Aardvark

Discussions and information on all Southern African Mammals
User avatar
Lisbeth
Site Admin
Posts: 67237
Joined: Sat May 19, 2012 12:31 pm
Country: Switzerland
Location: Lugano
Contact:

Re: Aardvark

Post by Lisbeth »

Aardvark starvation: Extreme drought killing off food sources

By Ufrieda Ho• 9 July 2020

Image
The secretive aardvark is increasingly being spotted in the daytime. (Photo: Wits University)

New research confirms that extreme droughts amid the deepening climate crisis are forcing nocturnal aardvarks in the Kalahari to feed and forage when the sun’s up — but even so, their ant and termite food sources are dying out as the vegetation they survive on is affected by the droughts.

Increased daytime sightings of the aardvark may offer wildlife watchers a rare glimpse of the secretive creature, but scientists are warning that this shift in behaviour is a red flag that not all is well for the nocturnal mammal.

Dr Nora Weyer, a former Wits University researcher, led a study into the adaptive drought responses of aardvark in the Tswalu reserve in the Kalahari between 2012 and 2015. Her research, which was the basis of her PhD, focused on 12 individuals fitted with biologgers and transmitters recording the animals’ body temperature, rate of activity throughout a 24-hour period and their location.

Weyer used satellite imaging showing the effects of drought on the vegetation and matched these with her data on how the aardvarks’ behaviour and body temperature were being affected by their environment during these periods.

The findings from that research have now been published in the journal Frontiers in Physiology. It confirms that increased periods of drought and hotter and drier climatic conditions are affecting these mammals both directly and indirectly. Aardvarks, which call sub-Saharan Africa home, have to find new ways to conserve energy to stay warm at night and the deepening climate crisis is also impacting on vegetation growth in the Kalahari. This, in turn, is affecting the availability of the aardvark’s prey of ants and termites.

The research team, that included scientists from the University of Pretoria and the University of Cape Town, found that as drought conditions became more severe the nocturnal animals emerged more frequently from their burrows in the daytime. They relied on radiant energy to stay warm as they foraged and fed. Temperatures in the Kalahari in winter can plunge to well below freezing at night.

Weyer, now based in Germany, says:

“The animals living in the Kalahari are already living at the limit of what they can cope with and while they have been always been able to adapt to ensure their survival in the past by feeding in daytime, it may not be sufficient in the future as droughts are lasting for longer periods and occurring with greater frequency, which is affecting vegetation, which is affecting the aardvark’s prey of ants and termites.”

In the paper, the authors, which include Weyer’s supervisors and other co-workers, point out that in semi-arid zones with summer rainfall, such as the Kalahari, the timing and amount of rainfall is critical in ensuring vegetation growth and replenished food sources like ants and termites. It also notes that summer droughts combined with heatwaves are becoming a more frequent reality in the region.

Weyer says while aardvarks are considered animals of “least concern” in terms of conservation status, the animals she followed were clearly affected by starvation as droughts persisted. She says an added pressure for the species is their slow reproductive rate. They have a seven-month gestation period and give birth to one offspring at a time. Weyer adds that the potential loss of aardvark in the Kalahari area ecosystem would have dire impacts on other animals.

“The Kalahari is arid at the best of times, but drought killed the vegetation that fed the ants and termites. Most of the ants and termites disappeared, leaving the aardvarks starving. It was heartbreaking to watch our aardvarks waste away as they starved.

“Animals like pangolins, blue swallows and bat-eared foxes shelter and live in the burrows and tunnels that aardvarks make, so we are talking about whole ecosystems that are affected,” she says of the animals that are called “the ecosystem engineers”.

Dr Robyn Hetem, one of Weyer’s co-authors on the paper and one of her PhD supervisors at Wits, says the findings gave them long-term comprehensive data “that confirmed that it was really drought that was causing this unusual shift in behaviour”.

The researchers say it paints a concerning picture of the impact of climate change on a unique and harsh ecosystem like the Kalahari. Hetem adds:

“We do need more research to help us identify how different species in the Kalahari are being affected as climate change pressures grow and for this to inform our conservation strategies.”

Hetem is part of the Wits Wildlife Conservation Physiology Lab. She adds: “There isn’t a quick fix to climate change but this research does show how we need to be stepping up our responses to limit carbon emissions from policies through to the choices such as when we choose to use our cars.

“What we do need is more wild spaces, more wild corridors for animals to move as climate patterns from area to area shift and we need greater awareness into just how species like the aardvark are being forced to the limit of how they can adapt.”

Researchers from the Wits Lab are undertaking new research into how other animals in the Kalahari that rely on termites and ants as a food source, such as pangolins, are being affected as well as studies into the climate change impacts on the bat-eared fox. DM


"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
Klipspringer
Global Moderator
Posts: 5862
Joined: Sat Sep 14, 2013 12:34 pm
Country: Germany
Contact:

Re: Aardvark

Post by Klipspringer »

What has a switch to more day time activity to do with drought?

I do not understand what is the point here -O-


User avatar
PJL
Posts: 2825
Joined: Mon Jan 13, 2014 10:12 am
Country: South Africa
Location: Port Elizabeth
Contact:

Re: Aardvark

Post by PJL »

Klipspringer wrote: Thu Jul 09, 2020 12:16 pm What has a switch to more day time activity to do with drought?

I do not understand what is the point here -O-
Drought means less food resource availability, so the aardvarks themselves are having to conserve more energy. That is achieved by staying warm in a burrow for a longer period of colder nights instead of burning energy staying warm whilst out foraging. Their feeding times then move into a portion of the mornings when they can stay warm via the sun.


Klipspringer
Global Moderator
Posts: 5862
Joined: Sat Sep 14, 2013 12:34 pm
Country: Germany
Contact:

Re: Aardvark

Post by Klipspringer »

\O


They become diurnal to prevent energy losses during high energy needs during cold periods and during periods of food shortage in drought summers.

But as far as I know there are still mass mortalities at the end of drought summers, so the diurnal approach does not work for the aardvark.

They better get themselves some fur --00--


User avatar
Richprins
Committee Member
Posts: 75834
Joined: Sat May 19, 2012 3:52 pm
Location: NELSPRUIT
Contact:

Re: Aardvark

Post by Richprins »

Very interesting! :shock:


Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596
User avatar
Lisbeth
Site Admin
Posts: 67237
Joined: Sat May 19, 2012 12:31 pm
Country: Switzerland
Location: Lugano
Contact:

Re: Aardvark

Post by Lisbeth »

Aardvarks and climate change

Posted on August 6, 2020 by Team Africa Geographic in the DECODING SCIENCE post series.

Image

Three years ago, a Wits University media release warned of the impact of climate change on aardvarks, particularly those in arid areas where temperatures are expected to rise in the coming years. Now the full peer-reviewed study on this research has been released and yields worrying results. The study, which was conducted on Tswalu Kalahari Reserve by the researchers of the Brain Function Research Group at Wits University, indicates that in drought years aardvarks are unable to meet the necessary nutrient levels to maintain their metabolisms, as indicated by dramatic changes in internal body temperatures. During the first year of the study, low rainfall levels and the subsequent dry season resulted in the deaths of numerous aardvarks, including five of the initial study subjects.

Image

Aardvarks (Orycteropus afer) are highly elusive creatures that are generally active at night and feed solely on ants and termites. To study the effects of seasons, rainfall and food availability, researchers implanted 12 adult aardvarks with sensors to measure body temperature and activity levels and monitored the data for varying durations over three years. Tswalu typically experiences rainfall during the summer months, between November and March, where temperatures regularly reach maximums of up to 40˚C, while the winter months are dry – with temperatures dropping below freezing at night. During the first year of the study period, the region experienced particularly low rainfall levels, with no rain falling during the hottest months of the summer and, as a result, the vegetation levels dropped below 54% of the maximum levels. The rainfall levels during subsequent years were higher, as were the resulting vegetation levels. The available vegetation impacts the prey availability for aardvarks (aardvarks in the Tswalu region feed mainly on the harvester termite Hodotermes mossambicus) – as vegetation decreases, so do termite and ant numbers.

Image

While diurnal animals in arid areas face the challenges of keeping cool and evaporative water loss during high daytime temperatures, nocturnally active mammals like the aardvark have to expend extra energy to stay warm during the cold nights. In times of reduced resource availability, the ability of these animals to increase their metabolic activity to maintain internal body temperatures becomes compromised and, as a result, they may increase diurnal activity to compensate for these demands.

Under ideal conditions, the internal body temperature of a large mammal remains as constant as possible, with the difference between maximum and minimum body temperatures being labelled the “amplitude”. The research revealed that during “good” conditions (higher rainfall years and increased food availability), the 24-hour body temperature rhythm of the aardvarks only varied by an average of 1.8˚C in summer and 2.1 ˚C in winter. By contrast, during the dry year, their minimum body temperature declined, with an average amplitude of 2.3 ˚C in summer and 4.7 ˚C during winter. One aardvark exhibited an 11.7 ˚C change in 8 hours, the most substantial change ever recorded in a large mammal – its body temperature dropped to a minimum of 24 ˚C.

Image

As expected, the low body temperatures were associated with increased diurnal activity but shorter periods of activity overall, with some aardvarks emerging in the afternoon and returning to their burrows at night, eliminating nocturnal activity. Yet despite their demonstrated behavioural flexibility, many were unable to meet their nutritional requirements, and of the six aardvarks initially fitted with monitoring devices, five died during this period. Those that survived demonstrated a return to a more level internal body temperature as conditions improved, but it took them time to recover.

Image Image

The concern is that the Kalahari region is one that is predicted to become hotter and drier as climate change progresses. While droughts are part of typical climate patterns, this research indicates that aardvarks are not sufficiently adaptable to cope with this change. As drought frequencies and durations increase, the vegetation in the area will suffer, and ant and termite populations will decrease, resulting in the death by starvation and dehydration for the aardvarks that depend on them. While they may not be considered threatened yet, aardvarks are ecosystem engineers, and numerous species of birds, mammals and reptiles utilise the burrows that they dig.

“Populations of many animals in South Africa are already declining as a result of habitat loss and over-exploitation,” says Professor Andrea Fuller, one of the co-authors of the study. “Climate change adds an additional threat, which may push species to extinction faster. By 2050, the aardvark may not be the only species removed from tourist checklists”.

Image


"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
User avatar
Richprins
Committee Member
Posts: 75834
Joined: Sat May 19, 2012 3:52 pm
Location: NELSPRUIT
Contact:

Re: Aardvark

Post by Richprins »

Image

Kruger Sightings
@LatestKruger
Last Night
7:33pm
1 Aardvark crossed the road
“First time ever seen one. It was a juvenile”
Tinga Lodge access road
Near Skukuza
5/5
Tinged by stylingsafari

8:37 AM · Mar 25, 2022


Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596
User avatar
Lisbeth
Site Admin
Posts: 67237
Joined: Sat May 19, 2012 12:31 pm
Country: Switzerland
Location: Lugano
Contact:

Re: Aardvark

Post by Lisbeth »

\O


"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
User avatar
Lisbeth
Site Admin
Posts: 67237
Joined: Sat May 19, 2012 12:31 pm
Country: Switzerland
Location: Lugano
Contact:

Re: Aardvark

Post by Lisbeth »

Image

THE “EARTH PIG” OF AFRICA

Image

Thursday, 20 October 2022

Image

There are signs if you know what to look for… Some are obvious, like a pile of dark, freshly excavated soil or a massive entrance hole. Others are more subtle: adjacent patches of bare ground or a place where a shadow doesn’t fall quite right....

Click on the title to read the whole story and see the fabulous photos


"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
User avatar
Richprins
Committee Member
Posts: 75834
Joined: Sat May 19, 2012 3:52 pm
Location: NELSPRUIT
Contact:

Re: Aardvark

Post by Richprins »

Image


Kruger Sightings
@LatestKruger
6:20am
1 Aardvark on the move
"I was so shocked. Had a couple UK folks with us for their first time in the bush who must have been the lucky charm"
H4-2, 5km S of Lower Sabie Rest Camp
5/5
Tinged by Paul - Leadwood Photography
4:17 PM · Nov 26, 2023


Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596
Post Reply

Return to “Mammals”