.

•Measuring corticosteroids in both fragmented and non-fragmented areas.

•Catching the birds via food source to obtain baseline hormone levels during winter months and during breeding season.

•Determine the long term ecological effects of the behavioral and physiological changes due to fragmentation.

WORKS CITED:•Fahrig, Lenore. "Relative Effects of Habitat Loss and Fragmentation on Population Extinction." The Journal of Wildlife Management 61.3 (1997): 603-10. JSTOR. •Goymann, W., Landys, M.M., Wingfield, J.C.,. “Distinguishing seasonal androgen responses from male–male androgen responsiveness—revisiting the challenge hypothesis.” Horm. Behav. 51 (2007): 463–476.•Hirschenhauser, K., Winkler, H., Oliveira, R.F.. “Comparative analysis ofmale androgen responsiveness to social environment in birds: the effects ofmating system and paternal incubation.” Horm. Behav. 43 (2003): 508–519.•Meddle, Simone L., Michael Romero, Lee B. Astheimer, William A. Buttemer, Ignacio T. Moore, and John C. Wingfield. “Steroid Hormone Interrelations with Territorial Aggression in an Artic-Breeding Zonotrichia leucophyrs gambeli.” Hormones and Behavior 42 (2002): 212-221.•Moore, Ignacio T., Haruka Wada, Nicole Perfito, D. Schallin Busch, Thomas P. Hahn, and John C. Wingfield. “Territorality and testosterone in an equitorial population of rufous-collared sparrows, Zonotrichia capensis.” Animal Behaviour 67 (2004): 411-420.•Stutchbury, B.J. and E. S. Morton. Behavioral ecology of tropical birds. 2001. Academic Press, San Diego.•Wingfield, John C.. “Short-Term Changes in Plasma Levels of Hormones during Establishment and Defense of a Breeding Territory in Male Song Sparrows, Melospizamelodia.” Hormones and Behavior 19 (1985):174-187.•Wingfield, John C., and Thomas P. Hahn. "Testosterone and Territorial Behaviour in Sedentary and Migratory Sparrows." Animal Behavior 47 (1994): 77-89. •Wingfield, J.C., Hegner, R.E., Dufty Jr., A.M., Ball, G.F.. “The challengehypothesis”: theoretical implications for patterns of testosterone secretion,

mating systems, and breeding strategies.” Amer. Nat. 136 (1990): 829–846.•Hamel, P.B., Smith, W.P., Twedt, D.J., Woehr, J.R., Morris, E., Hamilton, R.B., and Cooper, R.J. “A Land Manager’s Guide to Point Counts of Birds in the Southeast.” United States Department of Agriculture (1996): 1-38

ACKNOWLEDGEMENTS:I would first like to thank Tiffany Schendel for helping to record data and assistance in field work. I would also like to thank the Institute for Green and Sustainable Science for providing me with this opportunity to do research during the summer of 2010. Finally, I would like to thank Dr. O’Brien for her guidance and knowledge.

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Figure 6: Indianapolis Museum of Art

Broad Ripple Canal

Eco Lab

Lake Sullivan

IMA

8 birds per ~15,000m2

14 birds per ~215,700m229 birds per ~111,800m2

30 birds per ~100,000m2