Precocial vs. Altricial

Like most songbirds, robins start out life naked and helpless, totally dependent on their parents for survival.


 

My son sent me a photo of a baby robin, difficult to recognize because it was still about half naked, with feathers just beginning to grow. It had fallen from a nest and was, to my granddaughter’s dismay, quite dead. This baby was completely helpless, dependent on its parents for growth and survival, and they, in turn, were helpless when it came to getting it back in the nest.

Yet, other bird chicks are quite adept at getting around shortly after hatching. I think of killdeer, grouse, quail, ducks and geese when I consider young birds that can follow parents within hours of hatching. These young birds look different too, all covered in downy feathers with eyes wide open.

These birds represent the difference between precocial and altricial births (hatchings). Precocial birds hatch ready to go. They have already formed all the necessary equipment needed for them to forage and survive. Parents are there mainly as guardians and teachers.

Altricial chicks hatch completely helpless. They are usually naked and their eyes are not open. Considerable development must occur before they can leave the nest. They are dependent upon their parents for feeding, nest hygiene and protection. Examples of birds with altricial young include most songbirds, raptors and many waterbirds such as gulls, ibis and herons.

Elaborate nests usually mark species with altricial young. They need a substantial home in which to raise their brood. These nests must house their kids for several weeks and need to be sturdy and safe. It is common to find them in trees, on ledges or in tree cavities.

The parents of precocial chicks don’t need their nests once their offspring hatch. These nests tend to be more basic and are commonly located on the ground.

Mammals follow a similar pattern. The young of all ungulates—bison, deer, caribou, wildebeest, moose and more, are precocial, able to follow mama shortly after birth and are soon sampling the vegetation along with mother’s milk. However, some, such as deer and pronghorn fawns, are not able to outrun predators at an early age so their mothers hide them and move away to feed so as to not draw attention to them. These are usually the babies that humans perceive as “abandoned” and which end up being kidnapped when the bumbling human tries to “rescue” them.

On the other hand, rodents, bears, wolves, lions, weasels, rabbits and many more species (hares are precocial) all give birth to dependent, or altricial, young. They are totally helpless, impossibly cute and can do nothing but suckle for their sustenance for the first week or more of life. In the case of some rodents, it may take only a couple of weeks to reach maturity. For many mammals though, maturity isn’t achieved for several years as there is much to learn before the youngsters are ready to strike out on their own.

Humans are the clear winners when it comes to the need for parental care. Like altricial birds and mammals, no human would survive long without significant parenting, something that must continue for 18-20 years.

I find it fascinating that Nature takes so many different ways to reach the same end. Whether it starts life as a helpless naked lump or fully furred or feathered and ready to go, each animal eventually strives to mature and reproduce, for that is its biological destiny.


Help Idaho Wildlife

When we traveled across the state in October 2017, most of the vehicles we saw using the wildlife management areas did not have wildlife plates.

C'mon folks, let's help Idaho's wildlife by proudly buying and displaying a wildlife license plate on each of our vehicles! 

See below for information on Idaho plates. Most states have wildlife plates so if you live outside Idaho, check with your state's wildlife department or vehicle licensing division for availability of state wildlife plates where you live. 

Wildlife License Plates

Idaho Wildlife license plates provide essential funding that benefits the great diversity of native plants and wildlife that are not hunted, fished or trapped—over 10,000 species or 98% of Idaho’s species diversity. Game species that share the same habitats (such as elk, deer, antelope, sage-grouse, salmon, trout) also benefit from these specialty plates.

No state tax dollars are provided for wildlife diversity, conservation education and recreation programs. Neither are any revenues from the sale of hunting or fishing licenses spent on nongame species. Instead, these species depend on direct donations, federal grants, fundraising initiatives—and the Idaho Wildlife license plates.

Both my vehicles have Bluebird Plates. I prefer the bluebird because the nongame program gets 70 percent of the money from bluebird plates, but only 60 percent of the money from elk and trout plates - 10 percent of the money from elk plates supports wildlife disease monitoring and testing programs (to benefit the livestock industry) and 10 percent from cutthroat plates supports non-motorized boat access.

Incidentally, in 2014, the Idaho Legislature denied the Department of Fish and Game the ability to add new plates or even to change the name of the elk and cutthroat plates (very specific) to wildlife and fish plates, a move that would have allowed for changing images occasionally and generating more revenue. It would seem that they believe that we Idahoans don't want a well funded wildlife program. Go figure. 


"WOW. What a phenomenal piece you wrote. You are amazing." Jennifer Jackson

That is embarrassing but actually a fairly typical response to my nature essays. Since The Best of Nature is created from the very best of 16 years of these nature essays published weekly in the Idaho Falls Post Register (online readership 70,000), it is a fine read. It covers a wide variety of topics including humorous glimpses of nature, philosophy, natural history, and conservation. Readers praise the style, breadth of subject matter and my ability to communicate complex and emotional topics in a relaxed and understandable manner.

Everyone can find something to love in this book. From teenagers to octogenarians, from the coffee shop to the school room, these nature essays are widely read and enjoyed.

Some of the essays here are my personal favorites, others seemed to strike a chord with readers. Most have an important message or lesson that will resonate with you. They are written with a goal to simultaneously entertain and educate about the wonderful workings of nature. Some will make you laugh out loud and others will bring a tear to the eye and warm your heart.

Readers Write:

"You hit a home run with your article on, Big Questions in Nature. It should be required reading for everyone who has lost touch with nature...great job!" Joe Chapman

"We enjoyed your column, Bloom Where Planted. Some of the best writing yet. The Post Register is fortunate to have your weekly columns." Lou Griffin.

To read more and to order a copy, click here or get the Kindle version 

here

Copies are also available at:

Post Register

Barnes and Noble in Idaho Falls

Perfect Light Photo Supply

Museum of Idaho

Valley Books, Jackson Wyoming

Avocet Corner Bookstore, Bear River National Wildlife Refuge, Brigham City, Utah

Craters of the Moon National Monument Bookstore, Arco, Idaho