This post will be showing how we band and measure the birds. This example will involve a nest of Tree Swallow nestlings.
After bringing the box down, we pull out nestlings one by one, holding them over the ground to poop (they tend to poop from being stimulating by touch, this is how the parents make them poop so they can clean it out), then we put them in a cloth bag so they stay in one place.
Tree Swallow nestlings in a bag
Here is our banding and measuring kit, with the bands (in the capsules), banding pliers, wing ruler, and caliper. Different species have different sized bands. For our Tree Swallows here, we use size 1.
Banding and measuring kit
We take the next band off the string inside the capsule, and place it on the right leg of the nestling. After the band goes on the leg, we spin it around to make sure the band is not stuck on the leg and is placed on properly. Here is my lovely assistant Kristen banding this Tree Swallow:
Banding Tree Swallow
Here is another picture of her banding a Tree Swallow (from different box, but different angle).
Banding Tree Swallow
With the nestlings, it doesn’t matter what order we do this all in, but with adult birds it is important to band first in case he manages to escape and fly off. Banding first also helps avoid confusion on which bird is what if there are multiple birds being measured at the same time. After banding, we take measurements.
A very standard bird measurement is the wing chord. Here is Kristen measuring the bird’s right wing chord.
With the same ruler, we measure the tail length by sticking it up the middle of the tail until it hits the butt.
Measuring tail length
With the calipers, we measure the nares-to-tip (from the nostril to the tip of the bill), the skull (base of skull to tip of the bill), and tarsus.
Kristen reading off the calipers
The funnest, but also trickiest, measurement is the fat score. We basically see how fat the nestling is. We have a scale from 0-7 that determines how fat they are. We blow on their bellies to move the feathers aside and look for fat around their clavicle.
Checking out the fat score
And of course, we also weigh them. We put them in a cup on the scale. We have a little cloth bag in the cup as well to help the nestlings stay calm, since they like to grab onto things. Without the bag, they may frantically move their legs, trying to grip on something and won’t hold still.
Weighing the Tree Swallow
After that, we put them back in their nest and put the box back up so the parents can resume feeding them. 🙂
Tree Swallow nestlings