Separation of Little Egret (Egretta garzetta) from Snowy Egret (E. thula)

Little Egret (Egretta garzetta) is an Old World species that occurs as an occasional vagrant to eastern North America (Quebec, Nova Scotia, Newfoundland, New Hampshire, Massachusetts, Rhode Island, Delaware, Virginia) as well as a number of Caribbean Islands, most notably Barbados where the species has established a breeding toehold (Massiah, 1996).

Separation from superficially similar Snowy Egret (E. thula) is generally poorly described in the literature. A cooperative Little Egret at Bombay Hook NWR in Delaware provided an excellent opportunity to compare the two species. The photographs were taken on Sunday 18th July 1999.


Figure 1. The scene - Shearness Pool at Bombay Hook NWR, Delaware. A group of egrets and Glossy Ibis (Plegadis falcinellus) feed on a school of minnows in a small pool. It took only a few second to spot the Little Egret (third egret from the left) by virute of its slightly larger size, gray/blue lore patch, paler iris and longer-headed look. Photograph by Angus Wilson©


Figure 2. Proceeding from left to right, Snowy Egret, Little Egret and Great Egret (Ardea alba). Notice the slightly larger size and greater height of the Little Egret compared with the Snowy Egret on the left. In general, Little Egrets are larger than Snowy Egrets, appearing longer-legged and longer-necked. It is worth noting, however, that there can be significant size variation between individuals of either species and that males tend to be larger than females. Photograph by Angus Wilson©


Figure 3. A useful comparison of the two species. The Snowy Egret (lower bird) has bright yellow lores and iris. In contrast, the Little Egret (upper bird) has gray lores and a paler iris. The forehead of the Little Egret seemed to slope more gradually accentuating its long-billed, long-headed jizz. Notice the much more extensive pale gular area on the lower mandible. This was obvious at all times, and very distinctive. The single short plume is also clearly visible. Photograph by Angus Wilson©


Figure 4. The bird had a single 'lanceolated' head plume that is obvious in this photograph. Although not strictly definitive, the head plumes (when present) provide a useful identification feature. Most Snowy Egrets have bushier plumes, although several examples have been described with long Little Egret-like plumes emerging from a bushy cluster. The color and extent of the yellow leg markings is also helpful in separating Snowy Egret from both Little Egret and white-morph Western Reef Heron (E. gularis). Unfortunately, wet mud obscured the feet and legs in this shot. Photograph by Angus Wilson©


Figure 5. After the feeding frenzy had died down, the egret moved onto the bank and then took flight, heading down to a group of trees near Raymond Pool that is used as a roosting site. Even in this poorly focused flight shot, the pale gular patch is clearly visible. Obviously the bird is in the process of molting its flight feathers. Photograph by Angus Wilson©


Figure 6. A Little Egret photographed in January in Kyushu, Japan. Notice the dagger-like bill, solid black legs and the absence of yellow stripe running up the back of the tarsus. The yellow on the feet is largely restricted to the toes. The lores are paler than the iris. This bird has one well-defined lanceolated head plume. Photograph by Angus Wilson©


Figure 7. Another Little Egret again photographed in January in Kyushu, Japan. It is unclear whether the pale markings around the 'knee' joints represent aberrant coloration or patches of dried mud. Photograph by Angus Wilson©

Little Egret is a highly migratory and dispersive species. Many European breeders migrate south across the Sahara to winter in equatorial Africa. Birds seen in North America are thought to have been carried by the prevailing northeasterlies to the West Indies and South America and then restablished a 'normal' northwards migration in the summer months (McLaren, 1989; Massiah, 1996). The European origins are confirmed by the recovery of at least two individuals banded as nestlings in Spain.

For a detailed treatment of variation in both Little and Snowy Egret check out Martin Reid's fantastic series of web pages that highlight a problematic bird studied in Texas.

Acknowledgements

Thanks to Andy Guthrie for discussion of this bird. 

Useful Literature and Web Documents

Massiah, E. (1996) Identification of Snowy Egret and Little Egret. Birding World 9(11): 434-444.

Grant, PJ. et al., (1980) Bare-part colour of Snowy and Little Egrets. British Birds 73: 39-40.

McLaren, IA. (1989) Thoughts on North American Little Egrets. Birding 21: 284-287.

Sibley, D. (1997) Snowy vs Little Egret ID-Frontiers: 27 Aug 1997.
 

More images on the web

(European) Little Egret Photographed in Italy by P. Montanaro.

(Asiatic) Little Egret Photographed in Japan by F. Shibaori.

(Asiatic) Little Egret Superb flight shot, photographed in Japan by Takahashi Koike.

(Asiatic) Little Egret Photographed in Japan by 'Suzume'.

Beautiful image of an adult Snowy Egret taking flight Photographed by Arthur Morris.

Interesting shot of a white-phase Reddish Egret Photographed by Arthur Morris.

Hunched adult From the Weymouth RSPB web site.


Photographs and page layout copyright of Angus Wilson© 1999 All rights reserved.
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