House Finch (Carpodacus mexicanus )

The webcam

This webcam is placed above a hanging plant in the entrance porch of suburban home. The finches chose this hanging plant to place their nest in the shelter of a roof which provides protection from rain and most predators. Video, audio, and power cables from the camera are strung into the house where they connect to a MPEG4 video server which is connected by way of a cable router to the Internet.

The House Finch

The House Finch is a typical finch type bird between 5 and 6 inches long. Wingspan is 8 to 10 inches. It exhibits the defining finch characteristic of a strong conical beak. These birds have heavily streaked feathers on the underparts. The overall color is brown to grey-brown. There are two white wingbars. They display sexual dimorphism with the male being quite showy with its red spots on its chest, head, and rump. Actually, this color can vary from red to yellow with the color depending on the food the male eats as its feathers are replaced during a molt.

Range

The House Finch in the east is actually a transplant from the Southwestern United States and Mexico. These birds were once a part of the pet trade and sold as cage birds in New York in the 1940’s. A number of these birds from the pet trade were released on Long Island at that time and became the nucleus for the birds which are now spreading through the eastern US.

Breeding

These birds seem to have a built in affinity for people. They are often found in suburban settings near dwellings and nesting in hanging plant baskets is very common. The nest is an open cup neatly placed in a matrix of plant material. It consists of mostly fine grass material and fine twigs but may also contain found material such as string and feathers. The lining is similar, but of progressively finer material.  The eggs numbering 1-6 are pale blue with fine speckling.

Bringing up baby

The length of egg incubation is12 to 14 days. After hatching, the days to fledge are 11-19.  Both parents care for the brood. The parents keep the nest clean by eating the fecal sacs for the first days after hatching. Later on, the parents will drop the fecal sac some distance from the nest.

Diet

The House Finch diet consists of seeds, buds, insects, and fruits. We expect to see the young fed a diet consisting more of insects as this is common among many birds that are almost exclusively seed eaters as adults. The high protein diet of insects helps the growth of young birds. The preference for seeds by the adults makes these birds a common visitor at bird feeders. They are welcome guests as the male’s colorful appearance is very pleasing to birdwatchers.

Threat to survival

Beginning in 1994, a disease was noticed in eastern House Finch populations around the Washington, DC area. This disease was characterized by swollen, crusty, and runny lesions around the House Finch’s eyes. Birds do not generally succumb from the disease itself, but from the vision impairment that results in starvation, predation, or collision. The disease is known as Mycoplasmal conjunctivitis which is a parasitic bacterium infection. It is highly contagious and is spread among birds that flock and feed together. It is to a degree a population density dependent illness and it is thought that the rapid growth of the eastern population, together with the inbreeding of this population due to its small initial size has led to the current outbreak. The propensity of this species to gather in large flocks at feeders is thought to be a contributing factor to the spread of the disease. If you feed birds, it is important to clean feeders thoroughly on a regular basis and avoid caked or moldy accumulation of seeds in feeders or on the ground.

After a massive decline in numbers of the eastern population of House Finches, the population seems to have stabilized at a smaller number. The smaller population may either be less likely to transmit the disease to other birds, or the survivors may have developed some immunity. Time will tell.

Song

The song of the House Finch is a pleasant warble that varies rapidly up and down.