Blog #348 The Scoop on Osprey Poop

A fledgling jettisoning feces over the side of the nest, courtesy of Andy Morffew. 

What’s the scoop on that fishy white excrement Ospreys jettison while in flight or over  the sides of their nests? We do it, they do it, all animals do it. Every animal excretes  waste products from its body (except for demodex mites, which don't have anuses and  simply store waste in their bodies until they die.) 

Ospreys, like humans, defecate undigested remains from the food they’ve consumed.  Also like humans, Ospreys produce nitrogenous waste as a byproduct of digesting their  food into molecules usable by the body’s cells. Humans excrete excess nitrogen as  urea diluted in water or urine. Birds are more conservative. 

Staying light for flight, Ospreys and other birds do not have heavy bladders like ours. They also need their metabolic water reserves for other things, such as long distance  flights. Ospreys and other birds excrete nitrogen in the undiluted, white pasty form of  

uric acid. (Osprey fetuses excrete uric acid inside eggs and neatly stored until hatching.) The darker parts of the feces include undigested food and waste products and are 

Feces are ejected from the single vent or cloaca. 

simultaneously evacuated with the uric acid from the cloaca (vent under the tail). The  cloacal sphincter muscle provides ejaculatory force, as demonstrated in the photo above. 

Osprey guano has high levels of nutrients like nitrate and ammonium salts and chemical  elements such as phosphorus, calcium, and magnesium. By mass, bird guano is 8–21%  nitrogen; the nitrogen content is about 80% uric acid, 10% protein, 7% ammonia, and  0.5% nitrate. Ospreys improve the habitat around their nests by spreading their  nutritious waste to the nutrient deficient soils along the shoreline. Their rich, fishy, oily  excrement fertilizes and helps build the soil around the Osprey nests. 

Raptors like ospreys and owls eat whole organisms and digest almost everything. Owls  are well-known for regurgitating pellets of hair, bones, claws, and undigested parts of  the small animals they eat after a meal. Ospreys make compact pellets of scales, fins,  and other indigestible bits. Leaving pellets results in little solid waste in their droppings.  The areas around their nests and eating perches get covered with "whitewash"  droppings and the occasional pellets.

Ospreys occasionally bring up pellets consisting of indigestible material such as fish bones and scales, courtesy of Leicestershire and Rutland Wildlife Trust. 

. 

From birth, Osprey hatchlings instinctually defecate over the rim of the nest and seldom  make messes in the nest—but accidents happen. Earlier today, Lilibit missed her target  and covered Rosie’s head in white. Usually it’s Ophelia who is the recipient of such an  unwelcomed gift from a young hatchling, but she is able to take a quick bath. Rosie,  while fledged, is not quite ready to do that. 

Eyes to the sky! 

Candace  

Candace E. Cornell  

Friends of Salt Point  

Cayuga Osprey Network 

Lansing, NY  

cec222@gmail.com 

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 THE BIRD  VOCALIZES, 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.

Comments

Post a Comment

Popular posts from this blog

Blog #430 Is It Legal to Tear Down an Osprey Nest?

Image
  Female Osprey carrying stick to nest, courtesy of University of Montana. Nearly every spring outraged birders tell me about Osprey nests they have seen torn down by NYSEG (New York State Electric and Gas). How can this be legal? Don’t the Migratory Bird Act of 1908 (MBA) and the Migratory Bird Treaty Act of 1918 (MBTA) protect migratory birds, including their nests, eggs, and chicks? The 1908 law and its hundred years of treaties was the foundation of the America’s conservation legacy, that is until Trump came to town. One of his first moves was gutting the MBTA: industry benefited and the environment lost. Much of the MBTA has been reinstated, although there are still serious loopholes favoring industry by permitting "incidental takes" or animals unintentionally captured, live or dead, during industrial operations.  An Osprey nest is considered active if it contains viable eggs and/or chicks. A nest becomes active when the first egg is laid and remains active until fledged
Read more

Blog #397 Halfway Mark: Three Weeks

Image
  On Osprey Time On Osprey Time just moved to blogger.com. Pardon the delay in posting.  Please bookmark! A mother feeding her 3.5-week-old offspring, courtesy of Cynthia Sedlacek.   Three and a half weeks into the nestling period, the three chicks have grown halfway to their adult size with Moana, the eldest, weighing just shy of a pound. Full-grown adult males usually weigh 2 pounds and females can be up to 4.4 pounds. Sleeping through most of the day and all night, the pile of offspring springs to life whenever their father, Orpheus, brings a fish to the nest. When awake, the nestlings waddle around the nest with their enormous feet, defecating over the nest edge, and peering over the rim at the people below. They are starting to use their wings for balance and rock forward on them to get a good stretch. When it’s mealtime, the eager chicks make their way across the nest to get fed by their mother Ursula.   Once their crops (storage organs; see second photo below) are full of food,
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 South, wil
Read more