Jennifer+Chmielus


 * Non-Native Bird** **Introduction**

Every time I have visited my husband’s family in Germany, I have enjoyed the birds that regularly visit their garden. During one of my visits, I began to wonder what would happen if a non-native bird, such as a Blue Jay, was introduced into this habitat? Would the resident birds return? Would they ignore the new arrival and continue on as they always had?
 * Introduction:**

The garden itself provides a covered platform bird feeder surrounded by a chicken wire platform, around which this study is centered, a pond with a small waterfall, multiple birdhouses that are occupied by House Sparrows (//Passer domesticus//), and a wide variety of cover including vegetable plants, berry bushes, and a variety of bushes and shrubs. The House Sparrows are frequent visitors, and my father-in-law can identify several members of the flock. The birds are fed each morning after the rain ends and there have been up to seven observed species that frequent the feeder during the morning hours. The birds that frequent the garden seem to be used to human activity because they can be observed perching nearby and visit the feeder with people moving around the garden.
 * Information on the Garden**

How long after the introduction of a non-native bird decoy at an established food source will the native birds return?
 * My Question:**

If a ‍‍‍‍‍non-native bird decoy is ‍‍‍‍‍introduced at an established food source, then the native birds will return to the feeder after a delay to observe the intruder.
 * Hypothesis:**

Blue Jay (//Cyanocitta cristata//) decoy introduced at an established bird feeder
 * Independent Variable:**

Length of time needed for the native birds to return
 * Dependent Variable:**

Blue Jay (//Cyanocitta cristata//) decoy bird feeder bird seed camera on a tripod
 * Materials:**

1. Each morning, I placed the same amount of bird seed in the bird feeder. The seed was placed in the feeder after the rain had ended, so the time varied somewhat. 2. I returned inside and began recording the visits at the feeder with a camera on a tripod. This is to ensure that I was able to record the time of all visits. I also recorded the time that the recording began and the temperature. 3. I observed the number of visits to the feeder in a twenty minute time period, as well as the variety of birds who visited the feeder. I considered a bird landing on the feeder’s platform one visit. 4. After 3 days of observation, I introduced a blue jay decoy when I filled the feeder. It was placed on top of the feeder so the resident birds would have easy access to the feeder itself. The Blue Jay decoy was removed following the return of the birds. 5. I then repeated steps 2 and 3 on day 5.
 * Method:**


 * Photographs:**

Female House Sparrow (//Passer domesticus)//



Male House Sparrow (//Passer domesticus)// Great Tit (//Parus major)//

Green Finch (//Carduelis chloris)//

Eurasian Collared Dove (//Streptopelia decaocto)// Bird Feeder with Blue Jay (//Cyanocitta cristata//) decoy


 * Results and Analysis:**





During days 1-3, control data was collected. The birds began to frequent the feeder within 5 minutes of the food being placed in the bird feeder. More birds seemed to visit on days 2 and 3 when the temperature was lower, than on day 1 although day 1 was the only day that showed visits from a variety of species. Experimental data was collected during days 4 and 5. The birds returned to the feeder at 8 minutes and 7 minutes into the 20 minute data collection period despite the presence of a Blue Jay decoy at the bird feeder. More visits were recorded on day 5.The temperature on both days was higher than on the days when the control data was collected.

My data supported my hypothesis that birds would return to the feeder within one day of placing a non-native bird decoy at the feeder. I was surprised that the House Sparrows returned after a brief delay of several minutes. I believed that the birds would return quickly, but not that quickly**.** Prior to their return on days 4 and 5, the House Sparrows were observed in a nearby tree and would fly past the feeder in closer and closer proximity to the decoy. A female House Sparrow with a distinctive white patch on her breast returned first and seemed to lead the others to return to the feeder. She was later identified to be the adult female that nests in one of the garden’s birdhouses. More visits were recorded on day 5, leading me to conclude that the resident sparrows were becoming used to the presence of the Blue Jay decoy. Across both the control and experimental data, the number of visits seemed to be similar on days when the temperature was similar. For example, day 1 had a temperature of 17.1o C and 29 visits, and day 5 had a temperature of 17.5o C and 31 visits despite the presence of a non-native bird decoy at the feeder.
 * Discussion:**

Although my hypothesis that the native birds would return to the feeder after the introduction of a non-native bird decoy was supported, I believe that there may have been other factors that are not accounted for that may help to explain the way the visits occurred.
 * Conclusion:**

Given more time, I would like to have gathered a larger set of control data, so that I would be better able to compare the influence of temperatures on visits. For example, if I had control data for a day with a temperature of 19o C, would I have a similar number of visits? I also wonder why I only saw a variety of species on the first day of data collection. Was it because the day was overcast? Another question I have is whether or not the decoy’s lack of movement or its appearance affected the sparrows. This would be tested by collecting experimental data while a decoy of a native bird was present. ‍‍
 * Outlook:**