The Fishers of Harmony Hill
We are very lucky at Harmony Hill to be virtually surrounded by water. Whether it be a creek, a stream, a lake or even a small waterfall, the presence and sound of water is rarely far from us as we walk along the landscape. Water is life and we celebrate it. We strive to keep it as clean as possible, encouraging permaculture practices and limiting the use of chemicals; and we work to keep it as plentiful as we can, conserving it in our everyday lives and land management.
When you have abundant water, especially in the forms of ponds, lakes and rivers, Nature will bring visitors, guests, and residents to the land. And we are extremely happy to see two residents at Harmony Hill that, just a few decades ago, were struggling to survive. Their populations are now stable; but we still work to keep their numbers growing and we still get excited each time we see them on the wing. They are the fishers of Harmony Hill: the Bald Eagle (Haliaeetus leucocephalus) and the Osprey (Pandion haliaetus)!
It isn’t horribly uncommon to look out over a large lake or a flowing river and see these species either perched on a limb or gliding over the water’s surface in search of a fresh fish to catch. This has been far from the case. In the last 40 years, both species have made dramatic and wonderful comebacks from perilously low numbers. The use of chemicals, like the insecticide, DDT (Dichlorodiphenyltrichloroethane), caused populations to plummet to dangerous level. DDT would accumulate in the blood and tissues of birds higher in the food web and it would weaken the structural strength of eggs laid by these species, causing the eggs to collapse and/or break during the laying process and the incubation process.
Species from Peregrine Falcons to Swainson’s Hawks suffered mightily during the legal use of this chemical, from the 1940s until it was outlawed by the USEPA in 1972, with surveys each year showing fewer and fewer of the birds successfully reproducing. Perhaps no other two species suffered as much as the Bald Eagle and the Osprey. They became the “poster children” of the movement to outlaw DDT and, thankfully, have been able to see their number recover since it was removed from the market.
Let’s take a moment and talk about just how bad things got for these two species. In the early to mid-1970s, there were barely 415 breeding pairs of Bald Eagles in the United States! A few years later, in 1981, surveys showed between 7000-8000 nesting pairs of Ospreys in the US. We are EXTREMELY lucky to still have these birds with us and they serve as real success stories in conservation and the environmental movements of the 1960s and 1970s. In fact, the current Bald Eagle population in the United States is somewhere around 316,000 individuals (data courtesy of 2021 USFWS population trends).
Bald Eagles are considered by many to be the very symbol of majesty and strength. This is one of the reasons they were chosen as the national symbol (now the national bird) of the United States. However, for all their strength, and trust us, they are STRONG, they will just as readily steal a meal from another animal or pick a bit of carrion clean. That strength of which we speak? Well, they have a gripping strength in their talons that is equivalent to 6x-8x the gripping strength of a human.
While we’re on the subject of amazing physical abilities, we’ve all heard the term “eagle-eyed”. Why don’t we break down just how amazing the eyes of Bald Eagles really are. They have incredible binocular vision granting them the ability to see faraway objects much closer and in greater detail than we could ever be capable of. Perfect human vision is 20/20, meaning we can see at a distance of 20 feet what should be clearly seen at 20 feet. Well, Bald Eagles are equipped with vision that sits somewhere around what we would consider 20/4 vision. This means eagles see clearly at a distance of 20 feet what we can see perfectly at a distance of 4 feet. To break that down a little more, if a Bald Eagle could comprehend the numbers of a date on a dime, it could do it at the length of a football field!
This absolutely allows them to see prey, like fish just under the surface of the water, from high altitudes and it allows them to spot prey items from a distance that allows them to incorporate the element of surprise. While they are no strangers to thievery from other birds, like Osprey, Bald Eagles are MORE THAN CAPABLE of capturing fish to feed themselves or their offspring. And, unlike they’re distance cousins, the Osprey, Bald Eagles readily enjoy a varied diet and may hunt for reptiles, amphibians, mammals, other birds and carrion.
Bald Eagles are BIG! They sit at over 3 feet tall and have a wingspan of over 6 feet in length. They fly with a very flat overall shape, making them quit easy to identify on the wing. But their plumage varies as they age, giving several different looks until they acquire that distinctive white head and white tail. Depending upon the health, location and genetics of the bird, it takes AT LEAST 4 years for a Bald Eagle to reach that mature plumage. More often than not, it takes 5 years for most birds to molt into the definitive adult plumage. We will dedicate a future post to the molting process seen in Bald Eagles and how to identify how old they are by that plumage.
That really long and seemingly difficult-to-pronounce scientific name is just as descriptive as the often-misinterpreted common name. Let’s clarify both of them now! The genus name of Haliaeetus comes from the Ancient Greek word for Sea Eagle and the genus name of leucocephalus is derived from two Latin words meaning White Head. Forms of “Leuko” are used in words referencing things relating to “white”, as in leukemia and leucism. And “cephalus” is still used to refer to things rlating to “head”, as in hydrocephalus.
The common name of Bald Eagle is not at all relating to being hairless. Instead, the Old English word “balde” meant white. It wasn’t until the word “bald” branched from that word that any meaning of not having hair was brought into the lexicon. I guess the more correct name should’ve been Balde Eagle.
Onto the next fisher of Harmony Hill. This more skilled angler is often mistaken for a Bald Eagle; but, is quite a bit smaller. Ospreys come in at a height of about 2 feet tall and fly on wings that are usually 5 ½ feet wide. They also usually fly with their wings kinked in a shallow “W” shape, unlike the very flat flight shape of the Bald Eagle.
Ospreys are also designed to be more of a fishing specialist. In fact, their diets are almost exclusively fish; with any variation at all occurring when there is a sudden reduction in the availability of fish to capture. They’ve been documented taking frogs, snakes, small mammals and small birds; but, these items are a VERY small percentage of their overall documented diet. In fact, naturalists and biologists refer to these other prey items as “Rare and highly irregular”. Ospreys were built to catch fish, to the point that the bottoms of their feet are covered with rough, barb-shaped projections to dig into and hold onto slippery fish.
Ospreys may look like hawks and eagles, even being called “fish hawk” over much of its range of every continent, except Antarctica. They are; however, separated from both families of birds of prey and represent their own, distinct family of birds.
Having far more white on their bodies, they don’t really look a lot like eagles when you take a good look. Be sure to pay attention to this post’s photos and you’ll see the striking and noticeable difference in shape and plumage between the two species.
The scientific name of (Pandion haliaetus) has a great similarity to that of the Bald Eagle. Continuing what we discussed in the post on Coral Honeysuckle, we see some Latin names used in different ways for various species. This is yet another case in which a characteristic is similar enough between species that a word is used in some capacity for each. This time, we see the forms of “haliaetus” being used in both the scientific name for Osprey and for Bald Eagle.
Just as before, the Osprey species name of “haliaetus” means “Sea Eagle”. So much so that the logo for the NFL team, Seattle Seahawks, is an artistic version of an Osprey’s head.
The genus name of “Pandion” has us looking back at Greek mythology, where we find the Athenian king of Pandion getting a nod. Pandion had two daughters, Procne and Philomela, who were transformed into birds. The two daughters have complicated backstories; but, were transformed into a Swallow and a Nightingale, respectively. (Very briefly, Philomena suffered a brutal death; but, was brought back as a Nightingale, to sing a mournful lamentation for all to hear and know of her sorrow.)
The common name of “Osprey” goes back to an Old French word, “ospreit”. “Ospreit” appears to originate from a degraded form of the Latin term "avis praedae", which translates to bird of prey (bird that uses a predation technique) and was used to describe just about any hawk, eagle or other bird of prey.
Our happiness in the return of these birds comes with each sighting we have at Harmony Hill. We also know that there is no separation in nature and that conservation is a holistic goal. The protection of these birds doesn’t simply start and end with DDT being outlawed. No, it extends much farther than that. We know that Bald Eagles in our area overwhelmingly prefer to nest in tall, large pine trees and we protect old trees all over Harmony Hill. Research shows that roughly 75% of Bald Eagles in much of the southeast will nest in pine trees that are tall enough and have substantial limb structure to hold the large nest of this species, and which provide them a good view of their surroundings (data provided by 2006 Florida Fish and Wildlife Commission surveys).
Ospreys aren’t quite as closely tied to old, large pine trees; but, we know that, in conserving old, large trees at Harmony Hill, we are supporting potential nesting sites for Ospreys, as well.
Next time you see one of these beautiful birds in nature, take a moment to appreciate their presence and to celebrate their return to the landscape. And, take a moment to remember you are part of the landscape and your actions ripple out. There is no separation in nature.