Category: Ask SIB

One of our Facebook followers asked the question below:

Q: I found a photo of U5 that I took 8 years ago. How long do oystercatchers usually live?

Cindy Moore Johnson

A: We found this on the Cornell Lab of Ornithology website, All About Birds: 

“The oldest American Oystercatcher was at least 23 years, 10 months old. It had been banded as an adult in Virginia in 1989 and was found in Florida in 2012.”

As for U5, he is a popular blog subject for us. Two years ago we wrote:

“Just like the biologists, we can learn a lot from the approximately 60 resights in U5’s registry.  In December 2008, U5 was banded as an adult on Little Saint Simons Island, Georgia. According to SCDNR, he is 15 -16 years old, which is old for an American Oystercatcher!”

We all remember being so excited in 2021 when U5 & mate successfully fledged 2 chicks. Last year, they nested three times but lost their eggs to gulls & crows. Oystercatchers are formidable flyers and adversaries but their defenses can be overwhelmed by the coordinated attacks by groups of those predators especially when they are simultaneously defending their territory from other interloping pairs of oystercatchers. 

We are currently watching 3 pairs of oystercatchers who were on our beach last year as well: U5 & mate, EM & mate & a pair that is not banded. They are all trying to establish nesting territories now but unfortunately they only have half of the suitable habitat that they had last year. The current posted area is only large enough for one pair and the other pairs will be competing for whatever space is remaining. American Oystercatchers, while not officially listed as endangered or threatened, are listed as a species of concern. 

Please give these beautiful shorebirds space to rest, to nest & to eat. That means staying as far away as possible when walking on the beach. The signs are only a suggestion of the space they will need. This especially applies to photographers. Pushing in close to the signs to take a cellphone picture will only add further stress to the birds. They have stress enough now while competing with the other pairs!

If you are interested in becoming a Shorebird Steward, send us an email (SIBStewards@gmail.com) and we’ll schedule personalized training that works for you.

To learn more about American Oystercatchers, below are a few of the blogs we’ve published.

• SIB “Bird of the Week” – American Oystercatcher (August 8, 2022)
• First Glimpses of American Oystercatcher U5 & Family (May 20, 2021)
• Welcome to American Oystercatcher Chicks DY & DZ (July 11, 2021)

– Mark Andrews, Seabrook Island Shorebird Steward Program

Question: Have researched this question to no avail! We have tons of Brown headed Cowbirds this time of year on the feeders and on the ground. Often a male or two puffs himself up, tucks his head in, and naps on the ground under the largest feeder. Seems like a risk with all the birds of prey around. If you approach, they are not startled very easily. Never seen this before and is it normal? Thanks for any input! – Paula Adamson

Answer: This is not a behavior that I am familiar with, but we can always hypothesize. During the winter months, the Brown-headed Cowbird is a social bird hanging around with birds of a feather and other blackbirds. If multiple birds hang around together, every bird does not need to be watchful for predators. There needs to be some paying attention. Those birds sound the alarm and the quick reaction time for a bird would allow them to avoid predators.

If you had said that the birds fluffed themselves out, sat spread tail, and occasionally shook their head, I would have said the bird was anting. This common behavior lets ants roam over the birds body picking off parasites, but it usually does not look like sleeping.

About now, the Brown-headed Cowbird will start to pair up resulting in a whole host of displays, some to entice a mate others to define dominance. A bunch of males will go through an array of display postures which can be lifting their wings as they sing, fanning their tails, spreading their wings and bowing, or puffing up, arching their back and then move into a bow in an effort to entice a female. The male with the most moves will be the lucky one. Watch for some of these behaviors at your feeder.

While many birders revile the cowbird, they are a remarkable species. It is well known that these birds do not build their own nest, but lay their eggs in the nest of other birds who then raise their young. Scientist have documented 144 species that have raise cowbird eggs though they have seen cowbird eggs in the nests of over 220 species. Somehow once the baby is out of the nest, it recognizes that it is not the species of its adoptive parent. It then seeks out other cowbirds to hang out with at our feeders. Since we cannot do anything about their parasitic behavior, while we grumble about their abundance, maybe we should learn to watch and enjoy the uniqueness.

Resources:
The Brown-headed Cowbird: An Abundant Brood Parasite (avibirds.com)
Behavior – Brown-headed Cowbird – Molothrus ater – Birds of the World

– Bob Mercer, SIB’s “Resident Naturalist”

Postscript comment from Paula: Thanks so much for your input. I was mostly concerned that the sleeping cowbirds looked like a perfect target for birds of prey, and I was right. Bob was watching with binoculars the other day and a sleeping Cowbird was scooped up by a red tailed hawk and taken away. Of course, part of normal nature, but the Cowbirds maybe aren’t too smart? Happy bird watching everyone!

Bob’s response: “Predators can most easily take the weak, sick, or aged prey. Your cowbird probably fell into one of those categories. It would explain the odd behavior that you first noticed.”

Question:

This week, while birding on Ocean Winds, my group saw a Wood Stork sitting in a strange position as if their knees were bent in the wrong direction.  Can you explain?

Answer:

One of the lesson’s I enjoyed teaching to the PA Master Naturalist classes was on animal structure. In the world, certain structures exist throughout the animal kingdom. The premise being that the original design has been shaped and altered to meet the needs of animals, including humans. The term is homologous structures. 

The Dictionary of Biology describes the term as: “Homologous structures are organs or skeletal elements of animals and organisms that, by virtue of their similarity, suggest their connection to a common ancestor. These structures do not have to look exactly the same, or have the same function. The most important part, as hinted by their name, is that they are structurally similar.”

To understand this image of the Wood Stork, one must look at your own feet and legs. On your foot, you have toes that bend up and down. Then note the bones of the foot which don’t bend. Next comes the ankle to provide mostly up and down motion, but it cannot bend back as far as it can up. (Go ahead, I give you permission to wiggle your toes and feet.) From there it is more solid bone up to the knee which flexes backward. Finally, more solid bone to the hip. 

Next time you eat a chicken leg and thigh, notice how the joints move. The thigh is homologous to your thigh. The joint connecting the thigh to the chicken leg would be the knee and the meat on the leg would be the calf. Since little meat exists on the foot, it used to be you didn’t get chicken feet as part of your meal unless you are very poor. You can now find gourmet recipes, but I’ll pass. 

Look at this Wood Stork image. Note the toes are what a bird stands on. The foot holds birds up. The ankle in this picture still rests on the ground. The knee hides under the feather. While this position looks uncomfortable to us, it is the natural arrangement of bones in birds.

– Bob Mercer, SIB’s “Resident Naturalist”

Question: There have been a large number of Yellow-rumped Warblers at my feeders this fall and winter. Over the past month I’ve noticed that when they land on a bird feeder or on a tree limb they will flutter and open their wings and flash their yellow rump. I don’t believe that they nest here so I was wondering what might be the reason for this behavior. I don’t remember seeing this behavior in years past. – Joleen Ardaiolo

Answer: The Yellow-rumped Warbler is a remarkably understudied bird particularly when not on breeding territory. Therefore, this response is somewhat speculative. The only reference I can find as to this behavior on the web site Birds of the World reads: “Yellow rump-patch often displayed during foraging and hawking; may be passive display (perhaps territorial); spreads tail as threat (Morse 1989a).” Behavior – Yellow-rumped Warbler – Setophaga coronata – Birds of the World

What we learn from this scant information is the birds perform the behavior you see often—no big surprise there. The purpose is speculated as being a “passive territorial display.” This may indicate that the Yellow-rumped Warblers seen at feeders use the rump patch flash as a mechanism to tell the other nearby Yellow-rumped Warblers to stay away.

While researching this question, I had confirmed what I had heard in the past. The reason the Yellow-rumped Warblers spend the winter in in our area results from their ability to digest waxes and lipids. This enables Yellow-rumped Warblers to survive on a diet of exclusively Bayberry (Myrica pennsylvanica) if necessary. They will also eat Wax Myrtle (M. cerifera), Junipers, Poison Ivy and insects to name just a few of the winter foods. During the breeding season, they eat almost exclusively meats in the form of insects and other arthropods. So, these birds can frequently be seen between the beach and the forest.

While out exploring the environs around Seabrook Island, you may see a number of Yellow-rumped Warblers flitting about, but notice how they do not cluster together like American Goldfinches or Cedar Waxwings. The Yellow-rumped Warbler is not that social, though they do pay attention to their nearby neighbors as to may help them find new food sources. Yet, watch long enough and you will see birds chasing each other away for where they feed. I will now need to pay attention to see if that rump flash accompanies these interactions.

Yellow-rumped Warblers are very “pishable”. I don’t know why…maybe they are just curious.

-Bob Mercer

Question: I’m preparing for a trip to Florida and I’m confused about which birds should be posted in eBird and which should not. Some of the birds that led to my confusion are Monk Parakeet, Nanday Parakeet and Black Swans? Can you give me some guidance? – Judy Morr

Answer: The question above was sent as a text to my eBird experts, Aija Konrad, Bob Mercer and Nancy Brown. Several texts later we decided it merited a blog…possibly only interesting to bird nerds like me.

eBird’s Frequently asked questions starts with: eBird is intended for observations of wild, living birds. Please do not report dead or captive birds (e.g., do not include birds in a zoo exhibit or pheasants on a farm). I knew about living bird idea but some of the other aspects took more study. (Note: Italics below are all quotes from eBird web pages.)

Captive birds – do not include caged or pinioned birds. You may report wild birds you see at outdoor zoos, but birds that are part of a zoo or collection should not be reported. Do not report free-roaming pets, such as birds used in falconry, or birds that return to a pen or cage regularly. I already knew that I shouldn’t report chickens I see or hear in someone’s yard. That white “domestic” duck I saw at Christmas, I didn’t report. The peacock (aka Indian Peafowl) I saw at Magnolia Gardens was considered “captive” and Keith McCullough correctly told me to delete from a list submitted. The Great Blue Herons, American Cardinals, etc. I reported in the same list were valid as they weren’t captive. Similarly, the Indian Peafowl I saw roaming down River Road one day was a valid submission.

Exotic Species – are any species that occurs somewhere as a direct result of transportation by humans. These are further broken down into three subcategories: Naturalized, Provisional and Escapee. All should be reported in eBird but some may not count on some reports. This gets trickier (and some interesting considerations).

Naturalized: this exotic population is self-sustaining, breeding in the wild, persisting for many year and and not maintained through ongoing releases (including vagrants from naturalized populations). These count in official eBird totals and, where applicable, have been accepted by regional bird records committee(s). Examples of this are House Finch, Eurasian Collared Dove and European Starling. They are commonly seen here but still will have a black asterisk when you later look at checklist in eBird. For my trip to Florida, the Monk Parakeet and Nanday Parakeet will fall into this category.

Provisional: Provisional is often used for species that are established (i.e., occurring in substantial numbers in the wild for many years) but have not yet been declared Naturalized by a local ornithological authority. Provisional species count towards your eBird life list and appear in all public outputs, including Alerts. If on my trip to Florida I saw an Indian Peafowl (as someone reported on January 4) that would fall into this category. It appears on eBird with a rust asterisk.

Escapee: This is really the fun one. Escapees are exotic species known or suspected to be escaped or released, including those that have bred but don’t yet fulfill the criteria for Provisional. Escapee exotics do not count in official eBird totals. They are also not included in ABA countable birds for Big Year, etc. There is a whole list of escapees I hope to see in Florida: Graylag Goose, Black Swan, Swan Goose, Black-necked Swan, Red Junglefowl. If found, these will appear on my eBird checklist with a rust background around a white asterisk. Aija knows of a town in Georgia where the Red Junglefowl is ABA countable…so the category the bird falls into is dependent upon geography. Note, this nuance applies to all categories as my Indian Peafowl sited on River Road wasn’t even flagged as Provisional or Naturalized.

If you want to know more about all this, you can find detailed descriptions at: https://support.ebird.org/en/support/solutions/articles/48001218430-exotic-and-introduced-species-in-ebird and
https://www.aba.org/aba-area-introduced-species/

Submitted by: Judy Morr

Question: Yesterday a male pileated woodpecker started working on the opening to one of our owl boxes. We assumed he wanted the opening larger to get in for some bugs. He worked on it for a few hours (till dusk) and then is back this morning and has made the opening larger. He now goes in and out, pecks a little in the box, but is back making the opening larger from the outside. I know this is not their normal nesting season, so wonder what he is doing! Thanks for any input. – Paula Adamson

Answer: I had a similar question a couple years ago when a Pileated Woodpecker was excavating a hole in a dead tree in the conservancy lot across the street in the fall.  I therefore knew the answer but had to find the source of my knowledge.  I’m not sure if it’s the same source, but the answer is the same.  In National Audubon’s BirdNote, the podcast Listen for Woodpeckers Making Their Winter Homes This Fall says: 

It turns out that some woodpecker species stay year round in the region where they nest, while others migrate south in winter. Those that remain through the colder months – well, it’s safe to say they’re not nesting now. No, these fall excavators are chiseling out roosting cavities, snug hollows where they’ll shelter during the cold nights of fall and winter.  

Many woodpeckers roost in such cavities, usually by themselves. Even the young, once they’re fledged, have to find their own winter quarters.

With woodpeckers, once the nights turn cold, it’s every bird for itself.

I found another article Animals in Fall: The Pileated Woodpecker published by Shadow Lake Nature Preserve in the state of Washington.  It states:

Have you ever seen small mounds of wood chips at the base of trees? If you live in the Pacific Northwest, during the fall season that tree is probably the new home of a Pileated Woodpecker! This species of woodpecker is non-migratory, meaning that it does not fly south for the winter. They excavate holes in several different trees that they will nest in throughout the cold winter.

I think it’s safe to say, your Pileated Woodpecker thinks your owl box would make a nice winter home.

– Judy Morr

Question: Tonight on Jenkins Point we can hear four owls stretched in a line from Seabrook Island Road-or thereabouts-to our oak and then on out Jenkins Point with the fourth owl at the very end-I think. All were calling, sometimes solo but sometimes overlapping each other. I assume from their calls they are Great Horned Owls. We hear owls frequently in Spring and Fall, even occasionally in Winter. But never in the summer. Do they migrate or just go inland to deeper woods?
With all the calling back and forth are they looking for mates this time of year or are they just telling each other they are here?
Thanks for enlightening me. – Andy Allen

Answer: What an exciting experience having four owls serenading you. While it is impossible to know exactly what is happening, one can make an educated guess. Owls generally mate for life and a mated pair stays on territory year round. Starting in September, the male owl starts calling as part of his courtship ritual. Owl nest early in January and February to time the heavy growth period for their young to coincide with the fresh production of prey species, i.e. the young and naive. The young hang around through the summer, but come September, just like any good parent, the young get kicked out of the area and need to disburse. This happens most heavily in September. Understanding this, I suspect you encountered a situation where the local owls called to inform the intruders that the territory is full. The intruders called to test the strength and fidelity of the local pair. As you listen, the male sings with a deeper voice than the female. When you hear two mated birds performing a duet, the male and female alternate singing. In a territory dispute, that rigid pattern of male/female may not hold true.

– Bob Mercer, SIB’s “Resident Naturalist”

Question: The gulls seem especially aggressive this year at Pelican’s Nest. Does SIB have any suggestions what Seabrook Island Club can do to ease the situation? – Mitchell Laskowitz, Seabrook Island Club Manager

Earlier this summer, Mitchell Laskowitz reached out to Seabrook Island Birders asking for any humane ideas we had to help with the gulls at Pelican’s Nest. He had already done an internet search and talked to other restaurant managers about possible solutions so he already had an initial action plan defined.

As a Seabrook Island Club member, I had seen the Laughing Gulls swarm over the rocks outside the nest, waiting for a chance for an evening snack. As soon as a patron turned away, the gulls would attack sandwiches, fries or anything else that tempted them.

SIB was unable to provide any new suggestions to Mitchell other than suggest people with food near the pool would need to take steps as well as the ones he proposed for Pelican’s Nest. Obviously, people should also be discouraged from actively feeding the gulls. The steps taken at the Pelican’s Nest include:

• Installed additional wires to deter gulls from entering dining area
• Netting was placed between the Sunrails
• Metal Prongs (similar to icicles on a Christmas tree) were hung below wires
• High Frequency Noise Transmitters that can be heard by gulls but not humans were acquired
• Added fake owls to roof of Pelican’s Nest
• Added signs on each table to educate patrons regarding what they can do to help:
  • Cover your plate with a napkin when finished eating
  • Dispose of garbage properly in lidded bins
  • Do not leave food unattended

My recent visits to Pelican’s Nest has shown fewer aggressive gulls. It could be the season is changing, but I think it also has a lot to do with the steps the Club has taken to humanely address the problem.

Submitted by: Judy Morr

Question: Is this a Northern Cardinal? If so, why does its head look so small and its beak so large? – SIB member Lesley Gore

Answer: This question was also answered in Bird Watcher’s Digest. They say:

Soon after nesting season ends, many birds replace their feathers. Songbirds generally lose and regrow a few feathers at a time, so molt is hardly noticeable.

But some birds, especially northern cardinals and blue jays, can lose all their head feathers at one time—a catastrophic molt. Not all cardinals or blue jays do this, but a significant number do, and it’s considered healthy and normal. A week later, feathers will start to grow, and in a month, the bird’s crest will return and be perfectly normal and regal once again.

“Bald” birds could also be young individuals with head feathers still developing, or they could be the victims of avian feather mites that eat the feathers and cause a bird to “go bald.” The mites exist on a bird in the only place it cannot preen itself—on the head.

This commonly occurs in late summer and has been recorded on other species as well. We notice the bald cardinals more readily because they are common, resident (non-migratory) birds that come to our bird feeders. The mites are perfectly natural, not caused by diet, and relatively harmless, unless the bird is in an otherwise-weakened state.

A bald bird usually isn’t anything to worry about, and it’s kind of fun to see a bird’s naked skin and ear holes, isn’t it?

Question: A friend recently asked if we have heard of reports of dead birds on Seabrook Island Beaches. They have heard reports of at least 9 dead birds on Kiawah recently. Do you know what could be causing this? – Anonymous

Answer: Seabrook Island Birders has not heard of any increase in dead birds on Seabrook Island. I did notice several reports on my daily “Rare Bird Report” I receive from eBirds of rare birds in Charleston County. One recent report had Kiawah Island Biologist (and eBird reviewer) Aaron Given reporting Great Shearwaters on Kiawah. His siting on eBird stated: “Three alive and alert Great Shearwaters found while driving the beach. Picked them up and transported them to the far eastern end of the island. Also picked up 3 dead Great Shearwaters.”

I reached out to Aaron and asked if he had any insight into what was going on. His response: This is a cyclical thing that happens with Great Shearwaters. There was another mortality event since my time here but I can’t remember the exact year – at least 10 years ago. Most of the birds found dead are emaciated. I don’t think we really know the cause of it but it probably has something to do with a historically predictable food source not being available and causing the birds to starve.

Here’s a link to a paper published in 2013 about it: https://seanetters.files.wordpress.com/2015/07/grsh_mortality.pdf. In summary, my interpretation is that the causes of this apparent increase in strandings are unknown but may be due to an increase in reporting effort over the past two decades combined with changing oceanographic conditions in the South Atlantic Ocean, leading to large-scale mortality of emaciated Great Shearwaters along the east coast of the United States.

A later eBird siting by another observer stated: 1 deceased on beach near ocean course; appeared to have been washed up with the tide. 3 others resting on beach at far end, pointed out to us by DNR. One of the three seemed to be doing slightly better than the others but all were alive. My take away from this is that not only is Aaron aware but so is DNR.

Honestly, before seeing these reports, I had never heard of a Great Shearwater. Audubon’s Guide to North American Birds states Great Shearwater is: A common seabird off our Atlantic Coast, seldom coming close to shore except during storms. Since I haven’t been off shore and luckily I haven’t seen the stranding birds, I shouldn’t be surprised they weren’t on my life list of birds seen.

After I wrote this blog, someone forwarded Judy Drew Fairchild’s blog on Great Shearwaters are Unusual Guests on our Beaches. It has more good information.

If you have a question about a bird, submit a question via email to seabrookislandbirders@gmail.com or our Ask SIB web page.

Submitted by: Judy Morr