PLEASE HELP A biologist began studying a population of bullfrogs. In 1998, she found that most of the male frogs croaked, but some did not. A bat species known to
prey on male frogs migrated to the area in 2005. The biologist returned to the
area in 2008 and repeated population counts of male frogs. The table shows
her data.
1998
2002
2004
2008
244
Number of
noncroaking males
368
298
1086
Number of croaking
males
742
1165
791
305
What factor most likely caused the noncroaking male population to increase
after 2004?