The Company Canids Confront: Resource Partitioning in Sympatric - PowerPoint PPT Presentation

The Company Canids Confront: Resource Partitioning in Sympatric Carnivores in an Arid Ecosystem Kadambari Devarajan Post Graduate Program in Wildlife Biology and Conservation, National Center for Biological Sciences, Wildlife Conservation Society - India Program, Bangalore. M.Sc. Thesis Defense Guide: Dr. Abi Tamim Vanak (ATREE) Co-guide: Dr. Vishwesha Guttal (CES, IISc) Kadambari Devarajan (NCBS) November 18, 2015 1 / 43

Outline Introduction Goal Prior Research Study Area Study Taxa Methodology Analysis Results Conclusions Kadambari Devarajan (NCBS) November 18, 2015 2 / 43

Introduction Predators important for ecosystem function Multiple predators in a landscape Size-mediated interactions [Levi & Wilmers, 2012] Kadambari Devarajan (NCBS) November 18, 2015 3 / 43

Introduction: Carnivore interactions Lethal interactions Intra-guild predation Intra-guild competitive killing Sub-lethal interactions “Landscape of fear” Kadambari Devarajan (NCBS) November 18, 2015 4 / 43

Introduction: Species-scapes “... a spatial plane of species interactions that combines with resources and habitat structure to drive species distributions” [Fisher et al., 2012] Kadambari Devarajan (NCBS) November 18, 2015 5 / 43

Goal Identify how sympatric carnivores partition resources: space, time, habitat, and diet Kadambari Devarajan (NCBS) November 18, 2015 6 / 43

Study Area http://bannigrassland.klink.co.in/images/Banni%20Location_2.jpg Kadambari Devarajan (NCBS) November 18, 2015 7 / 43

Habitats Image source: Pankaj Joshi Kadambari Devarajan (NCBS) November 18, 2015 8 / 43

Taxa Indian fox image: Abi Vanak Kadambari Devarajan (NCBS) November 18, 2015 9 / 43

Other meso- and large carnivores present Indian wolf - very rare Jungle cat, caracal, desert cat Striped hyena Kadambari Devarajan (NCBS) November 18, 2015 10 / 43

Prior Research Bat-eared fox, cape fox, & black-backed jackals: South Africa [Kamler et al., 2013] Indian fox & domestic dog: India [Vanak & Gompper, 2009a; Vanak & Gompper, 2009b; Vanak & Gompper, 2010] Domestic dog & golden jackal: India [Jhala & Aiyadurai, 2006] Wolf - Coyote - Red/Swift fox: Canada, North America [Voigt & Earle, 1983; Gese et al., 1996; Smith et al., 2003] Red & Arctic fox: Canada, North America, Eurasia [Hersteinsson & Macdonald, 1992] Kadambari Devarajan (NCBS) November 18, 2015 11 / 43

Research Gaps Mostly 2-3 species at a time Significant dietary niche separation Human-subsidized carnivores - rarely considered Species-scapes ignored Kadambari Devarajan (NCBS) November 18, 2015 12 / 43

Methodology: Overview Kadambari Devarajan (NCBS) November 18, 2015 13 / 43

Methodology: Design Grid-based sampling approach: Occupancy framework Nested design Single season, multiple species Imperfect detection: Spatial replicates → track plots Temporal replicates → camera traps Kadambari Devarajan (NCBS) November 18, 2015 14 / 43

Methodology: Grids Kadambari Devarajan (NCBS) November 18, 2015 15 / 43

Methodology: Sampling Kadambari Devarajan (NCBS) November 18, 2015 16 / 43

Data Collection: Effort Camera trapping: All canids 74 grids * 4 camera traps * 4 days ≈ 300 cameras * 4 nights → 1200 camera trap nights ≈ 6500 videos - 30 seconds each Kadambari Devarajan (NCBS) November 18, 2015 17 / 43

Data collection: Effort Photographic capture-recapture: Dogs 17/50 villages in Banni - stratified random sampling based on village size (no. of households) Kadambari Devarajan (NCBS) November 18, 2015 18 / 43

Data collection: Covariates measured On ground: Vertical density Ground cover Vegetation type Presence of other canid species Food availability - burrow count, indirect signs of prey Anthropogenic influences - dung pat count, lopping Kadambari Devarajan (NCBS) November 18, 2015 19 / 43

Data collection: Covariates measured Remotely-sensed/GIS: Proximity to human habitation Proximity to road Proximity to water source Vegetation type Kadambari Devarajan (NCBS) November 18, 2015 20 / 43

Scat collection Desert fox & Indian fox - only at active den sites Golden jackal - recorded defecating in front of camera Kadambari Devarajan (NCBS) November 18, 2015 21 / 43

Analysis: Camera Trap Videos Desert fox in Banni Kadambari Devarajan (NCBS) November 18, 2015 22 / 43

Analysis: Camera Trap Videos Desert fox in Banni Kadambari Devarajan (NCBS) November 18, 2015 23 / 43

Analysis: Occupancy Assumption: Occupancy of larger canids not affected by smaller ones Model selection: Best model from multiple models for each species R package: unmarked Species maps: QGIS Kadambari Devarajan (NCBS) November 18, 2015 24 / 43

Results Kadambari Devarajan (NCBS) November 18, 2015 25 / 43

Very little dietary partitioning Kadambari Devarajan (NCBS) Frequency of Occurrence 0.00 0.25 0.50 0.75 0.00 0.25 0.50 0.75 0.00 0.25 0.50 0.75 rodent Vertebrates hare hedgehog bird stl reptile coleopteran isopteran Diet Composition Invertebrates arachnid orthopteran hymenopteran odonate crustacean suaeda prosopis grass_root Plants grass_leaf wood_piece November 18, 2015 zizyphus cucurbit Jackal Indian Fox Desert Fox 26 / 43

Wild canids crepuscular + nocturnal Desert Fox 10 5 0 10 No. of Encounters Dog 5 0 Golden Jackal 10 5 0 Indian Fox 10 5 0 00h 03h 06h 09h 12h 18h 21h Time Active Kadambari Devarajan (NCBS) November 18, 2015 27 / 43

Naïve occupancy From camera trap data: Species Sites Present Total Sites % Indian Fox 61 675 9 Golden Jackal 392 675 58 Desert Fox 81 675 12 Dog 74 675 11 Kadambari Devarajan (NCBS) November 18, 2015 28 / 43

DF & Dog - Complete separation ������ ���������� ��� ������� Kadambari Devarajan (NCBS) November 18, 2015 29 / 43

IF & GJ - Complete overlap ������ ���������� ������������� ������� Kadambari Devarajan (NCBS) November 18, 2015 30 / 43

IF & DF - Near complete separation ������ ���������� ���������� ������� Kadambari Devarajan (NCBS) November 18, 2015 31 / 43

GJ & Dog - Near complete separation ������ ������������� ��� ������� Kadambari Devarajan (NCBS) November 18, 2015 32 / 43

Spatial partitioning: All canids ������ ���������� ���������� ������������� ��� ������� Kadambari Devarajan (NCBS) November 18, 2015 33 / 43

Spatial partitioning: Conceptual diagram Jackal Village Dog Indian Fox Desert Fox Kadambari Devarajan (NCBS) November 18, 2015 34 / 43

Species interactions: Occupancy analysis From β values estimated from best model: Species IF DF Jackal Dog IF -ve +ve -ve DF 0 -ve -ve Jackal 0 0 -ve Dog 0 0 -ve Kadambari Devarajan (NCBS) November 18, 2015 35 / 43

Conclusions Very little dietary partitioning Especially among foxes Minor differences in plant matter Kadambari Devarajan (NCBS) November 18, 2015 36 / 43

Conclusions Wild canids primarily crepuscular + nocturnal Dogs diurnal No canids active - 2 to 4 PM Kadambari Devarajan (NCBS) November 18, 2015 37 / 43

Conclusions Desert fox - spatial partitioning with other canids Dog - spatial partitioning with other canids Indian fox & golden jackal - spatial overlap Kadambari Devarajan (NCBS) November 18, 2015 38 / 43

Acknowledgements Dr. Abi Tamim Vanak Dr. Vishwesha Guttal Dr. Ajith Kumar Chandni Gurusrikar Dr. Pankaj Joshi , Dr. Suhel Quader , Chandrima Home , Kulbushan S. Suryawanshi , Anil Gohil , Girish Punjabi , Ovee Thorat , N. Lakshminarayanan , Chetan Misher , Chintan Sheth , Ameya Gode , Jayashree Ratnam , Tarun Nair , Priyanka Runwal , Dharmaveer Shetty , Jayashree Ratnam , Megha Bhai , Rasul Bhai , Mutthalib Bhai , Kabul Bhai , Salim Mama Dr. Prabhu Ramachandran My parents and sister Kadambari Devarajan (NCBS) November 18, 2015 39 / 43