the photos survive. Some of these images have been reproduced in various media, copies of which are now kept at the Wisconsin Historical Society. It is unclear exactly where, when, and by whom these photos were taken, but some appear to have been taken in Chicago in 1896, others in Massachusetts in 1898, the latter by a J. G. Hubbard. By 1902, Whitman owned sixteen birds. Many eggs were laid by his pigeons, but few hatched, and many hatchlings died. A newspaper inquiry was published that requested "fresh blood" to the flock which had now ceased breeding. By 1907, he was down to two female passenger pigeons that died that winter, and was left with two infertile male hybrids, whose subsequent fate is unknown. By this time, only four (all males) of the birds Whitman had returned to Whittaker were alive, and these died between November 1908 and February 1909. The Cincinnati Zoo, one of the oldest zoos in the United States, kept passenger pigeons from its beginning in 1875. The zoo kept more than twenty individuals, in a ten-by-twelve-foot cage. Passenger pigeons do not appear to have been kept at the zoo due to their rarity, but to enable guests to have a closer look at a native species. Recognizing the decline of the wild populations, Whitman and the Cincinnati Zoo consistently strove to breed the surviving birds, including attempts at making a rock dove foster passenger pigeon eggs. In 1902, Whitman gave a female passenger pigeon to the zoo; this was possibly the individual later known as Martha, which would become the last living member of the species. Other sources argue that Martha was hatched at the Cincinnati Zoo, had lived there for 25 years, and was the descendant of three pairs of passenger pigeons purchased by the zoo in 1877. It is thought this individual was named Martha because her last cage mate was named George, thereby honoring George Washington and his wife Martha, though it has also been claimed she was named after the mother of a zookeeper's friends. In 1909, Martha and her two male companions at the Cincinnati Zoo became the only known surviving passenger pigeons. One of these males died around April that year, followed by George, the remaining male, on July 10, 1910. It is unknown whether the remains of George were preserved. Martha soon became a celebrity due to her status