Hurricane Irma and its effects on birds

DSC_8441

This is a photograph I took of a Sooty Tern on 12 September 2017 at Lake Strom Thurmond, SC, the day after Hurricane Irma (actually a tropical storm by then) passed through our area. Sooty Terns have no business being this far inland like this. They are a pelagic bird which means they spend their lives out to sea. They nest on isolated islands in the oceans around the world. I got the idea to write and research about this from my wife and her brother. What happens to these pelagic birds when they are blown inland by a hurricane? What kind of effects do hurricanes have on pelagic birds?

Here’s an idea of the world range map from eBird for the Sooty Tern. It’s not precise but gives you an idea. The purple dots are sightings for Sooty Terns.

Sooty Tern world

Here’s a zoomed-in version of the Caribbean range for the Sooty Tern via eBird. Notice the inland purple sightings, those sightings are the result of hurricanes pushing the terns hundreds of miles inland.

Sooty Tern

First, let me tell the story leading up to our sightings. On Monday, 11 September what was left of Hurricane Irma pushed through our area. Around 10:30 am EST, we lost power at our house. I was already well-prepared for the storm and had purchased everything I might need. The winds started during the night but it was around 10:00 am when things started to take a turn for the worse. The winds had picked up and were around 30 mph sustained. However, soon after 10:00 AM we started getting gusts up to 40 to 50 mph. Sustained winds of 40 mph eventually came on in the afternoon mixed with showers. The storm peaked between 12:00 and 13:00 in terms of winds. The rains seemed to mostly come afterward in the late afternoon. We ended up with around 5 inches of rain but luckily we had experienced a prolonged dry spell here leading up to this hurricane. The ground wasn’t saturated and the majority of the rain came after the more intense winds. The combination of a prolonged dry spell in our region and the timing of the rains with the storm saved us from a lot of upturned or downed trees. Most of the damage included leaves being blown off trees and small to medium-sized branches coming down. However, obviously there were trees and branches coming down on power lines which caused us to lose power for 24 hours. But our house typically takes the longest to fix power outages probably because our home is old or our screwy line is located through a dense stand of snags somewhere on the farthest outskirts of town only reachable by monster trucks. We’ve lost power for 5 days before during the Great Ice Storm of 2016.

Here’s the path of Irma with the extent of her tropical storm winds. I labeled Lake Strom Thurmond in bold on the map, the lake is just below my label. The lake is roughly 175 to 200 miles from the Atlantic Ocean.

Hurricane Irma

My birding friend, Matt, is a very sharp, enthusiastic, and energetic birder, especially when it comes to shorebirds and pelagic birds. He loves the coast. He had contacted me on Monday and mentioned the very good probability of birds being blown in from the ocean inland. I texted him back and told him to wake me in the morning. His plan was simple, go to Lake Strom Thurmond. We would have gone to the Savannah River Site, but it was closed until noon on Tuesday (the day after the storm) for non-essential personnel. The morning after the passage of the storm would be an ideal time to visit any inland lakes looking for stranded pelagic birds. Storm-driven waifs are well-known among birders. However, this was my very first experience even though I have been birding for over 15 years. I either haven’t been motivated to explore areas after a hurricane or a hurricane, at least a major one, hasn’t come through this area (I’ve been here 12 years). It’s mostly the latter. However, I typically don’t chase birds to increase my lists, so I’m not the gung-ho birder. This situation was different obviously. The storm was coming close to our area and so not much effort and time was needed.

I had spent most of the time during the storm on Monday at Panera Bread. They had power throughout the storm, food, and coffee. Everything you could need. I drank several cups of coffee while I worked and organized some old trail camera data and simultaneously giving my wife updates on my safety. I drank way too much coffee and didn’t sleep much that night. Matt called me at 06:30 am and said he was going to be at my house in 5 minutes. I rushed up out of bed, tired from the lack of sleep. Rounded up all my optics and cameras and we made a dash for it. Matt didn’t have a spotting scope, wait, I have an extra one in my trunk. We stumble away from my house. Matt had stopped at Bojangles and offered me a sausage biscuit to cover up the incredibly bad breath I had. We stopped by my favorite coffee dispenser, Dunkin Donuts, to cover up my bad breath with coffee breath. After getting lost for about an hour, we arrived at the visitor center parking at Lake Strom Thurmond (the dam) around 8:45 am. Nothing. But wait, there’s some terns, probably Forster’s terns maybe Commons mixed in. A Laughing Gull…, a Herring Gull…., okay, this is starting to get good. Oh wait, there’s a jaeger chasing a tern several hundred yards out. The jaeger disappeared around “Pine” island, a small island on the lake with a dense stand of pines. A few minutes pass by. The Jaeger is back!!!! We’re on it. I attach my cell phone to the eyepiece of scope and record some video of some interesting behavior. We call it, it’s a Parasitic Jaeger and it’s characteristically chasing the Laughing Gull. A good sign that it’s a Parasitic Jaeger.

We’re getting ready to call it a morning. The Savannah River Site is opening at noon and I need to get back into work. Matt spots some more distant terns. They’re dark! Dark terns! They’re Bridled/Sooty Terns! But they’re too far to say for certain which species they are. Matt quickly jogs up to the visitor center to get more information. The idea was to get closer to the terns and identify them. He emerges from the visitor center and informs me that the woman working there doesn’t know shit. But he figured it out on his own by looking at their maps. We jump into his truck. Going to work is on hold now. We drive around to Scott’s Landing, a boat landing. Scott's landing

It was great decision. We arrived at Scott’s Landing right where the mystery terns were foraging and flying. Matt instantly identified them as Sooty Terns. I immediately went to my camera to properly document the birds. I also knew that Bridled vs. Sooty Tern can be difficult so regardless of what we called them, we needed some good photographs to confirm our call.

Sooty Terns, Lake Strom Thurmond-Scott’s Landing, SC, 12 September 2017.DSC_8443DSC_8424

There were some Black Terns mixed in with the Sooty Terns. We watched and photographed them for about 20 minutes and then left fully satisfied that our time was well spent. Observing a Parasitic Jaeger and Sooty Terns a couple of hundred miles inland is a memorable experience. I won’t forget it. Later that day at work, I made a quick stop at a lake on the site and observed a very tired Brown Pelican. Brown Pelicans aren’t quite like Sooty Terns and Parasitic Jaegers. Pelicans inhabit coastal areas, and remain close to coastal areas while Sooty Terns and jaegers remain much further out at sea. Nonetheless, even coastal species like pelicans were blown inland by Irma.

A beaten down Brown Pelican at L Lake, Barnwell county, SC, 12 September 2017. This is about 130 miles inland from coastal areas where pelicans are supposed to be.DSCN0171

Some pelagic birding trips take you 20 to 30 miles out to sea on a good-sized boat to invade the homes and territories of pelagic birds in order to sneak a peek and maybe get a good photograph. I’ve gone on several pelagic birding trips which typically require a 05:00 am arrival time at docks and a half day of 3-5 ft waves looking for birds. You can take a pounding on those trips and/or get a nice sun burn. It can be difficult birding and it costs quite a bit of money. But hey, not after a hurricane right? It’s easy. Just go to the local large lake or river and look around. But what about the birds? Inland storm-driven pelagic birds are the apocalyptic reversal of a pelagic bird trip using a boat. The pelagic birds are forced and pounded inland by the sustained high winds of a hurricane. They don’t want to see people, pine trees, and “tiny” bodies of freshwater! How do they adapt to their new surroundings? Do they adapt to their new surroundings? I wanted to know more about this topic so I did some quick literature research.

Bridled Terns that I photographed about 25 miles off Cape Hatteras, NC, 26 July 2014. I was on a Brian Patteson pelagic trip. These terns are typically only observed miles out to sea just like Sooty Terns, but they too can be blown inland during hurricanes.10524327_827538160591938_5070102657413086474_n

Hurricanes are a regular occurrence in the southeastern United States and the Caribbean. From 1899 to 1992, states along the east coast and Gulf have had 219 direct hits by hurricanes, including 89 that were a category 3 or higher. Buy beach property in Delaware because they are the only state that did not experience a direct hit during this time. Between 1992 and 2005, there have been another 27 hurricanes that have affected the continental United States. Many of the Caribbean islands and coastal barrier islands have been shaped from hurricane activity for a long time and science is indicating that hurricanes and storms may affect these areas even more in the future due to climate change. Recent evidence suggests that climate change will increase tropical cyclone intensity. Webster et al. (2005) found tropical cyclones reaching the categories of 4 and 5 increased in the past 35 years in North Pacific, Indian, and Southwest Pacific oceans.

Storms and hurricanes can cause significant bird mortality. A properly-timed storm along the coast during the peak of bird migration can kill hundreds of birds, maybe thousands. Hurricanes have affected birds on the Caribbean islands for a long time. Here’s an account from Clark (1906): “On September 11, 1898, St Vincent experienced one of the most destructive hurricanes that has ever occurred in the West Indies. The center of the storm passed directly over the island, and the interior forest as well as the fruit trees on the cultivated areas were almost entirely destroyed. On the next day the island appeared as if it had been swept by fire: there was not a leaf nor any green thing in sight. Everything was brown. The number of birds was very sensibly diminished, those of the “high woods”, especially the [St Vincent] parrots [Amazona guildingii], appearing to have suffered the most. Hundreds, if not thousands of birds were killed on the island, and quantities were driven out to sea and lost. Allenia albiventris [Scaly-breasted Thrasher, Margarops fuscus] after the storm became a common resident on Union Island and Carriacou (possibly on some of the other Grenadines also), places where previously it had been unknown. It has since, however, died out at both places. One or two [St Vincent] parrots were picked up dead on the shores of St Lucia. The effects of the storm were not felt all at once. For days afterwards parrots and “Ramier” [Scaly-naped Pigeon Columba squantosa] would stray into the smaller towns in so helpless a condition that many fell prey to the negroes. It is possible that starvation was the cause of this, as every green thing had been destroyed, and it was several days before the trees began to put forth buds. When the vegetation did begin to recover from the shock, the whole island, I was told, presented much the appearance of a rugged New England landscape in the spring. A number of the parrots were obtained alive at this time, and some of them are living in captivity yet.” This account sums up direct and indirect effects of a hurricane on avian populations, especially on small islands in the Caribbean. Indirect effects most certainly involve vegetation that produce nectar and fruits used by birds and cover and food for invertebrates which in turn are preyed upon by birds. So there are a lot of complex cascading effects that hurricanes can have on avian populations. Judging from some of the satellite images post-Irma of the islands in the Caribbean and the Florida Keys, Irma negatively impacted avian populations on many islands perhaps in a similar fashion that Clark described in 1906.

A satellite image of Virgin Gorda on August 25 (left) and September 10 (right). The island turned brown after Hurricane Irma.satellite

South Carolina’s direct hit of Hurricane Hugo in 1989. A youtube satellite loop of Hugo.

A map of Hurricane David’s path in 1979. This hurricane supplied many inland and coastal observations of pelagic birds.

Hurricane David

Hurricane Hugo in 1989 damaged 90% of the colonies used by the Red-cockaded Woodpecker on the Francis Marion National Forest. This is a well-known fact and established a nest box insert program still used today by managers to enhance and increase recruitment of the endangered woodpecker throughout its range. Cely (1991) reported that 200-400 Brown Pelicans died as a result of the high winds from Hurricane Hugo in 1989. Although Hurricane David killed many Sooty Terns that were found by observers after the peak of the storm on 4 and 5 September 1979, David apparently pushed Sooty Terns inland and along the coast and generated record counts in South Carolina and North Carolina. Sooty Terns apparently headed offshore quickly after winds began to abate. No healthy individual was seen on the South Carolina coast after 5 September and none were observed on the North Carolina coast after midday on the sixth. This suggests that the Sooty Terns may have returned back to the Atlantic Ocean. Off the southern Outer Banks of North Carolina, an observer counted 245 and 668 individual Sooty Terns from 8 and 9 September 1979 which suggests some lingered off the coast for days. With Hurricane Irma the furthest inland sighting of a Sooty Tern has been at the Kentucky Dam on 13 September 2017, 3 days after landfall in Florida. However, it’s unknown whether these terns were pushed from the Caribbean or adjacent eastern coast of the Atlantic Ocean when Irma continued northward after landfall. But there is information that the eye of a hurricane can carry birds far beyond their normal range and some of these Sooty Terns may have been stuck in the eye of Irma. The Kentucky Dam is roughly 650 miles inland from Savannah, GA, which is on the Atlantic coast. What do Sooty Terns eat in their new temporary surroundings? Or do they essentially starve for a few days? We don’t know. Capturing a tern like the one in Kentucky is the only way we would learn something and capturing a free-flying tern away from its nest has got to be an extremely difficult task, bordering on impossible. One thing is certain though, pelagic birds like Sooty Terns have experienced these types of life-threatening storms for a long time. They’ve adapted by using lakes and rivers and based on what I’ve read not all the them necessarily die when pushed inland, some likely make it back to their home, the Atlantic Ocean. Inland sightings of Sooty Terns do not persist for many days. As I write this though, there is quite a bit of concern about what has happened to the birds in Florida and on the island of Barbuda. Apparently there is an endemic warbler there, the Barbuda warbler, and Hurricane Irma might have been an extinction-level event for the species. In sum, although it was thrilling to observe a Parasitic Jaeger and Sooty Terns far inland in comfortable surroundings, many birds paid a dear price during Hurricane Irma either with their lives or by an extended period of time under duress as they adapted to foreign surroundings. Hopefully the Sooty Terns that we observed on that day found their way home.

A map from eBird showing the furthest inland known sighting of a Sooty Tern (purple blocks are sightings of Sooty Terns) at the Kentucky Dam, near Calvert City, KY, on 13 September 2017. This is around 650 miles from Savannah, GA, which is on the east coast and 3 days after landfall in Florida.

KY Dam

The Sooty Tern, the “Hurricane” Tern.DSC_8441

 

Cely, J. E. 1991. Wildlife effects of Hurricane Hugo. Journal of Coastal Research 8:319–326.

Clark, A. H. 1906. Birds of the southern Lesser Antilles. Proc. Boston Soc. Nat. Hist. 32:
203-312.

Fussell, J. O., III, and A. Allen-Grimes. 1980. Bird sightings associated with Hurricane David. Chat 44:89–100.

Michener, W.K., E.R. Blood, K.L. Bildstein, M.M. Brinson, and L.R. Gardner. 1997. Climate change, hurricanes and tropical storms, and rising sea levels in coastal wetlands. Ecological Applications 7:770-881.

Webster, P.J., G.J. Holland, J.A. Curry, and H.R. Chang. 2005. Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment. Science 309: 1844-1846.

Wiley, J.W. and J.M Wunderle. 1993. The effects of hurricanes on birds, with special reference to the Caribbean islands. Bird Conservation International 3: 319-349.

 

 

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