Authors avatar image on their posts

Trying to get the author’s Gravatar pic to display, but this code isn’t doing it:

<?php query_posts("author=244&showposts=1"); ?>
<?php while (have_posts()) : the_post(); ?>
<div class="author-feature">
<?php echo get_avatar( get_the_author_email(), '36' ); ?>
<h3><?php the_title(); ?></h3>
<p style="text-align:right;">by <?php the_author() ?></p>
<?php the_content('_'); ?>
</div>
<?php endwhile; ?>

This: <?php echo get_avatar( get_the_author_email(), '36' ); ?> isn’t working. Anyone know what I’m doing wrong?