Birds show great memory for stored food
Through the years, I have usually recognized faces but have always struggled to remember names. However, with everyone wearing masks due to the virus, it has become even harder to recognize the people I meet on the street. My only saving grace is that most people are having the same problem.
At times, Mary Alice and I forget what we were going to say or do. This lack of memory can be dangerous; for example, if your wedding anniversary is forgotten, there could be repercussions.
We humans are aware that memory is an important part of our lives, but it is also invaluable to wildlife. Each year the robins and wrens return to our backyards. Studies done by biologists have proven that birds show a remarkable memory in returning to the same area year after year to raise their young.
There are birds, such as the white-breasted nuthatch and titmouse that carry seeds from the bird feeders to store in bark crevices, under leaves and also bury in the soft ground. In one study done, a white-breasted nuthatch carried away 38 pieces of suet in an hour. The suet, which was pushed into bark crevices, was later discovered and eaten by a brown creeper, a chickadee and other nuthatches.
Blue jays take acorns, sunflower seeds, peanuts, etc., from birdfeeders to store for later use. The question is how these birds find the stored foods. Biologists say it is by memory.
Some birds show a remarkable place memory when returning and retrieving their cache. Thick-billed nuthatches (Nucifraga caryocatactes), which are related to the jays, find their caches of pine seeds even when the ground is covered by snow. Nuthatches have been observed flying to spots, where seeds had previously been buried, and digging directly down to the stored food.
In one experiment, these birds recovered up to 70% of their stored food. This was done by visually remembering the exact places where each food cache had been buried. In another report, a Clark’s nutcracker, in the Rocky Mountains, had dug directly down through eight inches of snow to recover Douglas fir seed cones stored earlier in the fall.
In 1951, it was recorded that in the Hainault Forest, Essex, England, 35 to 40 Eurasian common jays collected acorns from oak trees for their winter stores. These jays gathered and buried an estimated 200,000 acorns as far as 3/4 of a mile away. Many of these acorns were recovered later, apparently by remembering the burial sites.
Woodpeckers, nuthatches, titmice, shrikes and members of the crow family all store food for later use. Their larders contain insects, mice, small birds, etc., which they hang on thorns, crotches of trees, bushes and on barbed-wire fences. These birds return to feed on their stores, up to eight months later. This storing of uneaten prey is also a well-known habit of the kestrel, goshawk, peregrine falcon and several owls.
Years ago, I attended a beginner’s GPS course. This Global Positioning System, which uses satellites to locate your position, is an aid in helping a person from getting lost. However, this is nothing new to wildlife. Homing pigeons are said to remember their homes, even after an absence of several years. While migrating, some birds use memory in remembering landmarks and nesting territories.
According to Augustus Brown’s book “Why Pandas Do Handstands,” memory experiments done with animals showed sheep are good at remembering faces. It was found some sheep are able to recognize the faces of up to 50 sheep and also 10 humans for approximately two years.
Tests conducted by the University of Michigan concluded while a dog’s memory lasts no more than five minutes, a cat’s memory can last as long as 16 hours, exceeding even that of a monkey and orangutan.
Small parasitic wasps can be trained to sniff out drugs and explosives. Unlike dogs that take years to be trained for this job, wasps learn the task in half an hour.
Of course, we have heard it said that elephants never forget. Research has shown herds of elephants draw on the wisdom and experience of elder females. By using their own memories, these elderly females show the younger herd members how to respond to threats and strangers; where the herd eats and drinks, and which young members are kept in the group and which are expelled.
In another study, it was learned that fur seal mothers and children remember the callings of each other long after they have been separated. Though unusual for mammals, the seals recognized and responded to each other’s voice for as long as four years after going their separate ways.
The more we study wildlife and nature, the more we realize how little we know about fish, birds and animals that share this planet with us.