Cowbirds, yellow warblers and red-winged blackbirds, research


This 2019 video from North America is called Male brown-headed cowbirds calling & spreading wings.

From the University of Illinois at Urbana-Champaign, News Bureau in the USA:

When warblers warn of cowbirds, blackbirds get the message

March 31, 2020

This is the story of three bird species and how they interact. The brown-headed cowbird plays the role of outlaw: It lays its eggs in other birds’ nests and lets them raise its young — often at the expense of the host’s nestlings. To combat this threat, yellow warblers have developed a special “seet” call that means, “Look out! Cowbird!”

In a new study, researchers at the University of Illinois at Urbana-Champaign report that red-winged blackbirds respond to the seet call as if they know what it means.

“Does this mean red-winged blackbirds understand that the call is specific to cowbirds or are they just responding to a general alarm?” said graduate student Shelby Lawson, who led the study with Mark Hauber, a professor of evolution, ecology and behavior at the U. of I. The researchers sought to answer that question by playing back the calls of several bird species in warbler and blackbird territories to see how the birds reacted.

They report their findings in the journal Communications Biology.

“We know that eavesdropping on the calls of other species is common across the animal kingdom,” Lawson said. “Birds do it. Mammals do it. There are studies of different primates that do it — and even birds that listen in when they do.”

In the rainforests of Ivory Coast, for example, tropical birds known as hornbills have deciphered some of the calls of the Diana monkey. The hornbills ignore the monkeys’ alarm calls for ground predators, which are no threat to the birds, but heed the monkeys’ calls for hawks, which are predators of hornbills.

Chickadees have very general alarm calls that we now know signal the size of different predators,” Lawson said. “A lot of birds will listen to these calls and respond based on the danger posed to them. There’s also a study of nuthatches listening to chickadee calls.”

But all these studies look at alarm calls directed at predators that can kill adult animals, Lawson said.

“Yellow warblers are the only bird we know about that has developed a specific call for a brood parasite,” she said. “When they see a brown-headed cowbird, yellow warblers will make the seet call and then females that hear the call will go back to their nest and sit on it tightly to protect their eggs. They only do this with cowbirds. They don’t seet at predators or anything else.”

In an earlier study, Lawson and her colleagues were playing audio of seet calls to study warbler behavior when they noticed that red-winged blackbirds were also responding aggressively to the calls. This prompted the new study.

To learn what the red-winged blackbirds understood about the calls, the researchers played a variety of bird calls in red-wing and yellow warbler territories and watched how the birds responded. They found that the red-winged blackbirds responded identically to the seet calls, the sound of cowbird chatter and blue jay calls — all of which signal a threat to their nests.

“They responded very aggressively to these calls, more so than they did to the warbler ‘chip’ call, which is just a general antipredator call,” Lawson said. When red-wings heard the warblers seeting, they flew close to the loudspeaker and looked around for the threat, she said.

When red-winged blackbirds see any kind of predator in their territory, they swoop at it and dive-bomb it. Male red-wings have so many mates in so many nests that they must defend a wide territory from interlopers and threats, Lawson said. This is why red-winged blackbirds are known as the “knights of the prairie.”

In defending their own nests from predators, they end up helping out other bird species — in particular, yellow warblers. Previous research shows that yellow warblers that nest near red-winged blackbirds suffer less from cowbirds laying their eggs in their nests.

The warblers also appear to help the blackbirds by warning of nest predators, the researchers said.

“We found that the red-winged blackbirds that nest really close to the warblers respond more strongly to the seet calls than those that nest far away,” Lawson said.

The researchers have more work to do to determine whether the blackbirds understand that the seet call means “cowbird”, specifically, or if it is just interpreted as a general danger to the nest. In a future study, the researchers will play the seet call to re-wings at the end of the nesting season to see if the blackbirds respond as aggressively to the sound after their eggs have hatched. Yellow warblers stop making the seet call when their nestlings are secure and too old to be bothered by cowbirds.

“This is the first report of a bird eavesdropping on another species’ warning of a brood parasite,” Hauber said. “We don’t yet know if the red-winged blackbirds understand that the warning is specific to cowbirds, but it’s obvious they understand that the call represents a threat to the nest — and that benefits them.”

The National Geographic Society supports this research.

Rare birds and conservation in Illinois, USA


This video from the USA says about itself:

Bell’s Vireo (Vireo bellii) singing 6-05-2014 Catalina Grove – Orland Park, Illinois.

From the University of Illinois at Urbana-Champaign in the USA:

Conservation efforts help some rare birds more than others

January 23, 2019

Land conservation programs that have converted tens of thousands of acres of agricultural land in Illinois back to a more natural state appear to have helped some rare birds increase their populations to historic levels, a new study finds. Other bird species with wider geographic ranges have not fared as well, however.

The research, reported in the journal Ecosphere, finds that one of the four species studied, the Bell’s vireo (Vireo bellii bellii), has bounced back from historic declines to more than double its last estimated abundance in Illinois.

“This increase surpasses state goals set for the bird in 2004, and speaks to some of the successes of the Conservation Reserve Enhancement Program, a national effort begun in 1996 to improve water quality, reduce erosion and restore lands and wildlife once lost to agricultural expansion,” said Illinois Natural History Survey avian ecologist Bryan Reiley, who led the study. “Other rare birds — particularly those most reliant on early succession grasslands — are still struggling, however.”

The growth of agriculture “has negatively affected biodiversity throughout the world,” the study authors wrote. Grassland species have experienced some of the sharpest declines. Conservation programs like CREP use monetary incentives to entice private landowners to voluntarily convert some of their land back to grasslands, wetlands or forest. More than 140,000 acres have been restored so far in Illinois through CREP.

To determine how this conservation effort affects populations of specific rare birds, Reiley and his colleagues surveyed 172 randomly selected restored fields in 10 counties in central and west-central Illinois during the 2012-15 breeding seasons. They focused on the Bell’s vireo and three other species in decline: the field sparrow (Spizella pusilla), northern bobwhite (Colinus virginianus) and willow flycatcher (Empidonax trailli trailli).

“We found that private land conservation efforts in Illinois are probably effective in achieving state population goals for some rare species, such as the Bell’s vireo, which prefers shrubby areas near grasslands,” Reiley said. “They also may help other species with similar habitat needs, like the willow flycatcher, which we estimate to be at 92 percent of the goal.”

The field sparrow and northern bobwhite still appear to be in trouble, however. Based on the researchers’ estimates, CREP has increased northern bobwhite populations by only 6 percent of the goal. Field sparrow abundance is better, but the conservation program has achieved only 33 percent of the goal for this species.

Reiley and his colleagues estimated that the amount of restored land would need to increase by 5 percent to rebuild populations of willow flycatchers to historic levels. Substantially more habitat would be required to support historic populations of field sparrows and northern bobwhites, however. To achieve state goals, those species would need habitat increases of 118 percent and 598 percent, respectively, the researchers found.

“Interestingly, all the species we studied, and probably many others not studied, would likely rebound to historic levels if 1 percent of the agricultural land in Illinois was restored through CREP,” Reiley said. “This program is clearly important to populations of declining wildlife — not only in Illinois, but also in the other 26 states where it operates.”

The Illinois Natural History Survey is a division of the Prairie Research Institute at the University of Illinois. The Illinois Department of Natural Resources supported this work.

An international group of researchers working on a wide range of species, from elephants and crows, to whales and chimpanzees, argues that animals’ cultural knowledge needs to be taken into consideration when planning international conservation efforts: here.

Big clerical sexual abuse cover-up in Illinois, USA


This 19 December 2018 video from the USA is called 500 more Illinois priests accused of abuse.

From CNN in the USA:

Illinois AG says Catholic Church failed to disclose abuse accusations against 500 priests and clergy

By Daniel Burke, CNN Religion Editor

Updated 0003 GMT (0803 HKT) December 20, 2018

In yet another blow to the Catholic Church in the United States, Illinois’ attorney general says the state’s six dioceses have failed to disclose accusations of sexual abuse against at least 500 priests and clergy members.

Illinois’ dioceses have released lists publicly identifying 185 clergy members who had been credibly accused of child sex abuse. But state Attorney General Lisa Madigan said preliminary findings in her ongoing investigation reveal that the church failed to disclose sexual abuse allegations against at least 500 additional priests and clergy members.

In many cases, the accusations have “not been adequately investigated by the dioceses or not investigated at all”, Madigan’s office said in a statement Wednesday. What’s more, the statement added, the church often failed to notify law enforcement authorities or state Department of Children and Family Services about the allegations.

“By choosing not to thoroughly investigate allegations, the Catholic Church has failed in its moral obligation to provide survivors, parishioners and the public a complete and accurate accounting of all sexually inappropriate behavior involving priests in Illinois”, Madigan said in the statement.

“The failure to investigate also means that the Catholic Church has never made an effort to determine whether the conduct of the accused priests was ignored or covered up by superiors.”

Madigan began her investigation in August, after a Pennsylvania grand jury released a 900-page report detailing horrific abuses by 300 Catholic clergy against more than 1,000 victims. Since then, 36 dioceses have publicized self-reported lists of clergy “credibly accused” of abusing minors. (There are 197 dioceses in the United States.)

But advocates for survivors of sexual abuse have challenged many of the lists, calling them incomplete or evasive. Few of the lists detail exactly when the abuse claims were made, or what was done about them. Madigan’s criticism seems to lend credence to those claims.

“The preliminary stages of this investigation have already demonstrated that the Catholic Church cannot police itself“, Madigan said. “Allegations of sexual abuse of minors, even if they stem from conduct that occurred many years ago, cannot be treated as internal personnel matters.”

Based on their review of the Illinois dioceses’ internal files, the dioceses have received sex-abuse-related allegations for approximately 690 clergy, according to the attorney general’s report. But they publicly reported just 185 of the allegations.

Nearly 75% of the allegations were either not investigated or were investigated but not substantiated, according to the report.

In many cases, the dioceses said they had not conducted investigations because the priest or clergy member was dead or had already resigned by the time the allegation was reported to the dioceses, according to the attorney general’s office. It did not specify which of Illinois’ six dioceses were responsible for the unreported accusations.

In other cases, the dioceses failed to “substantiate” an allegation when it came from only one survivor, even when church officials had reason to believe that survivor and reason to investigate further, according to the report.

“The dioceses also often found reasons to discredit survivors’ stories of abuse by focusing on the survivors’ personal lives,” the report says.

The six dioceses in Illinois are: Chicago, an archdiocese, and Belleville, Joliet, Peoria, Rockford and Springfield.

“The Dioceses of Belleville, Peoria, Rockford, and Springfield did not take the basic step of publishing a comprehensive list of clergy who had been ‘credibly accused’ until the Office became involved”, the report says.

Bishop Thomas Paprocki of Springfield said his diocese has cooperated with the attorney general’s investigation, but the decision to withhold names in the past was done with “a virtuous intent.” …

“A virtuous intent to protect the faithful from scandal …” …

In December, the Society of Jesus, popularly known as the Jesuits, released lists from four provinces of more than 230 priests who had been credibly accused of abusing minors.

CNN’s Rosa Flores contributed to this article.

Catholic Church in Illinois Withheld Names of at Least 500 Priests Accused of Abuse, Attorney General Says: here.

Alligator snapping turtles back in Illinois, USA


This 2015 video from the USA is called Alligator Snapping Turtle vs Common Snapping Turtle.

From the University of Illinois at Urbana-Champaign in the USA:

First wild alligator snapping turtle in Illinois since 1984

November 13, 2017

Researchers report the first sighting in 30 years of a wild alligator snapping turtle in Illinois. The discovery may be a sign of hope for this state-endangered species, or the animal could be the last of its kind to have survived in Illinois without human intervention, the researchers say.

The team reports the find in the journal Southeastern Naturalist.

In October 2014, when Illinois Natural History Survey herpetologist Chris Phillips donned a wetsuit and dove to the bottom of Clear Creek in Union County, Illinois, he was looking for a young male alligator snapping turtle with a radio transmitter on its back. That turtle had recently been released in the area to bolster the state-endangered turtle population in southwest Illinois.

“I was just about out of breath when I felt the turtle shell,” Phillips said. “I thought I had found the male turtle I knew was there because I detected its radio signal. I felt along its back to where I thought the shell should end, but my hand just kept going.”

Phillips plucked from the water a 22-pound, 15-inch long female alligator snapping turtle that was twice as long as the one he was looking for, and at least 18 years old. Since she had no tracking device, she was not one of the turtles that had been released into the area. DNA tests showed that she belonged at the site and was not a lone traveler from a southern state. Southern Illinois is at the northern end of the turtle species’ range.

For years, INHS researchers have conducted extensive trapping, and have called for citizen observations along Clear Creek for signs of wild alligator snapping turtles, but to no avail. Populations of this state-endangered species have declined because of habitat changes including dams, drained swamps and river dredging. Only Union and Jackson counties offer the habitat that the turtles need to reproduce and thrive. Locating any wild turtles in these counties will help determine the next steps — whether to preserve a population or reintroduce more alligator snapping turtles in Illinois.

“Bolstering a hidden population of an endangered species is better than starting a new population in the area,” said Ethan Kessler, a graduate student of natural resources and environmental sciences at the University of Illinois and a co-author of the study. “However, since no wild alligator snapping turtles have been found in Illinois since 1984, reintroduction efforts make sense.”

For several years, researchers have purchased turtles reared in a facility and released them at ages 2, 3, 4, 5 or 6. They also released about 90 adult turtles. Most of the animals go into creeks with radio transmitters attached to their backs so they can be relocated and tracked.

Researchers were conducting their biannual catch-and-release program when they found the wild turtle, close to the same spot and 30 years, almost to the day, after their last wild alligator snapping turtle was found.

“Finding this individual does not indicate that there is a functional, stable population of wild alligator snapping turtles in Southern Illinois,” Kessler said. “When a population dies out, a single turtle may wander around like a zombie waiting for the end of its days.”

Alligator snapping turtles can live 100 years, so the researchers working on this project today likely will not witness the advancing seasons of this female’s life. After finding her, the team marked her shell with a notch and attached a radio transmitter to her back for tracking. The transmitter battery died, however, and finding her again in the sediment-filled depths of Clear Creek or elsewhere would be like finding a needle in a haystack, Phillips said.

“She is marked, so in case of an incidental encounter, we will know it’s her,” he said.

One of the challenges of tracking turtles that have been introduced in Illinois is that they disappear underwater and may not be seen again until divers retrieve them.

“If we succeed with our project in introducing a new, viable population of alligator snapping turtles, it’s likely that no one will see them,” Phillips said. “It’s not as if we’re studying bald eagles that soar above us. I may never know the fate of these turtles, but it’s cool to know that this wild space exists in Illinois.”

The alligator snapping turtle is listed as threatened in the U.S.

The Illinois Department of Natural Resources funded this research. Mike Dreslik of the INHS and Scott Ballard of IDNR are co-authors of the article. The INHS is a division of the Prairie Research Institute at the University of Illinois.