An osprey plucks an alewife from the waters of the Sebasticook River in Benton as the alewives make their annual run up river. Morning Sentinel photo by Michael G. Seamans
I live on the Back Cove (in Portland). Last week for the third time in less than two weeks I saw an osprey fly inland literally overhead with a fish in its talons. I was surprised an osprey was flying inland. Do you know of one inland around here? Thanks for any information.
– Pam Cleghorn, Portland
How lucky we are to have osprey around, and in such large numbers. Though the population hasn’t been formally surveyed in Maine, we know there were steep declines in the 1960s, when the adverse effects of DDT (an insecticide used to control mosquitoes and other pests, which caused thinning of eggshells in some bird species) was most noticeable. Many species have rebounded since the post-DDT era and we now have hundreds of nesting pairs of osprey in Maine. Interestingly, as the bald eagle population is also making a remarkable comeback, eagles are starting to outcompete our osprey and causing their numbers to drop again.
We typically think of osprey as being associated with the coast, likely because of their fish-based diet. Similar to loons, though, they will move inland to larger ponds and lakes, where food is plentiful for the summer nesting season. Perhaps the easiest reference point for Mainers is to look at the utility poles along Interstate 95 (passengers only, drivers keep your eyes on the road) on a drive from Portland to Bangor. You’ll see nearly a dozen inland nests of osprey, and in late summer, you may even see the heads of a chick or two peeking out
While fish make up 99 percent of an osprey’s diet, these predators can and will capture other prey items – I’ve heard from too many lifelong Mainers that “saw the unseeable” to not mention this. They’ve been reported to capture everything from rodents to snakes, and there is a remarkable account of one, in Maine, attempting to take a muskrat. So, it is possible for them to feed on other things, though they have evolved specialized fishing tools that outperform even the saltiest Maine fishermen.
For a fun visualization of osprey distribution, you can see preliminary results of the Maine Bird Atlas, a project by the Maine Department of Inland Fisheries and Wildlife documenting breeding distributions of birds in Maine. Look for osprey nesting sites here: ebird.org/atlasme/map/osprey. The takeaway is that osprey nest all over the state, along the coast and inland, with confirmed records coming from every county!
Color variation can made bird identification a challenge
Is this a variant cardinal? If so, what makes it this color and is it a rare bird to see in Maine? This bird was spotted at my neighbor’s bird feeder.
– Joan McBurnie, Denmark
Late summer can be a challenging time to identify birds because a lot of them look, well, strange. Depending on the bird, they can look “off” because of the age of the feathers, being either very old or very fresh. Sometimes we don’t even recognize birds that aren’t in their summer plumage anymore, and on top of all that, we even see the occasional anomalies that can change colors.
A change in color for a cardinal, or any other bird, could be because the feathers are older and ready to molt, or other genetic anomalies. Submitted photo
Let’s start with the age of feathers. An important thing to know is that birds will molt (replace) their feathers at least once per year, for a variety of reasons. Some birds molt twice: once in the spring to grow their breeding feathers or “alternate plumage,” and then again in the fall for the nonbreeding or “basic plumage.” Using this northern cardinal as an example, they molt once a year, in the fall. As you can imagine, these feathers, that are now nearly a year old, have taken a beating. They’ve been rubbed against branches and exposed to a lot of sunlight, which can even bleach them out. This is exactly what I think is happening to the cardinal on your neighbor’s feeder.
The other side of the “age of the feathers” coin is how they look when they are newly grown in. These fresh feathers can even look different on the same species, whether it is a juvenile or an adult growing them in. One of the more prominent features of fresh feathers is a pale edge on the tips, which can give birds a very scalloped appearance. These new features will also, generally, be brighter or more contrasting than the worn feathers they are replacing. Many of these changes in appearance depend on the species and the time of year, with very few being the same, so use this as a guide, not the rule. Revisiting our northern cardinal, their red color comes from carotenoid pigments, and their vividness typically depends on the intake of those pigments when they are molting. This all makes sense when we see bright red cardinals standing out against the snowy backdrops in the winter.
The final thing I should mention is the genetic anomalies that can cause all sorts of interesting plumages in birds. Perhaps the most reported example of this is leucism, which you can think of as being partially albino. True albinism, the complete lack of any pigment production, is quite rare in nature, but birds are often seen and photographed with small white patches where a group of feathers often lacks melanin production. Much like the rare “blue lobsters” that are caught in Maine, we see the occasional bird equivalent.
In cardinals, there was the Internet sensation “Yellow Cardinal” of 2018 in Alabama, a yellow cardinal with a black mask. The abundance of yellow pigments is a phenomenon known as xanthochroism, which has been documented in Maine in evening grosbeaks. One other appearance to be on the lookout for, and your final multisyllabic tongue-twister in this column, is the gynandromorph, which often appears as bilaterally half male and half female. This will only be apparent in sexually dimorphic species, but is sure to make local news stations go crazy every time it happens.
Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about virtual and backyard birding, online classes, and other programs about Maine wildlife and habitat.
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