Pair of Red-Tailed Hawks (pics!) (1 Viewer)

[jgheels2003]

I see these guys all the time and its the first time I've ever been able to sneak a few pics of them together. Enjoy!

 

[ceasar]

Nice pictures! Is there any way to determine whether they are Male and Female or both of the same sex? The books I have don't have anything to say on this. Apparently there is no difference except for size.
Bob

 

[jgheels2003]

Nice pictures! Is there any way to determine whether they are Male and Female or both of the same sex? The books I have don't have anything to say on this. Apparently there is no difference except for size.
Bob

Great question. I know the females are a good bit larger and those two look similar in size. I have seen them hanging around the same areas a while so I guess they are still pretty young.

 

[tburke]

Great question. I know the females are a good bit larger and those two look similar in size. I have seen them hanging around the same areas a while so I guess they are still pretty young.

I believe the bird on right is the male (slimmer build and smaller head).
Redtails don't normally mature sexually until about three years of age.
Also iris color changes gradually from yellow to brown between second and fourth year.
If I see brown eyes generally I assume bird is at least three years old.
We know these birds are at least approaching their second birthday because the 2006 hatch year is still wearing juvenile plumage.

 

[jgheels2003]

I believe the bird on right is the male (slimmer build and smaller head).
Redtails don't normally mature sexually until about three years of age.
Also iris color changes gradually from yellow to brown between second and fourth year.
If I see brown eyes generally I assume bird is at least three years old.
We know these birds are at least approaching their second birthday because the 2006 hatch year is still wearing juvenile plumage.

I agree. After looking at the pics more today, even with the hawk on the right perching higher (throws off the size comparison for me at first) you can tell it is smaller.

Good catch!

 

[talon_dfa]

Size diff between sexes in Red-tails can be variable.
It is safer to sex by size for paired birds.

Sexing of Red-tails based on measurements is not 95% reliable, so not accepted by BBL.

Look for a subtle difference in the shape of the head (and bill).
(Male - more rounded - falcon-like)
(Female - more elongated - eagle-like)

Also look for a subtle difference in the shape of wing.

On the wing, the female should have a longer wing, but it may look shorter proportionally because the wing has more depth.

Middle Secondaries are longer for females giving a "broad-wing look. Wings of males will appear long and narrow.

I can't tell much from these photos, but both birds are adult (Red-tails and at least one bird has dark eyes.

I would look for nest nearby.

There has been much study on measurements to sex Red-tails (wing chord, sub-terminal band, foot volume, hallux length, foot spread, head length, bill depth, head width, tarsus width & length, etc).

Red-tails are so variable, no set of measurements work for all sub-species in all areas.

I have personally seen red-tails that ranged from 750 grams (small male - not starving) to 1600 grams (big momma). It is the birds in the 1000-1200 gram range that are hard to separate.

 

[jgheels2003]

Size diff between sexes in Red-tails can be variable.
It is safer to sex by size for paired birds.

Sexing of Red-tails based on measurements is not 95% reliable, so not accepted by BBL.

Look for a subtle difference in the shape of the head (and bill).
(Male - more rounded - falcon-like)
(Female - more elongated - eagle-like)

Also look for a subtle difference in the shape of wing.

On the wing, the female should have a longer wing, but it may look shorter proportionally because the wing has more depth.

Middle Secondaries are longer for females giving a "broad-wing look. Wings of males will appear long and narrow.

I can't tell much from these photos, but both birds are adult (Red-tails and at least one bird has dark eyes.

I would look for nest nearby.

There has been much study on measurements to sex Red-tails (wing chord, sub-terminal band, foot volume, hallux length, foot spread, head length, bill depth, head width, tarsus width & length, etc).

Red-tails are so variable, no set of measurements work for all sub-species in all areas.

I have personally seen red-tails that ranged from 750 grams (small male - not starving) to 1600 grams (big momma). It is the birds in the 1000-1200 gram range that are hard to separate.

Thats great info, and definately gives me more to think about when watching these birds. I've seen two different pairs together on the same day in areas on opposite sides of my trip to work so I'll go back and check previous pics of the individuals from those two areas to see if I can apply some of the info you metioned to them.

 

[ceasar]

After a close examination of their postures I agree that the bird on the right is smaller than the other one and they are both clearly adults. There is a good chance they are paired male and female. IF (big if!) this is so and since you see them so often, I would bet that they are nesting some where not far from where you see them.
Cordially,
Bob

 

[talon_dfa]

...There is a good chance they are paired male and female. IF (big if!) this is so and since you see them so often, I would bet that they are nesting some where not far from where you see them...

Birds in NC around March 1st?
I'll bet they are not just whistlin' Dixie!

 

[jgheels2003]

Here are another couple pics from probably the same hawk(s) in the same area (within 100 yards or so) last week.

 

[tburke]

Size diff between sexes in Red-tails can be variable.
It is safer to sex by size for paired birds.

Sexing of Red-tails based on measurements is not 95% reliable, so not accepted by BBL.

Look for a subtle difference in the shape of the head (and bill).
(Male - more rounded - falcon-like)
(Female - more elongated - eagle-like)

Also look for a subtle difference in the shape of wing.

On the wing, the female should have a longer wing, but it may look shorter proportionally because the wing has more depth.

Middle Secondaries are longer for females giving a "broad-wing look. Wings of males will appear long and narrow.

I can't tell much from these photos, but both birds are adult (Red-tails and at least one bird has dark eyes.

I would look for nest nearby.

There has been much study on measurements to sex Red-tails (wing chord, sub-terminal band, foot volume, hallux length, foot spread, head length, bill depth, head width, tarsus width & length, etc).

Red-tails are so variable, no set of measurements work for all sub-species in all areas.

I have personally seen red-tails that ranged from 750 grams (small male - not starving) to 1600 grams (big momma). It is the birds in the 1000-1200 gram range that are hard to separate.

I only made the call based on the assumption we had a mated pair.
Seperate the two and I wouldn't hazard a guess.I've seen quite a bit of overlap between large males and small females generally just over the 1000 gram threshhold.
It should be noted that at this time of year redtails become so territorial that its probably less likely to see same sex pair of adults within sight of one another on a nesting territory.

 

[ceasar]

Birds in NC around March 1st?
I'll bet they are not just whistlin' Dixie!

RTH's often winter over. There is at least one in my area which I see on an irregular basis and also a Sharpshin (or maybe a male Cooper's, I haven't had a good look--the tail looks like a Sharpy's) that's been hanging around for a few weeks.

T Burke makes a good point on their territorial aggressivness.
Bob

 

[talon_dfa]

I only made the call based on the assumption we had a mated pair.
Seperate the two and I wouldn't hazard a guess.I've seen quite a bit of overlap between large males and small females generally just over the 1000 gram threshhold.
It should be noted that at this time of year redtails become so territorial that its probably less likely to see same sex pair of adults within sight of one another on a nesting territory.

My assumptions also...