Flight Initiation Distance experiment

LS2203: Biology Laboratory IV FID Experiment Instructor: Prof. Dipjyoti Das Nilrup Ghosh (19MS011) Rohan Jena (19MS149) Soumyadeep Sar (19MS150) Sanmoy Saha (19MS157) Anurag Sharma (19MS159) Flight Initiation Distance of animals Aim: 1) To find effect of speed of the potential predator on FID 2) To find the effect of solitary or flock behavior on the FID of the selected species Theory: The flight zone of an animal is the area surrounding an animal that if encroached upon by a potential predator or threat, including humans, will cause alarm and escape behaviour. The flight zone is determined by the animal's flight distance, sometimes called flight initiation distance (FID) which extends either horizontally or vertically from the animal. It is the distance at which a prey flees from an approaching predator(humans). FID is one measure of an animal’s fear responses to humans. Several factors which affect FID are :– • • • • • Speed of approach of the predator If the prey is in a solitary or flock situation Environment around the prey – Open vs Crowded and Urban vs Rural Species Accustomed of being around human or not Urbanization is increasing across the globe and it is recognized as a major factor affecting many species. It is considered as a major threat to biodiversity. These are well built-up areas with crowded houses and multi-story buildings with fully constructed roads and little number of trees. However, rural areas contain lots of trees, ponds, open farmland with scattered houses and other habitats which are more favorable and suitable for birds. Hence, birds in both rural and urban habitats are exposed to human interactions in a regular basis. It is expected that human encounter is more in urban areas than rural. After the measurements are taken, the data is plotted using the Box Plot diagrams and finally compared and interpreted using the Mann-Whitney Test which is a non-parametric statistical test that does not assume the Gaussian Behaviour. Procedure: 1) A suitable site is chosen for conducting the experiment. For urban, I have considered an area of unconstructed road in the neighborhood of our home and for rural the open space in front of a house filled with mud and clayey soil is chosen. 2) A bird, which is foraging or resting is located in that area and chosen for the experiment. 3) Now a person has to move (normal walking speed) towards the individual bird sitting comfortably and mark the point from where the bird fled due to the person’s movement. I walked towards the bird with normal speed and marked the points of bird’s movement. 4) The distance between the person and the mark is measured using a measuring tape. 5) Now a flock of birds is located and the same process is repeated. Here, in this experiment, we have tried to calculate FID the following for two cases: a. Rural vs Urban b. Solitary vs flock Hypothesis: Experiment- 1 :- Urban vs Rural Null Hypothesis (H0): The environment in which the species are found i. e. urban or rural, has no effect on the FID of the species. Alternate Hypothesis: There is an effect of whether the environment is urban or rural, on the FID of the species. By conducting this experiment, we have to test these hypotheses. Experiment- 2 :- Solitary vs Flock Null Hypothesis (H0): Whether the individuals are solitary or in a flock, has no effect on the FID of the species. Alternate Hypothesis: There is an effect of whether the individuals are solitary or in a flock, on the FID of the species. Observation and Results: 1. For Rural vs Urban: Bird 1 Bird 2 Bird 3 Bird 4 Bird 5 Rural Black Drongo Flight Initiation Distance (m) 1.05 0.89 1.44 0.96 1.37 Bird 1 Bird 2 Bird 3 Bird 4 Bird 5 Urban Pigeon Flight Initiation Distance (m) 1.34 1.27 1.52 1.36 1.22 Bird 1 Bird 2 Bird 3 Bird 4 Bird 5 Rural Asian Pied Starling Flight Initiation Distance (m) 0.42 0.37 0.55 0.72 0.48 Bird 1 Bird 2 Bird 3 Bird 4 Bird 5 Urban Common myna Flight Initiation Distance (m) 0.48 0.56 0.4 0.39 0.44 2. For Solitary vs Flock: Pigeon Bird 1 Bird 2 Bird 3 Bird 4 Bird 5 Solitary Flock Flight Initiation Distance (m) Flight Initiation Distance (m) 1.34 1.66 1.27 1.81 1.52 1.12 1.36 1.05 1.22 1.96 Box Plot and Mann- Whitney U Test Result: 1. For Rural vs Urban: Rural Mean 0.825 Standard deviation 0.36401 Median 0.805 FID value (m) 0.825 ± 0.36401 Urban Mean 0.898 Standard deviation 0.45194 Median 0.89 FID value (m) 0.898 ± 0.45194 2. For Solitary vs Flock: Solitary Flock Mean 1.342 1.52 Standard deviation 0.102058807 0.368293361 Median 1.34 1.66 FID value (m) 1.342 ± 0.10205 1.520 ± 0.36829 Discussion: A very small sized sample data is being collected, hence statistical inference may not be absolutely correct. In each cases(solitary vs flock and urban vs rural) we collected 5 observations. Upon that distance estimation is purely based on our manually measured distance which we did using a tape. Hence no advanced equipments had been used in measuring these values, as a result of which there is small fraction of observational error associated with the data. In our experiment we conducted experiment for 2 cases: Case 1: :(Urban versus Rural) We used the species Black Drongo and Asian Pied Starling for rural and Pigeon and Common Myna for urban to perform the experiment. After getting the data we performed the Mann-Whitney test, at significance level 0.05 and obtained the p-value which is 0.86902. Using p-value we compare with critical values from table and hence inferred that Null hypothesis cannot be rejected. Therefore, there is no significant difference between FID of Urban birds and rural birds. Case 2:( Solitary versus Flock) We used the species Columbia livia in colloquium term it is called Pigeon. We performed Mann-Whitney test on the observed data. At significance level of 0.05 (95% confidence level) we calculated the p-value to be 0.69048 which suggests that there is no significant difference between FID observed in solitary and Flock cases. Hence, we cannot reject the null hypothesis. The Flight Initiation Distance (FID) could be influenced by a variety of factors: – a. The speed of approaching of the predator towards the prey. b. Whether the prey is in flock or solitary situation. c. FID differs for different species of prey and predator. d. The environment around the prey, like – open vs crowded area, urban vs rural e. The prey or focal individual is accustomed to being around humans or not. Conclusion: In both the cases we clearly inferred that there is no significant difference in FID of birds depending on their environment or whether they are in Flock or not.