Saturday, February 15, 2025

Winter Buds

 

American Beech (Fagus grandifolia) leaf bud.
Rowan County, North Carolina. 

The woods are quiet in winter.  The bare trees look stark against the sky, but on their branches they bear buds that are ready to produce the new growth of spring.  The buds contain tiny flowers or leaves just waiting to open.  In late summer and fall trees stop growing and buds form. The buds enter a state of dormancy that have low water requirements and low metabolic rates.  Buds are covered by scales that protect the tiny leaves or miniscule flowers that are waiting out the winter. The scales are waterproof and provide shelter from the cold, dry winter weather.  

Pignut Hickory (Carya glabra) leaf buds.
Rowan County, North Carolina. 

Mockernut Hickory (Carya tomentosa) leaf buds.
Rowan County, North Carolina.

Painted Buckeye (Aesculus sylvatica) leaf buds.
Davidson County, North Carolina. 

As winter wanes, the bud dormancy is broken.  This is triggered by environmental signals, usually day-length and temperature.  The buds expand and the bud scales fall off.  The leaves or flowers of the bud unfurl, and the new year’s flush of growth begins.  

Red Maple (Acer rubra) flower buds.
These buds will open before the leaves
revealing red flowers. 
Rowan County, North Carolina.

Pinxter Azaela (Rhododendron periclymenoides) flower bud.  
Rowan County, North Carolina. 

Flowering Dogwood (Cornus florida) flower buds. 
Rowan County, North Carolina. 

The four scales of the Flowering Dogwood bud will open
and produce the four white bracts we think of as petals.
Small yellow-green flowers will be at the center.
Rowan County, North Carolina.   

When identifying trees, leaves are the main feature I use. However, most deciduous trees drop their leaves in the fall.  But in winter, buds are good tools to reveal a tree’s identity.  Bud shape, size, color and arrangement are all clues in identifying trees. 

American Sycamore (Platanus occidentalis) leaf buds.
Rowan County, North Carolina. 

Winged Elm (Ulmus alata) leaf buds.
Rowan County, North Carolina. 

Some trees we think of as deciduous do not drop their leaves in the fall but retain them throughout the winter.  This condition is called marcescence.  American Beech (Fagus grandifolia) and Oaks (Quercus sp.) are often marcescent.  The marcescent leaves are commonly found on young trees or on lower branches of larger trees. There are several hypotheses about the reason for this, including one that says the leaves protect the buds for the coming year.  

American Beech leaf bud with a marcescent leaf. 
Rowan County, North Carolina. 
 

Post Oak (Quercus stellata) leaf buds on a branch
with a marcescent leaf and acorn cap.
Rowan County, North Carolina. 


I enjoy the quiet of winter.  Seeing the tree buds, ready to start a new season, makes me smile because they are a foretaste of what is to come.    

Thanks to Dr. Jay Bolin for identifying the hickory buds. 


Saturday, February 1, 2025

New Zealand Waterbirds 2

 

Variable Oystercatcher (Haeatopus unicolor). 
Tawharanui Regional Park, New Zealand. 

Our trip to New Zealand in October 2024 was during the spring of the year in the southern hemisphere.   We saw some lingering winter birds and many that were breeding or had young. I have written about these experiences in several blogs   I will finish discussing New Zealand with one final blog on waterbirds. 

Bar-tailed Godwit (Limosa lapponica).
Pukorokoro Shorebird Centre, New Zealand. 

Pukorokoro Shorebird Centre in Miranda was teeming with shorebirds.  The most abundant were the Bar-tailed Godwits (Limosa lapponica).  These large sandpipers had just arrived in New Zealand after completing an epic migration.  Bar-tailed Godwits fly from New Zealand to northern Australia, eastern China, the Russian coast then to western Alaska where they breed during the brief northern summer.  Then in September Bar-tailed Godwits make their most remarkable migration, directly across the Pacific to return to New Zealand, a distance of more than 7000 miles.    

Bar-tailed Godwits in flight.
Pukorokoro Shorebird Centre, New Zealand.

When we visited Pukorokoro Shorebird Centre there were many thousands of Bar-tailed Godwits feeding in the marsh.  Every so often the flock flushed, and the sky was filled with a wheeling mass of Godwits. They would swirl around for a few minutes then land again to feed or tuck their heads under their wings and sleep.  

Adult Red-breasted Dotterel (Charadris obscurus).
Tawharanui Regional Park, New Zealand. 

Juvenile Red-breasted Dotterel.
Tawharanui Regional Park, New Zealand. 

The Red-breasted Dotterel (Anarhynchus obscurus) is a large plover endemic to New Zealand.  It is brown above and in breeding plumage has an orange breast. We found an adult and newly hatched chick on the beach at Tawharanui Regional Park.  

Double-banded Plover (Anarhynchus bicinctus).
Tasman River, New Zealand. 

Double-banded Plovers (Anarhynchus bicinctus) breed only in New Zealand with most of the population nesting in braided river valleys of the South Island.  Many members of this Near Threatened species winter on the east coast of Australia. This is a rare case of east to west migration. Double-banded Plovers are brown above and white below with two bands, one black and one reddish brown on the breast.  We saw many Double-banded Plovers along the braided Tasman River in Aoraki/Mt. Cook National Park.  

Pied Stilts (Himantopus leucocephalus).
Pukorokoro Shorebird Centre, New Zealand. 

Pied Stilts (Himantopus leucocephalus) are found primarily in New Zealand and Australia but range to New Guinea, Indonesia, the Philippines and Malaysia.  They are small black-and-white wading birds with long pink legs and long thin beaks.  Pied Stilts are common on freshwater throughout New Zealand. 

Black Stilt (Himantopus novaezelandiae). 
Lake Tekapo, New Zealand. 

Black Stilts (Himantopus novaezelandiae) are an endangered New Zealand endemic bird.  The New Zealand Department of Conservation reported 169 birds in the wild in 2023 making Black Stilts one of the rarest birds in the world.  They breed in the braided river valleys of the South Island and the Department of Conservation has a breeding facility near Twizel.  Black Stilts live up to their name with a solid black body and the pink legs characteristic of the stilts. We were lucky enough to find a pair of Black Stilts feeding in a pond near Lake Tekapo. 

Hoary-headed Grebe (Poliocephalus poliocephalus). 
Lake Elterwater, New Zealand. 

We saw three different species of grebes in New Zealand. Grebes are waterbirds that swim on the surface like ducks and dive for food.  Hoary-headed Grebes (Poliocephalus poliocephalus) are small dark grebes with white feathers on their faces.  Most of the world population is in Australia where they are widespread and common.  A few have colonized New Zealand, and we found a single Hoary-headed Grebe at Lake Elterwater on the South Island.  

New Zealand Dabchicks (Poliocephalus rufopectus). 
Rotoroua, New Zealand. 

The New Zealand Dabchick or New Zealand Grebe (Poliocephalus rufopectus) is a New Zealand endemic.  It has a dark back and head, reddish brown breast and a striking yellow eye.  The New Zealand Dabchick is found only on the North Island where due to conservation efforts it has gone from Endangered to a Species of Least Concern in 30 years.   

Great Crested Grebe (Podiceps cristatus).
Lake Wanaka, New Zealand. 

Great Crested Grebes mating display.
Lake Wanaka, New Zealand. 

The largest and most impressive grebe we found was the Great Crested Grebe (Podiceps cristatus). This Old World grebe ranges from northwestern Europe and southern Africa to Japan, Australia and New Zealand.  The Great Crested Grebe has a white, black and rufous head with bright red eyes and a prominent crest.  They also have extravagant breeding behavior where males and females face off, stretch their necks and stand up in the water.  We saw Great Crested Grebes doing their courtship dance on Lake Wanaka on the South Island.  

Pacific Reef Heron (Egretta sacra).
Kaikoura, New Zealand. 

Pacific Reef Herons (Egretta sacra) are found throughout the western Pacific and reach their southern limit in New Zealand.  These dark blue-gray herons have a heavy beak and are found in many seaside habitats ranging from mangroves to rocky shorelines.  

White-faced Heron (Egretta novaehollandiae).
Tawharanui Regional Park, New Zealand. 

The most common heron we encountered in New Zealand was the White-faced Heron (Egretta novaehollandiae).  This medium-sized gray heron has a white face and ranges from Indonesia and New Guinea to Australia and New Zealand.   The White-faced Heron is a relative newcomer to New Zealand.  The first White-faced Herons colonized New Zealand in the 1940s and their numbers have increased since then.  Now they are now found throughout both the North and South Islands.  

Nanking Night Heron (Nycticorax caledonicus).
Wharganui River, New Zealand.  

We saw another heron that introduced itself to New Zealand from Australia, the Nankeen Night Heron (Nycticorax caledoinicus).  A small population of these herons is established along the Wharganui River on the North Island.  During the day they roost in trees and as their name suggests, Nankeen Night Herons feed along the river at night. 

Sacred Kingfishers (Todiramphus sanctus).
Whargunui River, New Zealand.

The Sacred Kingfisher (Todiramphius sanctus) is found throughout New Zealand, Australia and many Pacific islands.  It has a blue back, wings and head with a white collar, and white and buff underneath.  Sacred Kingfishers feed not just on fish but on a wide variety of invertebrates and even small birds. 

Oystercatchers are large black or black-and-white shorebirds.   New Zealand has two species, the Variable Oystercatcher (Haematopus unicolor) and the South Island Oystercatcher (Haemoatopus finschi). Both species are endemic.  Despite its name South Island Oystercatchers can be found on both the North and South Islands.  It breeds on the South Island and winters on the North Island. The South Island Oystercatcher has a black back and head, white breast and belly, a bright orange bill and a red eye ring.  

South Island Oystercatcher (Haematopus finschi).
Aoraki/Mt. Cook National Park, New Zealand. 

Variable Oystercatchers are found along the coasts of both islands.  They are usually black, but some have white on the belly giving them the name Variable.  Both species of Oystercatchers use their long, stout beaks to catch invertebrates, including oysters, in marshes and tidal flats. 

Variable Oystercatchers.
Tawharanui Regional Park, New Zealand. 

New Zealand has fired my imagination since I was a child.  Fueled by movies like Mysterious Island and In Search of the Castaways, I was convinced New Zealand was a realm of wonders.  Seeing the real thing did not disappoint.  Volcanos and glaciers, waterfalls and subtropical beaches, forests and salt marshes, and birds, birds, birds fulfilled my vision of New Zealand.  And beyond the natural world the residents of New Zealand were friendly, open, helpful and just plain glad to see tourists from half-way around the world.