Talking about Extinct Animals

The silver brown bears, lived in Mexico but be became extinct in 1964.

How did it they become extinct?  <=referring to brown bears

In the nineteenth century, the United States began to expand and people began to occupy the areas where these bears lived. In Mexico, people also began to populate areas characteristics the native habitats of these animals.

But they did not come alone. If there was no cattle left, which because they would occasionally become part of the food for prey for these bears, because they saw him as prey is brought about either; as a result the bears, in turn, began to be hunted and poisoned (by the settlers).

In By [1] 1960, there were only 30 bears in Mexico, since despite their protected status as protected against this continued hunting. At During that time, the farmers decided to end to exterminate the remaining, and the grizzlies were considered extinct in 1964.

Is it true some people saw the Mexican bear mexican after scientists reported its extinction?

Following a report that some copies bears [2] had were found at a ranch at the head of the Yaqui River in Sonora province in 1969, the American biologist Carl B. Koford conducted a search of for three months in the area but found no trace.

What are its characteristics and eating habits?

The hair color was generally reddish brown, and silver bands highlights in on the its head, legs and parts of his its body. Because of these strips of native silver, it was known as grizzly.

As for its dimensions, {better: size or measurements} its height could reach managed to reach [3] about 2m and could weigh more than 300 kg. He It reproduced only every three years, with litters ranging from one to three cubs, giving birth during hibernation season.

As for feeding, it is known to primarily eat honey, roots, fruits, plants and nuts, but sometimes, also came to detect found to be that could feed on carrion or hunt for small mammals.

1. "By" is better to use here instead of "In" because you are referring to statistics that are trending. So it's more common to say: There used to be thousands of bears, but by 1960, there were only 30 left".

2. I'm not sure why "copies" was used here. Did you mean "specimen"? "Specimen" would be okay, but the usage would be a little to clinical for this case (that would be more applicable when referring to cells or DNA)

3. "Manage to reach" refers to what the bear can touch if it extends its arm up (i.e. reach = height + arm length)