Уменьшить анимацию в два раза

body{ 
  background: #81d4fa 
} 
 
#wind{ 
  position: absolute; 
  width: 300px; 
  height: 300px; 
  top: 50%; 
  margin-top: -150px; 
  left: 50%; 
  margin-left: -150px; 
  animation: fly-up-down 8s infinite linear; 
} 
 
#bird{ 
  position: absolute; 
  width: 300px; 
  height: 300px; 
  top: 50%; 
  margin-top: -150px; 
  left: 50%; 
  margin-left: -150px; 
  animation: fly-rotate 8s infinite linear; 
  cursor: pointer; 
} 
 
#body{ 
  position: relative; 
  width: 60px; 
  height: 50px; 
  border-bottom: solid 10px #fff; 
  border-right: solid 5px #8B5A2B; 
  border-left: solid 5px #8B5A2B; 
  top: 50%; 
  margin-top: -30px; 
  left: 50%; 
  margin-left: -35px; 
  background: #8B5A2B; 
  border-radius: 28px; 
} 
 
#head{ 
  position: relative; 
  width: 40px; 
  height: 30px; 
  border-top: solid 4px #000; 
  border-bottom: solid 8px #df9e6f; 
  border-left: solid 4px #df9e6f; 
  border-right: solid 4px #df9e6f; 
  top: 50%; 
  margin-top: -60px; 
  left: 50%; 
  margin-left: -24px; 
  background: #fff; 
  border-radius: 100%; 
  animation: updown 7s infinite linear 
} 
 
#left-wing{ 
  position: absolute; 
  top: 50%; 
  margin-top: -15px; 
  right: 50%; 
  margin-right: 20px; 
  border-radius: 10px; 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
  border-right: solid 150px #fff; 
  border-left: solid 15px; 
  animation: l-wing 1.5s infinite linear; 
} 
 
#right-wing{ 
  position: absolute; 
  top: 50%; 
  margin-top: -15px; 
  left: 50%; 
  margin-left: 20px; 
  border-radius: 10px; 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
  border-left: solid 150px #fff; 
  border-right: solid 15px;  
  animation: r-wing 1.5s infinite linear; 
} 
 
#tail{ 
  position: absolute; 
  width: 24px; 
  height: 0px; 
  background: #8B5A2B; 
  border-bottom: solid 10px #000; 
  border-left: solid 20px transparent; 
  border-right: solid 20px transparent; 
  border-radius: 100px; 
  top: 50%; 
  margin-top: 20px; 
  left: 50%; 
  margin-left: -33px; 
  animation: updown 2s infinite linear; 
} 
 
#beak{ 
  position: absolute; 
  border-top: solid 22px #CD661D; 
  border-left: solid 10px transparent; 
  border-right: solid 10px transparent; 
  border-radius: 100%; 
  top: 50%; 
  margin-top: 10px; 
  left: 50%; 
  margin-left: -10px; 
} 
 
.beak-holes{ 
  position: absolute; 
  color: #9a330a; 
  width:3px; 
  height: 1px; 
  background: black; 
  top: 50%; 
  margin-top: -17px;   
} 
 
#bh1{ 
  left: 50%; 
  margin-left:-4px; 
} 
 
#bh2{ 
  right: 50%; 
  margin-right:-4px; 
} 
 
#left-foot{ 
  position: absolute; 
  top: 50%; 
  margin-top: 23px; 
  right: 50%; 
  margin-right: 5px; 
  border-radius: 25px; 
  border-bottom: solid 10px #CD661D; 
  border-left: solid 10px transparent; 
  border-right: solid 10px transparent; 
} 
 
#right-foot{ 
  position: absolute; 
  top: 50%; 
  margin-top: 23px; 
  left: 50%; 
  margin-left: 5px; 
  border-radius: 25px; 
  border-bottom: solid 10px #CD661D; 
  border-left: solid 10px transparent; 
  border-right: solid 10px transparent; 
} 
 
#left-eye{ 
  position: absolute; 
  top: 50%; 
  margin-top: -5px; 
  right: 50%; 
  margin-right: 3px; 
  border-radius: 100%; 
  width: 3px; 
  height: 3px; 
  background: #fff; 
  border-top: solid 1px #000; 
  border-bottom: solid 2.5px #000; 
  border-left: solid 2.5px #000; 
  border-right: solid 2.5px #000; 
} 
 
#right-eye{ 
  position: absolute; 
  top: 50%; 
  margin-top: -5px; 
  left: 50%; 
  margin-left: 3px; 
  border-radius: 100%; 
  width: 3px; 
  height: 3px; 
  background: #fff; 
  border-top: solid 1px #000; 
  border-bottom: solid 2.5px #000; 
  border-left: solid 2.5px #000; 
  border-right: solid 2.5px #000; 
} 
 
@keyframes fly-rotate{ 
  0%{ 
    -webkit-transform: rotate(10deg); 
    -moz-transform: rotate(10deg); 
    } 
  25%{ 
    -webkit-transform: rotate(-10deg); 
    -moz-transform: rotate(-10deg); 
    } 
  50%{ 
    -webkit-transform: rotate(10deg); 
    -moz-transform: rotate(10deg); 
    } 
  75%{ 
    -webkit-transform: rotate(-10deg); 
    -moz-transform: rotate(-10deg); 
    } 
  100%{ 
    -webkit-transform: rotate(10deg); 
    -moz-transform: rotate(10deg); 
    } 
} 
 
@keyframes fly-up-down{ 
   
  25%{ 
    -webkit-transform: translatey(-20px); 
    -moz-transform: translatey(-20px) 
    } 
  50%{ 
    -webkit-transform: translatey(20px); 
    -mozansform: translatey(20px); 
    } 
  75%{ 
    -webkit-transform: translatey(-20px); 
    -mozansform: translatey(-20px); 
    } 
} 
 
 
@keyframes r-wing{ 
  
  0%{ 
  margin-top: -5px; 
  transform: rotate(0deg); 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
    } 
   
  25%{ 
  margin-top: -25px; 
  transform: rotate(-10deg); 
  border-top: solid 20px #8B5A2B; 
  border-bottom: solid 10px transparent; 
    } 
  50%{ 
  margin-top: -5px; 
  transform: rotate(10deg); 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
    } 
  75%{ 
  margin-top: -25px; 
  transform: rotate(-10deg); 
  border-top: solid 20px #8B5A2B; 
  border-bottom: solid 10px transparent; 
    } 
   
  100%{ 
  margin-top: -5px; 
  transform: rotate(0deg); 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
    } 
} 
 
@keyframes l-wing{ 
 
  0%{ 
  margin-top: -5px; 
  transform: rotate(0deg); 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
    } 
   
  25%{ 
  margin-top: -25px; 
  transform: rotate(10deg); 
  border-top: solid 20px #8B5A2B; 
  border-bottom: solid 10px transparent; 
    } 
  50%{ 
  margin-top: -5px; 
  transform: rotate(-10deg); 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
    } 
  75%{ 
  margin-top: -25px; 
  transform: rotate(10deg); 
  border-top: solid 20px #8B5A2B; 
  border-bottom: solid 10px transparent; 
    } 
   
  100%{ 
  margin-top: -5px; 
  transform: rotate(0deg); 
  border-top: solid 10px #8B5A2B; 
  border-bottom: solid 15px transparent; 
    } 
} 
 
@keyframes updown{ 
   0%{ 
  transition-duration: 5s; 
  transform: translatey(-2px); 
    } 
  25%{ 
  transition-duration: 5s; 
  transform: translatey(4px); 
    } 
  50%{ 
  transition-duration: 5s;   
  transform: translatey(0px); 
    } 
  75%{ 
  transition-duration: 5s; 
  transform: translatey(4px); 
    } 
  100%{ 
  transition-duration: 5s; 
  transform: translatey(-2px); 
    } 
} 

<div id="wind"> 
 
  <div id="bird"> 
 
    <div id="tail"> 
    </div> 
 
    <div id="left-wing"> 
    </div> 
 
    <div id="right-wing"> 
    </div> 
 
    <div id="left-foot"> 
    </div> 
 
    <div id="right-foot"> 
    </div> 
 
    <div id="body"> 
    </div> 
 
    <div id="head"> 
 
      <div id="left-eye"> 
      </div> 
 
      <div id="right-eye"> 
      </div> 
 
      <div id="beak"> 
        <div id="bh1" class="beak-holes"> 
          </div> 
        <div id="bh2" class="beak-holes"> 
          </div> 
      </div> 
 
    </div> 
 
  </div> 
 
</div>