Bird assemblages in the Thale Noi

non-hunting area, southern Thailand

Kua Rittiboon (Lecturer in Environmental Science, PSU)

Seminar: “Research Methods in Practice” KMIT Lad Krabang April 25-26 2013

We used factor analysis to classify assemblages of bird species

with respect to incidence by season and location. For 23 common

resident species in Thale Noi reserve in Pattalung province, we

found five groups that correlated with their habitats and availability

of food. Group 1 (7 species) was found in flooded habitats. Group

2 (6 species) was found in terrestrial habitats containing grain and

insects. Group 3 (6 species) was found in habitats connecting from

shallow fresh water to suburban environments and typically

providing insect food sources in water and on land. Group 4 (two

species) was found in similar habitats to that of the second group,

but related to fruit trees. Group 5 (two species) was found in

lowland habitats with dense undergrowth providing different food

types including insects, seeds and fruit, particularly figs. This

classification reflects bird behaviour rather than taxonomy.

2What is a resident bird?

“A species which is present throughout the year and presumed

to breed.” (Lekagul and Round: 2005)

3Study area

1. Khuan Kreng

2. Khuan Nang Whean

3. Khuan Thale Mong

4. Klong Yuan

5. Khuan Khi Sian

6. Ban Pran

7. Laem Din

4

5

Data collection

• The bird data were obtained from the office of Thale Noi non-hunting area.

• Data were collected monthly between 2004 and 2007, at seven locations.

• The bird surveys were conducted on the same day each month, at each locations.

• Species were identified using binoculars and field guide (Lekagul & Round 2005).

6Data management

• Resident bird classification

23 species

• Lekagul and Round (2005)

• Found every study year

• Median incidence rate per day greater than zero

•Time definition

4 Seasons of year

• Jan-Mar : 1st season

• Apr-Jun : 2nd season

• Jul -Sep : 3rd season

• Oct-Dec : 4th season

•Incidence rate

Numbers of birds sighted per day (7 hours)

7

Factor Analysis

• To allocate the 23 bird species into a smaller

number of interpretable groups that tended to

appear on the same occasions

• The incidence rates of the 23 species: variables of

interest

• Each variables has 112 observations

(4 seasons x 4 years x 7 sites)

8Results of factor analysis

• Factor 1

• Factor 2

• Factor 3

• Factor 4

• Factor 5

9

Factor 1• Wetland

habitats (freshwater,marsh and shallow water);

• Providing aquatic plants;

• Identified ahabitat providing continuous flood and aquatic plants.

10

Factor 2

• Mostly land birds

• Terrestrial habitat

• Feeding on a variety of foods

• Greater Coucal,Spotted Dove & Cattle Egret

• Foraging on

ground

• Black Drongo: agriculture & insects.

• Identified terrestrial habitat; grain and insects.

11

• Wide range

of habitats.

• Freshwater, woodland, human habitat.

• Purple Heron feeds mainly on fish.

• Common Myna: urban & suburban environment.

• Little Egret, Black-winged Stilt: aquatic insects.

• Common Tailorbird, Barn Swallow actively forage on insects.

• Identified habitat connecting freshwater to suburban

environment, food sources on land and in water.

Factor 3

• freshwater marsh, denseundergrowth.

Forages on theground, feeds mainly on seeds, insects and small fish.

12

Factor 4

Factor 5

• Land birds• Open woodland to human habitat; fond of fruit.

• Lowland forest;Fig-eating specialist.

Conclusions13

• Factor analysis - groups of birds that reflect their

behaviours rather than their taxonomies.

• Habitat attributes and food types associated with the

occurrence of groups of resident birds.

• Birds in the same groups respond to their existence

in different proportions of vertical strata.

• Niche segregation enables these species to coexist in

the same habitat (Kwok, 2009).

ReferencesLekagul B and PD Round (2005). A guide to the birds of Thailand,

Saha Karn Bhaet Group, Bangkok, Thailand. 457 pp.

Kwok HK (2009). Foraging ecology of insectivorous birds in a mixed

forest of Hong Kong. Acta Ecologica Sinica. 29(6): 341-346.