Good attempt, I would look up the rule of thirds to try and hone your eye compositionally.
there is definitely movement blur, resulting from being zoomed in to 300mm,
if you're using a crop body try not to allow your shutter speed to drop below 460mm (500mm actual on camera display) try using AV (Aperture Priority) or TV (Shutter Priority) and bump the ISO upto 200 - 400 to allow better shutter and aperture settings.
Oh and don't take the dogs with you next time, with a little bit of stealth you might be able to get a little bit closer.
Good luck, looking forward to the next series
I just noticed that your 70-300mm lens has IS which case the absolute lowest shutter speed would be 1/60th of a second at 300mm which is 3 f stops, I would personally keep above 1/125th, (2 f/stops) again uping the ISO will help.