Is there a difference between these two ways of writing a constructor function?

Question

I would like to know if there is any particular difference between these ways of writing a constructor:

let Bird = function(name, color) {
  this.name = name;
  this.color = color;
  this.numLegs = 2;
}

function Bird() {
  this.name = "Albert";
  this.color  = "blue";
  this.numLegs = 2;
}