It's not known if this telephone hoax began in New York, but it certainly may have. Similar hoaxes go much further back in history.
Museum of Hoaxes
Reason #1: You Work At a Zoo
Zoo employees hate April Fool's Day, and complain about it bitterly, for one reason alone: the infamous phone-the-zoo prank.
Here's how the prank works. You leave a note on a co-worker's desk informing them that 'Jim Panzie' called. Your colleague innocently dials the number beneath the name and asks to speak to said person. Only then does he find out that he's called the zoo, and hilarity ensues. (If you don't get it, try saying the name a few times aloud). Of course, there's nothing special about the name Jim Panzie. I just chose it out of a hat. You could equally well claim that Mr. Bear, Mrs. Robin, Mr. Wolf, Mr. Lion, Mr. Bird, Ellie Font, Mr. G. Raffe, Al Gator, Bob Katz, Anna Conda, Ann Eagle, Albert Ross, Sally Mander, Sue Keeper, or (my favorite) Don Kee called. And this hardly exhausts the list of possibilities.
Every year major zoos such as the Los Angeles zoo receive over 2000 such calls on April Fool's Day. The calls come flooding in without interruption, tying up all the lines. The operators try to be polite. They explain that there's no one at the zoo by that name. Or maybe they'll say, "I'm sorry, but Mr. Lion is in his cage." Callers usually realize pretty quickly that they've been tricked, but sometimes they don't. Sometimes they become belligerent and begin to loudly insist that they need to speak with 'Ryna Soris,' because Miss Soris left an urgent message on their voice mail. It's callers like this that cause zoo employees to feel a dull sense of pain when they think of April Fool's Day.
2 April 1909, New York (NY) Times, pg. 9:
"DARWIN" ENJOYED APRIL 1.
Chief Guest in the Hotel de Monk Got
Many Telephone Calls.
Darwin, the chief guest in the Hotel de Monk at the circus in Madison Square Garden, was an unconscious aid yesterday in a score of All Fool's Day jokes. For many years practical jokers have on April 1 induced their unsuspecting friends to call up numbers on the telephone and ask for Mr. Camel, or Mr. Fox, or Mr. Lion. Usually the number given was the telephone number of the Bronx Park or the Central Park Zoo.
But yesterday the favorite number for the jokers was "1630 Madison," which is the telephone number of Madison Square Garden. And the "person" they were told to ask for was Mr. Darwin. The telephone operator at the Garden switchboard had been instructed to switch all such calls to the menagerie and to the Hotel de Monk.
They kept calling for Darwin at intervals throughout the day, and each time the little ape seemed to enjoy the experience.
19 September 1909, Washington (DC) Post, pg. M2:
[New York Sun.]
The next day perhaps, if a great light has now dawned upon him, he is persuaded to call up Mr. Lyon or Mr. Fish at a telephone number that proves to be that of the zoo or the aquarium.
12 June 1910, Washington (DC) Post, "Phun on the Phone," pg. SM14:
Particularly annoying is the telephone joker, generally epidemic about April 1st, who leaves on your desk a memorandum:
"Please call up Mr. Fish, 608 Main, as soon as you come in."
Of course you call up the number and ask:
"Is Mr. Fish there?"
A weary, disgusted voice explains that the number in question belongs to the Aquarium. Of course, it is "Mr. Lyon" at the "Zoo." There are innumerable versions of this supposed joke.
5 April 1917, San Francisco (CA) Chronicle, pg. 8 cartoon:
MUTT AND JEFF -- Jeff Should Have Called Up the Aquarium and Asked for Mr. Fish -- By Bud Fisher
2 April 1932, Washington (DC) Post, pg. 20:
Zoo Called 3,338 Times
During All Fools Day
Exactly 3,338 calls were received at the Zoo, between 9 a. m. and 9 p. m., and their makers were disillusioned just that many times when they asked for "Mr. Lion," "Mr. Bear," "Mr. Katz," and "Mr. Monk," and the other appellations of humans that phonetically resemble the cognomens of Zoo inmates.
1 April 1936, Washington (DC) Post, pg. 19:
Beware, Ye Who Are Gullible-
Day of Utter Nonsense Is Here
In keeping with the rollicking spirit of the day, the telephone at the Zoo is expected to jangle throughout the day.
"Is Mr. Lion there?"
"May I speak to Mr. Fox?"
"Tell Mr. Wolf to come to the phone, please."
So if someone leaves a note on your desk today to call any of the above, forget it.
1 April 1940, Los Angeles (CA) Times, pg. 2:
Griffith Park will get its share of calls for "Mr. Fox," "Mr. Lion," "Mr. Beaver" and other permanent guests. Some of the calls will be from persons who think they are fooling the zoo attendants, but most of the callers will be gullible folks who found a message on the desk telling them to "call this number and ask for Mr. Lamb."
29 September 1957, New York (NY) Times, pg. 76:
On April 1 the Bronx Zoo is bombarded with phony calls. Last year the zoo received 2,419 phony calls, 569 of them for Mr. Lion, 437 for Mr. Fox, 319 for Mr. Wolf.