use strict;
use warnings;

# Slurp data.
#
{
    local $/ = undef;
    $_ = <DATA>;
}

# Construct regular expression to pull out each data
# item; use extended syntax and single-line matching
# (i.e. a . matches newline).
#
my $rxExtract = qr{(?xs)
   (.+?)          # capture one or more characters
                  #   with non-greedy matching
   (?=            # zero-width look ahead
      (?:         # alternation group, either
         \d+\t    # digits then a tab
         |        # or
         \z       # end of string
      )           # close alternation
   )              # close look-ahead
   };

# Global match to pull data items out of string. Then
# replace all but the last newline in each data item
# with tabs. Print items out.
#
my @items = /$rxExtract/g;
s/\n(?=.)/\t/g for @items;
print @items;

__END__
1	John Doe, Joe Bloggs	title	journal	Animal
Female
Protein
2	Mary Clary	title	magazine	Fish
Nor
Fowl
3	Charley Farley, Piggy Malone	title	book	The
Phantom
Raspberry
Blower

##</code><code>##

1	John Doe, Joe Bloggs	title	journal	Animal	Female	Protein
2	Mary Clary	title	magazine	Fish	Nor	Fowl
3	Charley Farley, Piggy Malone	title	book	The	Phantom	Raspberry	Blower