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                                                                                                                        The Effect of Predator Growth Rate in a Prey-Predator








                                                                                                                       System Incorporating Intra-Specific Competition Using








                                                                                                                                                                                                               Bifurcation Analysis









                                                                                                                                                                                                  NAME: HASUAN AMIN BIN MOHD ROSDI



                                                                                                                                                                        SUPERVISOR : MADAM ZATI IWANI BINTI ABDUL MANAF








                                                                                                                                                                         FACULTY OF SCIENCE COMPUTER AND MATHEMATICS












                                                                                                                       1) ABSTRACT                                                                                                                                                                                                           2) PROBLEM STATEMENT







      This research studies how the predator's growth rate affects the balance between predators and                                                                                                                                                                           Most existing models focus on harvesting or toxins but ignore predator’s natural growth


      prey.  A  mathematical  model  was  created  to  include  both  predator  growth  and  competition                                                                                                                                                                       rate and competition



      among  predators.  Using  tools  like  MATLAB  and  XPPAUT,  the  study  found  that  when  the                                                                                                                                                                          This  research  fills  the  gap  by  studying  how  predator  growth  affects  survival  of  both



      predator grows too slowly, it goes extinct, and prey populations increase uncontrollably. When                                                                                                                                                                           species.



      the  predator  grows  at  a  higher  rate,  both  species  can  survive  together.  The  study  helps



      understand how to manage ecosystems and maintain balance between species.





                                                                                                                    3) OBJECTIVES                                                                                                                                                     4) METHODOLOGY                   &                                                                                                 IMPLEMENTATION





      1)  To  formulate  a  prey-predator  model  incorporating  growth  rate  of  predator  and  intraspecific                                                                                                                                                             PHASE 1:   To formulate a prey-predator model                                                                        CORRESPONDING JACOBIAN MATRIX  :


      competition between predators.                                                                                                                                                                                                                                    incorporating growth rate of predator and predator



      2)  To  perform  stability  analysis  and  determine  equilibrium  conditions  for  population  survival  or                                                                                                                                                                                                 competition


      extinction.


      3)  To  analyze  prey-predator  dynamics  by  varying  the  parameters  of  growth  rate  of  predator  using                                                                                                                                                   Original model:


      bifurcation analysis



                                                                                          5) RESULTS AND DISCUSSION

                                                                                                                                                                                                                                                                                                                                                                                                 STABILITY ANALYSIS :


      1) Summary of stability and bifurcation                                                                                                  3) 3-D phase plane for the system



      analysis by varying the growth rate of                                                                                                                                                                                                                                                                                                                                                     1.The equilibrium point

                                                                                                                                                                                                                                                                      New model:
      predator, e





















                                                                                                                                                                                                                                                                         PHASE 2: To perform stability analysis and determine


                                                                                                                                                                                                                                                                              equilibrium conditions for population survival or

                                                                                                                                                                                                                                                                                                                   extinction.




                                                                                                                                                                                                                                                                       Determine the equilibrium point:
                                                                                                                                                                                                                                                                                                                                                                                               2. The equilibrium point

                                                                                                                                                                                                                                                                           Let

                                                                                                                                          (a): Phase plane for growth rate of predator, e = 0.15
                                                       Case 1: e = 0.15



              Predators grow slowly.


              Predators cannot survive (they go extinct).
                                                                                                                                                                                                                                                                       Calculate Jacobian Matrix:
              Only prey remains stable and continues to grow.


              The ecosystem becomes unbalanced, dominated by                                                                                                                                                                                                               Let


              prey.






                                                          Case 1: e = 0.4                                                                                                                                                                                                Then,


                Predators grow faster


                Both predators and prey coexist in a stable balance.



                The system reaches a stable equilibrium, where


                neither species goes extinct.


                The ecosystem stays balanced
                                                                                                                                          (b): Phase plane for growth rate of predator, e = 0.4                                                                       Calculate eigenvalue by letting :

                                                                                                                                                                                                                                                                                                                                                                                              3. The equilibrium point




       2) Slicing the one parameter bifurcation                                                                                              4) Time series graph for different value of e



       diagram at e = 0.15 and e = 0.4 for x and y

                                                                                                                                                                                                                                                                       Critical points:
       populations















                                                                                                                                                                                                                                                                          PHASE 3: To analyze prey-predator dynamics by


                                                                                                                                                                                                                                                                        varying the parameters of growth rate of predator


                                                                                                                                                                                                                                                                                                    using bifurcation analysis














                                                                                                                                                         (a) Time series for growth rate of predator,


                                                                                                                                                                                                e = 0.15












       Stability analysis :
                                                                                                                                                                                                                                                                        One parameter bifurcation analysis:
              The  label  B  shows  the  transcritical  bifurcation
                                                                                                                                                                                                                                                                               XPPAUT and Auto software to generate bifurcation
              point where predator growth rate e = 2.62.                                                                                                                                                                                                                       diagram.


              At e = 0.15, E  (0.5882, 0): Stable (prey survives,                                                                                                                                                                                                              MATLAB software to acquire steady-state diagrams
                                              2

              predator extinct).                                                                                                                                                                                                                                               to analyze stable states by plotting graph phase


              E   (0.6583,  -0.0596):  Unstable  (not  a  real                                                                                                                                                                                                                 plane and time series.
                 3

              coexistence since predator value is negative).


              At  e  =  0.4  ,  E   (0.5882,  0):  Becomes  unstable                                                                                                                                                                                                                                                                                   7) RECOMMENDATION
                                                  2

              (saddle node).                                                                                                                                                                                                                                           For future research, it is recommended to explore how predator growth rate interacts with other factors such as prey availability, food


              E  (0.502, 0.074): Becomes stable (both predator                                                                                         (b) Time series for growth rate of predator,                                                                    quality,  habitat  conditions,  and  seasonal  changes.  Adding  more  ecological  elements  to  the  model,  like  resource  limitations  or
                 3
                                                                                                                                                                                                                                                                       competition for food, can make predictions more realistic. Researchers could also consider including different stages of predator life
              and prey survive together).                                                                                                                                                      e = 0.4                                                                 cycles or study how predator growth varies across different environments. These improvements will help create a deeper understanding


                                                                                                                                                                                                                                                                       of predator-prey interactions and support better strategies for conserving ecosystems and managing wildlife populations effectively




                                                                                                                                                                                                                                      6) CONCLUSION









                             The  research  successfully  built  a  predator-prey  model                                                                                                        A  transcritical  bifurcation  point  was  found,  showing  a                                                                                                 When predator growth is high enough, both predator and



                             focusing on predator growth rate and competition among                                                                                                             shift in system stability when the predator’s growth rate                                                                                                     prey can coexist in balance



                             predators.                                                                                                                                                         changes.                                                                                                                                                      The  study  achieved  all  objectives  and  highlights  the



                             Stability  analysis  showed  how  changes  in  predator                                                                                                            When  predator  growth  is  too  low,  predators  may  go                                                                                                     importance of managing predator growth rates to maintain



                             growth affect population survival or extinction.                                                                                                                   extinct, and prey populations grow uncontrollably                                                                                                             ecosystem stability
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