In the House Finch vs. bacteria arms race, so far it’s a draw,
and the battle rages on
Ithaca, NY—Cornell Lab of Ornithology scientists have been tracking the effects House Finch eye disease for more than 25 years. The disease causes red, swollen, watery, or crusty eyes. Afflicted birds can recover, but may die because they cannot see well enough to find food or avoid predators. The latest analyses, based on the observations of Project FeederWatch participants from eight northeast states, addresses the long-term impact of the disease on House Finch populations and points to the role of the finch immune system in the bird vs. bacteria battle. The findings are published in the Journal of Animal Ecology.
“We have an escalating arms race,” says Cornell Lab researcher and lead author Wesley Hochachka. “Finches who become infected but survive acquire some immunity to that version of the bacteria and its predecessors. The bacteria evolve to get around the strengthened finch immunity. Then birds acquire immunity to the latest strain, and the cycle keeps repeating.”
The study’s authors believe that acquired immunity—when the immune system creates antibodies in response to an infection—is actually driving the arms race between the birds and the bacteria. They say imperfect acquired immunity, just like imperfect vaccines against human pathogens, creates the conditions needed to favor the proliferation of new strains of the bacteria that can overcome immunity acquired against existing strains of bacteria.
Immunity can also develop through genetic changes to the House Finches, but this would be a relatively slow process, requiring multiple years for genetically novel and resistant finches to become widespread. In contrast, genetic changes to the bacteria can proliferate within hours—so fast that populations of House Finches can't possibly evolve a defense quickly enough.
“We should really pay more attention to the role that acquired immunity can play in the dynamics of disease in any animal,” said Hochachka. “Interactions can be much more complicated when both the host and the disease are able to change rapidly.”
The overall House Finch population was cut in half during the initial outbreak when the bacteria jumped to finches from poultry in 1994. House Finch populations now are mostly stable at their current, lower level. Hochachka says that's surprising because in other tracked animal diseases, the typical patterns are either that the animal populations rebound or fluctuate widely following the initial disease outbreak. But he thinks the finch population is not likely to return to pre-disease levels.
The finch eye disease dynamic has parallels to human health and the use of vaccines to give people acquired immunity to diseases. Here also, imperfect immunity—vaccines that do not provide perfect protection—are believed to accelerate the spread of new strains of pathogens against which vaccines are ineffective. “The emergence of new diseases is going to keep happening,” Hochachka said. “We just have to develop methods and systems for dealing with it as best we can when a lethal disease appears.”
— Cornell Lab of Ornithology
Critical Habitat Finalized for the Western Yellow-Billed Cuckoo
Agency: U.S. Fish and Wildlife Service, Department of the Interior. Final rule.
Summary: The U.S. Fish and Wildlife Service, designates critical habitat for the western distinct population segment of the Yellow-billed Cuckoo (Coccyzus americanus) under the Endangered Species Act. In total, approximately 298,845 acres are now being designated as critical habitat in Arizona, California, Colorado, Idaho, New Mexico, Texas, and Utah. This rule extends the Act’s protections to critical habitat for this species.
Executive Summary: Scope of this rule. The information presented in this final rule pertains only to the western distinct population segment of the Yellow-billed Cuckoo (western yellow-billed cuckoo) (DPS-distinct population species). Any reference to the ‘‘species’’ or to the western yellow-billed cuckoo within this document only applies to the DPS and not to the Yellow-billed Cuckoo as a whole unless specifically expressed.
Species Information: The western Yellow-billed Cuckoo is a migratory bird species, traveling between its wintering grounds in Central and South America and its breeding grounds in North America (Continental United States and Mexico) each spring and fall often using river corridors as travel routes. Habitat conditions through most of the western Yellow-billed Cuckoo’s range are often dynamic and may change condition or location within or between years depending on environmental conditions, vegetation growth, tree regeneration, plant maturity, stream dynamics, and sediment movement and deposition. The species’ major food resources (insects) are also similarly variable in abundance and distribution. As a result, the western Yellow-billed Cuckoo’s use of an area is tied to the area’s habitat condition and food resources, which as stated, can be variable between and within years. This variability in resources may cause the western Yellow-billed Cuckoo to move between areas in its wintering or breeding grounds to take advantage of habitat conditions and food availability. This rule is effective May 21, 2021. 20798 Federal Register
Starvation, weather blamed for bird die-off
SANTA FE, N.M. (AP) — Starvation and unexpected weather are to blame for a statewide die-off among migratory birds in 2020 in New Mexico, researchers said. Biologists from multiple agencies collected hundreds of samples of warblers, swallows and other birds and sent them to the U.S. Geological Survey’s National Wildlife Health Center in Wisconsin to be analyzed. The researchers found that nearly all the birds were severely emaciated, already starving when they moved into New Mexico. An unusual storm likely made things worse, they said, causing the birds to become disoriented and fly into buildings and objects. Some died from exposure to the cold weather, were killed by predators or hit by vehicles. The evidence of starvation included kidney failure, empty stomachs, small amounts of blood, depleted fat deposits, irritated lung tissue and shrunken breast muscles that control the birds’ wings, the researchers said. The researchers didn’t identify a single, definitive cause of death. They ruled out disease and poisoning. Countless birds died earlier this year, with the first signs in late August. They were reported in the Taos area and at Valles Caldera National Preserve in the north to the cottonwood forest along the Rio Grande to southern New Mexico, including at White Sands Missile Range. Residents reported seeing them dying in groups, flying low and exhibiting lethargic and unusual behavior. Large-scale birds deaths are rare, researchers at New Mexico State University have said.
White-throated Sparrow Sings New Song
White-throated Sparrows in British Columbia are singing a new tune and the song is sweeping across Canada. What began as a minor change to a common song has now morphed into a continent-wide phenomenon. In the 1990s, Biologist Ken Otter from the University of Northern British Columbia, Canada started hearing white-throats singing an unusual song. Instead of sticking to the species' usual three-note finish, local sparrow populations were ending their tune on two notes. Between 2000 and 2019, this minor change has traveled over 1,800 miles, from British Columbia to central Ontario, virtually wiping out a historic song-ending that's been around since the 1950s at least. For more, including a sound-video of the songs: Sciencealert.com
Rufous Hummer Decline
While commonly observed throughout its range, the Rufous Hummingbird is still recognized was an at-risk species. Unfortunately, the Breeding Bird Survey data suggest that this hummingbird’s population has declined by asa much asa 60% since 1974. The ongoing causes for decline seem to be unclear: however, recent research indicates that accelerated climate change could result in extensive range loss in the United States. Out of concern for the future of this species, the Western Hummingbird Partnership published a recent report with multiple partners, Rufous Hummingbird: The State of the Science and Conservation. It covers the biology and ecology of this classic western hummer, and it highlights the many gaps in information that impede our ability to effectively protect it. You can find it here: http://tinyurl.comE-bulletin.
Yellow-billed Cuckoo Still Protected
Despite a petition submitted to the US Fish and Wildlife Service in 2018 to de-list the Western Yellow-billed Cuckoo, and thanks to comments submitted by Audubon, our network, and countless partners, the Western Yellow-billed Cuckoo’s Federally Threatened status stands! This decision to maintain the Cuckoo’s protected status is a great step toward conserving this emblematic western species and its habitat.
“We’re grateful that this wondrous bird will continue to receive the life-saving protections of the Endangered Species Act,” Michael Robinson of the Center for Biological Diversity said in a news release. Now it’s time to designate critical habitat to ensure that when the cuckoos migrate here each summer from South America, they’ll still have places to nest and fledge their chicks.
More Hope for the Cerulean Warbler
Earlier this year, there was encouraging news that the dramatic declines of this iconic warbler had slowed. Like the Black-capped Vireo, this bird too, has long suffered from the Brown-headed Cowbird’s troublesome tricks, as well as habitat destruction. Now, their steadying numbers have resulted in this beautiful bird moving from Vulnerable to Near Threatened giving its admirers a more tangible cause for celebration.
While the outlook has improved, the global population of Cerulean Warbler Setophaga cerulea continues to decline, albeit more slowly, so we must keep a watchful eye on this flitting flash of blue. Photo: Ray Hennessy. → Birdlife International
Kirtland's Warbler De-Listing
Here, is a positive Endangered Species story, a success story involving a highly threatened migratory songbird, the Kirtland's Warbler. If anything, this is proof that when the FWS can document that a population of a species is healthy and exists in adequate numbers, de-listing should not be onerous.
Kirtland's Warbler nests almost exclusively in central Michigan in young jack-pine forests that are about 80 acres or larger in size, and include a multitude of small, grassy openings. The impact of habitat reduction and Brown-headed Cowbird parasitism originally led the FWS to list the Kirtland's Warbler when the Endangered Species Act was passed into law in 1973. In actuality, the estimated population had already plummeted to about 400 birds in 1971.
The goal of the conservation plan between the FWS and the state of Michigan's Department of Natural Resources was to eventually reach 1,000 pairs of nesting warblers per year, but that number has now been surpassed. Currently, about 2,000 pairs of this species highlight the success of this species' recovery. The FWS more than a year ago proposed to remove the Kirtland's Warbler from the ESA list, and the final decision is expected any day now.
The future of the Kirtland's Warbler still will depend on continued and regular hands-on management. Indeed, while the species awaits a de-listing, the FWS says that without continued human involvement, the birds' numbers would once again plunge. A specific designation - conservation reliant - indicates as much.
Right now, there many creative plans being implemented - including even arrangements with private forests and golf courses - across the warbler's breeding range to provide the specific on-the-ground habitat mix that these birds will need into the future. Of course, this will also have to include some creative and long-term funding.
Fortunately, the forces behind the Kirtland's recovery insist that the ESA works and that the Kirtland's Warbler federal/state and public/private model can serve as an example to help other fragile species. RefugeAssociation.org/birding-community-e-bulletin
Have You Ever Seen A Blue-throated Mountain-gem?
The AOS Committee on Classification and Nomenclature-North and Middle America has decided to rename the Blue-throated Hummingbird as Blue-throated Mountain-gem. This is primarily a Mexican species, ranging from Oaxaca north through woodland mountains and canyons to southeastern Arizona, southern New Mexico, and western Texas. Vagrants have occurred as far north as northern Colorado, eastern California, and eastern Louisiana, according to eBird. Similarly, the name of the closely related Amethyst-throated Hummingbird, a resident in Mexico and Central America, is now Amethyst-throated Mountaingem. birdwatchingdaily.com
Possessive (PATRONYMIC) Bird Names
There is a movement afoot to abandon the fairly common possessives in English bird names. Indeed, the removal of the possessive apostrophe and “s” from patronymic bird names – mainly concerning the names of people – would result in new names such as Wilson Snipe, Barrow Goldeneye, Swainson Thrush, Audubon Oriole, and Brewer Blackbird.
The case was made last fall to the Classification Committee for the American Ornithological Society (AOS) which oversees such things. See the arguments presented by Ted Floyd here: Checklist.aou.org/assets/proposals/PDF/2019-A.pdf
Needless to say, this is not just about birds. The apostrophe – with or without the accompanying “s” – is increasingly falling into disuse in the current age of text-speak, signage, and character-counting. So choose a side, because this battle will surely continue! [from Birding Community E-bulletin]
Red List of Threatened Species
The IUCN (International Union for Conservation of Nature) maintains a record of how close species may be to extinction. BirdLife International is responsible for annually measuring the health of the world of birds, and each year updates which birds are stable, which are in recovery, and which have slipped toward extinction. In the most recent release, there were a few surprises for us in North America. First the troubling stories:
Common grackle populations have been dropping. With numbers plummeting by more than 50% between 1970 and 2014, the species has now been classed as Near Threatened by IUCN. Pest-control measures may have contributed to this decline.
Eastern Whip-poor-will data have revealed that the species population fell by over 60% between 1970 and 2014. With a dependence on flying insects for food, the species may be declining due to pesticides, intensive agriculture, and other factors reducing insect availability. The species has been up-listed to Near Threatened this year
Rufous hummingbird could be sliding to extinction in plain sight, and the species has also been up-listed to Near Threatened this year. Its reliance on nectar and on insects during the breeding season may combine to put the species in jeopardy. This hummer may become a victim of climate change as early-blooming flowers in some locations could mean that hummingbirds arrive from migration too late to take advantage of this vital food source. Forest fires and changes in post-fire habitat conditions could also be contributing to the species' decline.
Now! The upbeat stories
Red-headed woodpecker, with formerly declining populations, may have stabilized. Now placed in a "Least Concern" category, the species' population is considered healthy and stable enough that it is unlikely to face extinction anytime soon.
Henslow's sparrow has stabilized, thanks in part to habitat management. In particular, the species has benefited from the Conservation Reserve Program (CRP), where farmers are paid to remove land from cultivation and instead plant species that will improve the health and quality of the habitat.
Some of these changes fit into familiar patterns of habitat alteration, pesticides, and climate change. Whether or not you agree with all these findings, they deserve consideration. Please find more info here: BirdLife.org
Lack of Red Squirrels Results in Another ABA Checklist Change
According to the 28th American Birding Association (ABA) checklist committee report, there is 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, and will be acceptable as being “countable” on your North American ABA area list.
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
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
What is eBird?
eBird is a bird sightings website, managed by Cornell Lab of Ornithology, that receives over 100 million bird sighting reports every year from around the world. Enter your data to maintain a personal bird list, while providing information for others and data for science — submit info, photos & audio recordings with the eBird app, Android or Apple.
Curious about when and where a bird species is found? The Explore feature allows you to go to a specific county & view illustrated checklists, get information, lists and sighting location maps before or during your travels. Whether you list or not, your data is part of an immense citizen science project helping to inform the public and research that helps with conservation decisions. eBird.org
Winter Feeder Maintenance
Once considered a wintertime activity, backyard bird feeding now takes place all year. But the practice nonetheless accelerates in winter, so now is a good time to consider your own feeder maintenance schedule.
Simply put: keeping bird feeders clean is a good way to help keep your visiting birds healthy. Odd seeds, stuck in the nooks and crannies of feeders, can become wet and moldy. These can easily be removed with a brush and water sprayed from a hose. To be sure your feeders are clean, use a highly diluted solution of bleach and water (nine parts water, one part bleach). Tube-feeders are the most important ones to clean thoroughly. Immerse the feeders in the liquid mix for a couple of minutes, then rinse and let dry before refilling with seed. (Note: even diluted bleach can discolor your shirts, blouses, pants, etc.)
Also, rake and remove seed hulls and other debris immediately below your feeders on a regular basis to retard mold and bacterial growth. Birding Community E-bulletin: RefugeAssociation.org.