Family Adventures: Into the Nest - bird watching at a higher level

I have always had great interests in birds, watching them fly, listening them chirp. I formally started "bird watching" about a dozen years ago, with a summary on what I observed thus far in 2009 - "See who my neighbors are". Early on, I saw many birds, but mis-identify some, could not tell many. Later, with new apps - Google lens and SEEK, I could identify a lot more species of birds. But lack of knowledge of birds, I was like a blind man feeling an elephant, I made ignorant conclusions from limited and fragmented observations: laughing at woodpecker pecking gutter … but that's what they do … drumming to claim territory or attracting mates; excited to see two or three nests in a tree … thought to be from different bird families ...in fact from the same northern mocking bird family -they just didn't reuse the same nest!

Reading this book "Into the Nest", I know a lot more in depth about the circle of bird's life

Looking for a mate

Bird calling is mostly for male to attract female, but like human, they need more than just singing to attract a mate, many birds build nest together - such as the birds I see frequently Heron, others build nest(s) first, such as blue birds, then pursuing mates. Bald Eagles are more elaborate they will sky dance and then build the nest together!

from the book Into the Nest

The bird chirps are not just for attracting mates, they are also used to claim and defend territory. I actually witnessed such activities from northern mocking birds first hand at the front yard of my old house in Texas: Northern mocking birds made screaming calls to house finches who were building their nest in a pine tree in the yard, away from mocking birds' nest and trees, and trying to chase them away, on the other hand house finches, playing tricks with mocking birds, and successfully evading them and built their nest, raised their family.

Building nests

Many birds build their nests in trees, such as bald eagles, which build the largest bird nests of all birds; some birds build their inside cavities in a tree, such as hornbills or woodpeckers; some others may build their nests in shallow ditches on the ground, such as killdeers. There are birds who don't build nests at all, but steal/rob other birds' nests, brown-headed cowbirds for example,

The killdeer stood by its nest in front of it, under the steel net

Bird Biology - Mating/Laying Eggs

From reading, and some observations, e.g. ducks in the ponds, I knew that birds are mating when a male birds sit on top of female's back. But the anatomy of birds' sex organ was unknown until reading this book.

Ornithologists call bird mating "cloacal kiss", because birds' mate through cloaca, an expandable multipurpose chambers in both sexes, near their tails. When they mate, the female twist her tail upwards, and he turns his tail to meet hers so their cloacals meet.

One thing I knew none about was the female birds will produce eggs (ovum) irrespective if she has mated or not, or if the eggs are fertilized or not! An egg starts to form when ovum is formed at ovarian follicles. Matured "ovum gradually makes its way along oviduct, if the sperm reaches the upper part of oviduct as the ovum passes through, the ovum maybe fertilized, the oviduct walls first secret egg white (albumen), and then the minerals to form the shell. Finally the finished egg reaches the cloaca", and is laid. The eggs look the same whether they are fertilized or not.

egg spedition

During nesting season, most female birds ovulate once everyday or two, and lay eggs 12 to 36 hours later. Ovulation ends when the female has laid an entire clutch - the number varies by species. Some female are determinate layers, which means they only lay certain number of eggs, and stop; others are indeterminate layers, they continue to lay eggs, if eggs are removed from the nests, until the clutch number is reached. The most familiar case is the barnyard chicken, which can lay eggs indefinitely because the eggs are removed all the time! The farmed hens are robbed of hatching chicks without knowing it.

Incubating and Hatching

Once a clutch of eggs is laid, the hen starts to brood the eggs to incubate them. Many nesting birds develop a bare patch skin on their belly - brood patch. A fertilized egg does not start to form embryo until the temperature reaches ~ 38C, that's why incubation is needed. Note that male bird can brood as well.

It is not the whole yolk (ovum) that develops into an embryo, it is only a small part of the surface of the yolk where tiny cells divide to form the embryo. The embryo is attached to the yolk sac at the abdomen for nutrient during hatching. It typically take 2 - 4 weeks for a bird to hatch.

A very interesting phenomenon is how the chicks break egg shell to come into this world. All chicks have egg teeth on their bills. The teeth are hard and pointed. As hatching nears, chicks use their egg teeth scrape against inner shell, until a small hole is formed, upon further scraping, the hole grow into a crack, and chicks come into the world.

There are two types of hatchlings, precocial or altricial. Precocial chicks are those who can walk/follow their parents soon after. Altricial chicks who have sparse feathers, closed eyes, have to stay in nests. They are called nestlings. They are called fledglings when they can fly.

Altricial chicks totally rely on their parents for food. They look very similar like the above photo show, The parents typically swallow food they get and then regurgitate the semi-digested food to feed their young.

Fledging….parting ways … empty nests

This is the stage I actually witnessed: observations of house finches in our front door flower basket, from incubation, hatching, nestling … to empty nest.

Bird watching

Of course I learned a few things myself during my bird watching over the last a few years. In the pat ten years I wrote about 60 blogs which involved birds. Most notably are the followings:

See who my neighbors are

Spring Time Stories

Wildlife we saw at Yellow Stone

Hagerman Wildlife Refuge

Birds and Flowers at Banff and Jasper

From Dawn to Dusk at Bosque del Apache

Egrets and Mallards at Russell Creek Pond

Dallas Bird Sanctuary

My bird neighbors

Bird Watching Notes

A predator over Russell Creek area

Hagerman Wildlife Refuge -Bird Watching