Hummingbirds in July

i Jun 29, 2024 No Comments by

The blisteringly hot month of July does not seem like the best time to raise young, especially if you are a bird, working tirelessly every day to defend your nest and find food for your helpless chicks. The summer heat isn’t ideal for baby birds either. Young birds that have just learned to fly must navigate the world outside their nest and be wary of numerous dangers. Just when you thought it couldn’t get any harder, let’s consider the Ruby-throated Hummingbird. Weighing only 0.11 ounces, this tiny bird faces additional challenges in raising its young during the summer months due to its small size and high energy levels.

The hummingbird lifestyle.

Let’s start by exploring the hummingbird’s lifestyle. These small creatures have incredible adaptations, allowing them to fly in all directions, hover, and reach inside flowers. Each adaptation helps hummingbirds access nectar, their main food source. Nectar is abundant, with bees and butterflies being the only competitors. This ability to drink nectar is advantageous for birds, providing them with an untapped food source. However, this efficient flight ability comes with a significant drawback: the need to eat every 15 minutes. Hovering is energy-intensive, so hummingbirds can only go without food for about an hour, usually feeding every 10-15 minutes. This demanding lifestyle is challenging, as hummingbirds often visit over 1,000 flowers daily. Now, imagine trying to visit all these flowers while also caring for chicks.

A male Ruby Throated hummingbird perched on a branch (look at that bright red neck!)

The hot summer sun, combined with the constant need to refuel, makes raising young even harder for hummingbirds. Yet, these bright little birds manage to raise new generations. So, how do they do it?

Stage 1: Eggs and Hatchlings. 

The first step in raising chicks is building a nest. Female Ruby-throated Hummingbirds construct small cup-shaped nests from twigs, mosses, and lichens. These nests are narrow but deep enough to hold a few chicks. The female lays 1-3 eggs and keeps them warm until they hatch. Once the eggs hatch, the mother must feed them and keep them warm since they are featherless. The hatchlings eat almost as much as their parents and need food every 20 minutes. This means the mother must feed herself and two hatchlings back at the nest, requiring her to leave the nest around 200 times a day. Exhausting, right?

Stage 2: Nestlings and Fledglings. 

A hummingbird chick’s diet mainly consists of nectar but also includes small insects. The chicks need this nutrition because, in a few weeks, they will learn to zip around the sky like their mother. Around this stage is when the hatchlings begin to develop pin-like feathers and small fuzzy down. These birds are now known as nestlings. Nesting mothers hunt more insects than usual to ensure the nestlings hit their protein goals. Even though these nestlings are currently helpless, the one thing they can do is eat. These tiny pink creatures react to the wind of their mother’s wings which is how they know it’s feeding time. After about three weeks of development, the nestlings grow from helpless beings that require warmth and food from their mother into fully feathered birds. These young birds are known as fledglings. The chicks can now regulate their own body temperature and move around in the areas near their nest. Although the tails of these fledglings are still short, they now have the ability to fly. Although they can fly physically, they still need to learn how to take off into the air. Around this stage in hummingbird development, it is common to find fledglings on twigs and the ground away from their nest. 

Female ruby-throated hummingbird perched on a branch. 

The one thing that makes this process of raising a chick from egg to adult seem a little easier is that it lasts a short 3 weeks. In these 3 weeks, an egg can develop into a fully functioning bird that can visit thousands of flowers daily. 

Stage 3: Learning life skills.

Although the chicks are fully developed, the mother bird’s job is not done yet. Most female hummingbirds look after their fully grown chicks a week after they fledge in order to ensure their protection. It is at this time when the mother hummingbird teaches the chicks how to fly, catch insects mid-air, and the best places to find nectar. If all goes well, the hummingbird chicks will learn skills that will set them up for a life in the skies. Just remember, in one year, these very chicks will have to put in the same hard work into their children, just like their mother once did for them!

Female Ruby-throated hummingbird hovering and drinking nectar. 

Now that we see the hard work mother ruby-throated hummingbirds put in while taking care of their young, it is important to remember to treat these beautiful animals with respect. If you ever come across a nesting hummingbird, be sure not to disturb it since you never want to cause extra stress on an already stressed mother. If you want to photograph the cute fledglings, be sure to take pictures from a distance and avoid scaring adults and young. Do not remove any branches concealing the nest and avoid walking around the nest a lot, since this can attract predators to the nest. Around this time, female hummingbirds also come to feeders more often. To ensure proper health and safety for these hard working parents, never use honey, corn syrup, or powdered sugar in your hummingbird feeders, since these food sources can cause dangerous fungal infections. 

Female Ruby-throated hummingbird at a feeder (make sure to never use honey !) 

Conclusion. 

Ruby-throated hummingbirds are always a wonderful sight to see in any backyard. Whether it be the iridescent red throats of males or their wonderful acrobatics in the air, seeing these unique creatures at a feeder is a great feeling. Now, after learning about the dedication mother hummingbirds have toward their chicks gives us a whole new reason to love these already lovable little birds. 

All images were taken by Bob Oberfelder. 

 

The (Humming) Birds and the Bees

i Apr 30, 2024 No Comments by

By Brittany Richards

Pollen – so much pollen – is not the only thing wafting on the breeze these days. Love is also in the air! Signs of nature’s fecundity are all around us this time of year. For all of us backyard birders, we delight to see the mating pairs of so many of our songbirds succumbing to the call of the season; the males wooing their mates with fancy feathers and fanciful flights. We know in a few weeks’ time we will see the fruits of their efforts when our feeders are visited by the first fledglings, feathers still fluffy, wings still wobbly. So what about Ruby-throated romance? How do our hummingbirds court and couple?

The Ruby-throated Hummingbird courtship story is a brief affair, more fling than lasting love. It begins when the migrating males arrive first in the summer breeding grounds and stake a claim. They will look for abundant food sources and then aggressively defend an area of up to a quarter acre. Tiny but feisty, males jealously guard both food and females within their boundaries. While these fights are typically more about intimidation than injury, with flaring feathers, harsh chirps, and darting dives, there may be occasional casualties. If you find an injured bird, it is best to confine it in a small container, like a shoebox, lined with a towel, and take it to a nearby wildlife rehabilitator. (On the Wake Audubon “Links” page you can find a list of local organizations under “Injured birds and other wildlife”.) 

Threat Display. Photo by Mike Dunn.

Threat Display. Photo by Mike Dunn.

Food is such a precious resource for hummingbirds who need to feed so frequently that females will also guard food sources such as nectar feeders. To encourage fewer squirmishes, you can plant flowers to offer more feeding locations in your yard, or put out multiple feeders. The Cornell Lab of Ornithology offers this advice: “Overall, you’ll feed far more hummingbirds by setting out four tiny one-port feeders than one giant eight-port one. Spread them out and the birds won’t have to see one another, arousing their territoriality.”

But back to our love story! After a male has successfully claimed a territory, he will attempt to mate with as many females as possible. When a potential mate is within his range, he will try to get her attention with a courtship display that includes whirring and chirping, flashing the feathers of his gorget (that beautiful ruby throat of his name), and a signature U-shaped flight with dramatic dives from as high as 50 feet above her. When she is perched, he will make short flights buzzing back and forth in front of her. Like many facets of this solitary and somewhat secretive bird’s life cycle, it is not precisely known which aspects of this behavior are most persuasive to females. The flashiness of his throat? The energeticness of his display? But some studies of hummingbirds suggest it is the quality of his territory more than his physical attributes that is most attractive. 

Male with gorget on full display. Photo by Bob Oberfelder

Male with gorget on full display. Photo by Bob Oberfelder

When a male has successfully won the affection of the female, the act of mating lasts only a few seconds. As with most birds, this involves a “cloacal kiss” where the cloacae (the single rear opening that is used for digestive, urinary, and reproductive purposes) are briefly pressed together. And this is where the romance ends! Unlike the doting males of some species, who may build the nest or feed their partner or help rear the young, Ruby-throated males will part ways as soon as mating is complete, leaving the female to perform all the duties of raising the young on her own. But while she may be a single parent, she may still receive some indirect support from the male. There is some debate whether females will build their nests precisely in the territory of their mating partner, or a neighboring territory of her own. But it is believed that she and her young will benefit from the male’s territorial guarding in her vicinity because she and her young will have less competition for nearby food sources. 

Ruby-throats are definitively polygynous, meaning the males will mate with multiple females in a season. But it is also believed that they are polygynandrous, meaning the females will mate with multiple males as well. A female will have one to two broods a year, with a single brood more common in the northern part of the breeding range where the season is shorter, and a third brood being possible in the southernmost part of the range where the season is longest. Here in North Carolina, a female will typically have two broods, almost always of two eggs each. 

With spring fully sprung, and the season of romance in full swing, hopefully your backyard is aflutter with love birds of all sorts. Meaning in a few weeks time, you’ll be treated to some adorable baby sightings as well! 

A male’s ruffled ruby throat. Photo by Bob Oberfelder.

A male’s ruffled ruby throat. Photo by Bob Oberfelder.

 



Welcome to the month of spring!

i Feb 29, 2024 No Comments by

Authored by John A. Gerwin

As I write this, in late February, there are many trees in flower, along with the usual spate of Daffodils and a few other early herb arrivals.  Speaking of early, I watched a pair of Carolina wrens gathering large clumps of moss, and begin constructing a nest in a shrub in the backyard, on February 21. It seemed amazingly early.  Soon, we will be seeing additional “early birds”.

Normally, we expect to see the first returning Purple Martins to Wake County in early March. That said, our colleague Courtney Rousseau recently reported one from Holly Springs, on February 24. Things are happening earlier and earlier.  Considering history, we expect to get a few reports of Ruby-throated hummingbirds in North Carolina in late March. However, most of us in Wake County are accustomed to seeing our first of the year hummers in the first two weeks of April.  You can follow along at this website: https://maps.journeynorth.org/map/?map=hummingbird-ruby-throated-first&year=2024

In most migratory bird species, males move through or arrive to a territory prior to the females. This makes sense in that males are racing to get back, get a prime piece of habitat, and establish a territory. Ruby-throats are similar in this regard.

In order to return to its breeding area, a given hummingbird will once again fatten up, the way it did when it was getting ready to head south. An individual that is not in migratory status or condition will weigh 3-4 grams. By the time it is ready to migrate it may weigh 6g. Note that in some cases, the bird has doubled its weight!

So, for most Ruby-throats, March is a month of gluttony as it were – they are still on the non-breeding grounds in a Mexican or a Central American locality. Many are also completing the body molt. Studies show that the head and throat (gorget) feathers will finish growing in by around mid-March.

Indeed, when you see your first males, try to assess the lower edge of the red gorget. A bird hatched in the previous year will often show a somewhat jagged edge whereas the older birds (greater than 1 year old) exhibit a more concise, straight-edge. It’s now always easy to tell with binoculars, but it can be with a digital photograph. That red gorget by the way will look black at certain angles and the way the light is hitting – but the edges are still edges.

Note that across the species broad range, we see quite a bit of variation from year to year in terms of “first seen” dates, and numbers visiting feeders. This is how nature is – there are various factors that affect the timing of movements of birds, and their subsequent distribution. And we don’t understand all of these factors.

As we are seeing more and more, plants are springing forth sooner in the season. Some birds are beginning to nest earlier than ever before. One way we discern these patterns is through the contributions of many amateur naturalists. So if you are so inclined, be sure to post your observations to your favorite website  – which may be eBird, or Journey North, or iNaturalist.  Here’s the map from 2023 for Ruby-throat observations submitted to Journey North. You can use the slider to see how things look by the week.

https://maps.journeynorth.org/map/?map=hummingbird-ruby-throated-first&year=2023

And now that you know some hummers may show up as early as late March, you can plan to have your hummingbird feeders ready to go.  In the early spring, I prefer to start out with very small quantities of my homemade nectar. I know that visits to my feeders, in early April, we will few and far between. If I put out a feeder full of nectar, it usually gets moldy long before it is consumed. So I wait and see how many hummers seem to be around before I put out a larger quantity.

And remember – these little tykes consume many small arthropods. Indeed these make up about 50% of their diet.

Attached are some pictures to get your ready. I realize this only makes the month of March feel that much longer….. but this year we have Easter Weekend to help with the waiting….. maybe your Good Friday will be super good when you spot your first Ruby-throated Hummingbird of 2024.

Photo legends:

All photos by Bob Oberfelder

#1: Here is a “classic” view with full light hitting the gorget of a male Ruby-throat.

#2: This male might be a younger male – the edge of the gorget is slightly jagged. Note the darker area of the throat due to the angle of light, which in this case is not refracting to allow the red wavelengths.

#3: The color on the gorget of this individual appears a bit duller. The color is derived from the interaction of light waves and the feather structures and the way they overlap. Small changes in the structures (wear) or overlapping (puffed up or not)  can yield slightly different hues to the red.

#4: A classic “I think I have discovered a new species of hummingbird!”.  I have received many such emails and phone calls. Many folks do not realize that the gorget color is the result of structural features of the throat feathers, and not pigments. If the light does not hit and/or refract back in a Goldilocks manner (“just right”), the color appears dark, or black, as in this individual.

Ruby-throated Hummingbird – February

i Feb 1, 2024 No Comments by

Author: John A. Gerwin

February is a chilly, darker month. In the Piedmont of North Carolina, we experience some of the coldest nights, and least amount of daylight. The Ruby-throat is a Neotropical migrant, similar to the warblers, vireos, thrushes, tanagers and more that breed in NC. Most of “our” hummingbirds departed months ago. In NC, some leave as early as late July, others follow as summer turns to fall, and most are gone by late October. They make their way to Mexico or countries in Central America.

Ruby-throated Hummingbird, back view with tail spread. Photo by Mike Dunn.

Ruby-throated Hummingbird, female. Photo by Mike Dunn

Most Ruby-throats migrate south. However, not all of them do. For years, folks have reported wintering hummers in NC. And for some of those years, Susan Campbell and colleagues have caught, measured, photographed, tagged, and released many. They have found a mix of species, but many were Ruby-throats. We do not know why this happens (but we have some opinions all the same. We’ll see if we can get Susan to chime in one month).

During the winter months in Mexico/Central America, a Ruby-throat will be in places with a handful of other species. Keepers of bird lists currently list 340+ species of hummingbirds – all in the western hemisphere.  “Neotropics” means New World Tropics.  I’ve seen a few Ruby-throats on the west side of Nicaragua for example. Where the Ruby-throat can be found in Nicaragua, one might also find two dozen other species of hummingbirds. I have included pictures of a few of these other species.

In the non-breeding season, the Ruby-throat prefers habitat in areas that are drier overall, and often a bit scrubby (forest openings with second growth, forest edges, and some agricultural settings; among others). They will nectar at flowers we might grow in our gardens – various Salvia species for example. They continue to feed on minute arthropods for protein, and have an inordinate fondness for small spiders.

We know that hummingbirds exhibit some extreme life history behaviors and physiological adaptations. One of these concerns the molt cycle and there are aspects of the molt cycle we do not yet fully understand. Hummingbirds, as a group, rely on flight for feeding. Due to their small size, they are subject to extreme “stress” in order to maintain their high body temperature and functions. All to say, they do not molt quite like other birds. I can’t get into all the details here but will note that adults undergo a complete molt (body and flight feathers) after the breeding season. What’s really curious is that recent research has shown that some individuals undergo a molt in summer and apparently another during the winter.

In songbirds the post-breeding season molt can be completed in 6-8 weeks. In Ruby-throats, it is reported to be slower and much more protracted, when compared to the migrant warbler or thrush.. An interesting aside: in 1936 a researcher counted the number of body feathers on some Ruby-throats; he came up with 940.

At the species level then (Ruby-throat), the molt cycle runs from late summer to mid-winter. Individuals will do things differently, and as mentioned some may begin to molt body feathers in late July. These Ruby-throats then migrate while they are molting (or, if you prefer, molt while they are migrating). The question is, when does that July-molting bird complete the molt? No one knows for sure. One researcher did a fairly thorough study of the molt of Ruby-throats, assessing individuals in Mexico and Central America. His data showed that many Ruby-throats began a molt of the flight (wing/tail) feathers in November and completed it by the end of February. Many (most?) individual Ruby-throats complete the body molt in March, when the males’ new gorget feathers grow in.  Still, other aspects of the molt remain unknown. To understand precisely which birds are molting what/when/where, we will need a lot of marked birds that can be followed, month to month.

In February, Ruby-throats are sharing time/space with a large variety of tropical hummingbird species. In addition, they are preparing for the northward migration and some will indeed begin to migrate north during February. Many aspects of their migration also  remain unknown – but we do know that some will arrive in the southern U.S. by early March.

Here we provide a link to Cornell’s eBird website for the non-breeding range of the Ruby-throated Hummingbird. This is a page where the user can zoom in and do other ‘animations’ (note also options on the right-hand side).

https://science.ebird.org/en/status-and-trends/species/rthhum/range-map?season=nonbreeding

Finally, I have included photos a few species of tropical hummingbirds in Nicaragua, which ranges overlap that of a given non-breeding Ruby-throated Hummingbird.

Crowned Woodnymph – male

Crowned Woodnymph – female

Long-tailed Hermit

Rufous-tailed Hummingbird

Wake Audubon “Long Live Longleaf” Field Trip

i Apr 26, 2023 No Comments by

Authored by Jeff Beane, trip leader.

15 April 2023 (9:00 a.m. – ca. 5:30 p.m.)

NC Sandhills (Moore, Richmond, and Scotland counties)

Participants: Jeff Beane, Louise Belk, Mary Frazer, Ernie Hahn, Stephanie Horton, Michelle Measday, Tess Moody, Dave Powell, Stephen Prior

We had a great time.

We saw many wildflowers.

Unusual find of the day: Mary spotted this Venus Flytrap in an area west of the species’ known range, in a county that has been intensively surveyed by botanists for decades. Flytraps are transplanted by well-meaning but misguided plant enthusiasts, and given that this is an extremely well-known botanical site, several the state’s botanists agree that this occurrence probably represents an introduction.

 

Vertebrate Species Observed (list is probably incomplete)

Fishes

Elassoma evergladei  Everglades Pygmy Sunfish (at least 2)

Amphibians

Necturus punctatus  Dwarf Mudpuppy (several juveniles)

Notophthalmus viridescens dorsalis  Broken-striped Newt (1 adult)

Eurycea arenicola  Carolina Sandhills Salamander (1 larva)

Pseudotriton m. montanus  Eastern Mud Salamander (1 adult)

Acris gryllus  Southern Cricket Frog (several seen and heard)

Hyla andersonii  Pines Barrens Treefrog (a few heard)

Pseudacris crucifer  Spring Peeper (tadpoles seen)

Rana [Lithobates] clamitans  Green Frog (a few heard; a few tadpoles seen)

Rana sphenocephala  Southern Leopard Frog (many tadpoles seen)

Reptiles

Kinosternon s. subrubrum  Eastern Mud Turtle (1 juv.)

Sceloporus undulatus  Eastern Fence Lizard (1 adult)

Cnemidophorus sexlineatus  Six-lined Racerunner (1 dead adult)

Eumeces [Plestiodon] fasciatus  Five-lined Skink (1 adult)

Eumeces [Plestiodon] inexpectatus  Southeastern Five-lined Skink (1 juv.)

Heterodon platirhinos  Eastern Hognose Snake (1 adult female DOR)

Pituophis m. melanoleucus  Northern Pine Snake (1 telemetered adult male)

Birds

Aix sponsa  Wood Duck

Colinus virginianus  Northern Bobwhite

Zenaida macroura  Mourning Dove

Archilochus colubris  Ruby-throated Hummingbird

Cathartes aura  Turkey Vulture

Colaptes auratus  Northern Flicker

Dryobates pubescens  Downy Woodpecker

Melanerpes carolinus  Red-bellied Woodpecker

Tyrannus tyrannus  Eastern Kingbird

Lanius ludovicianus  Loggerhead Shrike

Vireo flavifrons  Yellow-throated Vireo

Vireo griseus  White-eyed Vireo

Vireo olivaceus  Red-eyed Vireo

Corvus brachyrhynchos  American Crow

Cyanocitta cristata  Blue Jay

Baeolophus bicolor  Tufted Titmouse

Poecile carolinensis  Carolina Chickadee

Tachycineta bicolor  Tree Swallow

Sitta pusilla  Brown-headed Nuthatch

Thryothorus ludovicianus  Carolina Wren

Polioptila caerulea  Blue-Gray Gnatcatcher

Turdus migratorius  American Robin

Dumetella carolinensis  Gray Catbird

Mimus polyglottos  Northern Mockingbird

Sialia sialis  Eastern Bluebird

Haemorhous mexicanus  House Finch

Spinus tristis  American Goldfinch

Peucaea aestivalis  Bachman’s Sparrow

Pipilo erythrophthalmus  Eastern Towhee

Spizella passerina  Chipping Sparrow

Spizella pusilla  Field Sparrow

Icterus spurius  Orchard Oriole

Parkesia motacilla  Louisiana Waterthrush

Setophaga americana Northern Parula

Setophaga discolor  Prairie Warbler

Setophaga dominica  Yellow-throated Warbler

Setophaga pinus  Pine Warbler

Setophaga ruticilla  American Redstart

Cardinalis cardinalis  Northern Cardinal

Mammals

Sigmodon hispidus  Hispid Cotton Rat

Ways to Help Vultures

i Nov 29, 2022 No Comments by
Authored by  Kyra Thurow Bartow.
Vultures are vital for our ecosystems. As many of them are obligate scavengers, vultures help to keep ecosystems clean of decaying matter. They also provide disease control as their extremely acidic stomachs as well as special enzymes can help destroy anthrax, tuberculosis, botulism, cholera, and rabies. Vulture populations throughout Africa, Europe, and Asia have plummeted by up to 99% since 1990, and vultures often encounter persecution throughout the entire world. Here are some ways you can help vultures:
1. Tell people about how important and cool vultures are!
2. Get a different perspective on vultures by following some social media accounts:
– Andy N. Condor (Andean Condor) from the Tracy Aviary
– George the Vulture (Turkey Vulture) from the American Eagle Foundation
– Bash the Vulture (Black Vulture) from the American Eagle Foundation
3. Support Association of Zoos and Aquariums (AZA) facilities. These organizations are required to have conservation actions in order to be accredited under the AZA umbrella. One such project is called AZA SAFE (Saving Animals from Extinction), with a focus on African Vultures. They have partnered with the Denver Zoo, NC Zoo, VulPro, Kalahari Research and Conservation, and the Peregrine Fund in order to have people on the ground in Africa looking into how to save their vultures. Visit these websites for more information:
– AZA SAFE African Vultures
– Raptor TAG
4. If you are a hunter or know a hunter, have them switch to copper bullets rather than lead bullets. Better for people and vultures!
5. Celebrate International Vulture Awareness Day! This occurs on the first Saturday of September each year.

6. Tell your local government about your commitment to vultures and vulture-safe practices.

Close-up of Turkey Vulture

Turkey Vulture photo by Bartow

Close-up of Black Vulture

Black Vulture photo by Bartow