Thursday, January 25, 2018

Shadowed by a Shrike

Loggerhead Shrike and waning SuperMoon:

Shrike and Moon HDR 20161117

A murky morning on the local wetlands:

Murky Morning little island 04-20161113

Around the world there are thirty shrike species, but the Loggerhead Shrike is the only whose range is limited to North America.


The population of this species has declined dramatically since the mid-Twentieth Century, believed to be attributable to human alteration of habitat such as elimination of fence rows in its favored open pastures and their replacement by cropland. Other factors may include the effects of pesticides, strip mining and expanded dense urbanization. It is listed as threatened or endangered in several Midwestern States.

Loggerhead Shrike 01-20171228

Loggerhead Shrike 03-20180110


The hooked beak and striking plumage pattern of the Loggerhead Shrike make the little bird look fierce indeed.

Loggerhead Shrike 20171210


 

When I was about 10 or 11 years old (before I started my Birding Life List at the age of 13), while walking in the river bottoms near my home in New Jersey, I came across a barbed wire fence which had a mouse and several grasshoppers impaled on the spikes. I already knew from my reading that this is a practice of shrikes. It allows them to secure and tear prey despite their lack of talons. I returned to look for the shrike and finally saw it.

Here in south Florida, as in the southern half of the contiguous 48 States, it is found all year around. It also breeds up through the western central US into Canada, but migrates south in winter.

A courting pair:

Loggerhead Shrike courtship 4-20130607

I usually see one or a few on my daily morning walks, and they often forage in our suburban neighborhood.

Loggerhead Shrike with waasp 20161130


A few times over the years a shrike would fly down and pick up a prey item near where I was standing. The large grub in the second photo below is probably the larva of a Horsefly:

Loggerhead Shrike 01-20171222


Shrike with big grub (prey ID please) 20100719

I thought this to be a random occurrence until one day while walking along the path I noticed that, after it plucked an insect  near me, it continued to follow me along, flying from one perch to the next. Once again, it flew down behind me and seized an elongated prey item. I was not sure whether it was an insect or a small lizard or snake.

Loggerhead Shrike 20171204

The shrike likely learned that my walking along the path often frightened some grasshopper or other creature out into the open. When I lived in Dallas the mockingbirds often followed me as I mowed the lawn, surely for the same reason. Similarly, gulls follow boats, and inland,  the plow.

I watched for this behavior and it was repeated by the shrikes on other occasions. The shrike sometimes moved along behind me for several yards but I did not see it fly down. Once a shrike picked up a butterfly which flew up from my feet and landed several yards away. It was a Gulf Fritillary, and I photographed it. Just as I lowered the camera the shrike snatched it and flew into a nearby bush. A missed photo-op!

Gulf Fritillary 20171108

It seemed to take a bite and then immediately dropped the butterfly. It must have tasted horrible, as it shook its head and cleaned its bill. 


This observation led me to research the dietary habits of Loggerhead Shrikes and discover that they may impale prey which contain toxins, such as the Monarch butterfly, leaving them for 3 or more days and then "...consuming them afterward, presumably after poisons have degraded... In addition, regularly impales lubber grasshoppers (Romalea guttata) in peninsular Florida for 1–2 days, and then feeds on head and abdomen, discarding thorax which contains poison glands" REF: Birds of North America, Cornell Laboratory of Ornithology [Subscription required].

It is not clear whether this behavior is innate or learned from unpleasant experiences such as the episode which I witnessed. Indeed, larvae of the Gulf Fritillary accumulate toxins from host plants such as passion vine or manufacture them in their own bodies. Adult butterflies also release noxious chemicals from glands in their abdomen when disturbed, to deter predators such as birds. REF: Beautiful but stinky: Gulf Fritillary


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Linking to Misty's  CAMERA CRITTERS,

Linking to Eileen's SATURDAY'S CRITTERS,

Linking to SKYWATCH FRIDAY by Yogi, Sylvia and Sandy

Linking to WEEKEND REFLECTIONS by James

Linking to BirdD'Pot by Anni

Linking to Our World Tuesday by Lady Fi

Linking to Wild Bird Wednesday by Stewart

Linking to Wordless Wednesday (on Tuesday) by NC Sue

Linking to ALL SEASONS by Jesh

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Please visit the links to all these memes to see some excellent photos on display

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Thursday, January 18, 2018

Crops & Clips: Purple Gallinule

The Purple Gallinule is a Florida favorite. It was one of those species in my bird book whose picture looked so exotic and which, as a kid in New Jersey, I hoped one day to see. It took a while, but I finally set eyes on one in Avery Island, Louisiana, in 1967. Here in south Florida it is easy to find them in the right places, especially the settling ponds at water treatment plants such as Green Cay Wetlands in Boynton Beach:

Green Cay Nature Center HDR 20150722
 

This is the nature center and beginning of the boardwalk at Green Cay:

Green Cay Nature Ctr HDR 20150212

Peaceful Waters Park in Wellington is another such location. Here a Purple Gallinule shows off its long toes which allow it to walk across the floating vegetation:

Purple Gallinule 07-20160221

Purple Gallinule 05-20160221

Purple Gallinule 02-20160221

The juvenile can be rather drab. This one was at Loxahatchee National Wildlife Refuge in Palm Beach County:

Purple Gallinule immature 20150722

The first time I saw this species in our neighborhood Wounded Wetlands was in January, 2015, when a pair showed up. I hoped the pair would breed, but they disappeared after only a week or so:

Purple Gallinule 20150117

One year later, also in January, a single adult Purple Gallinule appeared in the same location. Try as I did, I could not find a second bird. It remained into March:

Purple Gallinule 093-20160318

Purple Gallinule 0991-20160318

This December I saw a juvenile gallinule in the same local wetlands patch. The light was bad and it was rather secretive, so at first I was not sure of its identity. I patiently waited for it to come out into the open. It was eating the flowers and seed of Alligator Flag:

Purple Gallinule immature 09-20171225

Alligator Flag must have its roots in water most of the time, so it is found on the edges of marshes and other persistent bodies of water. In the Everglades, this plant often signals the presence of an alligator hole.

Purple Gallinule immature 08-20171225

The tiny flowers of Alligator Flag rise high above on slender stems and the only way the bird can get up to them is to gather several stalks in each of its huge feet and take advantage of the construction principle of triangulation (the use of triangular shapes to give stability to structures such as buildings and towers-- the Eiffel Tower is a good example). In good light, the beauty of this immature Purple Gallinule is revealed. I love this striking pose:

Purple Gallinule immature 03-20171225


= = =  = = =  = = = =  = = = = =

Linking to Misty's  CAMERA CRITTERS,

Linking to Eileen's SATURDAY'S CRITTERS,

Linking to SKYWATCH FRIDAY by Yogi, Sylvia and Sandy

Linking to WEEKEND REFLECTIONS by James

Linking to BirdD'Pot by Anni

Linking to Our World Tuesday by Lady Fi 

Linking to Wild Bird Wednesday by Stewart

Linking to Wordless Wednesday (on Tuesday) by NC Sue

Linking to ALL SEASONS by Jesh

________________________________________________

Please visit the links to all these memes to see some excellent photos on display

________________________________________________