HART BEAT: SNAIL INVASION

Snail Kites (female pictured) will carry an Apple Snail to a post for feeding.

Snail Kites (female pictured) will carry an Apple Snail to a post for feeding.

Snail Kites and Limpkins until quite recently were almost impossible to find. In the 1970s and 1980s when I led field trips to Florida, I would contact local Florida birding experts during trip planning (in those antediluvian pre-computer, internet or cell phone days all calls were by expensive land-line dial phones only). None could give me specific location information, but would only offer very general possible spots where we might search for them.

On the first couple of group trips I brought from Pennsylvania to Florida we were unsuccessful in finding either species, but with much more determined effort and finally more specific information on the last such trip I led in 1988 we found one very distant, edge of telescope range, male Snail Kite on the Tamiami Trail at the northern boundary of Everglades National Park, and after much diligent searching, a very skittish pair of Limpkin in John Prince Park in Lake Worth. It’s amazing how different the two species’ situations are today.   

While neither species may now be considered common, they certainly are not as rare as they were forty to fifty years ago. Snail Kites are still on the Federal Endangered Species List, and Limpkins, while not federally list as Endangered, are still protected by the Florida Endangered and Threatened Species Rule. A thorough survey in 1985 found only 407 Snail Kites in all of Florida, but the most recent estimate is now in the neighborhood of 2,000. And Limpkins are now much more easily found, with occasional appearances around the small lakes right in our Fort Pierce condo complex and their loud calls from a mile away in the Savannas County Park ringing daily in the late winter early spring as they prepare for nesting.

So what has made the difference? We have had an invasion of large exotic Apple Snails. First of all, please understand that Snail Kites feed exclusively on Apple Snails, and Limpkins, while also feeding on other mollusks, prefer Apple Snails for their primary diet. Snail Kites will find an Apple Snail and carry it to a post (photo 1 and top of page) where it will hold down the snail with its talons and use its hooked beak to cut the tender snail body from its shell, (photo 2) let the shell fall to the ground and proceed to eat the meat. (photo 3)

On a recent St Lucie Audubon Society field trip to Lakeside Ranch STA just east of Lake Okeechobee where we observed and photographed numerous Snail Kites, we were able to observe an obvious favorite Snail Kite eating spot. (photo 4) Florida Apple Snails are smaller, approximately two to three inches in size, while the invaders from South America grow up to five inches. Both examples appear to be in the pile at the base of the pole in the photo. Florida Apple Snail egg masses may contain 20 to 80 pea-sized eggs, while the invader’s masses can be several inches long and contain up to 2.000 very small pink eggs. (photo 5 from Platt’s Creek Preserve in Fort Pierce)

Curiously, Snail Kite bills have evolved into larger hooks in just the past few years to make it easier for them to dine on the larger invasive Apple Snails. Limpkin’s bills, on the other hand, do not have the convenient hook, so they have to hold the snail with the upper beak while digging out the snail meat with the lower beak. (photo 6) However, Limpkins will also eat clams as well, as this mother feeding her young just behind our Fort Pierce condo demonstrates. (photo 7)

Finally, I remind you that Snail Kites are dimorphic, in that females (photos 1 – 3) are brown while males are charcoal gray, (photo 8) but both sexes sport the diagnostic white rump patch. (photo 9) With the snail invasion both Snail Kites and Limpkins can now be found in various locations throughout southern Florida: several sites in western St Lucie County; Savannas County Park; Joe Overstreet Road; Lakeside Ranch STA; and of course, in the Everglades.

One might ask, “If we have so many large snails, why don’t we harvest them for escargot?” I simply ask, “How many of you, Dear Readers, have EVER eaten escargot?” While I know they are a French delicacy, they simply have not caught on here in America. But there is an even better reason: these Apple Snails, both the native Florida variety and the South American invaders are water snails, while the French escargot snails are land snails, thus completely different creatures. (Surprise: Apple Snails are indeed edible. https://www.applesnail.net/content/various/eating_snails.htm.)

In any event, we should leave the snails to the Snail Kites and Limpkins and worry about all the other invaders that have a more direct impact on our lives, like Covid viruses. Now if we could only find a bird or ANY other kind of creature that would like to dine on the Covid virus we would really have something. At least then we wouldn’t have to use Lysol.

References: Apple Snail invasion with photos of the different size snail egg masses, Florida vs. exotic: https://myfwc.com/research/freshwater/species-assessments/mollusks/apple-snails/

Snail Kites on the Endangered Species list: https://fl.audubon.org/birds/everglade-snail-kite#:~:text=Today%20the%20Everglade%20Snail%20Kite,government%20as%20an%20endangered%20species.

407 Snail Kites found after the drought in 1985, but now estimated to be over 2000. https://www.encyclopedia.com/environment/science-magazines/florida-snail-kite

Limpkins protected on Florida’s Endangered and Threatened Species Rule: https://myfwc.com/wildlifehabitats/profiles/birds/waterbirds/limpkin

For more on the Snail Kite bill size evolving, see: https://www.nytimes.com/2017/11/28/science/birds-beaks-evolution-snails.html#:~:text=But%20the%20number%20of%20snail,to%20handle%20the%20bulkier%20snails.

Earlier Hart Beat column on Snail Kites: “The Other Kites” at page 85 of the book.

HART BEAT: FLORIDA OWLS

Burrowing Owl (1)

Burrowing Owl (1)

The request came by phone: “I would like to have one of your Owl photos to display.” The caller, our non-birder but avid art collector brother, went on to explain that he had a wall where he displayed a number of owl paintings, sketches and drawings and wanted one of my owl photos to add to the collection. While I was quite honored by the request, I had no idea what he was actually looking for. He gave me size parameters for printing and said I should just pick out a favorite owl photo and send it to him.

I sent him email copies of all of the owls depicted here, as well as several northern owls that very rarely, if ever, are seen in Florida. He punted the ball back to me and suggested I just print up what I considered to be my favorite and send it to him. I printed four from this collection and forwarded them to him. I now leave it to you to decide which four I picked and I hope you will let me know your choices. My brother has informed me that he has not been able to decide, but will definitely add one to the Owl Wall Art Collection and hang another one in another room. I remain curious to find out which ones he chooses.

Florida has five regularly occurring species of owls.  Arguably the cutest, most interesting and smallest of the bunch is the Burrowing Owl (photo 1 at the top of the page and photo 2). While I do not know of any current locations for them in St Lucie County, they were present here back in the 1990’s when I first started coming to Fort Pierce. Birding friends have told me they have been seen more recently at a location in Port St Lucie.

Burrowing Owls are ground nesters, quite active in the daytime and can be found at Brian Piccolo Park in Hollywood, Florida, Lakeside STA on SLAS field trips, and are quite easy to find in Cape Coral on the west coast of Florida, where they nest in some resident’s lawns. Those residents fortunate enough to have them are very protective of them and even provide little perches for them near their nesting burrows.

Another Florida owl that is active in the daytime is the Barred Owl. (photo 3) A common resident of swamps and wetlands, their call of “Who cooks for you, who cooks for you all” drawing out the “all” at the end, can be heard even if the caller can’t be found. We have found them in Savannas County Park, in the swamp at Gordy Road Preserve, Bluefield Ranch and have heard them at other locations in St Lucie County as well as on SLAS field trips. Cavity nesters, we have seen Barred Owls in their nest holes in Bombay Hook NWR in Delaware in past years.

Probably the most common of the Florida Owls, as well as up north, is the Eastern Screech Owl. (photos 4 and 5) While they are harder to find because they are not active during daylight hours, when we do night-time owling on Christmas Bird Counts, virtually every patch of woods will yield one or more Eastern Screech Owls, responding to recordings of their own whinny call. Cavity nesters, the parents will remain close to the nest hole when they have young in the nest. The pair in photo 4 was seen on an SLAS field trip to Green Cay in Boynton Beach, where the park staff had erected a barrier to protect the owls from observers, some of whom were thoughtlessly harassing them in an effort to get them to move to more open locations for better viewing. Eastern Screech Owls come in three flavors, gray, brown and red, and young in a brood can be color mixed and matched from the same pair. The pair in photo 4 is one gray and one brown. The red phase Eastern Screech Owl in photo 5 is in the elongated, ears up threat posture to make it appear larger than it really is in its effort to scare us off.

The largest of the Florida owls is the Great Horned Owl (photos 6 and 7). While most active at night, Great Horned Owls can also be found at dawn and dusk and their hooted calls can be heard at that time, particularly in the late fall, early winter time frame when they are getting ready for nesting. Great Horned Owls are famous for taking over some hawk’s nest rather than building their own. Photo 6 was taken in the evening right behind our condo unit in Fort Pierce several years ago, and photo 7 was taken in the early morning in western St Lucie County when this parent was staying close to its young chick which was nearby. I also have photos of the chick, but did not think my art collector brother would want one of those as they are not particularly attractive and certainly don’t qualify as cute.

The fifth and hardest to find of Florida’s owls is the Barn Owl. (photos 8 and 9) Barn Owls are becoming quite scarce. When I first began birding in the late 1940’s I could go to at least five different locations in our small hometown in Pennsylvania where one could find Barn Owls. Today active birders in my Pennsylvania home county, Bucks, approximately the geographical size of Indian River, St Lucie and Martin counties combined, tell me they do not know of a single location where Barn Owls can be found. It is very distressing to say the least.

The bird depicted here was found a number of years ago in a barn in western St Lucie County and is the only one I have ever seen in Florida. Photo 8 shows its brownish back, while photo 9, getting ready to fly, shows its all white under-side. Barn Owls are also cavity nesters and out west, where they are more common, property owners will put up nesting boxes for them, particularly in vineyards where the Barn Owls serve as rodent control.

Everyone knows that owls are famous for being “wise.” I’m not sure where that reputation came from but I still remember a psychiatrist that I sometimes worked with once referring to a patient as “crazy as a hoot-owl.” So take your pick: “wise” or “crazy.”  Maybe it’s in the eyes: they can look wise with the big round “smart glasses” look; or they can look “bug-eyed” suggesting a crazy person.

Either way, owls take a little more effort to see than most other species. But finding them can be quite rewarding and satisfying. Maybe it’s because birders often stumble upon them unexpectedly. Kind of like finding a rare seashell while walking on a beach. Or some left over ice cream in the back of the freezer that you forgot was there. Hopefully, chocolate.

For more on the Owls of Florida, see: http://www.nbbd.com/godo/ef/OwlsOfFlorida.pdf. 

HART BEAT: LESSER BLACK-BACKED GULLS

Many birders avoid trying to identify all the different gulls they see in large flocks on beaches and around shopping center parking lots. After all, they do seem to come in all different shades of mottled gray, black, and brown, don’t they? Then again, there are birders who take a special interest in gulls and pride themselves on being able to identify as to species and age each individual bird they see. Lesser Black-backed Gulls are a relatively recent addition to our gull birding scene, and it might be well to evaluate them as we prepare for a socially distanced winter that might take us birding to the beaches.

My birding brother, Bob, (see reference below) sent me an article about Lesser Black-backed Gulls concentrating in the winter at Lake Nockamixon State Park in Pennsylvania, where they were banded to learn where and how far they traveled during their migrations and winter wanderings. Lesser Black-backed Gulls are found in the winter at Lake Nockamixon, and concentrate almost exclusively there and at nearby Peace Valley and Green Lane Reservoirs in Pennsylvania and Round Valley and Spruce Run Reservoirs in New Jersey.

Our farm in Pennsylvania is just over a mile from the western end of Lake Nockamixon, five miles from Peace Valley, and 15 miles from Green Lane Reservoir. Both Nockamixon and Green Lane are in the Upper Bucks Christmas Bird Count circle that I compiled for over 20 years before spending our winters in Florida. During those years virtually no Lesser Black-backed Gulls were found on those counts. More recent counts have found close to 200 Lesser Black-backs and seem to be increasing yearly.

Birding friends who bird Lake Nockamixon frequently inform me they have found over 800 Lesser Black-backs there now occurring regularly in the winter. And they are now being found in Florida as well. While they were rare in Florida in the 1970s, they are now being found with increasing regularity, particularly on the west coast of Florida, but occasionally on east coast beaches. All of my photos of Lesser Black-backed Gulls depicted here are from Florida.

Lesser Black-backed Gulls in breeding plumage (Photo 1 and top of page) are quite attractive, with a dark charcoal back, bright yellow legs, red ringed yellow eyes, and a yellow bill with a red gonys spot that chicks know to peck at when begging for food. Like most large gull species, Lesser Black-backs take four years to reach maturity and in their third year (Photo 2) might be confused with Ring-billed Gulls. (Photo 8) But third year Lesser Black-backs are somewhat larger than Ringed-bills, have darker backs and slightly pinkish legs compared to the Ring-billed’s distinctive yellow legs.

When a Lesser Black-backed Gull is surrounded by smaller Laughing Gulls, Black Skimmers, Forster’s and Royal Terns, not to mention a tiny Sanderling, it can look positively regal. (Photo 3) Great Black-backed Gulls (Photo 4) are significantly larger and darker than Lesser Black-backs, and have pinkish-gray legs. Juvenile Great Black-backs (Photo 5) are also larger and have a more mottled black and white body than Lesser Black-backs in any of their plumages.

The gull that Lesser Black-backs are most frequently confused with is the Herring Gull (Photo 6) as it is only slightly larger than the Lesser Black-backed, but has a lighter gray back, and pink legs and feet. However, the juvenile, first year Herring Gull (Photo 7) can be almost indistinguishable from the first-year Lesser Black-backed Gull. (See reference below) Finally, juvenile Ring-billed Gulls (Photo 9) should not pose any identification conflicts with Lesser Black-backs at all.

Yes, gulls can be difficult to identify, particularly, juvenile and immature birds. However, on the east coast of the United States there are only six gull species, and they can be broken down by size. Largest and most distinct is the Great Black-backed which stands out by itself, both as an adult and during its four year maturation. Smaller than Great Black-backs, the Herring Gulls and Lesser Black-backs are pretty close in size, but can be distinguished as noted above.

Lesser Black-backs are only here in the winter, breeding in Greenland and Europe, while Herring Gulls are here year round. Ring-billed Gulls, with a three-year maturation, are smaller than either Herring or Lesser Black-backed; and the final two east coast gull species, both reaching full maturity in two years: Laughing and Bonaparte’s, are significantly smaller than the first four. (photo 3 again) Once a birder becomes completely familiar with all the expected east coast gull species he/she is then ready to start picking through the gull flocks to seek out the rare stray from out west or across the ocean. And if you think gulls are hard to identify, let me suggest you start studying the fall warblers.

In this time of pandemic, while many school children are getting virtual home instruction or opting for home schooling, it may be time for birders to do the hard studying that is necessary to be able to identify and know all those hard to separate species that we all have been meaning to learn for a long time. And home is the place to do it because when the studying gets tough and a serious break is needed, the wine is right close at hand. There may even be a bird’s picture on the bottle if you have the right vintage. Here’s looking at you. Cheers.

References:

My birding brother, Bob, wrote the Forward for the book of early columns, Birding in a Hart Beat, now online here. He also co-conspired with Mary Dodge, webmaster for the SLAS web site and my faithful editor, to produce that book and present it to me as a surprise birthday gift five years ago. Here is the article Bob referred me to: https://www.hawkmountain.org/blog/in-the-field/the-mystery-of-pennsylvanias-lesser-black-backed-gulls

Article about Lesser Black-backed Gulls in Florida in 1974: https://sora.unm.edu/sites/default/files/FFN_02-1-p20-21Woolfenden%5B1%5D.pdf.

For all you wanted to know about Lesser Black-backed Gulls, see: http://larusology.blogspot.com/2010/10/lesser-black-backed-gull-to-z-part-1.html .

For discussion of differences between juvenile Herring and Lesser Black-backed Gulls, see: https://avonbirding.blogspot.com/2016/08/separating-juveniles-herring-lesser.html .

For all you ever wanted to know about gulls and terns in general, see: https://assets.press.princeton.edu/chapters/i13273.pdf