Wild Nature Institute
  • Science
    • Giraffe
    • TUNGO
    • Spotted Owl
  • Education
    • Environmental Education
    • Snag Forest
    • Forest Fire Truths
  • Action
    • Save The Giraffe
    • Corridor Campaign
    • Snag Forest
    • Forests For Everyone
  • Donate
    • Ways To Give
    • Purchase NFT
    • Adopt A Baby Giraffe
  • Blog
  • About Us
    • Monica
    • Derek
    • James
    • Veila
    • Our International Team
    • Our Tanzanian Partners
Updates From the Field and News From Wild Nature

New study reveals how human settlements and rainfall affect giraffe space use

2/22/2019

0 Comments

 
By Derek Lee, Wild Nature Institute
Picture
Highlights
•Home ranges of giraffes near populated towns were larger than those farther away.

•Dense human areas may force giraffes to range farther to obtain resources.
•No such negative relationship was evident with indigenous pastoralist homesteads.
•Rainfall explained 74% of the variation in giraffe home range size across Africa.
•Home ranges were smaller in regions with higher rainfall and greater productivity.

ARUSHA, Tanzania, 22 February 2019 – Giraffes are huge browsing animals that live in African savanna ecosystems where they must find everything they need to survive and reproduce in landscapes increasingly impacted by human activities. People are converting natural savannas to towns and farms, and cutting trees for fuelwood and charcoal industries, all of which potentially degrade giraffe habitat. The spatial area over which an animal repeatedly travels in search of food, water, shelter and mates is the home range, a concept used by ecologists to describe space use by animals. Home range behavior is an expression of an animal’s decision-making process about how to access the resources needed for survival and reproduction. A new study examining what affects the size of giraffe home ranges was published this week in the journal Animal Behaviour by an international team of wildlife researchers from University of Zürich, Penn State University, and Wild Nature Institute. The team found that giraffes living closer to towns had larger home ranges than giraffes living far from towns, suggesting a need to range longer distances—and expend more energy—to obtain critical resources in human-impacted areas. No such relationship was evident with bomas, which are homesteads built by indigenous livestock-keeping Maasai people, suggesting that giraffes are tolerant of more traditional, lower-impact land uses. “Giraffes are vulnerable to extinction after a 40% population decline during the past 3 decades,” said Mara Knüsel a graduate student at the University of Zürich and first author of the study. “Identifying factors affecting space use help wildlife conservationists to make better decisions for at-risk species such as giraffes.”

As one of the largest herbivores on earth, giraffes have a profound impact on plant populations, vegetation structure, and ecosystem processes where they live. Giraffes are also a favorite animal sought by ecotourists on safari in Tanzania, where the safari industry is the number-one dollar earner and the largest economic sector in the country. “Most studies that previously looked at home ranges of giraffes didn’t look for environmental factors that determine the observed home range size, so this study goes beyond the pattern to reveal the process behind it,” said Monica Bond, PhD candidate at University of Zürich and senior author of the study.

The team quantified home range sizes for 71 adult giraffes from data collected over 6 years, and examined correlations between individual home range sizes and environmental and anthropogenic factors in the spatially heterogeneous Tarangire Ecosystem of Tanzania, to better understand potential mechanisms driving space use of this threatened megaherbivore. They also compared home range estimates from published data for 8 giraffe populations across Africa, and examined the relationship between giraffe home range size and mean annual rainfall at the continental scale as a potential explanation for observed variation in space use among populations. Rainfall was negatively correlated with home range size and explained 74% of the variation in giraffe home range sizes across Africa. This relationship between rainfall and space use by a large herbivore is not surprising, given that rainfall is the main driver of vegetation productivity and thus food availability. Greater availability and access to critical resources such as food and water leads to smaller home range sizes. “Human disturbance and fragmentation of habitat in and around densely populated areas likely reduced the local forage and water resources available for giraffes, forcing individuals to increase their movements and use of space to obtain these resources,” said Knüsel. “Similarly, lower rainfall and lower primary productivity forces individuals to range more widely.”

The study at the publisher's site:
https://doi.org/10.1016/j.anbehav.2019.01.017
download giraffe home range study
0 Comments

Your comment will be posted after it is approved.


Leave a Reply.

    Science News and Updates From the Field from Wild Nature Institute.

    Follow @WildNatureInst

    RSS Feed


    If You Love Us,
    Make A Donation!

    All Photos on This Blog are Available as Frame-worthy Prints to Thank Our Generous Donors.
    Email Us for Details of this Offer.

    Archives

    January 2023
    September 2022
    August 2022
    June 2022
    May 2022
    March 2022
    January 2022
    December 2021
    November 2021
    September 2021
    June 2021
    April 2021
    March 2021
    February 2021
    January 2021
    December 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    January 2020
    December 2019
    October 2019
    September 2019
    August 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    April 2018
    February 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    February 2015
    January 2015
    December 2014
    November 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013
    June 2013
    May 2013
    April 2013
    March 2013
    February 2013
    January 2013
    December 2012
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    June 2012
    May 2012
    April 2012
    March 2012
    February 2012
    January 2012
    November 2011
    October 2011
    September 2011
    August 2011
    July 2011
    June 2011
    May 2011
    April 2011
    January 2011

Home
About Us
Monica Bond
Derek Lee
James Madeli
Our Tanzanian Partners
Our International Team
Juma The Giraffe
Celebrating Africa's Giants

Science
   Giraffe
   TUNGO
   Spotted Owl
Education
   Environmental Education
   Snag Forest
   Forest Fire Truths

   Sinema Leo Video Children's Books
Action
   Save The Giraffe
   Corridor Campaign
   Snag Forests
   Forests For Everyone
Donate
   Ways To Give
   Purchase NFT
   Adopt A Baby Giraffe


Wild Nature Institute Logo
Mailing Address:
Wild Nature Institute
PO Box 44
Weaverville, NC 28787

Phone: +1 415 763 0348
Email: info@wildnatureinstitute.org

The Wild Nature Institute is a New Hampshire non-profit corporation and a 501(c)3 tax-exempt organization.
© Copyright 2010. All Rights Reserved.
View Wild Nature Institute's Privacy Policy
  • Science
    • Giraffe
    • TUNGO
    • Spotted Owl
  • Education
    • Environmental Education
    • Snag Forest
    • Forest Fire Truths
  • Action
    • Save The Giraffe
    • Corridor Campaign
    • Snag Forest
    • Forests For Everyone
  • Donate
    • Ways To Give
    • Purchase NFT
    • Adopt A Baby Giraffe
  • Blog
  • About Us
    • Monica
    • Derek
    • James
    • Veila
    • Our International Team
    • Our Tanzanian Partners