Showing posts with label Raven. Show all posts
Showing posts with label Raven. Show all posts

Wednesday, June 1, 2011

Juvenile Ravens

Juvenile Ravens on the roof tops


As expected, since the Ravens were nesting in February, their young have fledged way ahead of most other bird species.  There are five of them.  For a couple of weeks now they have made their presence known in the neighborhood with their loud calls.   They seem to be practicing their flying and landing skills, as I see them diving, swooping and climbing in the sky all over the neighborhood.   One of them is even a bit clumsy, which is actually quite endearing.

Juvenile Raven
Ravens are very intelligent and as I learned from both my research and through observation, their young engage in active play.  This takes the form of chase games with each other, as well as other birds, and has the added bonus of turning them into excellent fliers.   When I was watching them, it was almost as if they were encouraging each other to try landings and take offs from trees and other high places, such as a church tower, and hoping from one roof top to the next in my complex.

Preening
In Flight

The parents, who are very caring and protective, check up on them regularly.  In the picture directly below you can see some of them in a family huddle with one of the parents.  I have observed this behavior several times now.

Joyous greeting of parent
The parents also seem always to be close by.  When the juveniles are giving off distress calls, the parents swoop in almost immediately.  The first time that I saw the juveniles, they were being mobbed by crows.  The crows however didn't stick around for long once the parents arrived on scene, as Raven parents are very aggressive in their defense of the juveniles.   They will engage any threat to their young with aggression, as I have even observed the Ravens chasing and harassing an Eagle, until it was well away from their nest site.

Juvenile Raven taking off
Juvenile Ravens will stay with or near their parents for six months after they fledge.  They also stay in a group,  while the parents are elsewhere.  As far as I know this is the only bird species to do so.  Although the juvenile Ravens are anything but quiet when they play, I quite enjoy watching their antics.


Enjoy,
Susan

Sunday, March 6, 2011

Raven love : the intelligence of spring fever

Raven's flight silhouette


Several weeks ago I saw a Raven pair in mating flight.  It was minus thirty five degrees outside at the time; very typical February weather for us here in Alberta.   At first I thought perhaps I mistook what I saw.   After all spring, when the weather is warming and things are re-awakening to life, is the season for mating and nesting, as we all know.   But then a little more than a week ago, I saw these same Raven's carrying nesting materials back and forth between the little forest to the west of my house, and their nesting site somewhere to the east, confirming what I had seen.



It seemed a little research was in order, which led me to some very interesting facts about Ravens.   It turns out that they typically mate mid February, although in colder climes, such as Tibet's, they might delay their mating until March, or even April.  The problem is, the temperatures here have remained below the minus twenty eight mark and so I was somewhat puzzled.  While it is true that the weather forecasters predict warmer weather fairly soon, it seems unlikely that the Ravens' young would survive once hatched, less than twenty days from now.   A Raven pair does not mate however, until they have established a territory and demonstrated the ability to defend that territory, as well as the ability to provide food.  So it is unlikely that they would begin nesting if there was no ready food supply available.

Raven foraging

The male feeds the female while she sits the eggs in the nest and I wondered what exactly he would feed her.  It occurred to me that there must be many creatures in the wild who do not survive the cold, or are weakened by it.  Ravens do eat carrion and they also hunt.  In fact, apparently there isn't much that Ravens do not eat, as they are opportunistic feeders and omnivorous besides.

As anyone can observe, Raven's are extremely  intelligent.   So it is unsurprising that they create cashes of food during periods of abundance, and also steal such cashes from other creatures who do the same.   I have seen them dining on Pigeon a number of times and Pigeons are quite numerous in this city.  In addition, Ravens are adept dumpster divers and can be seen quite often near, and on top of the dumpsters at restaurants such as Tim Horton's, Wendy's and Taco Bell.  There are many restaurants in the neighborhood in which I live, well within this Raven pair's newly staked out territory.

Raven in flight


When I got to thinking about what the young would be fed, I realized that their young will actually have an advantage by being delivered early into the world.  Aside from the above mentioned food sources, there is this.   While other birds are struggling with the long and hazardous process of migrating north, the Ravens' young may be fed insects in plenty as they emerge from their winter hiding places with the warming weather.  This, without the competition which would come with the arrival of numerous migrant birds in the spring, were they to be hatched then.  The same can of course be said for other food sources, even carrion.

Raven perched near a dumpster


By the time the Ravens' young have fledged, some  thirty five to forty days after hatching, other birds will have laid their eggs and some may even have hatched.  Although Ravens are certainly not the only birds to do so, and as sad as it is, they do raid the nests of other birds for eggs, as well as hatchlings.  Which makes for easy pickings for newly fledged young Ravens learning to hunt and forage for food on their own. 
Raven in flight close-up
As you can see, it does make sense for the Raven to perform the mating flight and begin nesting, even if it is extremely cold in February.  The Raven is indeed a highly intelligent bird.  There are of course other birds with similar nesting habits, among these is the Great Horned Owl, who begins it's nesting behavior in December, and the Red Tailed Hawk who breeds and nests not long after the Raven in March.  If you wish to learn more about the Raven just follow these links:

http://www.desertusa.com/mag99/oct/papr/raven.html
http://www.angelfire.com/id/ravensknowledge/crowfacts.html

Enjoy,

Susan
 
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