Sam Crowe on July 16th, 2017

I found this article on the Black-capped Vireo and cowbird predation especially interesting as several years ago I had the opportunity to spend the day at Fort Hood in central Texas, where much of this study took place. The fine folks from the Nature Conservancy were studying both the Black-capped Vireo and Golden-cheeked Warbler and working on conservation of the these two endangered species. Black-capped Vireos prefer to nest in disturbed areas and it was interesting to learn that a popular nesting location was located where training ordinances were detonated.

black-capped-vireo

Black-capped Vireo. © Greg Lavaty

From Avian Conservation & Ecology
Lauren E Walker, School of Environmental and Forest Sciences, University of Washington, Seattle, Washington, USA
John M Marzluff, School of Environmental and Forest Sciences, University of Washington, Seattle, Washington, USA

Abstract: Full article here.
Breeding birds vocalize to find mates and establish and defend territories, but these same critical communications may also attract predators or brood parasites, placing birds in a cruel bind. Although vigilant birds may better maintain social relationships with mates and neighbors through frequent vocalizations, reticent birds may reduce risk to their nests by being relatively quiet and making infrequent vocalizations. Selection for vocalization patterns that minimize brood parasitism might be particularly strong for birds that are unable to fledge both their own young and the parasite. Temporal plasticity in the frequency of vocalizations near nests, however, may allow birds to balance trade-offs and optimize nest-defense strategies. The Black-capped Vireo (Vireo atricapilla) is an endangered songbird that faces intensive brood parasitism in areas where Brown-headed Cowbirds (Molothrus ater) are present. Vireo nests that produce cowbird fledglings always fail to fledge vireo young. We recorded vocalizations at vireo nests across three nesting stages (building, laying, and early incubation) and three periods of the day (morning, midday, and evening) and compared vocalization frequency with eventual depredation or parasitism fate as well as local cowbird density to test two hypotheses. The predator-attraction hypothesis predicts that predators will be attracted by frequent vocalizations, whereas cowbirds will parasitize nests with relatively quiet parents and less predation risk; thus, vireos will experience trade-offs between reticence and vigilance in mediating specific risks. The parasite-assessment hypothesis predicts that vireos will become more secretive as local cowbird densities increase. Vireo vocalization response to nest predation and parasitism risk interacted with nest stage, and we found little evidence of risk mediation through vocalizations except during the building stage. Vireos, however, did benefit overall by optimizing temporal patterns in vocalizations. Vireo nests were less likely to be depredated or parasitized if males vocalized most during laying and least during the middle of the day. Birds vocalized more during the midday and less during the laying period when local cowbird densities were higher, however, perhaps demonstrating limited plasticity in social communication.

Sam Crowe on July 9th, 2017

Zoologists at the University of Cambridge filmed a group of Mallards hunting other birds on a reservoir in Romania.

mallard eating redstart

Two fledglings – a grey wagtail and a black redstart – were chased and swallowed when they landed in the water.

Mallards normally feed on seeds, plants and insects. Small fish are occasionally on the menu but consumption of larger vertebrates by Mallards is quite rare.

The BBC web site has more on the story and images of the predator female Mallards.

Sam Crowe on July 4th, 2017

A new parrot species has been identified from the Yucatán Peninsula: The Blue-winged Amazon.

I had no idea there were remote parts of the Yucatán Peninsula but apparently there are. The next time I make a trip to Cancun think I’ll wonder inland a little bit.

In 2014, during a visit to one of the remote locations of the Yucatán Peninsula in Mexico, ornithologist Dr. Miguel A. Gómez Garza discovered a new species of parrot, which has been named the Blue-winged Amazon (Amazona gomezgarzai). The new species has a distinctive call and distinctive color pattern.

A complete report on the discovery and study of the new species is available on the PeerJ web site.

Blue-winged Amazon

Sam Crowe on June 26th, 2017

The speculum is a patch of often iridescent color on the secondary feathers of many duck species.  It is often seen as a bright patch of color on the rear of the wing when the wing is spread during flight or when the bird is stretching.  The color and size of the speculum varies by species.

The speculum may also be edged with white or other colors.

The leading edge of the wings of several duck species can also be very colorful and a nice aid to identification.  Here are some examples of very distinctive speculums and other wing colors.

The underside of the wings, referred to as the wing linings, are usually very plain in appearance.

Blue-winged Teal
It is easy to see where this species obtained its name.  Note the speculum is green.  Compare the colored parts of the wing to the the image that follows.

blue-winged teal in flight

duck wing pattern

Northern Shoveler
The male Northern Shoveler wing pattern is very similar to the Blue-winged Teal.  The distinctive large bill of the shoveler is clearly noticeable.

northern shoveler in flight

Gadwall
The Gadwall has a very different wing pattern. The white speculum is very visible in flight.

gadwall in flight

Mallard
The Mallard has a very distinctive speculum that can appear blue to purple, depending on the light. The speculum is edged above and below with white.

mallard in flight

Sam Crowe on June 18th, 2017

What is the only North American (U.S. and Canada) songbird that breeds exclusively in Canada?  It is one of our most beautiful, and one of my favorite sparrows – the Harris’s Sparrow.

The Harris’s Sparrow nests primarily in the boreal-tundra transition of the Northwest Territories, Nunavut, and the northernmost parts of Saskatchewan, Manitoba, and Ontario.

The species is primarily monitored on its wintering grounds in the U.S., where numbers have declined by nearly 60% since 1980. The Harris’s Sparrow was assigned the status of Special Concern on the basis of this trend, and concerns of ongoing threats such as habitat conversion, cat predation, and climate change.

Plumages vary. Harris’s Sparrows have dominance hierarchies in winter, with body size and the extent of black feathering on the bib contributing to a bird’s position in the hierarchy.  The winter range is limited to the central United States.

Sam Crowe on June 4th, 2017

This little bit if happy news is from The Birding Community E-Bulletin.

In a refreshing move of bipartisanship, Rep. Mike Quigley (D-IL) and Rep. Morgan Griffith (R-VA) recently introduced the Federal Bird-Safe Buildings Act. The bill (H.R. 2542) is designed to amend title 40 of the United States Code to direct the General Services Administration (GSA) to incorporate bird-safe building materials and design features into public Federal buildings.

It is believed that as many as a billion birds a year currently die in collisions with buildings in North America alone. Achieving city-by-city, county-by-county, or even state-by-state compliance in assuring bird-safe design and seasonal lighting is an excellent conservation approach, and so is asking for state-government, company-wide, and now Federal policy to engage in this endeavor.

The bill calls for each public building constructed, acquired, or significantly altered by the General Services Administration to incorporate, to the maximum extent possible, bird-safe building materials and design features. Many bird-friendly design techniques – such as installing screens or grilles on windows, and minimizing the use of glass on lower floors – are already used in some federal buildings to control heat and light or building security. Where practicable, this new legislation would require GSA to take similar actions on existing buildings.

“By pursuing cost-neutral, responsible, and realistic solutions we can play an important role in preserving the intrinsic, cultural, and ecological value birds bring to our society,” Rep. Quigley said. “This bill will put an emphasis on constructing buildings with bird-safe materials and design features, which in turn will help eradicate unnecessary bird deaths caused by collisions with glass.”

You can read a statement by Rep. Quigley here:

And also see comments from the American Bird Conservancy here:

Audubon has launched a pilot program called Climate Watch. The plan is to use bluebirds and nuthatch observations to validate Audubon’s predictions on how birds’ territory ranges will shift in response to a changing climate.

Audubon released its Birds and Climate Change Report in 2014. It used Christmas Bird Count and Breeding Bird Survey data to model how different bird species’ preferred climatic conditions, like temperature and rainfall, may shift in response to climate change.  Although based on data the models were educated guesses.

By studying common, easy-to-identify birds the program hopes to establish base-line information and then track changes over time.

Many models that attempt to predict changes in territory rely on the fundamental assumption that a species’ preferred climatic conditions won’t change. That is, birds will search for the climate they’re used to rather than to trying to adjust to the climate change in their historic range. Climate Watch allows scientists to test this underlying assumption, in addition to seeing whether birds match the model’s predictions.

Birds included in the study include all three bluebird species plus White-breasted, Red-breasted, Brown-headed and Pygmy Nuthatches.

Mountain Bluebird

Mountain Bluebird

Details available on the Audubon web site:
Information on the participating in the Climate Watch Program.

The Climate Change Report with Audubon’s findings, their implications, and how to interpret the data is available in both a quick overview video and detailed information.

Audubon’s climate change news and programs.

Warmer weather brings noticeable changes in the Great Backyard Bird Count

Sam Crowe on May 21st, 2017

The australian bird guidePrinceton University Press has had a great year introducing new bird guides.  First across my desk was Raptors of Mexico and Central Mexico.  Raptors can offer a real identification challenge so this new guide was a welcome addition.

Next was the gorgeous Birds of India Guide. This guide featured over 4,000 stunning photographs of birds of India and the surrounding area.  (Both reviewed previously.)

The latest to arrive is the masterful “The Australian Bird Guide” with a blue cover.  The books skilled authors are Peter Menkhorst, Danny Rogers, Rohan Clarke, Jeff Davies,  and Peter Marsack.

The guide includes information on over 900 species, with 249 color plates and 4,000 beautifully drawn color images!

The descriptive information for each species is almost encyclopedic in nature, more than any other general field guide that I have seen.  Range maps are included for each species and a Visual Quick Reference guide to the different bird groups is included on the inside front cover and facing page.  This feature will be a great aid to anyone not already familiar with the great diversity of birds and habitats in Australia.

A nice touch is a narrow red ribbon attached to the spine of the book that can be used to mark a particular page in the guide.  This built-in bookmark will be very handy when studying a particular plate, especially when several species are very similar in appearance.

raptor images for the new australian bird guide

Sample plate from the Australian Bird Guide. Identification notes are included on most images in the guide.

The guides is roughly the size of the original Sibley guide, but slightly wider and quite heavy.  Most people will find it too large and heavy to slip in their pocket but will find it a great resource to have in the car.  On two previous trips to Australia I used the Slater guide to Australian birds, a smaller guide easy to carry in the field and an excellent guide in its own right.   The two guides together would be a perfect combination for birders visiting Australia.

For anyone contemplating a visit to the island continent, Australia is home to some of the most beautiful birds in the world, and some are quite common.  There are also some very challenging identification problems, so this new guide will come in very handy.

For those looking for something extra-special on a visit to Australia I recommend some time on Heron Island, located on the Great Barrier Reef.  Sir David Attenborough considers it one of his most magical places on earth.  If you spend time there you will also.  My wife and I spent a week on the island several years ago diving and relaxing.  At the right time of year birders will find 100,000 Black Noddys and 30,000 Wedge-tailed Shearwaters nesting on the island. Other resident birds include:

Bar Shouldered Dove
Black-Faced Cuckoo-Shrike
Buff Banded Rail  (One walked right onto our porch.   The birds on the island are not generally afraid of humans.)
Capricorn Silver Eye
Eastern Reef Egret (formally known as a Reef Heron)
Sacred Kingfisher
Silver Gull
White-Bellied Sea Eagle

 

Where to go first?
So India, Australia or Mexico and Central America – a tough choice but any of these new guides will make your birding trip much more successful.

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Sam Crowe on May 14th, 2017

The 21st International Conference of BirdsCaribbean will take place July 13-17, at Topes de Collantes Nature Reserve Park in Cuba.

Cuban Trogon

Cuban Trogon © Max Schwenne

The five-day conference will bring together participants from the fields of  ornithology, conservation, education, ecotourism, and birding.

The theme of the meeting is “Celebrating the Diversity of the Caribbean.” This theme relates not only to the wonderful diversity of avian species found in the region, but also to the passionate and dedicated scientists and conservationists that work tirelessly to study and protect them. From todies and trogons to parrots, peeps and petrels, there is ample reason why the Caribbean is a biodiversity hotspot.

In addition to the five days of the main conference, there will be pre- and post-conference workshops and field trips to the best bird sites of Cuba.

Visit the BirdsCaribbean Conference Web site for additional information.

Sam Crowe on May 4th, 2017

Recently returned from a quick trip to the Galveston, Texas area.  About 2 days of birding yielded 118 species.   Warblers were only fair and numbers of other usually common migrant landbirds were way down.  Hopefully just the timing.  Laffite’s Cove toward the western end of Galveston Island was more productive than High Island for warblers and yielded a rare-for-Texas Black-whiskered Vireo.

Here are a few photos from the area.

Wilson's Phalarope and Lesser Yellowlegs

This Wilson’s Phalarope and Lesser Yellowlegs were palling around for 2 days.

 

Whimbrel

Whimbrel’s were unusually common on Yacht Basin Road near Roll-over Pass.

cardinal eaten by snake

The water moccasin took a young Northern Cardinal that was not paying attention. It’s a jungle out there.

 

Spotted Sandpiper

Not the best photo of a Spotted Sandpiper but I love the way the bob their tail as they move along. Spotted’s are now along the golf course near my home in Dallas.

 

roseate spoonbill

A trip to the rookery at High Island is always worth the time. Hundreds of nesting Roseate Spoonbills and egrets.

 

rose-breasted grosbeak

This Rose-breasted Grosbeak was only about a foot off of the ground and paid no attention to attentive birders that walked by within a few feet of the bird.

 

long-tailed duck

A rare, for Texas, Long-tailed Duck resting on the beach on Bolivar Peninsula.

 

lesser scaup

Several Lesser Scaup were also resting on the shore.

 

Fluvous (left) and Black-bellied Whistling Ducks.

Fluvous (left) and Black-bellied Whistling Ducks.

 

The amazing legs of the Black-necked Stilt.

The amazing legs of the Black-necked Stilt.