Blog # 278 What it is like to be a nestling Osprey?

 I would imagine that for Salt Point nestlings Hope and Lucky must melt into night in a  continuum of eating, sleeping, and lazing in the shade of their mother, Ophelia. When  hunger gnaws at their stomachs, they beg for fish from their father, Orpheus, and when  the urge strikes, they squirt a fluid, fishy feces for least a yard over the rim of the nest.  (Watch out below!) When danger is near one squeal from Ophelia and the camouflaged  nestmates flatten in stillness. 

Just after dawn, Hope 26 days old, showing its growing wing  

and body feathers. Salt Point Osprey Cam screenshot.

Orpheus (L) bringing a small fish in the early morning. He will bring several in the next hour to feed the  entire family. Salt Point Osprey Cam screenshot.

Compare the size and feather growth of Lucky (L, 23 days old) and  

Hope (R, 26 days old) as they are fed by Ophelia. Salt Point Osprey Cam screenshot. 

It takes a great deal of energy to make feathers, which only grow a few millimeters a day, and are very itchy as they emerge, This triggers the youngsters to preen. Preening  also works on pesky insect bites. Stretching and moving about help fast-growing bones  and muscles. Much of their time, however, is spent resting and sleeping in the shade  created by Ophelia as their bodies digest fish, develop, and grow at an astounding rate.  Hope and Lucky are in the rapid growth phase of Osprey development.

At 26 days old, Hope is just entering the steepest part of this exponential growth curve. This "sigmoidal” or S-shaped growth curve is typical of many young raptors on the  pursuit for independence. Lucky is just three days behind. 

The exponential sigmoidal growth curve of Osprey nestlings, showing the 

phase where Hope and Lucky are today, courtesy of Dyfi Scotland. 

When not begging for fish or yawning, the nestlings open their mouths to pant. Birds’ bodies operate at high temperatures: Ospreys are 104 °F. The young are well insulated  with feathers, so how do they stay cool when not under Ophelia’s wings? 

This curious nestling’s dark plumage on top helps to insulate it, courtesy of Andy Morffew. 

To begin, their dark plumage can actually be cooler than light colors. The nest also insulates the young from getting too warm or too cold. The nestlings also can reduce  their feathers’ insulation by compressing the air out between their feathers. The young  also expose their less feathered body parts such as their upper legs and underwing.  Most importantly, they pant.  

An 9-week old Osprey fledgling panting in the heat, courtesy of Andy Morffew. 

By opening their bills wide, expanding their throat to expose lots of moist skin, and  tripling their breathing rate, high evaporation rates cool the surfaces of their throats and  air sacs. All Ospreys must replenish any water evaporated during panting by eating fish. 

Not all is tranquil at the nest these days. The skies are always filled with avian predators  such as Bald Eagles, crows, and Great Horned owls that threaten to steal the nestlings.  Intruding Ospreys, looking to take over nests and partners, are still pestering  established pairs. Just as Orpheus was about to fish, he was called into guard duty to  defend the nest against an unseen enemy overhead.

Orpheus arrives to defend the family. Salt Point Osprey Cam screenshot.

Orpheus helps defend the nest with fluttering and calls. Salt Point Osprey Cam screenshot.

Orpheus gives wing alarm displays and alarm calls to rebuke overhead threat.  

Salt Point Osprey Cam screenshot.

Orpheus takes off to chase the threat away. Salt Point Osprey Cam screenshot. 

Eyes to the sky! 

Candace 

Candace E. Cornell  

Friends of Salt Point, Lansing, NY 

cec222@gmail.com

Read!  

On Osprey Time (blog) 

Ospreys of Salt Point 

  

Explore! 

Cayuga Lake Osprey Trail    

Watch!  

Salt Point Osprey Nest Cam

Comments

Post a Comment

Popular posts from this blog

Blog #481 Sunshine at Last!

Image
  Last week’s 2 week old chicks. Now they look completely different, courtesy of Facebook. Meteorologists report this is the 6 th  day of sun in all of May with more rain in the forecast. This is good for the plants but potentially damaging to the Ospreys. Foul weather rots eggs and makes hunting difficult to impossible at a time when the hatchlings are most vulnerable to the starvation, cold, and predation. Despite the challenges of fishing in windy, rainy conditions, Orpheus succeeded in keeping the family fed by catching small, nearshore fish and making up for deficiencies with large trout whenever there was a break in the weather. A foggy morning feeding the 2 ½ week-old chicks, Salt Point Osprey Nest Cam. The 3 week-old chicks in their reptilian phase, courtesy of YouTube. Oakley, the eldest chick, just turned two-weeks old and is passing into the Reptilian Phase,  where the now darker, scaly chicks. In this transitional phase Oakley’s buff down is quickly replaced w...
Read more

Blog #482 Where Ospreys are Starving

Image
Male Osprey landing a beauty, enough to feed the entire family trout, courtesy of Patrick Marshall. Ospreys of the Cayuga Lake Osprey colony, live in the stunning heart of New York’s Finger Lakes of a terrific about centered on Cayuga Lake may lull us into complacent thinking that all is well in their world. Life for Ospreys near Cayuga is certainly good for our in this inland colony with lots to eat and seeming endless nesting possibilities, but an ecological tragedy is in the making not far away. Osprey chicks are starving and whole colonies collapsing in the Chesapeake Bay region, home of the world’s highest concentration of breeding Ospreys (until recently estimated at 10,000 breeding pairs). The tragedy is caused by a sharp decline of their dietary staple, menhaden, called “the most important fish in the sea” by author H. Bruce Franklin. Ospreys, striped bass, bluefish, weakfish, whales, and a myriad of other coastal and marine species dependent on menhaden for food are all declin...
Read more

Blog #461 Sneak Peek at Osprey Season 2024

Image
  Orpheus (L) and Ursula at their Salt Point Nest March 26, courtesy of Cindy Sedlacek. The following is a sneak peek at what this Osprey summer will entail. Our northeastern Ospreys return to their breeding habitats just after the early spring thaw. This year’s first Osprey was seen in Cayuga Lake Basin on March 15, an early date many attribute to  the mild winter. Most nest occupants will have returned to their nests and reunited with their mates by this weekend. These returning Ospreys have just completed their 2,000–4,000-mile migrations from their wintering areas along the coasts of South America and in the wild Amazonian tropics. The range of landscapes that a cosmopolitan Osprey can experience in its lifetime is staggering. In general, the older breeding males arrive on their nests followed by their mates in a few days. After that first wave of older Ospreys arrive, unmated adults and second-year birds migrating north for the first time after spending two years in the S...
Read more