Kia Kiawa wah h Is Isla land nd Bo Bobca bcats: ts: A Ke Keystone tone Species cies in in a De Develo loping ping Landsca dscape pe Shane Roberts The Mystery an and Mag agic of f Bobcats March 26, , 2019
Pe People, ple, De Deer, r, & & Pr Predators dators
Pe People, ple, De Deer, r, & & Pr Predators dators
Pe People, ple, De Deer, r, & & Pr Predators dators
Pe People, ple, De Deer, r, & & Pr Predators dators Miss. State Univ.
Re Resid sidential ential De Devel velopment opment 1970 1975 1980 1985 1990 1995 2000 2005 Red = Developed
Re Resid sidential ential De Devel velopment opment 1970 1975 1980 1985 1990 1995 2000 2005 Red = Developed
Bo Bobc bcat at & De Deer r Re Rese searc arch h on K n Kia iawah wah 1996-1997 • Dense but healthy deer population • Dense bobcat population (≈30) • Bobcats eat mostly rodents (>40%), some deer
Bo Bobc bcat at & De Deer r Re Rese searc arch h on K n Kia iawah wah 2000-2001 • Relatively stable bobcat population • Similar diet • Bigger home ranges and higher mortality on west end vs east end
Bo Bobc bcat at & De Deer r Re Rese searc arch h on K n Kia iawah wah 2002-2003 • Objectives – Deer survival rates and causes of mortality? – Differences between east and west ends?
Deer De er Mo Monitoring nitoring • Collared 30 does each year – Radio-collar, eartag, VIT • Neonatal fawns – Expandable radio-collar – Monitored year round
De Deer r Faw awn n Sur urvi vival val • 61 fawns monitored during 2002 & 2003 • 51 mortalities (16% survival) – 31 bobcat (61%) – 8 vehicle – 5 alligator – 7 other
Bo Bobc bcat at (L (Lynx nx ru rufu fus) • Moderately sensitive to habitat fragmentation • Typically avoid interactions with humans • Not usually a major deer predator!
Bo Bobc bcat at & De Deer r Re Rese searc arch h on K n Kia iawah wah 2004-2005 • Objectives – Deer survival and causes of mortality – Bobcats ecology – Bobcat habitat suitability
Bobc Bo bcat at Mo Monitoring nitoring • Collared 16 bobcats – Home range size & overlap – Reproduction & survival – Habitat use & movements – Interactions with deer
De Deer r Faw awn n Sur urvi vival val • 134 fawns radio- collared • 105 mortalities – 70 bobcat (67%) • Bobcat predation – 66% within 2 weeks – 97% within 5 weeks
De Deer r Faw awn n Sur urvi vival val • Yearly variation – Individual bobcat prey selection • #795 at 35% (8) in 2002 2-week Survival from Bobcat (%) 100 80 60 40 20 0 2002 2003 2004 2005
De Deer r Faw awn n Sur urvi vival val • Yearly variation – Diet optimization – Rodent abundance 2-week Survival from Bobcat (%) 100 80 60 40 20 0 2002 2003 2004 2005
Hab abit itat at & & Bo Bobcat bcat Pre Predation dation More concentrated fawning habitat = higher chance of bobcat predation
Bo Bobcat bcat Re Reprod production uction • 6 dens located – 1.8 kittens/den (range = 1-3) – >5 acre patches of forest or shrub
Bo Bobc bcat at Home me Ra Rang nges es • Males had larger home ranges than females • Juvenile females had larger home ranges than adult females • Adult females on the west-end had larger home ranges than those on the east-end
Bobc Bo bcat at Inte nterac ractions tions • Typical bobcat behavior – Males typically overlap several females – Males-males and females- females don’t typically overlap • Kiawah females overlapped 0-90% of their home range with another female – DNA suggested high relatedness for 90% overlap; denned 160 m and 85 m apart – Abundant resources?
Bo Bobcat bcat Mo Moveme vements nts Day movemen ents ts depres essed, sed, no decre reas ase e at night ht 350 Avg Movement Rate (m/hr) 300 250 200 150 100 50 0 Dawn Day Dusk Night Time Period
Hab abita itat t Selection ection Habitat tat Rankin ing Time e Period od Selected cted Avoide ded Diurnal nal Shrub Dune Forest est Develop lop Marsh sh Altered ered Noctu turna rnal Shrub Develo lop Dune Forest est Alter er Marsh sh • Selected habitat differently day vs night • Shrub selected over all other habitats • Development selected and Altered not avoided during nocturnal
Hab abita itat t & & Home ome Ra Range nge • Female home ranges ↓ when % Shrub ↑ • EE vs WE differences may be inherent differences in landform & Shrub availability
Bo Bobcat bcat Hab abita itat t Sui uitability tability • Habitat Suitability Index – Scoring system that is based on biology – Modified from Boyle and Fendley (1987) – Considered food, cover, and reproductive capability of habitat
Bo Bobcat bcat Hab abita itat t Sui uitability tability
Re Resear search ch Co Concl nclusions usions • Kiawah bobcat = keystone species – A species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically – Natural regulation of deer • Maintenance of bobcat abundance – Individual prey selection
Re Resear search ch Co Concl nclusions usions • Conservation of suitable habitat – Shrub, edge – Understory – bobcats & rodents • Local conservation and education efforts are key
Cr Creating ating Bo Bobc bcat at Hab abitat itat • Backyard habitat – Native plantings that provide understory – Creation of “soft edges”
Kiawah iawah – Uni nique que in in Am America rica Suburban bobcats do not make Kiawah unique
Kiawah iawah – Uni nique que in in Am America rica Suburban bobcats do not make Kiawah unique
Kiawah iawah – Uni nique que in in Am America rica Your efforts to maintain bobcats at a level where they function as a keystone species DOES!
Th Thank You! ank You!
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