In order to establish the minimum adverse effect of the sex identification method in birds, the droppings of 11 orders of 42 species of Japanese birds were collected for DNA analysis. The chromosomes used for sex identification were the protein-encoding spindlin gene (SPIN), presumptive pseudogene (EE0.6), and chromo helicase DNA-binding gene (CHD). The CHD gene was reported to be conclusive in gender discrimination and was amplified using the polymerase chain reaction (PCR) by changing the primer and temperature conditions for each species. As a result, although sexing in some species and samples was not confirmed, the amplification of specific gene regions for sexing was confirmed in 10 orders of 36 species of birds. In species and samples where amplification was not confirmed, selection of adequate extraction procedures for sex identification using bird droppings was needed. Nine species that confirmed the amplification of regions for sexing, from the number of tested samples and the population in which amplification was confirmed, determined that this method was practical for sex identification. This method can also be used for sex identification using the droppings from chicks. Thus, this method not only reduced the burden on the birds compared to conventional methods but also suggested that the sexing condition was wide.

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This paper reports the numbers of newly banded birds in Japan during 2011 by prefecture. The total number of banded birds for each prefecture were shown in Fig. 1. The number of banded birds by species for each prefecture were shown in Table 1.

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