Lazarus ecology: Recovering the distribution and migratory patterns of the extinct Carolina parakeet

Abstract

The study of the ecology and natural history of species has traditionally ceased when a species goes extinct, despite the benefit to current and future generations of potential findings. We used the extinct Carolina parakeet as a case study to develop a framework investigating the distributional limits, subspecific variation, and migratory habits of this species as a means to recover important information about recently extinct species. We united historical accounts with museum collections to develop an exhaustive, comprehensive database of every known occurrence of this once iconic species. With these data, we combined species distribution models and ordinal niche comparisons to confront multiple conjectured hypotheses about the parakeet's ecology with empirical data on where and when this species occurred. Our results demonstrate that the Carolina parakeet's range was likely much smaller than previously believed, that the eastern and western subspecies occupied different climatic niches with broad geographical separation, and that the western subspecies was likely a seasonal migrant while the eastern subspecies was not. This study highlights the novelty and importance of collecting occurrence data from published observations on extinct species, providing a starting point for future investigations of the factors that drove the Carolina parakeet to extinction. Moreover, the recovery of lost autecological knowledge could benefit the conservation of other parrot species currently in decline and would be crucial to the success of potential de‐extinction efforts for the Carolina parakeet.

Georeferenced sighting and specimen occurrence data of the extinct Carolina Parakeet (Conuropsis carolinensis) from 1564 - 1944

“…We also include sightings of what are likely vagrant birds (from Colorado, Maryland, Michigan, New Jersey, New York, North Dakota, Pennsylvania, and South Dakota; see Burgio et al 2017 for more information). Additionally, we kept all georeferenced points in the dataset, regardless of the size of the estimated uncertainty associated with the coordinates.…”

“…The Carolina parakeet has two named subspecies differentiated by geographic range: C. c. carolinensis which occurred along coastal southeastern United States, and the more westerly C. c. ludovicianus (colloqiually known as the Louisiana parakeet), which had a range from central Texas to Nebraska, west to Ohio, and south to Louisiana, with little overlap with the eastern subspecies (Burgio et al 2017). The two subspecies were largely divided by the Appalachian mountains, only coming into contact in the area around Mississippi and Alabama (Ridgway 1916, Swenk 1934).…”

“…McKinley 1965, McKinley and Hardy 1985) and Noel Snyder (Snyder and Russell 2002, Snyder 2004), there has been relatively little research on the Carolina parakeet since the last captive individual died in the Cincinnati Zoo in 1918. However, with the progression of increasingly sophisticated analytical approaches, such as genetic sequencing and species distribution modeling, researchers are starting to provide new insights into Carolina parakeets' evolutionary relationships within the parrot phylogeny (Kirchman et al 2012) and the range size and migratory behavior (Burgio et al 2017). To facilitate more research on this understudied, extinct species, we present the most detailed dataset yet compiled of georeferenced observations and specimens of the Carolina parakeet, ranging from 1564 to 1944.…”

The two extinctions of the Carolina parakeet

“…We are entering the early stages of the "Sixth Mass Extinction" (Ceballos et al 2015), where 25 estimates of the proportion of species to go extinct over the next century are dire (e.g., Urban 26 2015, Carlson et al 2017) and species may not be able to adapt quickly enough to respond to 27 climate change (Keogan et al 2018, Radchuk et al 2019). This amount of loss will destabilize 28 already compromised ecosystems, while conservation agencies are finding it difficult to plan for 29 the challenges and uncertainty ahead (Armsworth et al 2015).…”

“…50Atlantic coast to Nebraska, and south to Florida(Burgio et al 2017). The Carolina parakeet has 51 two subspecies (C. c. ludovicianus and C. c. carolinensis) but was not studied in detail while 52 extant.…”