By: Carlee Luttrell
Background photo from: www.popsmart.com
Everyone understands that birds migrate with the seasons. The understanding seems to fade away when we start getting into how they migrate, or more specifically, how they navigate while migrating. This topic is something that no one understands entirely. There are several who claim to understand or theorize how birds navigate. Most experts theorize degrees of the following navigational systems: celestial, magnetoreception, and olfactory. Bird navigation is a scientific mystery that has yet to be clearly defined, and will not be understood until we are able to research these navigational systems with ease.
Imagine waking up one morning to an overwhelming feeling of insecurity. A sense of danger overrides your system and your gut tells you that you should probably leave town for a while. You can’t shake an unexplainable, instinctual sensation that something life-threatening is coming and you need to escape whatever that may be. So you flee the first chance you get. You travel thousands and thousands of miles away to a place you have never even been before. Oh, and you make your way there without the GPS in your car or on your phone. You travel to your makeshift home with no map other than your own intuition and no transportation other than your own two feet. I am sure by now you are thinking, “Why in the world would I ever do that?” Well, not only does your life depend on it, but your entire species depends on your safe travels to contribute to the survivorship for years to come.
Although this scenario might sound a bit overboard, this is the reality for birds. Thousands of birds fly from their breeding site to their wintering site yearly without ever previously visiting their destination. From first-hand experience with Monitoring Avian Productivity and Survivorship (MAPS) program, I can confirm that birds are able to migrate back to the same location (within an acre) year after year with great accuracy. This magnificent skill is enabled by true navigation. True navigation is defined in a number of ways with the same basic meaning: “the ability to choose the correct direction to a goal when carried in a new and unaccustomed direction” (Holland et al., 2009).
True navigation, although still technically a theory, is widely accepted throughout the scientific and birding communities as the process in which birds are able to navigate so accurately time and time again. It is also widely accepted in these communities that true navigation occurs in a two-part process: map and compass. Guilford and Taylor, specialized animal behavior zoologists at Oxford University, define compass as “any mechanism that provides absolute geographical direction” (2014). Later in the same article, the map portion of true navigation is described as the homing of unfamiliar places or for lack of better terms the distance separating the current location and destination. Summed up, compass portion tells which direction and the map expresses how far in that specified direction.
The compass portion of avian navigation is fairly understood, thus there is no need for a debate there. The necessary debate lies within the map portion, and all sensible researchers agree that birds use a combination of mapping systems. The controversy gets heated when discussing which systems or senses are primary, secondary, complimentary, etc. Experts from across multiple fields of study often debate the mapping systems birds use for navigation. There are ornithologists who claim birds use celestial cues, like the sun and stars, for mapping. Researchers truly believe birds use Earth’s magnetic fields to guide their navigation, while yet other researchers are certain that birds use their olfactory senses, or sense of smell, to navigate. After doing extensive research, I strongly believe migratory birds who utilize true navigation navigate using their olfactory senses. Research suggests that birds navigate primarily by using their olfactory senses, however, birds are believed to have the ability to use other navigational systems as well, but this has yet to be factually proven.
To put this abstract idea into perspective, imagine being thrown into a maze and having to find your way out. The natural reaction would be to look around and navigate your way through the maze. In this case your primary sense would be sight. Now picture being thrown into a maze with a blindfold on. Your primary sense, vision, is unable to function properly, and you must resort to another navigational tool to find your way out. You naturally stick out your hands and start to feel around for walls and openings. You have just resorted to another sense, touch. Although you have had it and have been capable of using that sense the entire time, you didn’t, because it wasn’t the most accurate or efficient sense you could utilize. I believe birds navigate in the same manner. A majority of scientists believe the same concept, but debate the primary sense for navigation in birds. While I believe that olfactory senses are the primary senses used, I also believe that magnetoreception and celestial cues may assist in navigation in case of failure or malfunction of the primary.
Imagine waking up one morning to an overwhelming feeling of insecurity. A sense of danger overrides your system and your gut tells you that you should probably leave town for a while. You can’t shake an unexplainable, instinctual sensation that something life-threatening is coming and you need to escape whatever that may be. So you flee the first chance you get. You travel thousands and thousands of miles away to a place you have never even been before. Oh, and you make your way there without the GPS in your car or on your phone. You travel to your makeshift home with no map other than your own intuition and no transportation other than your own two feet. I am sure by now you are thinking, “Why in the world would I ever do that?” Well, not only does your life depend on it, but your entire species depends on your safe travels to contribute to the survivorship for years to come.
Although this scenario might sound a bit overboard, this is the reality for birds. Thousands of birds fly from their breeding site to their wintering site yearly without ever previously visiting their destination. From first-hand experience with Monitoring Avian Productivity and Survivorship (MAPS) program, I can confirm that birds are able to migrate back to the same location (within an acre) year after year with great accuracy. This magnificent skill is enabled by true navigation. True navigation is defined in a number of ways with the same basic meaning: “the ability to choose the correct direction to a goal when carried in a new and unaccustomed direction” (Holland et al., 2009).
True navigation, although still technically a theory, is widely accepted throughout the scientific and birding communities as the process in which birds are able to navigate so accurately time and time again. It is also widely accepted in these communities that true navigation occurs in a two-part process: map and compass. Guilford and Taylor, specialized animal behavior zoologists at Oxford University, define compass as “any mechanism that provides absolute geographical direction” (2014). Later in the same article, the map portion of true navigation is described as the homing of unfamiliar places or for lack of better terms the distance separating the current location and destination. Summed up, compass portion tells which direction and the map expresses how far in that specified direction.
The compass portion of avian navigation is fairly understood, thus there is no need for a debate there. The necessary debate lies within the map portion, and all sensible researchers agree that birds use a combination of mapping systems. The controversy gets heated when discussing which systems or senses are primary, secondary, complimentary, etc. Experts from across multiple fields of study often debate the mapping systems birds use for navigation. There are ornithologists who claim birds use celestial cues, like the sun and stars, for mapping. Researchers truly believe birds use Earth’s magnetic fields to guide their navigation, while yet other researchers are certain that birds use their olfactory senses, or sense of smell, to navigate. After doing extensive research, I strongly believe migratory birds who utilize true navigation navigate using their olfactory senses. Research suggests that birds navigate primarily by using their olfactory senses, however, birds are believed to have the ability to use other navigational systems as well, but this has yet to be factually proven.
To put this abstract idea into perspective, imagine being thrown into a maze and having to find your way out. The natural reaction would be to look around and navigate your way through the maze. In this case your primary sense would be sight. Now picture being thrown into a maze with a blindfold on. Your primary sense, vision, is unable to function properly, and you must resort to another navigational tool to find your way out. You naturally stick out your hands and start to feel around for walls and openings. You have just resorted to another sense, touch. Although you have had it and have been capable of using that sense the entire time, you didn’t, because it wasn’t the most accurate or efficient sense you could utilize. I believe birds navigate in the same manner. A majority of scientists believe the same concept, but debate the primary sense for navigation in birds. While I believe that olfactory senses are the primary senses used, I also believe that magnetoreception and celestial cues may assist in navigation in case of failure or malfunction of the primary.