Fall Banding Update: Week 5 (9/13 – 9/19)

Words by Laura-Marie Koitsch, 2018 Bander In Charge

The fifth week of the inaugural season of NJ Audubon’s Cape May Bird Observatory banding station saw a continuation of the easterly winds and variable totals from day-to-day. For example, on September 11th, we banded 107 birds, the following day we banded 41 birds, and on September 13th, we banded 19 birds total. Although we may have only banded 19 birds, it was of 12 species, which is a rather good diversity. On slow mornings, we remind ourselves that it’s not always about quantity but, rather, about quality. We banded our first House Finches of the season, two recently fledged individuals that both still had a big yellow “baby” gape and were quite adorable. We had 11 recaptures that morning, including a Black-and-white Warbler that we had banded nine days prior and which had gained 1/3 of its original body weight over that time frame. Needless to say, that was rather exciting! We did have to close a few nets early due to wind gusts over 20mph that always seem to hit the same five nets the hardest, regardless of which direction the wind is blowing. We closed the entire station down after five hours due to sustained 19 mph winds.

The easterly winds continued into the 14th, with winds out of the SE overnight changing to straight offshore from the east in the morning and once again cutting our previous day’s totals in half. We managed to band 9 individuals of 6 species before the winds decided to kick it up to sustained 24mph, which when combined with the scattered rain, shut us down after only three hours. Again, we had closed the five nets that were taking the brunt of the gusts earlier than we closed the rest of the station. We used the opportunity that a really gusty day presented to us to see where the nets blew & how the trees bent and then trimmed back the net lanes accordingly.

The easterly winds continued strong into the 15th but instead of cutting our previous day’s totals in half, we had our biggest day yet. The radar the night before was certainly interesting but we never expected the amount of birds that we caught that day (124 new, 13 recaptures). Besides sheer numbers of birds caught, it was also our highest species diversity day, with 24 different species handled. We had FIVE first of season species, including a smashing Connecticut Warbler, a Marsh Wren (finally!), and a beautiful Wood Thrush.

Connecticut Warbler courtesy of Ian Lewington

The easterly winds continued into the 16thand throughout the morning changed from NNE to ESE to E and then back again. We closed an hour earlier than usual after the winds decided to kick up to around 19mph. Plus, the straight easterly winds blow directly down many of the net lanes, rippling the nets in a way that’s counterintuitive to how they’re designed to blow. We did band 58 individuals of 18 species. We also banded our first Blue Grosbeak and Warbling Vireo of the season.

Warbling Vireo © Laura-Marie Koitsch

September 17thwe once again closed early but, this was partly due to it becoming slightly gusty and also because we hadn’t caught a single bird in 2.5 hours. Interestingly, we had heard many Veery calling throughout the morning right next to the nets and yet we didn’t catch any. Overall for the day, we banded 14 individuals of 8 species. We did capture three “Traill’s” flycatchers, and upon extensive wing morphology measurements, we concluded that one was an Alder and the other two were Willows. Some might argue that (traditionally) it’s a bit late to still be catching Willow Flycatchers here in Cape May but, others are pointing out that this season has been exceptionally hot with a high heat index and that could be having an effect on the birds migratory timing.

Blue Grosbeak © David La Puma

There was no banding on the 18th. That night the radar was simply insane as birds began taking off right after sunset and we thought, finally, migration has been uncorked. We prepared for the 19thto be a BIG day, making sure to have the largest number of volunteers yet on hand. We banded 70 birds of 16 species, which is by no means a slow day but, compared to all of the movement on the radar and the strong NW winds, we expected to be much busier. We had our first Pine Warbler of the season, a young female that sparked quite the guessing game as to her species, once again proving that yes, there are difficult fall warblers. We also banded our second Marsh Wren of the season but, the highlight of the day absolutely had to be capturing a Veery that weighed 51.9 grams! We actually double checked the scale to make sure that it was working properly and checked the weighing cone to make sure that no other birds were hiding in there! This bird weighed over 20 grams more than it’s counterparts and it was a fantastic sight to behold. Not only that but, the bird was also an adult bird, the less expected age-class at coastal banding stations.

Hatch-year female Pine Warbler © David La Puma

Overall, the fifth week of banding was another amazing week. We were able to operate seventeen nets on six days for a total of 500 mist net hours (mnh). We had 294 total new birds of 33 species. American Redstarts stole the top species banded back from Northern Waterthrush with a total of 88 individuals. Gray Catbirds came in second with 40 individuals banded and Common Yellowthroat finished off the top three with 37 individuals banded. Only 9.18% of the total birds banded with adult birds (AHY). This could be due in part to the large number of American Redstarts banded this week, all of which were HY birds. In fact, of the 330 redstarts we’ve banded this season, only roughly 2% were adults. Again though, this is what we would expect to see, large numbers of HY birds moving towards and then along the coastline. This week the majority of the AHY birds were species that breed locally such as Common Yellowthroat and Gray Catbird but, we are still seeing adult Northern Waterthrushes stopping over here as well the aforementioned Veery.

We recaptured 42 individuals of 9 species. Some of the individuals we recaptured multiple days in a row, notably four Northern Waterthrush that were recaptured on two or more days in the same week. 88.10% of the recaptured individuals were neotropical migrants, with the exception being 4 Carolina Chickadees and 1 Carolina Wren. Interestingly, we are still continuing to see the majority of our recaptures with significant weight gain. Veeries are averaging a weight gain of 2-3 grams a day and Northern Waterthrush are averaging .5 – 1grams per day. Northern Waterthrush are continuing to use The Meadows as a (relatively) long-term stopover site. We recaptured five individuals eight days after previously banding them, two individuals were recaptured after seven days, and another two individuals were recaptured after six days. We do have one individual that has been repeatedly recaptured over the course of fifteen days, showing a steady decline in weight over time. There doesn’t appear to be anything physically wrong with the bird upon inspection but, it is a HY bird and we have to remember that migration is tough on birds and a relatively high number of them do not survive their first year. All in all though, we are nothing short of ecstatic to be recapturing birds that we previously banded and seeing both that they’re gaining weight and also that they’re using the habitat for an extended period of time.

American Woodcock 2
Hairy Woodpecker 1
Yellow-Shafted Flicker 4
Great-crested Flycatcher 1
Traill’s (Alder/Willow) Flycatcher 9
Warbling Vireo 1
Red-eyed Vireo 12
Marsh Wren 2
Carolina Wren 3
Veery 9
Wood Thrush 1
Gray Catbird 40
House Finch 4
Baltimore Oriole 2
Ovenbird 2
Worm-eating Warbler 1
Northern Waterthrush 32
Black-and-White Warbler 3
Connecticut Warbler 1
Mourning Warbler 1
Common Yellowthroat 37
American Redstart 88
Northern Parula 8
Magnolia Warbler 2
Yellow Warbler 6
Palm Warbler (western) 7
Pine Warbler 1
Prairie Warbler 4
Wilson’s Warbler 1
Northern Cardinal 4
Rose-breasted Grosbeak 1
Blue Grosbeak 1
Indigo Bunting 3
Week 5 TOTAL 294

Total species banded this season: 53
Total birds banded this season: 1309