Goatsucker Infestation

CWWI_100917_2_ALC crop

We had an exciting Monday morning when three Chuck-will’s widows and a Whip-poor-will were all captured on the first net run. Both species are strange-looking when compared to most birds. They are adapted to hunt while flying at night, and as a consequence they have very large eyes and a huge mouth. Don’t be fooled by the tiny beak; the gape extends behind the eye and the whole head seems to open up like Pacman when it wants to swallow something. Chucks (left) and Whips (right) are similar to each other, but the Whip-poor-will is smaller and we have captured far fewer of them. 


Adult males of both species have white in their tails: the top bird is the Whip-poor-will and the bottom is the Chuck-will’s widow. Both are named for their calls.

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Some other interesting captures include our second Summer tanager of the season, here looking around for fingers to nip.


A beautiful resident species of Cape Florida is the Common ground-dove.


We have continued to band a steady stream of birds this week; our daily totals are lower than usual since we have fewer nets up than before the hurricane, but the species diversity has been interesting. Red-eyed vireos, Ovenbirds and Black-throated blues remain our top captures for now. There is no sign of a cold front coming to our latitude in the long-range forecast and the easterly winds have been pushing most of the migrants inland, away from our banding site.

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CFBS is back!

We finally were able to return to the site on Friday Sept 29 and start the process of cleanup and setting the nets up again after Hurricane Irma’s pass over Florida on Sept 10. There was a lot of tree damage; most of the big ficus trees were still standing but they have shed a lot of branches. The nets are much sunnier now so we will have to be extra careful about closing many of them as the sun gets high towards midday. We have 17 nets back up of the original 26; most of the rest will have to be completely relocated.

There was some excellent migration movements through our part of the world in the days following the storm, and there was still a nice variety of species flitting about when we setup on Friday. We were rewarded with a diverse couple of days over the weekend; this is typical for late September and early October as we near the peak of migration.


Red-eyed vireos were our number one capture; an indication of the lack of canopy in the woods since they normally stay high in the trees above our nets. A burst of Cape May warblers flew in right after sunrise on Sunday and we banded 7 of them; this is a season total in some years.

12 year olds (crop)

The Northern cardinal who is the same age as one of our volunteers was recaptured on Saturday. They are both 12 now! This cardinal has now survived three hurricanes at Cape Florida; Katrina and Wilma in 2005 and Irma in 2017.

Here are our totals for the weekend:

Sept 30/Oct 1

Totals: 32/47

  1. Red-eyed vireo: 11/13
  2. Black-throated blue warbler: 3/8
  3. Cape May warbler: 0/7
  4. American redstart: 2/3
  5. White-eyed vireo: 2/2
  6. Black & white warbler: 2/2
  7. Swainson’s thrush: 1/3
  8. Ovenbird: 1/3
  9. Veery: 2/0
  10. Common yellowthroat: 2/0
  11. Northern cardinal: 2/0
  12. Worm-eating warbler: 1/1
  13. Yellow-throated vireo: 1/0
  14. Northern parula: 1/0
  15. Painted bunting: 1/0
  16. Alder flycatcher: 0/1
  17. Blue jay: 0/1
  18. Magnolia warbler: 0/1
  19. Wilson’s warbler: 0/1
  20. Summer tanager: 0/1


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Hurricane Irma and CFBS

As everybody has probably already heard, Hurricane Irma engulfed a majority of Florida and several other states in the Southeast US after leaving a swath of damage through the Caribbean. The closest approach of the eye to Cape Florida was in the lower Keys, but the storm was so massive that there was storm surge in Biscayne Bay, nearly 200 miles away. At this time the banding station is broken down and all of our volunteers are cleaning up the messes at our homes. Still, Irma could have been a lot worse. Facing down a Category 5 for days on end was, um, unpleasant, so I personally am very relieved that things weren’t worse for us. The site is probably still there and we should be able to get out there before the field season ends and start banding again, but we don’t know when that will be. The damage is probably similar to Hurricane Wilma from 2005, when we had to almost completely re-do the net lanes. But at least there should not be a complete overwash of the Cape. We will see.

We were having a slow but steady season up until we closed and broke down the station on Sept 6. Ovenbirds (above) and Worm-eating warblers were the most abundant captures, as is typical for early September. A couple of Louisiana waterthrush were also lingering. A Chestnut-sided warbler (below, left) banded on Sept 4 was a treat! Hooded (below, right), Prothonotary and Swainson’s  warblers added some diversity.


The trickle of birds in August was becoming a steady stream, and now in the days following Irma there are lots of warblers moving through Florida. We can hear them calling while we clean up debris. Local birds seem to have survived the storm well, which is surprising since there were winds of at least 40 mph for 48 hours with a few hours of gusts in the 90’s.

Irma breakdown crew on Sept 6. Note the sweatkini.

Pre-Irma Total (Aug 15 to Sept 6): 184 birds of 18 species

  1. Ovenbird: 47
  2. Worm-eating warbler: 26
  3. Black & white warbler: 25
  4. American redstart: 24
  5. Northern waterthrush: 24
  6. Blue-gray gnatcatcher: 7
  7. Northern cardinal: 5
  8. Swainson’s warbler: 4
  9. Louisiana waterthrush: 4
  10. Northern parula: 3
  11. Common grackle: 3
  12. Red-eyed vireo: 2
  13. Prairie warbler: 2
  14. Prothonotary warbler: 2
  15. Kentucky warbler: 2
  16. Hooded warbler: 2
  17. Chestnut-sided warbler: 1
  18. Black-throated blue warbler: 1


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Unusual species to start the Fall 2017 banding season

Our first day open turned out to be a nice day for mid-August, with 9 birds of 5 species banded. The very first bird out of a net was this Kentucky warbler, a species we usually only catch 1 to 3 times a year. Other birds on the move right now include Worm-eating warbler, Black & white warbler, Ovenbird, Northern waterthrush, American redstart and Red-eyed vireo. The numbers remain low, although we are hoping for some interesting weather interactions later on this week involving a weak front and a tropical wave. The unsettled weather could get some migrants to stopover in our area. We will see!

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It’s a wrap!

We ended the 2016 banding season today with a Gray catbird return from 2010 as our final capture. We were frustrated by a solid month of strong NE winds which killed any chance we may have had for big October movements. In fact, the busiest day between Oct 12 and Nov 7 was 24 birds on Oct 22. This time of year is usually when we can expect to get multiple 3-digit days, but not this year. We hope this weather pattern does not re-occur for a long time!


One of the consequences of the lack of strong fronts this fall is that there are migrants running late mixed in with arriving wintering birds, like the Eastern phoebe above. We banded 3 Red-eyed vireos and one Swainson’s thrush in the last week; these are September migrants that usually have completely moved through our area by November. Still, we were able to band record numbers of a few species this season, including Swainson’s thrush, Swainson’s warbler and Worm-eating warbler. Ovenbirds, Black & white warblers, American redstarts and Northern waterthrushes were captured in typical numbers. Gray catbirds and Black-throated blues were noticeably lower in numbers this year. Cape May warblers seemed to be having a good year and we saw a lot more around than we captured. In addition to the weather, our banding totals were affected by a lack of fruiting strangler fig trees in the netting area. These trees are a favorite source of food and fruiting trees draw in dozens of birds that can spend all day chowing down in a single big tree.

Here is an adult Red-shouldered hawk that escaped out of the net before we could grab it, but it left its iguana prey behind.


We presented a poster with some preliminary results from 14 seasons of banding at the Florida Ornithological Society meeting last weekend at Archbold Biological Station. Representing CFBS are Miriam, Nico, Michelle, Lucas and Mario.


Once again, huge thanks go to the fantastic team of volunteers that make the season happen! The Cape Florida Banding Station currently receives $0 funding, except for the generosity of our Adopt-a-Net sponsors that enable us to replace nets and other essential equipment. Thank you all!

 Total captures: 1930 birds of 62 species

  1. Ovenbird- 337
  2. American redstart- 276
  3. Black-throated blue warbler- 244
  4. Worm-eating warbler- 162
  5. Black & white warbler- 137
  6. Common yellowthroat- 106
  7. Northern waterthrush- 96
  8. Gray catbird- 92
  9. Swainson’s thrush- 54
  10. Blue-gray gnatcatcher- 49
  11. Swainson’s warbler- 41
  12. Painted bunting- 38
  13. Western palm warbler- 35
  14. Red-eyed vireo- 33
  15. Prairie warbler- 30
  16. Northern parula- 25
  17. Myrtle warbler- 14
  18. White-eyed vireo- 12
  19. Northern cardinal- 12
  20. Gray-cheeked thrush- 11
  21. Cape May warbler- 10
  22. Common grackle- 10
  23. Veery- 9
  24. Alder flycatcher- 8
  25. Yellow-billed cuckoo- 7
  26. Great crested flycatcher- 7
  27. Sharp-shinned hawk- 5
  28. Traill’s flycatcher- 5
  29. Magnolia warbler- 5
  30. Indigo bunting- 5
  31. Chuck-will’s widow- 4
  32. Eastern phoebe- 4
  33. Hooded warbler- 4
  34. Red-bellied woodpecker- 3
  35. Yellow-throated vireo- 3
  36. Prothonotary warbler- 3
  37. Louisiana waterthrush- 3
  38. White-crowned pigeon- 2
  39. Acadian flycatcher- 2
  40. Common ground-dove- 1
  41. Mangrove cuckoo- 1
  42. Eastern wood-pewee- 1
  43. Yellow-bellied flycatcher- 1
  44. Blue jay- 1
  45. Philadelphia vireo- 1
  46. Black-whiskered vireo- 1
  47. Gray-cheeked/Bicknell’s thrush- 1
  48. Bicknell’s thrush- 1
  49. Wood thrush- 1
  50. House wren- 1
  51. Blue-winged warbler- 1
  52. Nashville warbler- 1
  53. Orange-crowned warbler- 1
  54. Yellow warbler- 1
  55. Chestnut-sided warbler- 1
  56. Bay-breasted warbler- 1
  57. Blackpoll warbler- 1
  58. Kentucky warbler- 1
  59. Connecticut warbler- 1
  60. Savannah sparrow- 1
  61. Blue grosbeak- 1
  62. Rose-breasted grosbeak- 1
  63. Bobolink- 1
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Very slow October

Strong northeast winds have been in place for nearly the entire month of October, and the forecast shows no signs of them abating before we close. We have had mostly single-digit daily captures for the past three weeks, when usually we should have a few 100 plus days mixed in. Persistent high pressure to the north of us has combined with low pressure in the Caribbean to increase the wind speeds to 25-30 mph over the last few days, so the station has had to shut down for now. The Saturday crew tried to band today, opening only the most protected nets in the forest, and were rewarded with one gray catbird for their efforts.


A few interesting birds did trickle in during the past few days. Here is a portrait of a female Sharp-shinned hawk. We banded three Sharpies on Oct 21, and hawk migration during those days was phenomenal! Every time we looked up into the sky while doing net runs we saw raptors; mostly Sharp-shins, Cooper’s hawks, Merlins, Kestrels, Broad-wings and a few Northern harriers and Short-tailed hawks.


A dry front passed that night, but few birds landed at Cape Florida. Several wintering species did arrive following the front, such as this Myrtle warbler.


This very cute Philadelphia vireo was banded on Oct 19.



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Birds and Hurricanes, Part II

The winds on the west side of Hurricane Matthew were surprisingly weak, and it only gusted into the high 30’s at the site with little rain. The banding area was completely unharmed, so we reopened the day after the storm passed. We have had a steady stream of migrants with new species for the season since then, but no huge numbers on the ground because the weather is so nice that the birds are flying straight through! A weak front passed a few days ago and it lowered the humidity while providing great conditions for migration. Since then high pressure has set in north of us and we have had steady, fairly strong NE winds, which are bad for getting birds at our site. This time of year is usually our peak for numbers since it normally is our first real cold front of the season, and the Black-throated blue warblers and Gray catbirds are moving through. We are getting antsy for a new weather pattern!


We have been asked several times about what happened to the migrating birds during Hurricane Matthew. The following is speculation based on radar observations and the condition of captures at Cape Florida. Large numbers of migrants used the NW and N winds on the backside of the storm as a tailwind, beyond the worst of the wind and rain. These birds were nowhere near the center of the storm and had a quick ride south. Few of them bothered to land at Cape Florida. In the radar image below from the night of Oct 8-9, the yellow is Matthew raining himself out over North Carolina while the green blobs are millions of birds heading south in the night sky.


Of the birds we did catch, most were fat and healthy but a couple were in horrible condition with no fat and most of their pectoral muscle mass consumed. One Ovenbird was so weak that it died shortly after capture. I had not seen a bird so emaciated in years! The other hard cases were able to fly off and resume foraging, so they should be able to fatten up again because of the abundance of food at Cape Florida. It is hard not to think that these individuals had a bad run-in with Matthew somewhere along their route south, but the majority of birds avoided the worst weather and are continuing their migration in great shape. Below is our first Wood thrush of the season.


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