Tuesday, August 4, 2020

Tompkins Square hawks survey tree damage after Tropical Storm Isaias

Tropical Storm Isaias blew through the city today, causing chaos across the five boroughs. When the rain subsided, I ventured outside to check out the damage done to Tompkins Square Park.

When I arrived, I found one of the red-tailed hawk fledglings with prey (pigeon) perched on a tree in the SE corner.

Fledgling red-tail in Tompkins Square

The hawk seemed to be checking out the huge American Elm that was severely battered by the storm. In the video below, one of the hawk's siblings swoops in from the left and the two tussle briefly before taking off in different directions.



The two fledglings were so energized, they reminded me of excited little kids, flying back and forth and taking playful shots at each other. I can only imagine what they were thinking, having just survived a serious storm, and then seeing their environment ripped to shreds.

One of the fledglings posed on top of the broken elm:

Fledgling red-tail posing on storm-damaged tree in Tompkins Square

Fledgling red-tail posing on storm-damaged tree in Tompkins Square

I didn't have my bird camera with me, so I took more video. The hawk seemed to be enjoying (or at least curious about) its new vantage point.



I went to check on the hawks early this morning, before the storm, and found two fledglings chasing Christo around the park. Amelia was perched on the cross of Most Holy Redeemer church on E 3rd Street, and I was unable to find the third fledgling. When I returned to the park after the storm, I didn't find the other hawks, but I don't think there's any reason to be concerned. It's worth noting, though, that the hawk nest is now gone, and it was definitely there this morning. Fortunately, the hawks are done using it for the season.

Governors Island red-tailed hawks

Our Tompkins Square Park red-tailed hawk family is doing well and can still be seen in and around the park. In anticipation of the tropical storm forecast for today, I went to check on them this morning and found two fledglings chasing Christo around, screaming at him to get breakfast. As it's been miserably hot and humid, and because of the pandemic, I've not spent much time in Tompkins Square recently, but the hawks appear to be doing fine.

This last spring saw many hawk nests throughout the city, and one I was really looking forward to observing was on Governors Island. When the island closed for the season in October 2019, I observed what appeared to be a mated pair of red-tailed hawks. This was especially intriguing as I don't believe a hawk nest had been recorded on the island before. Throughout the winter, I was able to participate in a bird survey project on the island which allowed me to keep tabs on the hawks and I was really looking forward to documenting their nesting season.

December 26, 2019

This is the hawk pair, with the female on the left and the male on the right. Note the difference in size - she is significantly larger. Their coloring is also different with the male having a much darker head and markings on his belly. It's hard to see in this photo, but his eyes are bright amber-yellow with a dark ring around them that gives him a very striking look. The female has a paler head with prominent light supercilia (eyebrows) and a broader chest.

Red-tail pair

The two were perched together screaming repeatedly. What was disturbing them?

Red-tail pair

This guy!

Great Horned Owl

A great-horned owl was minding its own business, perched quietly in a tree, but the hawks, a mockingbird, and several crows did not let it go unnoticed. The mockingbird gave the owl away first, then the crows proceeded to harass it relentlessly. The hawks seemed content to scream at it from a distance and let the crows do all the physical bullying.

Great Horned Owl and Crow

By perching together and acting defensively against the owl, the hawks further convinced me they were planning to nest on the island. Prior to this season, I'd seen red-tails on the island, but they never acted so territorial. These two were definitely different.

This is the female perched on one of the buildings.

Governors Island red-tail

I later saw her gathering sticks and grass at Hammock Grove. Definitely a sign of nesting!

Governors Island red-tail

Governors Island red-tail

January 9, 2020

With the coming of the new year, the hawk pair remained together and appeared to still be vigilantly defending their territory. In the photo below, the male is on the left and the female is on the right.

Governors Island red-tail

This is the female perched near the Hills. This was a freezing day and I recall this side of the hill was sunny and out of the wind, making it pleasantly warm. My notes from that day say it was 24°F.

Governors Island red-tail

This is the male flying by - note his bright eyes.

Governors Island red-tail

January 17, 2020

On another cold winter day (22°F), I found the female hawk sunning herself on a pile of sand, which was probably warm.

Red-tailed hawk

She kept her feet buried in the sand for almost an hour. This area was also sheltered from the wind.

Red-tailed hawk

After enjoying the sand for a while, she relocated to a sunny spot on the lee side of Outlook Hill and remained there the rest of the afternoon.

Red-tailed hawk

February 10, 2020

On a subsequent visit, I found the hawks hanging out together (male on the left, female on the right) but they remained mysterious about their nesting activities.

Red-tailed hawk pair

Red-tailed hawk pair

March 9, 2020

Finally, in March, there was confirmation of a nest. This is the male taking food (pigeon) up there.

Governors Island red-tail

Later that day, the female was lying down in the nest and appeared to be brooding.

Governors Island red-tail

Unfortunately, the pandemic caused the island to close to non-essential workers, so my last visit was March 16, just as the nesting season began. My last photo was of the female hunkered low in the nest.

Governors Island

Fast-forward to July 20, which was my first opportunity to visit the island after it reopened to the public on July 15. I was heartbroken to have missed the entire nesting season, but was curious to see if I could find the hawks and if any fledglings might still be around.

I found the male hanging out in the shade trying to beat the heat (93°F).

Governors Island red-tail

He's molting, so appears a lot lighter - especially his head - but his distinctive eyes are the same.

Governors Island red-tail

I watched as he scavenged some scraps from the ground before being scared off by a vehicle.

Governors Island red-tail

Looking up, I spotted a juvenile, who must be one of the fledglings. I'd been told there were two, but so far, I have only been able to see one at a time. This one was intently watching the adult male.

Governors Island red-tail fledgling

It later perched on the weather vane, a favorite perch for the adults.

Governors Island red-tail fledgling

Flying overhead and looking great:

Governors Island red-tail fledgling

Although I'm disappointed not to have been able to observe these hawks as they hatched and raised their young, I am thrilled they successfully nested on the island and hope this pair continues to hold this territory. This definitely gives us something to look forward to next year.

Friday, July 24, 2020

Hawks and squirrels: tough guys of Tompkins Square

I've been observing red-tailed hawks in Tompkins Square Park for well over a decade now and one thing that continues to fascinate me is their relationship with the resident squirrels. The two species interact frequently, and one might think the hawk would always win an argument, but that's not necessarily the case. In fact, the squirrels are more likely to come away victorious in a hawk-squirrel showdown.

This raptor-rodent interaction has been on display recently as the fledgling hawks are learning to hunt prey. Below, two of the three hawk siblings met up in a tree on the center lawn on a recent morning.

Tompkins Square red-tail fledglings

The tree, however, was already occupied by a squirrel, who was not happy to see these two on its property. The squirrels are extremely territorial and will confront the hawks when they land in their tree. As I see it, the squirrels own the trees and the hawks merely borrow them from time to time.

Red-tail fledglings and a squirrel

The young hawks are obviously interested in this squirrel, and I love seeing how they study its every move.

Red-tail fledglings and a squirrel

What these photos do not convey is the sound the squirrel was making. If you're walking through the park and hear this alarm call, that is a squirrel alerting to the presence of a hawk. Look around and you are almost guaranteed to find a hawk nearby. The squirrels make several other sounds, but this one is specific to the danger of a predator. I don't know if it specifically means "hawk" or is a general predator warning, but in Tompkins Square Park, the hawks are the only predator that upsets the squirrels.

About six weeks ago, dad Christo showed his kids how to catch a squirrel, and they've been trying ever since, but the squirrels have been too quick and wily, easily escaping the young hawks. Most confrontations end with the hawk giving up and leaving the tree.

Tompkins Square red-tail fledglings

On a recent morning, one of the fledglings was being much more patient, allowing a bold squirrel to get very close.

Red-tail fledgling and squirrel

Red-tail fledgling and squirrel

I watched this scene for about 30 minutes as the squirrel kept approaching the hawk, running away, then approaching again. From this very low perch about two feet off the ground, the hawk could see all the squirrels running around under the bushes, and this squirrel definitely did not like the hawk sitting there in its territory.

Red-tail fledgling and squirrel

While this was happening, one of the other fledglings was directly above in a tree with another squirrel.

Red-tail fledgling and squirrel

The squirrel seemed confident enough to turn its back on the hawk. Does it know the hawk can't catch it (yet)?

Red-tail fledgling and squirrel

The hawk never takes its eyes off the squirrel.

Red-tail fledgling and squirrel

The squirrels we have here in the city are Eastern Gray Squirrels. They come in a variety of colors (gray, blonde, dark brown, two-tone brown), and I recently found this interesting study that explains that some of them have black coats due to inbreeding with Fox Squirrels, who range across the southeastern US. The original paper can be found here.

Adult squirrels weigh 400-600 grams, or just over a pound. The hawks weigh anywhere from 1.5 to 3.5 lbs. For reference, Dora weighed 3.15 lbs when she was picked up by WINORR back in April 2018. Christo is smaller than Dora, Amelia is larger than Dora, and the fledglings appear to be somewhere in between.

For the hawks to catch and carry a squirrel means lifting almost half their body weight, which takes strength. To accomplish this, the young hawks have been practicing with inanimate objects like this substantial branch (below).

Red-tail fledgling catches a huge stick

We've seen fledglings in the past struggle to lift and carry off heavy prey, like this hawk who barely managed to clear a fence with a big rat and drag it down Avenue B in 2014. The youngsters seem to go for the most difficult prey first, like the squirrels and large rats, and eventually settle for things they can manage like smaller rats and mice.

Hawk-squirrel confrontations are nothing new in Tompkins Square, as we've been observing them over the last several years. Diving into the archives, I found this photo of a fledgling hawk checking out a squirrel in 2018:

Fledgling hawk confronts a squirrel

This is Christo staring down a squirrel in 2018. As the hawks and squirrels all co-exist in the same small area of the park, I imagine they are all familiar with each other and, as Christo is a top-notch hunter, you can bet the squirrels don't like him at all.

Christo annoyed by squirrel

Another fledgling hawk faces off with a squirrel in 2017:

Showdown

If the squirrel is upside-down, you have to look at it upside-down! (2017)

Tompkins fledgling #2 with a squirrel

Christo (2017):

Christo and a squirrel

Fledgling (2016):

Fledgling hawk trying to catch a squirrel

Another fledgling (2016):

Tompkins Square fledgling with a squirrel

Dora (2015):

Dora and friend

Fledgling (2014):

Red tail fledgling and squirrel

Christo (2014) - if you look closely, you can see the feet of another squirrel sticking out below Christo on the right. Even seeing that one of its kindred was caught, this squirrel still challenges the hawk.

Christo and Squirrel

The squirrels are masters of maneuvering through the trees and they are not easy prey for the hawks. If a squirrel is on top of a branch, it can escape in nearly any direction. When I've seen Christo successfully catch one, he usually does it by grabbing it from the side of a tree, as demonstrated below in 2014. The two squirrels were together on the trunk of the tree when Christo came swooping in from around the corner and snatched one of them.

Christo catches a 
squirrel

Although the hawks are able to catch the squirrels, they prefer prey like rats, pigeons and mice. The squirrels seem to know this, and rarely display fear of the hawks, although they do sound the alarm when one is around. The squirrels in Tompkins Square are well-fed, healthy, strong and have a courageous attitude that I think is unique to the park. I love that we have this unique opportunity to observe these wildlife interactions in this urban environment.

Red tail in Tompkins Square
Immature red-tailed hawk and a squirrel in Tompkins Square Park (2014).