Endling: A Journey to Extinction

“Endling.” The story of the last dusky seaside sparrow predates the origin of the word used to describe it. The term Endling was coined in 1996 and is used to refer to the last surviving member of a species or lineage. ¹  The recorded history of the dusky seaside sparrow begins in 1872 when they were first described by ornithologist, Charles Maynard. ²  It took less than 120 years to close the history books on the dusky seaside sparrow forever.

Both Howell and Longstreet remarked on how abundant the duskies were at the time but also how restrictive their range was, a major component in their eventual downfall.

"It has a very restricted range, probably not more than 25 miles in length, but is very abundant in that area, and so far as known, is not migratory"

Howell also noted that "In 1927, [D. J. Nicholson] observed 8 nests containing eggs on April 19, 24, and 30." ⁴  USF Special Collections has copies of these original observations, as well as records of dusky eggs collected for natural history collections. Harold H. Bailey, the author of The Birds of Florida, is also noted to have preserved dusky eggs in 1923 when the species were still plentiful. The first sentence of Bailey's description in The Birds of Florida was, "Of the several varieties of 'seaside sparrows' found in Florida, this one is no doubt the most numerous of all, though equally restricted as well in area." ⁷  The duskies' close relative, the Cape Sable seaside sparrow, is also described and illustrated in Bailey's text. Although still found in south Florida, the Cape Sable sparrows are currently listed as endangered and were very elusive during the 1920s as well. The image below is of the aforementioned Donald Nicholson wading across a stream in search of these reclusive birds. Because Cape Sable seaside sparrows also have a limited habitat range, ⁸  if precautions are not taken, they may succumb to the same fate as the duskies.

Cape Sable seaside sparrows are under similar threats to those that wiped out the dusky seaside sparrows, primarily habitat destruction and installation of water management structures. ⁹  The main difference is that the Cape Sable sparrow's habitat overlaps a largely protected, underdeveloped area of Florida: the Everglades. However, the duskies were not so lucky. Their relatively secluded and open home range around North Merritt Island was deemed a perfect location to establish a space station. Ultimately, the road to a fully functional Cape Canaveral Space Station was simultaneously the pathway to the duskies' demise, and the first stop along the journey was mosquito control.

"It's hard to imagine the number of mosquitoes that can come off a single marsh, but to give you an example, there have been instances where as many as 12,000 eggs have been counted in one square foot of dry marsh which could conceivable hatch 516,000,000 mosquitoes in one acre of marsh." - Brevard Co. mosquito control director, Lee Wenner

Mosquitoes were so numerous in this area, that they were even integrated into the identity of Brevard County locals. The community group, the Mosquito Beaters, was founded in 1986 to bring together locals who had weathered the pre-1950, mosquito-infested landscape. The Mosquito Beaters meet annually and publish memory books to help document "the way it was" before the mosquito population was effectively controlled. ¹¹  Prior to the construction of Cape Canaveral in the 1960s, work was already being done to control mosquitoes and sand flies in this area of Brevard County, including spraying pesticides such as DDT (Dichlorodiphenyltrichloroethane). DDT was heavily utilized in the 1940s before its adverse effects on human health and the ecosystem were fully understood, leaving most of the mosquitoes resistant by 1950. Subsequently, focus shifted to constructing impoundments that could selectively flood areas of the marsh, thereby removing prime habitat for mosquitoes to lay their eggs. While this was a highly successful approach in terms of regulating mosquito and sand fly reproduction. It wreaked havoc on the duskies' habitat, destroying nests, affecting their diet, and altering the landscape as certain marsh plants could no longer survive the constant flooding. ¹⁰ 

The continual onslaught on the duskies' habitat was met with awards and accolades for Brevard County's mosquito control director, Leon "Jackie" Salmela, whose work was credited for helping get the space program off the ground. In 1986, one year before the last dusky died in captivity, Salmela also received a Conservation Service Award from the US Fish & Wildlife Service for his "'care and perseverance' in protecting wildlife and the environment while controlling mosquitoes in Brevard County's salt-marsh impoundments." ¹⁰ 

With mosquito control protocols in place, the duskies' numbers began to dwindle down to around 1000 pairs ¹²  as they prepared to face their next hurdle: the Martin Anderson Beeline Expressway. Despite being announced at the 1969 Titusville dusky conservation conference, ¹²  this proposed highway would cut straight through prime dusky habitat, further reducing the number of breeding pairs. Two key dusky advocates outlined in Mark Jerome Walters' book A Shadow and a Song were Brian Sharp and Herbert Kale II, both of whom spoke at the 1969 dusky conference. Allan Cruickshank, another renowned ornithologist and author of The Birds of Brevard County ¹³ , also presented at the conference. USF Special Collections houses records from this conference, including a conference agenda, a draft environmental impact statement for the Beeline Expressway, and correspondences between Kale and the Governor's office. Kale and Cruickshank also have extensive individual records within FLENH's  Florida Ornithological Society Records .

Even though the environmental impact statement explicitly lists the endangered status of the dusky seaside sparrow and that "approximately 200 acres of habitat potentially valuable to the Dusky Seaside Sparrow will be destroyed by the expressway extension," construction began. By 1970, a total estimated 900 breeding pairs remained of the mainland population. ¹⁴  In addition to having their habitat bifurcated by highway construction, the duskies' habitat also succumbed to widespread fires. ¹³  Every year from 1972 to 1976, precious dusky habitat suffered fire damage to some extent, leaving over 5,000 acres of habitat charred. ²  The number of duskies dropped exponentially over these years.

Even though wildfires waned in the late 1970s and the duskies were given a small window to try to repopulate their numbers, researchers saw effects that could not be undone. As evidenced by other bird extinction events, biologists knew that if populations dropped below a certain threshold, the animals stop exhibiting breeding behaviors. Kale had estimated this number for the duskies to be around 75 individuals. ²  Consequently, by 1979, none of the 13 remaining birds were exhibiting breeding behaviors. ¹³  Moreover, all of the birds located were males, with the last female sighting being recorded in 1976. ²  Three of these final 13 birds were collected to initiate a captive breeding program, with one older sparrow dying shortly later. In 1980, a final attempt to collect all wild individuals for the emergency breeding program yielded three more duskies, with one evading capture to live out his days in the marsh. ² 

In 1980, all captive duskies were brought to the Santa Fe Community College Teaching Zoo in Gainesville, Florida. Because all remaining duskies were male, crossbreeding began with the closely related Scott's seaside sparrow. Even if the program was completely successful, the "back-cross" breeding of the 50% dusky offspring would only ever yield offspring with 90th percentile dusky genetic makeup. The initial results of the breeding program were poor, and the duskies were transferred to Discovery Island at Walt Disney World in Orlando, Florida, to be under the direction of curator Charles Cook. ¹⁵  USF Special Collections is home to a multitude of news articles, proposals, agreements, photographs, and correspondences regarding the duskies' recovery plan and outcomes. The majority of the featured materials is housed within the Florida Audubon Society Maitland Records (Coming Soon).

The last pure dusky was nicknamed "orange band" because of the colored, identification band on his leg. Orange band was the Endling of his species. He died from old age on June 16, 1987. By 1989, four dusky-Scott's seaside crossbred sparrows were all that remained of the breeding program. The final stop along the duskies' journey to extinction ended up being wind. Although the exact details are unknown, a storm on March 27th, 1989, left the sparrow's enclosure on Discovery Island damaged. One dusky was found dead, another was still in its cage but escaped during transfer to another enclosure, and the other two duskies presumably escaped through the damaged roof. The freed sparrows were presumed dead as there was no adequate habitat in Orlando to sustain them. ¹⁶  The following excerpts showcase a few media stories and correspondences related to orange band and the extinction of the dusky seaside sparrow.

The featured article "The Dusky Seaside Sparrow: Have we learned anything?" by Herbert Kale concludes with a poem by Robert Quintal Sousa-Fernandes, a copy of which is also found within the archives and summarizes the duskies' journey to extinction :

Ashes to Ashes Dusky to Dusk

The Silence of Indifference Is the most heinous nonsound in the world The Condor is being saved It's Big In this Society "Little" Doesn't mean much The dusky seaside sparrow shot down by an arrow Of Official Crass DDTed to Death As Federal Wildlife Officials were confined to a dumb show A Shrug of . . . "Don't Know" Ashes to ashes dusky to dust The Silence of Indifference Is the most heinous nonsound in the world

The issues that the duskies faced, and which eventually led to their extinction, are not unique. Habitat destruction from development and exposure to chemical control methods continue in Florida today and threatened the existence of several species, especially the Cape Sable and Florida grasshopper sparrows. While some larger, more charismatic birds, may find a stronger foothold in the hearts of the American public, sparrows attract less attention. Their lack of flashy colors or size could be a key factor in determining their fates. However, by studying the data, recovery plans, and history of the dusky seaside sparrow, perhaps conservationists can learn from the past and write a different ending for these extant sparrow species.

The parallels between duskies and Florida grasshopper sparrows is highlighted in this article from the early 1980s. Florida grasshopper sparrows continued to decline in numbers until 2019 when the population was thought to be only 100 birds, ¹⁷  which was near the aforementioned minimum population required to maintain breeding behaviors according to Kale. Thankfully, biologists had been quicker to react this time around and started a breeding program back in 2014. By 2019, the breeding program was successful enough to release 100 grasshopper sparrows into the wild, followed by another 50 in 2020. The captive breed sparrows are reported to have successfully nested and reared young, thereby establishing a foothold on their journey back from the brink of extinction, ¹⁸  a journey that may not have been possible without the lessons learned from the duskies.

The majority of the resources pulled for this Storymap are located within the archives of the Florida Ornithological Society and the Florida Audubon Society Maitland Records. Follow the links below to see their full holdings in ArchivesSpace. We hope you enjoyed this exhibit and invite you to explore our resources further using the links below.  Special Collections is located on the 4th floor of the USF Tampa Library and is open Monday - Friday, 9am – 4pm by appointment only . For more information on how to request materials or use our resources, click the How To button to visit the FLENH LibGuide.

The  Florida Environment & Natural History (FLENH)  unit here at the University of South Florida’s Special Collections library recently acquired additional materials that document the duskies' eventual extinction. This exhibit chronicles the story of the dusky seaside sparrow through the lens of materials available within USF’s Special Collections library and highlights the importance of documenting the natural history of Florida. Preservation of these resources may inform future recovery plans for species whose survival also hinges on their ability to navigate the ever-developing Florida landscape, such as the Florida scrub jay, Cape Sable seaside sparrow, and the Florida grasshopper sparrow.

Due to copyright restrictions, some of the items are only available for preview. Follow the links below to request materials and visit the Reading Room for full access. The featured materials are located within Special Collections on the 4th floor of the USF Tampa Library.

1. Webster, R. M., Erickson, B. (1996). The Last Word? Nature, 380, 386. 
2. Kirkpatrick, D. (1981, September) The Search for One Tiny Precious Bird. New Florida, 1(3), 60-65. [USF Holdings: SP/COLL FLA F306 .N4] 
3. Audubon, J. J. (1981) Birds of America. Artabras, Inc. [USF Holdings: SP/COLL Rare-F98] 
4. Howell, A. H. (1932) Florida Bird Life. Coward-McCann, Inc. [USF Holdings: SP/COLL FLA QL 684 .F6 H6 1932] 
5. NatureServe Explorer. (2024, March 1) Dusky Seaside Sparrow.  https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.104789/Ammospiza_maritima_nigrescens   
6. Longstreet, R. J. (1956) Ornithology of the Mosquitoes. Burgman & Son. [USF Holdings: SP/COLL ENVR F 598.2 L857 1956] 
7. Bailey, H. H. (1925). The Birds of Florida. Williams & Wilkins. [USF Holdings: SP/COLL Rare E-228] 
8. Florida Fish and Wildlife Conservation Commission. (n.d.). Cape Sable Seaside Sparrow.  https://myfwc.com/wildlifehabitats/profiles/birds/songbirds/cape-sable-seaside-sparrow/  
9. Gaston, D. (2020, November 27). Audubon Florida: Defending the Cape Sable Seaside Sparrow.   https://fl.audubon.org/news/defending-cape-sable-seaside-sparrow   
10. Patterson, G. (2004). The Mosquito Wars: A History of Mosquito Control in Florida. University Press of Florida. [USF Holdings: SP/COLL FLA RA 640 .P28 2004] 
11. Central Brevard Mosquito Beaters. (1997). Memory Book. [USF Holdings: SP/COLL FLA F317 .B8 M46 1997] 
12. Walters, M. J.(1992). A Shadow and a Song. Chelsea Green Pub. Co. [USF Holdings: SP/COLL FLA QL 696 .P2438 W35 1992] 
13. Cruickshank, A. D. (1980). The Birds of Brevard County. Florida Press. [USF Holdings: SP/COLL ENVR QL 684 .F6 C94 1980] 
14. U.S. Fish and Wildlife Service. (1980, March). Selected Vertebrate Endangered Species of the Seacoast of the United States: The Dusky Seaside Sparrow. [USF Holdings: Florida Audubon Society Maitland Records: Box 32, Folder 1] 
15. Kale, H. W. (1983, December). Duskies Transferred to Discovery Island. The Florida Naturalist. 3. [USF Holdings: Florida Audubon Society Maitland Records: Box 32, Folder 1] 
16. Renner, L. (1989, June 16). Last Link to Dusky Blows Away at Disney. The Orlando Sentinel, A-1, A-19. 
17. Audubon Florida. (n.d.). Florida Grasshopper Sparrow.  https://fl.audubon.org/birds/florida-grasshopper-sparrow   
18. Audubon Florida. (2020, June 5). Fantastic News for Florida Grasshopper Sparrows.  https://fl.audubon.org/news/fantastic-news-florida-grasshopper-sparrows