They use a certain chirp because they have 4 types of chirps.
A crow has 4 talons (toes) on each foot.
there are four (4).
Lindon Crow was born on April 4, 1933, in Denison, Texas, USA.
Zeena hardly talked to Ethan Frome due to their strained relationship and mutual feelings of resentment and dissatisfaction. Their lack of communication could stem from underlying tensions and unspoken grievances in their marriage.
Crow
Dove or Crow
crowrook
Crow.
The Crow were allowed to keep about 4% of their original land, and now live on the Crow reservation in south-central Montana. In recent years the Crow have seen a rapid rise in their population. In 1930 there were less than 1900 Crow, and now (2010) there are over 13,000.
crow
Temperature affects the rate of the cricket's chirping. Each type of cricket has its own speed, but the Snowy Tree Cricket can be used to estimate temperature is degrees Fahrenheit by adding 40 to the number of chirps in 15 seconds. The common field cricket is not so accurate, but this formula will give a reasonable approximation for them as well.