Blog #339 Feathers

Worn tail feathers of an immature Osprey. 

Feathers are complicated structures vital to the lives of Ospreys. Feathers are some of the lightest yet strongest materials in nature. Flight feathers, critical to the  Osprey’s existence, are extra strong. Feathers can withstand raging winds, rain,  snow, high doses of sunlight, and collisions with tree branches. Feathers are flexible too. If bent, a feather shaft will straighten. 

Much goes into making the complicated interwoven structure of a feather, but they  are not meant to last forever. As we watch the Salt Point nestlings develop, the  wing and tail feathers are growing in quickly and will be complete within a few  weeks. The young bird will keep these over a year, at which point they are  replaced during a process called molting. This first set of feathers are not as strong  as adult feathers as they are thought to cushion blows during the early stages of  flight and fishing.  

When looking at the Salt Point Osprey Nest Cam 2021 footage, you can  differentiate the chicks by their growing barred tail feathers. Rosie’s tail is coming  in the fastest, and the size of the barring is growing. Lilibit’s tail is a much smaller  buff colored bar at the moment. Olan’s tail is somewhere between the two  extremes. Using the tail to determine the relative age of the chicks will hold true for  the next few weeks until their tails are complete. Their wings feathers are also  filling out a great rate. Every day, subtle changes in their feathers can be seen. All  three have a rusty wash on the nape of their necks. Dark contour feathers with buff  colored tips are emerging from their waxy sheaths creating a brindled pattern on  their backs and causing them to frequently preen and scratch. Rose, as judged by 

her plumage, is by far the most mature of the nestlings with the others not far  behind. Lilibit is catching up to the others and beginning to resemble Olan. 

From the "Feather Atlas" FWS Forensics Laboratory. 

During the flying and fishing learning processes, young Ospreys commonly bump  into objects, damaging the feathers. It is thought that the softer feathers of  immature Ospreys cushions the impacts of crashes, tumbles, and minor collisions. 

An Osprey, like other birds, can move each of its feathers independently, using tiny  muscles in the skin. This helps a bird place its wing feathers, for example, into  position to make a turn or slow down. The Ospreys can also raise and lower their n  Feathers are some of the lightest yet strongest materials in nature.  Osprey feathers are either varying shades of brown and white or all white on the  breast and belly. The Osprey’s brown feathers are colored by a pigment called  melanin, which is made within their body. Melanin absorbs certain wavelengths of  light and reflects the rest. Humans see the reflected light as shades of brown. The  white feathers lack all pigment.

Types and identifying numbers of contour feathers in an Osprey, courtesy of  IWRC. 

A variety of feathers cover an Osprey’s body, which all look different and are  modified to serve certain functions. Down feathers are the fluffy feathers that trap  warm air, insulating the bird from cold and heat. The reason why down is so fluffy  is because the feathers lack the barbules needed for a smooth surface. The  contour feathers give the Osprey it’s aerodynamic shape reducing drag while in  flight. Flight feathers are the largest, most substantial, and most impressive of the  contour feathers. They vary widely in shape across the bird's body from the primary and secondary wing feathers to the tail feathers. 

Adult Ospreys replace or molt all their feathers yearly although it takes young birds  a bit longer. The major flight feathers on the wings are the ten primaries, which  grow from the wrist to the wing tip, numbered Primary 1-10 or P1-10 and the ten secondaries (S1-10) starting at the wrist and progressing inwards toward the body.  Between the secondaries and the body is another tract of feathers called the  tertiaries. The primaries come in many sizes and shapes adapted for optimum  aerodynamics of flight. 

The 12 colorful tail feathers called rectrices are numbered starting from the middle  of the tail (Rectrices 1 or R1), and they work out to both the right (R1-R6) and left  (R1-L6) side of the tail. These feathers often get battered as the tail is used for a  rudder and break in the air and underwater. The buff edges on the juvenile feathers  are weaker and more apt to be damaged without impacting the functioning of the  feather and the flight of the bird. 

The chicks are well camouflaged from above; their light stripes resemble the top of  a stick, and their dark sides look like the shaded area. The chicks have learned to  lie low—a defense from aerial predation and all assume this posture as their 

mother sounds a warning call—a harsh Cheerp! 

One of last year’s Salt Point chicks peering out through the nest.  

Eyes to the sky! 

Candace  

Candace E. Cornell  

Friends of Salt Point  

Cayuga Osprey Network 

Lansing, NY  

cec222@gmail.com

From the "Feather Atlas" FWS Forensics Laboratory. 

From the "Feather Atlas" FWS Forensics Laboratory. 

From the "Feather Atlas" FWS Forensics Laboratory.

EYES ON OSPREYS 

WATCH! 

Salt Point Osprey Nest Cam 2021 

READ! 

On Osprey Time—A Blog on the Ospreys of Salt Point 

VISIT! 

Cayuga Lake Osprey Trail 

HELP PROTECT OSPREYS 

• AVOID GETTING TOO CLOSE TO NESTING SITES DURING THE BREEDING SEASON. IF AN ANIMAL  VOCALIZES WHEN YOU'RE NEAR, YOU ARE TOO CLOSE! BACK OFF IMMEDIATELY. 

• CARRY BINOCULARS TO VIEW WILDLIFE FROM AFAR. 

• RESTORE, CLEAN, AND PRESERVE LAKESHORE AND WETLAND HABITAT. • RECYCLE USED FISHING LINE, WHICH CAN BE HAZARDOUS TO OSPREY.  

• JOIN THE CAYUGA OSPREY NETWORK AND VOLUNTEER TO HELP MONITOR OSPREY NESTS. WRITE TO: CEC222@GMAIL.COM.