Posted by: NatureIsAwesome | April 24, 2011 @ 10:44 am

Birds Heading North; Another Push Out Of Cuba

This is the radar from 5:00pm last night to 10:00am this morning.

Frames are every 1/2 hour. Click on the thumbnail to view the full-sized animation.
Base Reflectivity image from Key West, FL Base Velocity image from Key West, FL Base Reflectivity image from Miami, FL Base Velocity image from Miami, FL Composite base reflectivity for the Southeastern USA

Southerly winds in the upper atmosphere and clear skies triggered another big flight across the SE last night. The bulk of birds were moving in a general S–>NW direction riding the tailwinds all the way out of Florida. Winds and the lack of heavy precipitation or frontal boundaries in the forecast should keep bird concentrations down to a minimum. If these conditions persist birders here in Florida will continue to have mediocre days with both reduced quantity and diversity.

The axis of migration as visible on both the Key West and Miami velocity radar has been generally SE–>NW which means that birds are taking the west bound road up the state. Clear skies and favorable winds at altitudes in which nocturnal migrants travel while aloft has made for a clear passage north this spring. These conditions are reinforced by the Bermuda High which is a semi-permanent area of high pressure. This high is a key role player in bird migration over the southeast during spring. The clockwise circulation engulfs the state with favorable winds for nocturnal migrants hoping to reach the breeding grounds. With all these factors taken into account, we should expect a slower migration for us on the ground. If we were birding at 3K feet migration it would be a different story.

That said spring migrant traps hold your best chances of seeing migrants in Florida. Surface winds across much of the state have been generally east -> west pushing migrants out to he west and over the Gulf. Spring migrations as such are a great chance to learn about how meteorological factors play a key role on nocturnal migration. Please leave your comments in the comments section and share your thoughts about what factors you think have made this spring migration slow in your eyes.

Nature is Awesome,
Angel and Mariel

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Responses

  1. If i may ask a novice birder question, with good weather and winds approximately how long does it take groups of birds to get from the Keys to Jacksonville/so Georgia?

    • That is a great question Pamela.

      There are many factors that come into to play when looking at how long it takes for a specific bird to fly from KW to JAX. If you are talking about warblers then we can estimate that the typical wood warbler can make a flight from KW to JAX in approximately two days with favorable winds/weather. This of course is contingent on a couple of factors. With sufficient fat reserves and a tailwind, warblers typically fly 200-300 miles a night. This can change rapidly when you are talking about a trans-gulf migration which can lead a bird on a non stop flight over the Gulf. A flight as such can take a bird ~20 hours.

  2. Migratory birds were present in pleasant-to-good numbers through the Upper Keys into the Middle Keys. Birded several locations, below include the highlights.

    Dagny Johnson:
    Warblers were in relatively low numbers compared to past week.
    Both breeding cuckoo species were vocal.

    Windley Key State Park had quite a nice surprise of songbirds, including:
    Northern Parula
    Prairie Warbler (various)
    Cape May Warbler (various)
    Blackpoll Warbler (most common warbler migrant in Upper Keys today)- seen nearly everywhere down to Bahia Honda
    Black-throated Blue (various)
    Black-throated Green Warbler
    The surprise was a female Blackburnian Warbler – great for spring in SFL.
    Black-whiskered Vireos – quite vocal – were easy to locate.

    The majority of the above-mentioned birds were found behind the visitors’ center, near the watering Wild Coffee area – ask the park rangers about it. Birds were congregating to bathe, great looks. Was joined by a merry group of California birders to enjoy the feast.

    Elsewhere in the keys, picked up the following:
    Black-and-white Warbler
    Worm-eating Warbler
    Northern Waterthrush
    Yellow Warbler
    White-eyed Vireo

    Best to all!!
    Rafael

  3. Lead field trip to Fort Desoto park for Orange Audubon morning was very very slow after 3 hours we had 2 Cape May (1 male, 1 female) and 2 Indigo Bunting males, plus a few Gray Catbirds. After checking out the shorebirds we headed over to Arrowhead Picnic area about 2:30-3:00pm and hit some birds Cape May (8-12 mostly males), Black & White (6-8 about even split male/female), Blackpoll (1 male), American Redstart (1 male, 1 female), Worm-eating (1), Nashville (1 female), Common Yellwothroat (4-6 mostly males), Northern Parula (2 Male), Ovenbird (1), Black-throated Blue (6 males, 1 Appalachian Male) still very dead day considering time of year but hard work paid off for those who stuck with me! Nashville was photographed by Janson Daly and posted to ID forum confirming ID that I was 98% sure in the field but I’m not overly familiar with this species so it was good to get other opinions, the grayish head and distinct eye-rings gave it away but I wanted to be sure since I knew it wasn’t an adult male which would have been easier.


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