Woodlark?

Three of these birds were seen in short scrub on an island at Rainham Marshes. The consensus in the hide was that they were Woodlarks, but having examined my photos I'm not so sure. They don't have 'the distinctive black mark bordered in white on the edge of its wing' and they seem to have longer tails. We couldn't confirm that the white stripes above the eyes met around the back, but 2 guys said they saw one of them raise its crest. Any ideas?