Haliacetus leucocephalus: Bald Eagle–The Race Rocks Taxonomy

In November 2009, Ryan Murphy captured this set of images when a juvenile eagle was making his daily pass by to prey on a seabird. The juvenile california gull provides the meal for that day. Click the image to see a slide show video of this sequence..See the Eagle Set on Ryan’s Flickr site

Bald Eagles measure from 30″ to 43″ ( 76 to 109 cm) in length and from 70″ to 96″ ( 2 to 2.4 m) in wingspan. They have a high thin, chittering voice which contrasts with its magnificent appearance. Bald Eagle’s diet is primarily based on fish catching. It also eats carrion and crippled waterfowl. At Race Rocks, eagles frequently take adult Gulls and Pigeon Guillemots as can be seen in the accompanying images.

The adult Bald Eagle has a snow-white head and tail, the immature ones have brown head feathers which develop white underneath and gradually grow out over several years.
It was formerly found living all over North America. Hunting, poaching and the growth of civilization has had a negative impact in the Bald Eagle population whch has dimished considerably in the last decades. Nowadays it is found only in the Aleutians, Alaska, sections of Northern and Eastern Canada, British Columbia, Northern United States and Florida.

Its habitat is on or near seacoasts as well as close to large lakes and rivers, where the fish population is abundant. It nests in tall conifers, often old growth Douglas Fir or Cedar. Nests are common in the Southern part of Vancouver island. The closest to Race Rocks are on Bentinck Island and along Taylor Beach. The nests are renovated every year starting in January with new sticks, often ripped from tall dead fir trees. The eggs are white and come in groups of 1 to 3 each time.Its beachcombing , scavenging role, and the fact that it eats at the highest trophic level, can cause the Bald Eagle to accumulate pesticides in its body ( from contaminated fish and wildllife. ) The Bald Eagle population remains high in the rain forest coastal area of central and Northern British Columbia and Alaska.

This image comes from the slide show “Fresh Kill” It provides a closeup of an eagle whose head coloring is almost mature, but has not yet lost its dark speckling.
Reference: Miklos D. F. Uduvardy ,1977 The Audubon Society, Field Guide to North American Birds, Western region., Chanticler press, fifth edition: NY

 

The nictitation membrane is a transparent inner eyelid in birds, reptiles, and some mammals that closes to protect and moisten the eye. It is also called the third eyelid.
Pam captured these images of young eagles close to camera 5 in the spring of 2005 to help us demonstrate this adaptation.You can find further information about this feature at: http://ebiomedia.com/gall/eyes/protect.html

Bald Eagles in the Rain

 

 

 

 

Bad Hair Day for the Eagles

 

 

 

Other Members of the Class Aves at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams. Carolina Munoz 1987

 

Histrionicus histrionicus: Harlequin duck–The Race Rocks Taxonomy

rmharley copy

Histrionicus histrionicus –Harlequin Duck

In the fall of 2006, there was a large flock of males and females around the shores of the island. They were frequently visible in the waters and shoreline around the docks. These pictures were captured on the remote camera 5 by Pam Birley.

Interesting Facts:

  • English name from characters in Italian comedy that wear a mask and have an oddly painted costume
  • Locally may be called “rock ducks” due to their habit of staying out on rocks.
  • Population of 200 – 300 thousand on the West Coast but endangered on the Atlantic Coast
  • A group of up to 30 harlequins overwinter at Race Rocks, arriving in early November and departing in the spring, numbers vary as they come and go during that time.

Identification:

  • Length: 12 inches
  • Wingspan: 26 inches
  • Small diving duck
  • Small gray bill
  • Dark wings

Males have a striking feathers with dark blue, dark orange, and white streaks
Females are discrete and have a subtle brown color that camouflages them for nesting

Ryan Murphy has an album of images of Harlequin ducks which he took while he was an Ecoguardian at Race Rocks- 2009-2011.

Biotic Associations:

  • Predation from Sea Lions ( We have seen them leave the water and come up on the rocks when sea lions are near.)
  • Spend majority of time feeding in Kelp Beds on aquatic invertebrates and lesser quantities of fish.

Food:

Freshwater invertebrates

  • Fish eggs consumed when available
  • Use their stubby bill to pry invertebrates such as snails, limpets, crabs, chitons, and mussels from the rocks
    during the winter months
  • In the late winter months they feed on herring spawn in large congregations.

Domain : Eukarya
Kingdom:  Animalia
Phylum : Chordata
Subphylum:  Vertebrata
Class : Aves
Order:  Anseriformes
Family:  Anatidae
Genus:  Histrionicus
Species: histrionicus
COMMON NAME: Harlequin Duck

See other posts on this website with reference to Harlequin Ducks

Other Members of the Class Aves at Race Rocks.

taxonomyiconReturn to the Race Rocks Taxonomy
and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.

This file was originally produced by Dec. 2001 Karim Ladha (PC yr 27)