 Outside of densely populated areas there is normally around a 5\% drop in sleep duration for Great Tits' females during their nesting period.
<meaning-changed>  Outside of densely populated areas there is normally around a 5\% drop in sleep duration for Great Tits' females during their nesting period.
 Outside of densely populated areas there is normally around a 5\% drop in sleep duration for blue-tit females during their nesting period.