  We conducted an exploratory search for quasars at z~ 6 - 8, using the Early
Data Release from United Kingdom Infrared Deep Sky survey (UKIDSS)
cross-matched to panoramic optical imagery. High redshift quasar candidates are
chosen using multi-color selection in i,z,Y,J,H and K bands. After removal of
apparent instrumental artifacts, our candidate list consisted of 34 objects. We
further refined this list with deeper imaging in the optical for ten of our
candidates. Twenty-five candidates were followed up spectroscopically in the
near-infrared and in the optical. We confirmed twenty-five of our spectra as
very low-mass main-sequence stars or brown dwarfs, which were indeed expected
as the main contaminants of this exploratory search. The lack of quasar
detection is not surprising: the estimated probability of finding a single z>6
quasar down to the limit of UKIDSS in the 27.3 square degrees of the EDR is
<5%. We find that the most important limiting factor in this work is the depth
of the available optical data. Experience gained in this pilot project can help
refine high-redshift quasar selection criteria for subsequent UKIDSS data
releases.
