Birds and Memory

Summary: How well can birds remember? Join Cheryl and Kiersten for a short discussion on bird memory. It’s an episode you won’t forget!

 

For our hearing impaired listeners, a transcript of this podcast follows the show notes on Podbean.

 

Show Notes:

https://allaboutbirds.org/brain-power-wins-over-brawn-when-male-hermit-humingbirds

https://audubon.org/magazine/march-april-2016/meet-bird-brainiacs-american-crow

https://learnbirdwatching.com/do-birds-have-a-good-memory

https://theconversation.com/inner-gps-of-bird-brains-may-be-better-than-that-of humans-32648

 

Our email address, please reach out with comments, questions, or suggestions:  thefeathereddesert@gmail.com

 

Transcript

Cheryl: Intro

When I decided on bird Memory as a topic for this podcast, I really wanted it to be about a bird’s memory.  Sometimes, when we are observing a bird’s behavior we think “oh, that is so smart”, or “how did it know to do that?”  Our thought process leans towards intelligence of the bird, but sometimes it’s the bird’s ability to remember things and not its smarts that we should be impressed with.  Birds and mammals, yes-that includes humans, have what is called a “Hippocampus”. 

Kiersten: What is a hippocampus?

Well, hippocampus is a neural structure located in the medial temporal lobe of the brain.  It is responsible for the formation and retrieval of memories.  Birds possess a hippocampus that senses many of the same spatial and mnemonic functions as the mammalian hippocampus but achieves these outcomes with a dramatically different neuroanatomical organization.

Cheryl:

Studies have found that some types of birds can remember details about their environment for up to two years. Birds have been observed exhibiting signs of recall related behaviors, such as recognizing people or objects from previous encounters.

Songbirds can remember the melodies they heard earlier in life.  Recent studies suggest that birds are capable of long-term memory, meaning they can store and recall specific memories over an extended period of time.  This is largely due to the fact that their brains contain a region known as ‘song nuclei’ that helps them to store information related to songs and other vocalizations.

Kiersten:

It is clear that birds possess an impressive ability to remember details about their environment over extended periods of time which makes them adept problem solvers.   Some birds participate in a   behavior known as caching, and it allows birds to store food for later.  The birds that cache food need to remember where they have stored their food.  Birds that cache have-well developed hippocampus (responsible for spatial memory).  Birds that do not need to remember the location of stored food won’t have the same memory power as a bird that does.

 So, the question was asked by researchers “Are Black-capped Chickadees smarter in Alaska than their relatives in the lower forty-eight? (Colorado) In 2016, a study was done comparing the caching behavior and memory of Black-Capped Chickadees from Alaska and then from Colorado, as well as the size of their hippocampi (again the brain regions associated with learning and memory) and how many neurons they contained.  Thought behind the study was that because Alaska birds experience harsher winters, they would need to be better at caching and recovering food.  When the study was over it was clear that the higher the elevation-harsher the winter – the more neurons-dense the bird’s hippocampus was.

Cheryl:

In 2014 the Nobel Prize for Physiology and Medicine was awarded to three neuroscientists for their pioneering work on the brain’s “inner GPS system”.  Over the course of four decades, they revealed that a small part in the brain called the hippocampus stores a map of animals’ surroundings and helps them navigate.

  The award-winning work was done in mice, but it was shown to be true in seed-caching birds.  Seed-caching birds store food in hundreds or even thousands of sites, like the fore-mentioned Chickadees, the Clark Nutcracker is the most remarkable example of this because it displays a striking caching behavior, making more than 5,000 caches of seeds in the autumn and recovering them seven to nine months later in the spring.  These birds remember 95-97% of their caches. 

This surpasses our own capacity for long-term memory.  Other birds may possess longer term memory as well, but none are known to store and retrieve such large amounts of information so accurately.  The Clark’s Nutcracker has a much larger hippocampus size than most other species in its genus. Which may be partially responsible for their superior long-term memory.  The Clark’s Nutcracker is in the Corvidae family.

Another bird found to have an extra spacious hippocampus is the Brown-head cowbird.  The female has a larger hippocampus than the male Brown-headed cowbird.  Brown-headed cowbirds do not raise their own young.  These birds trick other birds into raising their young for them.  So, the female will perform, a meticulous daily examination of various nests before making a decision and returning to the selected one a few days later.

 The reason for this is in order for her ruse to work the timing of her egg hatching and of the host eggs hatching have to be in tune.  The female cowbird can only lay her eggs in the host’s nests when the host is also laying her own eggs, making the nest briefly available to the cowbird.  Nests must therefore be erased from the cowbird’s memory as “potential” targets once they are no longer available, just as seed-caching birds have to discard sites once they have recovered the food stored in it.

Kiersten:

In the case of small but mighty, brains win over brawn when hermit Hummingbirds of Costa Rica compete for a female’s attention.  Researchers found that the dominant male Long-billed Hermits have better spatial memories and sing more consistent songs than less successful males.  The benefit of a good spatial memory even outweighs the advantage of bigger body size and extra flight power.

The Long-billed Hermit is common in the rainforest of costa Rica.  It’s about twice the size of the familiar Anna’s or ruby-throated Hummingbird, with a long, curved bill just right for sipping nectar from brilliant-orange heliconia flowers.  Males perch in the forest understory and sing incessantly, every day during their 8-month breeding season, at display sites known as leks.  The dominant males fight over coveted singing perches. 

Displaying males risk losing their spot each time they leave to refuel, so there’s a premium on getting to nectar-rich flowers quickly.  But feeding trips are like giant games of concentration, with each bird often flying for a mile and having to choose among thousands of blooms to get their fill.  Males who could remember where the reliable food sources were consistently more likely to be dominant birds with perches at the lek.  So, males with good spatial memories did better in the mating market. 

The spatial memory could help in two ways- by making foraging trips faster, or by helping the males keep track of where their rivals sat within the lek, making it easier to defend against them.  Males with better spatial memory also sang more consistent songs.  It’s thought this ability is attractive to females, because it means the singer sounds less like an inexperienced youngster and more like a veteran survivor.

Cheryl: Closing

The more I learn about birds the more I find there is to know.  Crows needs only one experience to form a long-lasting memory of who can be trusted and who can’t-essential knowledge when you are dealing with humans who might either feed you or shoot you.  We always think we are the smart species—we are the ones with game -changing intelligence, but it’s a matter of degree, and we are more similar to the other species such as birds- then we think.