Declining population of one species may play a role
Ithaca, NY—Scientists have shown that a bird found in Pennsylvania is the offspring of a hybrid warbler mother and a warbler father from an entirely different genus—a combination never recorded before now and which resulted in a three-species hybrid bird. Photo: Rare triple-hybrid warbler (Golden-winged Warbler, Blue-winged Warbler, and Chestnut-sided Warbler), Photo by Lowell Burket. This finding has just been published in the journal Biology Letters.
eBird’s Taxonomy Update - 2018
SPECIES SPLITS for birds in our area
Mexican Duck Anas diazi
The sexually monochromatic Mexican Duck is split from the widespread species Mallard Anas platyrhynchos. Mallard occurs widely in Eurasia and overlaps (and interbreeds) with Mexican Duck in its US range (border regions of Texas, New Mexico, and Arizona) as well as in northern Mexico in winter. Mexican Ducks appear to be expanding in the northern portions of its range and also as a vagrant (north to Wyoming and Colorado and west to California).
Red-eyed Vireo Vireo olivaceus
Formerly considered one widespread species with migratory northern populations breeding in the USA and Canada, resident populations in northern and central South America, and migratory populations in southern South America. The species is now split, with North American breeders pertaining to Red-eyed Vireo Vireo olivaceus and South American breeders pertaining to Chivi Vireo Vireo chivi.
SHUFFLES of other Taxa and Subspecies Group Lumps
Roadside Hawk Rupornis magnirostris
Former group Roadside Hawk (Mainland) [magnirostris Group] is now split into two groups, which differ substantially in plumage. The Northern group includes all of North America and much of northern South America, while the Southern group includes much of Amazonia and southern South America.
Dusky-capped Flycatcher (lawrenceii) Myiarchus tuberculifer lawrenceii
Subspecies groups in Dusky-capped Flycatcher were incompletely defined until this year. As part of this revision, our former subspecies group Dusky-capped Flycatcher (lawrenceii) Myiarchus tuberculifer lawrenceii was expanded this year to include all 8 North American subspecies, except Myiarchus tuberculifer olivascens, which is still recognized as a monotypic subspecies group Dusky-capped Flycatcher (Arizona).
American Pipit (alticola) Anthus rubescens alticola
The subspecies group American Pipit (alticola) Anthus rubescens alticola is now merged with the rubescens Group. Although there are some subtle differences in breeding plumage, these subspecies are not reliably identifiable at most times of year and are hereby merged.
Common Name Changes
Mallard (Northern) > Mallard
Mallard (Mexican) > Mexican Duck
Gray Jay > Canada Jay
Gray Jay (Northern) > Canada Jay (Northern)
Gray Jay (Rocky Mts.) > Canada Jay (Rocky Mts.)
Gray Jay (Pacific) > Canada Jay (Pacific)
Black-capped Vireo Delisting
The U.S. Fish and Wildlife Service (USFWS) announced the successful recovery of the Black-capped Vireo, thus removing the species from Endangered Species list protection. Thirty years ago, the population was down to about 350 individuals. Today, however, there are more than 14,000 birds estimated across the bird’s breeding range in Oklahoma, Texas, and Mexico. No longer will this species be listed among those considered Endangered and Threatened.
The vireo was Federally-listed in 1987, primarily due to the impacts of habitat loss and nest parasitism by Brown-headed Cowbirds. The USFWS concluded that the primary threats to the Black-capped Vireo have been reduced or adequately managed, and vireo populations are now expected to be viable in the future. Birding Community E-bulletin
Kirtland’s Warbler Proposal
The USFWS is proposing to remove this species from Endangered Species Act (ESA) protection. The Kirtland’s Warbler has traditionally nested in young jack pine forests in central Michigan, and has recently spread to parts of Wisconsin and Ontario. Still, this warbler has one of the most geographically restricted breeding distributions of any bird in the continental United States. The current Kirtland’s Warbler population is now estimated to be over 4,600 individuals, actually more than double the recovery goal. In fact, the warbler’s population has exceeded recovery goals for the past 16 years.
We now know that the warbler’s population had declined primarily for two reasons: loss of nesting habitat and brood parasitism caused by the spread of Brown-headed Cowbirds which significantly reduced their nesting success. After ESA listing, the first Kirtland’s Warbler Recovery Plan was crafted, involving multiple partners and outlining steps to increase the population of the warbler. The management of jack pine areas (involving the regular replanting of the trees in appropriate sandy soil) was essential, as was the control of Brown-headed Cowbirds.
Multiple partners have been crucial to the warbler’s recovery. “Without a doubt, this bird’s recovery is the result of cooperation among states, local residents, federal agencies, and conservation groups. This dedicated conservation community is committed to addressing the needs of the Kirtland’s Warbler into the future,” said Tom Melius, Midwest Regional Director for the USFWS. Before making a final decision, the USFWS must gather and analyze public comments and any new information. Publication of the proposed rule opened a 90-day public comment period, which closed July 11.
Facing Extinction: Some Examples
It’s interesting to view some predictions made by BirdLife last month. The organization reviewed a number of species that were once considered quite common and widespread but whose numbers are now plummeting. They looked at seven of these species last month, and some of them might surprise you. For the full listing, see → BirdLifeSurprises. Among the seven they include three that occur in North America:
- Snowy Owl – Experiencing a rapid decline, most likely driven by climate change. Disruptions to snowmelt and snow cover can affect the availability and distribution of prey.
- Atlantic Puffin – Regional overfishing and climate change have created serious food shortages.
- Black-legged Kittiwake – Rising sea temperatures are driving catastrophic declines in plankton populations, with an impact to the rest of the food chain, including fish. Plastics at sea (consumed by the kittiwakes) may be another threat.
The ESA Is Also Endangered
The Endangered Species Act (ESA) has been the strongest legal protection for wildlife since it was enacted in 1973. The success of the law is confirmed by the delisting of recovered species such as the Bald Eagle and Peregrine Falcon which probably would have been lost forever without the ESA’s protection. There are still many species whose survival depends on continued listing as endangered or threatened. The effects of climate change will likely imperil many more species as described above. Ongoing Congressional attempts to “modernize” the law are poorly disguised attempts to weaken the law. Audubon is one of many organizations that will continue efforts to maintain the ESA.
28th ABA Checklist Committee Report
. . . a hummingbird with two verified north American records, will be acceptable as being “countable” on your North American ABA area list. The Amethyst-throated hummingbird (Lampornis amethystinus) normally resides in Mexico and Honduras. It will be placed on the list between Plain-capped Starthroat and Blue-throated hummingbirds.
The Pine flycatcher (Emidonax affinis) was found in 2016 in the Santa Rita mountains in Arizona, where it unsuccessfully attempted to nest with a Cordilleran flycatcher. It will be placed between Dusky and Pacific-slope flyctchers on the ABA list.
There is also a “split” from the Red crossbill (Loxia curvirostra). This newly separated crossbill is called Cassia crossbill (L. sinesciuris). It is recognized as being endemic to the South Hills and Albion mountains of Idaho. Its large bill has resulted from co-evolution with thicker pine cone seeds, mediated by a lack of red squirrels in the region. The scientific name sinesciuris translates to “without squirrels.” It will follow Red crossbill on the ABA list.
Magnificent no more!
The Magnificent hummingbird was named in honor of the Duke of Rivoli, after it was described in the 1920s - the Anna’s hummingbird is named after his wife, the Duchess of Rivoli. It remained “Rivoli’s hummingbird” until the mid-1980s when it was re-named Magnificent. This most recent Supplement has split Magnificent hummingbird into the Rivoli’s and Talamanca hummingbird (the latter is found in Costa Rica)...
This split separates birds of southern Central America from those of Mexico, the U.S., and northern Middle America. Rivoli’s hummingbird (Eugenes fulgens) is found in pine–oak woodlands from the southwestern U.S. south to northern Nicaragua; adult males have a peridot-colored (yellow-green) throat and blackish underparts. Talamanca hummingbird (Eugenes spectabilis) is found in cloudforest and high oak forests of Costa Rica and western Panama; adult males have a turquoise- or teal-colored throat and dark green underparts. The latter was originally named “Admirable hummingbird” by Robert Ridgway, but his suggestion was unheeded. Instead, Eugenes spectabilis has been named for the Talamanca Mountains of eastern Costa Rica. This split raises the not particularly serious question of what to call a Berylline X Magnificent hybrid, which birders had playfully dubbed “Beryificent Hummingbird”. Berivoli’s? Riviline? Photo: naturespicsonline.com
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