nan yang 1 , k. zhang 1 , j.h ran 1 , h. lloyd 2 & b.s yue 1
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Does group size influence territory size and overlap Does group size influence territory size and overlap in a cooperative breeder, an experimental population in a cooperative breeder, an experimental population
of Buff-throated Partridge?of Buff-throated Partridge? • Nan YangNan Yang11, K. Zhang, K. Zhang11, J.H Ran, J.H Ran11, H. Lloyd, H. Lloyd2 2
& B.S Yue& B.S Yue11
1 College of Life Sciences, Sichuan University, Chengdu 610064, China;
2World Pheasant Association, Close House Estate, Heddon on the Wall, Newcastle upon Tyne, NE15 0HT, United Kingdom;
*corresponding author: rjhong-01@163.com
Medium-sizedMedium-sized
Endemic to ChinaEndemic to China
VulnerableVulnerable
Buff-throated Partridge (Buff-throated Partridge (BTPABTPA)) Tetraophasis szechenyii
Distribution areasMainly distributed in high altitude habitatsMainly distributed in high altitude habitatsin Western China.in Western China. southwest Sichuan
south Qinghai northwest Yunnan and southeast Tibet
The typical habitat of BTPA is mixed conifer forests, alpine shrub and tundra above the tree-line at the altitude between 3300 to 5000 m.
• Little is known about mating system, according to Little is known about mating system, according to previous observations it is presumed to be a previous observations it is presumed to be a monogamous or polygynous species, but our study monogamous or polygynous species, but our study suggested this species turn out to be a suggested this species turn out to be a COOPERATIVE BREEDING species.
Cooperative behavior• Living in family groups, roost together • Group size: 2.81 ± 0.09 (n = 68) • 65% (44/68) breeding pairs have up to three helpers • Don’t form big winter flock• All helpers exhibited brooding, vigilance and territorial
display
3♂1♀, +3Juveniles
3♂2♀, lasted 2 years.≧
Cooperative breeding
Environmental constraints
Cooperative breeding
Arise Rare in Galliformes
Larger groups Better & high-quality territory
Greater reproduction
Conflict of interest betweengroup size & composition
Exist
Inhabit
Little knowledge exist
Year-round residents
Objectives• Determine seasonal territory size and degree
of overlap between neighbors • Identify relationship between group size and
territory size and overlap
• Using an experimental population, partially habituated through supplemental feeding
• Implications for studying ‘truly wild’ populations
Study area and habitat types
Pamuling Tibetan Monastery
●
Pamuling Mountains in southwest of Sichuan from 2006 to 2009Ranged:3900-4200Snow covered: November to April
The main habitat types
Characterized by a series of dark coniferous forest, oak thickets, rhododendron shrubs and meadow.
Hollyleaf alpine Oak Forest
Alpine Meadow
Flaky Fir Forest
Violet-purple Rhododendron Shrub
Pamuling Monastery
Territory sizeWe defined territories as the area that the BTPA occupy and defend against other groups for the purpose of reproduction, and providing foraging resources for all breeding individuals, nestlings, and other members.
Methods• Locating groups and data collections: direct tracking of
colour-marked individuals
• Data analysis: using SPSS for windows release 11.0; All tests were two-tailed (α =0.05). Mean values are given ± the standard error (SE)
• Seasonal divisions: breeding season and non-breeding season
• Territory size and overlap: BIOTAS software v.2.0 with 100% Minimum Convex Polygon
ResultsTable 1. Territory size (100% Minimum Convex Polygon ) for a experimental
population of BTPA direct tracked from March 2007 to July 2009.
• Territory size was independent of group size in breeding season and non-breeding season ( F3,17=0.1, P=0.96; F2,11=2.5, P=0.132).
• All territory sizes did not vary during the duration of study (F2,17=1.7, P=0.22; F1,11=4.3, P=0.07, respectively).
Table 2. Percentage overlap in 100% Minimum Convex Polygon territory for neighboring groups in BTPA.
• The difference in territory overlap between breeding pairs with and without helpers was significant in the breeding season (ANOVA, F3,17=4.2, P=0.024).
• But group size did not affect territory overlap in the non-breeding season (ANOVA, F3,24=0.8, P=0.516).
Discussion • Main factors associated with cooperative breeding in
BTPA:Severe/harsh climate (unpredictable weather)?Direct benefits (e.g. increase food access and survival, enhanced breeding experience)?Lack of breeding habitat or vacant territories?
15 days
3 days
• Possible factors constraining ranging behaviors in BTPA:
• Forage and roost together, take active care and guard the nest and chicks
• Predation and neighbor competition pressure?
We found that:
• Group size does not affect territory size in this Group size does not affect territory size in this experimental populationexperimental population
• Food not limited?
• Effect of supplementary feeding?
• Currently examining correlations between territories, home range, roost sites and supplemental feeding
Other studies:
• Breeding Pied Wagtails permit ‘satellite’ (non-breeding) wagtails to share and defend territory when food is abundant
• Direct tracking data of Tibetan Eared-pheasant Crossoptilon harmani showed that spatial location of foraging and roosting sites were only determinant of home range size
• Food availability at roosting sites (on the ground) for Tibetan Eared-Pheasant was lower than at foraging sites.
• Cooperative groups had smaller territory overlap than pairs without helpers in breeding season:
• Energy and nutrient requirements?• Reduce predation risk and competition?
• Larger territory overlap in non-breeding season:
• Increase encounter rate and reduce inbreeding?
Acknowledgements
Dr. Philip McGowan Dr. Ying Wang Dr. Siegfried Klaus Wangqing Li Pamuling MonasteryForestry Bureau of Yajiang County
Thank Thank you!!!you!!!
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