the herons

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The Herons Family Ardeidae Michael Bennett

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The Herons. Family Ardeidae. Michael Bennett. Systematics. Kingdom: Animalia. Phylum: Chordata. Class: Aves. Order: Ciconiiformes. Family: Ardeidae. Genus: Ardea Butorides Nycticorax Nyctanassa. Long, S-shaped neck. Heavy, pointed bills. Slender legs. - PowerPoint PPT Presentation

TRANSCRIPT

The HeronsFamily Ardeidae

Michael Bennett

Kingdom: Animalia

Phylum: Chordata

Class: Aves

Order: Ciconiiformes

Family: Ardeidae

Genus: Ardea Butorides Nycticorax Nyctanassa

Systematics

Characteristics of Herons

Long, S-shaped neck

Heavy, pointed bills

Slender legs

In Flight

Legs Tucked

Neck Folded

Except at take-off

Heron Life History Traits

Nest In Trees -Rarely on ground

-Rarely far from water

2 – 6 pale blue eggs

Mostly Colonial

Complex Breeding Displays

Territorial esp. in breeding season

Heron Life History Traits Cont.

Piracy is Common

Diet primarily fish -Also invertebrates, insects,and rodents

Forage by wading/stalking

Seasonally monogamous -Most breed second year

Both sexes care for young-Altricial young

Populations Then and Now

1800’s –1900’s saw drastic declines

Habitat lossShootings

Plume Trade

Populations Then and Now Cont.

Increases in 1950’s

Most pop. stable or increasing

-Habitat protection and restoration

-Beaver protection

Heron Diversity

App. 65 species in Ardeidae - With argument and more to come - 13 species in N. America

Family divided into four groups (Payne & Risley 1976)

Night HeronsDay Herons

BitternsTiger Herons

Heron Diversity Cont.Herons are present on every continent (except Antarctica) -Highest diversity in Central and South America

Heron Diversity Cont.

The oddest of the group:

Boat-Billed Herons

Heron Diversity Cont.Most colorful(arguably) of the group:

Agami Heron (Brazil)

Heron Diversity Cont.

Many others:

Herons in Kentucky

Four occur in Kentucky

Yellow-Crowned Night Heron

Black-Crowned Night Heron

Great Blue Heron

Green Heron

The Yellow-Crowned Night Heron

Nyctanassa violacea

Summer

Winter

Range maps courtesy of USGS CBC/BBS

Nocturnal/Crepuscular

Relatively Selective

Yellow crown

Obvious head plumes

White face patch

Prefers forested wetlands

Black-Crowned Night Heron Black cap

Short neck

Single plume

Red eye

Nycticorax nycticorax

Primarily Nocturnal

Cosmopolitan(except Australia)

Prefers swamps/marshes

Often nests with other species

Black-Crowned Cont.

Feed on a wide variety of foods -Prefers fish

Often shot at fish hatcheries

Black-Crowned Range

summer

winter

Range maps courtesy of USGS CBC/BBS

Found throughout N.A.

Range seems to be expanding(Based on CBC/BBS)

Found in W. Kentucky

Winters into Central America

Great Blue Heron Intro.Blue Heron Intro.

-Largest heron in N.A.

-Wide spread and common

-Most widely studied heron

-Many subspecies

- Up to 20 in the past

- Currently around seven

-Great white most obvious subspecies

Ardea herodias

Identification

Black shoulder patch

Occipital plumes (Not always obvious)

Bluish-grey in color

Grey heron is similar but lives in Europe/Africa

Identification Cont.Ardea herodias occidentalis

- Entirely White

- Larger than Egrets

- Great White Heron

Great blue summer range

Range maps courtesy of USGS BBS

Great blue winter range

Range maps courtesy of USGS CBC

Breeding and NestingFresh & brackish water

Most often in marsh/swamp - prefers trees

Male collects material, female builds nest

Breeding and Nesting Cont.Highly territorial when nesting

Nest defense by both sexes

Bill fencing common

Many courtship/defense displays

Eggs and YoungTwo – six eggs

-Increases with latitude

Semi-altricial young

-Eyes open, has down

Both parents brood/feed young

Fledge around 80 days-Varies with latitude

Eggs and Young Cont.• Adults tend young up to 3

weeks after fledge

• Foraging skill increases with age (Butler 1991)

• Most breed in second spring• Rarely return to natal site

Management Concerns

Highly adaptable to varying habitat(Powell et al. 1981)

Habitat Loss

-Cont. restoration/protection esp. pacific coastal

Will abandon if disturbed -Less likely later in incubation

-appropriate measure limit this

-Butler 1992 recommends 300m buffer

Will adapt to human presents

Management Concerns Cont.• Shootings common in past

• Federally protected

• Attitudes have changed

• Varity of control methods

• Netting most effective

• Pesticides effect success(ddt/dde)• Levels currently dropping• Home use is a problem• Better testing of chemical pesticides

and herbicides is needed

Green Heron IntroOne of the smallest herons

Most common heron in it’s range (and possibly N.A.)

Undergone many taxonomic and name changes

Green-backed heron

Blue-backed heron

Little green heron

Butorides virescens

Identification Blue-green back

Chestnut neck and head

Dark cap

Crow like in Flight

Identification Cont.Juveniles Can be confused with American/Least Bittern

Least Bittern

American Bittern

Green Heron

Larger than least

Smaller than American

Breeding Range

Range maps courtesy of USGS BBS

Green Heron Range

Map courtesy of Cornell Ornithological Laboratory

As far south as Ecuador

As far north as Vancouver

Common breeder in Ky

Habitat and Foraging

Stand still or stalks prey

More likely to inhabit streams

Typically Grabs rather spears prey

One of the few tool using birds

Habitat and Foraging

• Usually solitary nester• Will nest in loose colonies

• Seasonally monogamous• Aerial and non-aerial breeding

displays • Includes vocalizations

• Territorial (less so than others)

• Male selects nest site and begins construction• Female finishes nest while male brings

material

Breeding and Nesting

Eggs and Young• Clutch size 3 – 5

• Both parents incubate• “relief ceremony” when

switching• Includes bill rubbing

and preening

• Can be multi-brooded in southern range

• Fledge in 16 days• Flightless until 21st day

Eggs and Young• Young swim well after

fledging• Est. 30-35 days until

independent of parents (Davis & Kushlan 1994)

• 1 – 2 yrs until first breeding

Management Concerns• Habitat loss

• Esp. ephemeral wetlands• Identification of semi-permanent wetland essential

• Often shot (more so in the past)• Considered a pest at fish hatcheries• Current regulations limit lethal control measures

• River usage • Limits heron usage• Can lead to nest failures • Underscores the need to protect smaller inaccessible

wetlands

Herons are diverse and complex group that span the globe

Their future health depends primarily on habitat protection and restoration

Much more research is needed in the fields of:Post fledgling survival

Habitat usesPopulation dynamicsEffects of disturbance

Works Cited• To be continued

Questions