http://www.ck12.org Chapter 12. Understanding Biodiversity: Animals: Birds
Habitat
Long-eared owls’ habitats range all throughout the Northern Hemisphere, in areas such as North America, Japan,
and Europe. More isolated populations are found near North and East Africa, and the Canary Islands. They are
known to inhabit inland, coastal, and desert areas. The long-eared owl can often be found near areas with many
tree groves, wetlands surrounded by thickets, grasslands, marshes, and areas near farmlands. During nesting season,
long-eared owls will create nests in the old homes of hawks, crows, magpies, and squirrels, or occasionally in natural
tree cavities.
Biology
Cell Biology
Like all animals, long-eared owls have eukaryotic cells, which are cells that are found in all plants, animals, and fungi
(and protists). All eukaryotic cells contain a nucleus and also have many different types of organelles. Organelles
basically means “little organs” due to the fact that each organelle plays an important part in the cells function. The
organelles of a eukaryotic cell include, aside from the nucleus, the endoplasmic reticulum, which is network of
membranes inside the cell; the Golgi bodies, which transport proteins out of the cell and other places throughout
the cell; ribosomes, which are particles consisting of RNA and additional proteins, and mitochondria, which is an
organelle in which the biochemical processes of cellular respiration and energy production occur. Eukaryotic cells
also contain deoxyribonucleic acid, DNA for short. DNA consist of genes with “codes” that serve to make protein
for the cells.
The cells of the long-eared owl divide through the process of mitosis and meiosis. Mitosis is when the nucleus of
the cell divide is followed by cytokinesis, producing two new cells with the same DNA as the original cell. These
cells are said to be genetically identical. This is similar to meiosis, which is the division process of cells in which
gametes, which include eggs and sperm cells, are created with half of the chromosomes of the original cell. These
chromosomes are compiled of DNA and include “codes” that are responsible for your many traits (ex. hair color,
eye color, etc.).
Long-eared owls get their oxygen from the red blood cells in their blood. These red blood cells take oxygen from the
lungs and transport it throughout all the organs in the body, including the heart. Like all birds and unlike mammals,
the red blood cells of the long-eared owl contains a nucleus. (In mammals, the lack of the nuclei allows higher levels
of oxygen to be transported throughout the body.)
Evolution
The owl species, along with many other birds, are thought to have evolved from theropods, a type of bipedal
dinosaurs. Many believe the ancestor of birds was similar to a specific theropod known asDeinonychus. The
Deinonychuswas a predatory carnivore with many birdlike features such as feathers and wings, along with similar
respiratory, circulatory, and digestive systems to modern-day birds. Before the fossils of theDeinonychuswere
discovered in the 1960s, many scientists did not believe that birds had evolved from dinosaurs. The discovery of
these fossils helped to convince the many scientists who had debated the evolution of birds, an idea that had been
challenged for close to a century.
Scientists have always pondered on the topic of the evolution of the flight of birds. Several hypotheses and scientific
ideas have been presented over many years by various scientists about how and why birds have wings and how these
wings evolved. Two of these many theories are listed below.