"Chick-fil-A Appreciation Day" drew customers to their local franchises in record numbers in support of the fast food chain yesterday. However, those patrons -- many of whom are likely to defend Chick-fil-A President Dan Cathy's proclaimed anti-gay marriage stance -- are overlooking a key fact, according to a new petition.

Titled "Chick-fil-A: End the hypocrisy! Stop serving gay chickens," the petition points to what it calls a "harsh fact": instances of homosexual behavior in chickens themselves.

"As early as 1764, male chickens have been observed sexually mounting other cocks," Steven Hoffman, the petition's Ohio-based organizer, writes. "How can Chick-fil-A claim to be truly committed to their selective and hateful misreading of the Biblical definition of marriage when the nearly 300 million sandwiches they sell yearly contain chickens, some or all of which might be gay?"

The petition, which currently has over 1,500 signatures, concludes, "Tell Chick-fil-A to put their money where their mouth is and only sell animals that are 100 percent heterosexual."

And those chickens apparently aren't the only fowl to swing both ways -- as Time magazine reported, more than 100 bird species engage in some sort of homosexual behavior, "ranging from casual sex to child-rearing partnerships."

You can view the full petition here.

Next up for the Atlanta-based fast food chain: a same-sex "kiss-in" at local franchises, organized by lesbian, gay, bisexual and transgender (LGBT) rights advocates, is scheduled for Friday, Aug. 3.

Take a look at other instances of "gay" animals here:

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  • Though speculation over the true nature of Buddy and Pedro's relationship continues, the African penguins will soon be separated and paired with females for breeding.

  • A bisexual penguin love triangle? In 2009, Harry and Pepper, two male penguins at the San Francisco Zoo, were a "couple" who even briefly raised a chick together when zookeepers gave them an egg. But Harry eventually left Pepper for Linda.

  • Roy and Silo, two male Chinstrap penguins, met in 1998 at the water tank in Central Park Zoo. After they eventually raised a chick hatched from another penguin's egg, their "relationship" became the subject of the children's book "And Tango Makes Three."

  • Germany's Bremerhaven Zoo has been home to several pairs of same-sex penguins. In 2009, Z and Vielpunkt, two male Humboldt penguins at Germany's Bremerhaven Zoo, became the proud new parents of a healthy penguin chick."Another couple threw the egg out of their batch. We picked it up and put it in the nest of the gay penguins," veterinarian Joachim Schöne is <a href="http://latimesblogs.latimes.com/unleashed/2009/06/gay-penguin-dads-in-german-zoo-hatch-chick.html" target="_hplink">quoted as saying</a>.

  • Ninio was moved to a zoo in Poznan, Poland in hopes he would sire a herd, but the elephant showed a lack of interest in females, and his attitude toward fellow males was described as "affectionate."

  • As Haaretz reported in 2009, two male vultures (not pictured) named Dashik and Yehuda once engaged in a "fiery romance" at the Jerusalem Biblical Zoo that made headlines in the international media, even building a joint nest. The birds' "relationship" eventually dissolved, when they eventually paired off with females, but, in a surprise twist, those females laid eggs on the same day, which also hatched on the same day.

  • As<em> Pink News</em> <a href="http://www.pinknews.co.uk/news/articles/2005-410.html/" target="_hplink">is reporting</a>, Carlos and Fernando, two male flamingos at Britain's Slimbridge Wildfowl and Wetlands Trust (not pictured), "came out" as a couple in 2001 and even raised chicks together after they stole eggs from neighboring straight couples.

Earlier on HuffPost: