Why are the shrubs responsible for
migrating animals?

They are responsible for animal migration because the chemicals they contain cause the animals to move to a different environment.

Explanation:

I found this information from https://jeb.biologists.org/content/222/Suppl_1/jeb191890

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.

the  different  of  these  two  are  that  they  differently  handle  their  team.

an  expressive  leader  focuses  on  the  task  at  hand  and  make  sures  that  their  goal  is  achieved.  they  accurately  finish  the  task.  an  instrumental  leader  on  the  other  hand  works  on  the  unity  of  the  group,  they  care  more  about  their  employees.  all  the  while  creating  a  good  environment.