By Benjamin P. Burtt
TOPIC: THE CHANGE IN THE ATTITUDE OF CROWS TOWARDS HUMAN BEINGS
Many more crows are being seen in cities and near our homes than in the past. They roost in cities where they never roosted before. They visit our yards and even our feeders.
Are there just more crows or has something else made them more tolerant of human beings?
INTRODUCTION
This column is divided into two sections
Section 1 contains a copy of the column as it appeared in the Post Standard in Syracuse on the above date.
Section 2 contains additional information for the reader who is interested in learning more about the change in habits of crows.
SECTION 1: THIS IS A COPY OF THE COLUMN THAT APPEARED IN THE POST STANDARD ON NOVEMBER 14, 2004
Mr. Burtt: These days I have crows in my back yard under my feeder. Years ago I only saw them in the distance at a road kill. Are they less wary now? K.M., Nedrow, NY.
Dear K.M.: Indeed they are more tolerant of humans today. Several things have happened.
There are more crows in the State. Some of them live and nest in urban areas where they never lived before.
They have always gathered to roost together in a patch of woods on winter nights. However, the big change is that many of these roosts are now in towns. There was a huge roost a few miles south of Auburn in 1911 and it was still there in the 1930s. Now the crows roost in the center of town.
What are the reasons for these changes? Why are crows living closer to humans? I consulted Dr. Kevin McGowan at the Cornell Laboratory of Ornithology. He has been studying the behavior of crows for years.
Here are some suggestions. Crows were scarce in New York before the forests were cleared for farms. After land was cleared and crops planted, more food became available and there were small wood lots where nests could be placed.
Crows thrived, but were considered pests. There was no law against shooting them and were they were killed at every opportunity. They began to keep away from people and their population grew and reached a peak around 1938. After that, the numbers decreased as agriculture declined.
At that time, crows did not visit feeders, did not nest in towns or roost there in winter.
Starting in 1972, hunting crows was restricted to only 124 days per year. In the years following 1972, the feeder survey shows an increase in the percentage of people who had crows around their homes. This suggests that crows were losing some of their fear of humans.
There are some roosts in towns these days. Roosting in towns has advantages for crows. Discharging firearms in cities became illegal in the 1950s so they avoided the shooting by sleeping in town. It is also warmer in town. Their most feared predator, the great horned owl, is seldom there. The town is well lit so an owl that wanders in will be more easily seen.
CAPTION: Crows are not as afraid of humans as they once were. This crow in the town of Dryden finds easy pickings on trash day! ( Courtesy of Kevin and Jay McGowan)SECTION 2. More About Crows .( Much of the following is adapted from writings of Dr. Kevin McGowan mentioned above).
The material in Section 1 that was published in the newspaper serves as an introduction to my answer to the question, why do we see more crows near our homes nowadays?
Seeing more crows near our homes is true whether we live in the country or in a city. Two things come to mind, it could be because there are just more crows in our state, or perhaps crows have changed their habits and are more willing to live near people. Actually, I believe the latter is the major reason.
Some 40 years ago, if we lived in a city, we never saw a crow. Even if we lived in a small town the same thing was true. You had to drive to the country to see crows. Crows did not come to feeders or feed under them as they do now. When they roosted in huge flocks during winter nights, such roosts were far from buildings or barns or towns. Crows just kept away from people.
Their fondness for corn early on earned them the title of pest in the eyes of the early farmers. This gave rise to the shooting in the 1800s and early 1900s.
Crows are attracted to corn when the plants are just a couple inches high. They go down a row tearing out the little plants as they go. Presumably it is the soft and nutritious seed and perhaps the tender plant that attracts them.
Later when the plants are tall and the first ears of corn develop and are soft and tender, the crows return again. This time they attack the rows at the edge of the field or along a roadway that goes through the field. They do not wander into the center of a field where they are unable to watch for danger.
Crows were a serious threat to corn and other crops. Scarecrows were put out and many crows were shot. The crows became wary of humans. Crows have the same habits today and are still a serious threat to corn.
Population has grown.
How has the crow population changed in New York State? Breeding Bird Surveys have been conducted since 1966 and these give a rough approximation of the change in the population of crows. The breeding population now is about 1.7 times the population in 1966.
Where are the crows being seen?
When we examine the Feeder Survey, we find that the percent of people who report crows has gone up from about 30% to 80%. Remember, on a survey, observers list the species that are either at their feeder or can be seen out the window or from a point near the house. Birds on hikes nearby are not to be tallied. So the survey results are actually for birds seen near houses!
The graph shows the percent of feeder survey reports that list crows seen near homes in and around Syracuse in Central New York over the past 32 years. The observations were made by readers of my newspaper column in the Post Standard. Note that the first large increase came after 1977. This suggests that crows were responding to the decreased hunting pressure. It took about six years before we began to see a significant increase in the number of crows around our homes.
Crows are more abundant on farms too and a real problem for those who grow corn. Joe Mueller has had a farm on Seneca Turnpike in Jamesville for years. He sees more crows now and says that crows are more of a threat today than they were 10 years ago.
Frank Mueller, Joe’s father, worked that same farm and often said, “we always have to use extra seed. Only about a third is harvested. About one-third doesn’t grow and the remaining third is eaten by wildlife .”
After 1990, the percent of the reports listing crows has remained constant at about 85%. So it appears to me that the decrease in the amount of shooting is quite likely the reason crows are not as wary as they once were and it probably is the reason that the population has gone up too.
The Family Life of Crows
The graph shows the percent of feeder survey reports that list crows seen near homes in and around Syracuse in Central New York over the past 32 years. The observations were made by readers of my newspaper column in the Post Standard. Note that the first large increase came after 1977. This suggests that crows were responding to the decreased hunting pressure. It took about six years before we began to see a significant increase in the number of crows around our homes.Crows are more abundant on farms too and a real problem for those who grow corn. Joe Mueller has had a farm on Seneca Turnpike in Jamesville for years. He sees more crows now and says that crows are more of a threat today than they were 10 years ago.
Frank Mueller, Joe’s father, worked that same farm and often said, “we always have to use extra seed. Only about a third is harvested. About one-third doesn’t grow and the remaining third is eaten by wildlife .”
After 1990, the percent of the reports listing crows has remained constant at about 85%. So it appears to me that the decrease in the amount of shooting is quite likely the reason crows are not as wary as they once were and it probably is the reason that the population has gone up too.
The Family Life of Crows
Dr. McGowan studies crows by attaching numbered leg bands and wing tags to the nestling crows so he can track them (at least until the wing tags fall off, which they do). The wing tags have a color and a large printed number and letter which makes it possible to identify the bird at a distance. After the tag hs dropped off, the aluminum leg band and its number identify a bird if it dies and the carcass is found.
Crows mate for life. Offspring from several earlier generations remain with the original parents to form a family group for several years. Several of these adult crows help with the nest building and incubation. They feed the nestlings and they bring food to the parent on the nest.
These helpers also spend some time chasing away predators such as horned owls and red-tailed hawks. Since there normally are huge losses of eggs and nestlings for most birds, these extra helpers for crow families probably have helped the survival of the crow and have accounted for the increase in numbers in spite of the shooting.
Each breeding pair of crows has an established home territory where they build nests and raise their young. In towns, territories are about 10 acres, but rural territories are much larger. Crows hold their territories year-round.
Non-breeding crows may leave the family territory for a while in the winter, but many return to their parents in the spring. Young crows don't leave to breed for two or more years, so family groups on the home territory can grow large. One crow family in Ithaca has up to 15 members. And it's not unusual to have three or more adults attending a single nest.
Crows in cities do eat a lot of earthworms. One year there was a very dry winter and spring in Ithaca and the crow nestlings that season were quite underweight. The dry earth meant fewer worms and smaller crows.
. For most birds there normally are huge losses of eggs and nestlings during the breeding season when only two parents are available. With the crows extended family, there is extra help from grown offspring of earlier nestings. This probably contributes to their success in raising so many offspring.
So crows are adapting to city life and living around our homes They are interesting and successful birds, try to enjoy them!
To read still more about crows, visit Dr. McGowan’s web site at http://birds.cornell.edu/crows/
If clicking on this does not work, you can copy and paste it into the address bar of your browser or just type it there.
Crows mate for life. Offspring from several earlier generations remain with the original parents to form a family group for several years. Several of these adult crows help with the nest building and incubation. They feed the nestlings and they bring food to the parent on the nest.
These helpers also spend some time chasing away predators such as horned owls and red-tailed hawks. Since there normally are huge losses of eggs and nestlings for most birds, these extra helpers for crow families probably have helped the survival of the crow and have accounted for the increase in numbers in spite of the shooting.
Each breeding pair of crows has an established home territory where they build nests and raise their young. In towns, territories are about 10 acres, but rural territories are much larger. Crows hold their territories year-round.
Non-breeding crows may leave the family territory for a while in the winter, but many return to their parents in the spring. Young crows don't leave to breed for two or more years, so family groups on the home territory can grow large. One crow family in Ithaca has up to 15 members. And it's not unusual to have three or more adults attending a single nest.
Crows in cities do eat a lot of earthworms. One year there was a very dry winter and spring in Ithaca and the crow nestlings that season were quite underweight. The dry earth meant fewer worms and smaller crows.
. For most birds there normally are huge losses of eggs and nestlings during the breeding season when only two parents are available. With the crows extended family, there is extra help from grown offspring of earlier nestings. This probably contributes to their success in raising so many offspring.
So crows are adapting to city life and living around our homes They are interesting and successful birds, try to enjoy them!
To read still more about crows, visit Dr. McGowan’s web site at http://birds.cornell.edu/crows/
If clicking on this does not work, you can copy and paste it into the address bar of your browser or just type it there.
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