Crow Communication

American Crow on Feeding Platform

The American Crow (Corvus brachyrhynchos) is an interesting species.  It has abilities that are surprising.  Many studies have been done but some of their behaviour is still unexplained.  The following was observed by me recently.

Crow Communication

On the early morning of July 27, 2020 I was listening to the local crows communicating.  A single crow near our house was calling and being answered by a more distant crow. The local crow ‘cawed’ 4 times and was immediately answered by the more distant crow with 4 'caws' . The local crow then cawed 5 times and was answered by the more distant crow 5 times. That pattern repeated; local crow 6 times and answered with 6 caws; local crow 7 caws and answered with 7 caws. That went on in order through 8 and 9 caws. After a brief rest the local crow started again with 6 caws and was immediately answered with 6 caws. Next, 7 caws to be answered with 7 caws. This pattern continued through 8, 9, 10 and 11 caws. The answering crow did not make any mistakes until it got to 10 where it paused slightly, dividing the answer into 2 groups.  At 11, mistakes were made and the answering crow replied hesitantly with only 9 caws at which point the local crow ceased the exercise.

I was amazed by this display of repetitive behaviour and also by the ability of the local crow to keep increasing its delivery by one caw. I wonder if the local crow was an adult and the answering crow a juvenile or perhaps a mate. I would love to know more about crow communication and their behaviour. Crows truly are amazing.

American Crows Waiting for 'Breakfast' (Feeder) on a Wintery Morning

Pied-billed Grebe

Pied-billed Grebe [Internet Photo]

The Pied-billed Grebe (Podilymbus podiceps) is our smallest grebe.  Grebes are classed in the Podicipedidae family.  All members have lobed toes.  They build nests of matted vegetation on the ponds and lakes on which they live.  There are 7 species in 4 genera of the grebe family of which we normally have 3 species here in New Brunswick; Horned Grebe, Red-necked Grebe and Pied-billed Grebe.  The former 2 species are seen on salt water and Pied-billed Grebe prefers fresh water.  When the young of grebes are hatched, they are striped, very distinctive looking.

The Pied-billed Grebe is about 32 cm (13 inches) long.  It appears very small among the reeds and grasses of the ponds on which it lives.  This grebe is a fairly common summer resident here.  It is stocky in appearance and has brown upper parts with barred sides and flanks.  It has distinctive white undertail coverts.  The chin is black and the white bill has a distinctive black ring.  The bill is thick and the head appears large.  Both adult genders look the same.  In winter the adults lose the ring on the bill.  See photo below showing the ring beginning to fade.

Pied-billed Grebe 

 

The voice of this grebe is remarkable. They make a lot of noise for the size of them.  The long call is described in National Geographic Complete Birds of North America as, "a series of slightly hollow, rapid-paced cooing notes run into slower-paced, gulping clucks that can fade away or run on into more prolonged variations".  That sound is characteristic of many of our marshes.  When one learns that it is made by this small grebe, it is not forgotten.  The Pied-billed Grebe spends its summers in most of southern Canada and the northern US.  It winters in southern and central US, Mexico and the West Indies.  

The floating nest of this species is well-hidden and made of dead vegetation anchored to emergent plants.  The 2 to 10 light blue eggs are incubated for 23 to 27 days by both adults.  They eat fish, crustaceans, beetles, dragonfly nymphs and aquatic insects.  They forage by diving and collect their food usually underwater.  

Pied-billed Grebe Showing Young [Internet Photo]

The Pied-billed Grebe rarely flies when encountered, preferring to hide in the vegetation.  It has the unique feature of being able to submerge itself so just the head is showing.  This makes it nearly impossible to see.  Folk names for this species are interesting: dabchick, devil-diver, dive-dapper, hell-diver and water witch.  I have heard it called hell-diver by duck hunters who spend time on marshes.  

This neat little grebe is fun to watch and should be fairly easy to spot in New Brunswick in the summer.  A good place to see them is from the boardwalk at the Ducks Unlimited Marsh in Sackville.

Blackburnian Warbler

Blackburnian Warbler [Internet Photo]

The Blackburnian Warbler (Dendroica fusca) may be our most beautiful bird. The male in breeding plumage is breath-takingly beautiful. The mix of oranges, yellow, white, gray and black are masterfully arranged. It is unmistakable with its flaming-orange throat. The female is much drabber and can be distinguished from other warblers by her dark cheek patch which is surrounded by yellow. She also has a yellow incomplete eyering and pale stripes on the back. The juvenile is similar to the female.


There aren’t many warbler species one would mistake for the Blackburnian. The immature female Cerulean Warbler is similar but almost never found in New Brunswick. In the fall it may be confused with the Bay-breasted and the Blackpoll Warblers but they do not have the stripes on the back and they do show a supercilium (line over the eye).

Blackburnian Warbler [Internet Photo] 

We are lucky to be part of the Blackburnian Warbler breeding range. They spend their summers throughout eastern Canada from the central areas of Saskatchewan and Manitoba eastward to the Maritime Provinces. In the fall they take an easterly route through the eastern part of the US to their wintering grounds in mountainous forested areas of the northern Andes, the Amazon and northern South America. In the spring they return by a more westerly route up the central flyway. Their preferred habitats are mixed forests of hemlock, spruce and hardwoods. They are very useful birds in keeping our forests healthy. They eat caterpillars and beetles and other insects.


Blackburnian Warblers nest high (up to 30 m/85 ft) in a conifer tree, usually building their nest way out on the branch. The nest is made of twigs and lined with lichens, moss and hair. The 4 to 7 brown spotted white or pale green eggs are incubated for 11 to 12 days by the female.


The song of this species is very high-pitched and not able to be heard by some people. It is an ascending series on notes ending with a trill. It can be described as 'see see see see ti ti ti siii’.

Blackburnian Warbler [Internet Photo] 

The Blackburnian Warbler among other species is very important in controlling insect damage to our forests, e.g., the Spruce budworm outbreak. This small species is an important part of the forest ecosystem.

The Blackburnian Warbler was named after an English botanist, Anna Blackburne. It is unusual for a species to named after a woman. Also interesting about this species is the advantage it has because it builds its nest and often feeds very high up in the forest canopy. This protects the nest from parasitism by the Cowbird which lays its eggs in other species nests. The lofty habitat also gives it access to more insects which birds which feed lower do not get. 

 
Hemlocks are the favourite tree species for feeding and nesting for this species. Our hemlocks are large and healthy so the Blackburnian Warblers are doing well here.