Lorena Rivas

Factors affecting the distribution of the Darwin’s rhea in the Auca Mahuida Reserve in Argentine Patagonia

STUDY AREA

Darwin´s RheaRhea pennata pennata

1.10 m

Adapted to run

Flightless

Diet:

Omnivorous

SocialStructure: Gregarious

Reproduction:Territorial malesHarems of 4-5 females

10-50 eggs per nestEggs incubated by the male

Almost simultaneous hatching

Habitat:Darwin's

Rhea lives in areas of open shrub in the grasslands of Patagonia

Status: Near threatened (IUCN)• Hunting• More

predation due to changes in trophic communities

• Habitat degradation due to livestock overgrazing

• Egg collection

Landholdings

Livestock

Oil industry

Oil trails

(Sheep Units/km2)

Mean ±SE ±1.96*SE Absence Presence

Absence/Presence Darwin´s rhea

-2

0

2

4

6

8

10

12

14

16L

ive

sto

ck d

en

sity

(S

he

ep

Un

its/k

m2

)

p= 0.88

Mean ±SE ±1.96*SE Absence Presence

Absence/Presence Darwin´s rhea

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8O

il tr

ail

de

nsi

ty (

km/k

m2

) p= 0.14

What we are going to record…

Rhea density in Payunia and Auca Mahuida reserve and intermediate lands

Oil trail densityLivestock density Habitat qualityRelative

abundance of predators

To i

To all of you

To WCSTo all the people who works

with me in Argentina

Contact: lrivas@wcs.org / rivas_lorena@yahoo.com.ar