community.kjrh.com

HLC in Chicago:

Ok, good idea to have them all in one place, Raptorman, so I've moved my question:

The nest site is terribly windy.  When the hawklets begin to exercise their wings and especially when they get to the point when they can hop up on the railing, are they in danger of being blown off the tower long before they are ready to fledge?

As we continue to watch this nest and the family we will become more and more aware of the marvels of these bird's instincts, adaptations and learned behavior that aid greatly in their survival.

As they develop in size and strength they are also implementing their instincts and gaining experience in the use of their body and air (including air movement). Situations can certainly arise which might put them in some perilous situations but these are uncommon. By the time they are ready to branch (jump to perches away from the nest bowl) they will have learned a great deal about moving air.

In the evolution of raptors and nesting in high locations various species have learned to survive the risks of such choices. Though this location might not be the optimum nest site, from the point of view of fledging, the hawklets may beat the odds of raptors in general (mortality rate of greater than 60% within the first year). Time will tell.

Russell posted in todays Observation thread:

"Interesting that the female tends to feed both chicks, but in this case he only fed one of them."

I thought I would add a comment on this observation to point out the interaction between hawklet(s) and adults and also to possibly relieve some potential concerns that some viewers may have about preferential treatment. The controlling factor in which hawklet or if any hawklet gets fed is in the stimulation behavior given by the hawklet(s). Generally they control if they get fed (with the understanding their is available prey). It is called food begging when the hawklets vocalize for food. This begging stimulates the adult(s) (there can be simultaneous feeding) to feed but if there is not begging the adults will not be motivated.

Not to be argumentative but simply to express a different interpretation of the events observed, I believe it was the F (female) at the nest and I did not see the younger hawklet attempt to beg.

On that whole topic as humans we must, for the sake of the Redtails, attempt to minimize our anthropomorphizing. The role of the reproductive aspect of the species is to increase their population but to do so with the greatest guarantee of some survival but not at the risk of no survival. This means the adults will look after their survival first (without that the progeny would perish anyway) they look out for the strongest hawklet first while attempting to provide for the other nestling or eyass (terms for the young of any bird- not specific to raptors or hawks but the latter is more commonly used with falcons) but without undue risk to the strongest. If the habitat (food, water, space and shelter of a species) is in very good condition this will allow for a much greater opportunity for nesting success.    

On Wednesday night I discovered a red tailed hawk down in a storm in Dallas, she was flopping around on one wing and the bird ended up in the street so I kept the traffic from running her over until animal control could pick her up 2 hours later.  She just  stood there and didn't move, I figured she was in shock, she kept putting her head down towards her right side.Animal control came and approached her from behind with big gloves and a blue towel and put her in the truck.

She has feathers pulled out of her wing and her wing has a dislocated shoulder.  No broken bones.  She is in the hands of Rogers Wildlife in Hutchins.  They say she will pull through.  How long does it take for a bird to recover from something like this and is this common?   I figure she was blown into a tree because it was really windy and rainy all night.

James Pepper

James: Asking me to make a prognosis over the Internet is at best a risky comment on my part. A dislocated shoulder is not as common as broken bones of the wing (much like our arm, wrist and fingers). Depending on the severity of the dislocation relocation is not a long term process but if the joint was severely damaged repair may not be possible. Also of great concern would be the extent of plumage damage. Again depending on the type of damage the feathers may never be naturally replaced or if they are the process can take weeks. The best answers to your question should be available from that rehab facility.

I can't think of an analogy to compare feathers to a portion of the human anatomy. They are so unique in their development, dependency on one another and yet flexibility, strength and durability.

My best guess is the Red-tailed hawk was thrown against some type of structure by a gust while the wing was fully extended creating the dislocation. I don't have enough information to surmise the cause of the feather damage.

Neither of the adults are banded or marked for identification with any human system.

The "mark" you are referring to on the females right foot (about halfway between plumage on tarsus and toes I believe is the result of "being in the line of fire" when one of the hawklets defecated. This has left a white "dot"

Thanks Raptorman, we are all getting an education here.  It is fascinating and repulsive at the same time.  You can tell that we had an eventful day here and we missed your posts.  I think it is human nature to root for the "life" that we have seen unfold since we saw the first hawlet's egg begin to crack.  I know you said to be careful about giving the hawks human characteristics and I understand that, but it is hard to do, but I will work on that.  Thanks so much for your input - it helps us understand.

Will this pair lay more eggs in the nest this season or is this the one shot for this summer?

hawkeye:

Will this pair lay more eggs in the nest this season or is this the one shot for this summer?

The current situation in effort (having hatched a pr of hawklets and raised them to almost 2 weeks of age), no there would not be any more eggs laid or another brood raised this breeding season.

Now that the simple story BUT if certain circumstances may have been different it is possible and not uncommon for Redtails to lay a second (replacement) clutch (assuming the first was destroyed) but timing is everything.

Normally speaking raptors are effected by photoperiod (the length of daylight hrs) to trigger the reproductive system. Generally speaking this is not enough to trigger egg laying though. It is also possible for a hen to lay an egg without any of the following support situations in place which would normally happen prior to viable egg production and an average to maximum clutch.

Sexual maturity, good health, abundant food supply, mate, courtship, food transfers, nest building, copulation and experience.

This is a complex process and I will attempt to add to the above as time permits.

mdfadotca:

Raptorman,

I have a question re: feathers. I was under the impression that whenever feathers are lost for whatever reason, they always eventually grow back. Your post above, however, suggested otherwise that there may be situations when they don't. Could you please expand on that a little? What sort of damage would prevent the feathers from growing back?

Margaret.

Raptors have 5 main types of feathers: flight, contour, down, filoplumes and crine feathers. Feathers once grown completely are dead, only the socket is alive. Each feather is moved by individual sets of muscles. Feathers are made of keratin (like your fingernails). Feathers are maintained by preening, often using oil from the preen gland, by bathing in water or dust and sun bathing

Broken feathers are not normally molted out as a means to "repair" the break. The feather will be replaced during the annual molt. (with the exception of a few species that go through a molt midway through their juvenile (first year). If through injury to the feather germ or follicle a new feather developing may be retarded or not produced at all. Nutrition, blood supply quality, stress or fear can also retard feather development. During the molt feathers do not drop out but are pushed out by the incoming new feather. If there are health issues this can be retarded or the new feather lack quality and it will break or fall out after a period of time. Damage through injury to the feather socket can also permanently prevent replacement feather growth.