KEYWORDS
Habitat utilization; Himalayan marmot; Human activities; Burrow feature;
Burrow site selection
1 ǀ INTRODUCTION
Nature
is increasingly affected by human disturbances around the world. With
the human population growing, more than 80% of global land surfaces are
affected by human activities (Sanderson et al., 2002). Besides affecting
environments on a macro level,
human
activities also affect aspects of wildlife interaction with those
environments such as distribution, population dynamics, and ability to
survive in changing conditions
(Trombulak
&
Frissell, 2000; UNEP, 2001; Gül et
al., 2013).
Human
activities generally exert direct and indirect negative effects on
animals. Direct and fatal disturbances include both illegal poaching and
legal hunting (Ménard et al., 2014; Brockman et al., 2020), road killing
by vehicles (Richini-Pereira et al., 2008), which will kill victims
directly, and sometimes result in a population decline of some species
(Rija et al., 2020), and damage
regional community structure (Trombulak & Frissell, 2000; Clark et al.,
2016). Indirect and less fatal effects include habitat degradation,
traffic noise, light pollution, or hunting derived competition between
different species, which will trigger reduced reproductive output and
decline in body condition of affected animals
(Safina & Burger, 1983; Primack,
2008; French et al. , 2011;
Hellgren & Polnaszek, 2011; Muhly
et al., 2011; Webber et al., 2013), and, may result in local extinction
at population level due to habitat removal (Griffin et al., 2007;
Imperio et al., 2013).
Furthermore,
species that accompany humans, such as domestic dogs
(Canis lupus familiaris ),
also negatively impact the survival of wild animals (Mainini et al.,
1993; Mori, 2017).
On
the other hand, some animals benefit from human activity. For instance,
some prey species experience reduced mortality because humans drive
their predators and/or competitors away from human-dominated habitats
(Hebblewhite et al., 2005; Muhly et
al., 2011;
Lambe,
2016). Some species have improved feeding efficiency due to human
activities (Xiang et al., 2011; Marty et al., 2019) or gain higher
reproductive success due to better nesting conditions in areas with
human activity (O’Donnell & Denicola, 2006), benefits that can directly
promote the population growth.
Different
animals have greater or lesser chances to survive in the face of
different human disturbances (Imperio et al., 2013; Ménard et al., 2014;
Lambe, 2016; Amphibiaweb, 2021) depending upon the type and degree of
human activities (Griffin et al., 2007; Ménard et al., 2014), as well as
the species’ ability to adapt to disturbance (Griffin et al., 2007;
Muhly et al., 2011; Webber et al., 2013; Yang et al., 2019). Possible
outcomes for these populations include either coexistence with humans or
active avoidance of humans (Magle et al., 2005; Griffin et al., 2007;
Braczkowski et al., 2018), or local extinction (Imperio et al., 2013;
Amphibiaweb, 2021). Generally,
small-bodied species may survive more easily in areas of intense human
activity than bigger species and even benefit from the altered
landscape. For example, red foxes (Vulpes vulpes ) occur at higher
densities in the city than in rural areas because of the absence of
coyotes (Canis latrans ), and some urban-living macaques
(Macaca spp.) obtain better food relative to their rural
populations (Lambe, 2016, Marty et al., 2019). On the other hand,
large-bodied species tend to avoid habitats impacted by humans
regardless of whether humans actively kill them (Paudel
& Kindlmann, 2012; Macedo et al.,
2018; Klaassen & Broekhuis, 2018). Though in rare cases populations
forced to share habitats with humans, such as leopards (Panthera
pardus ) in Mumbai, India, develop particular strategies like adjusting
their daily time budget and prey selection to survive
(Braczkowski et al., 2018).
Additionally, some animal species adopted different strategies and have
different destinies under different human disturbances, depending on the
type and intensity of disturbances (Murdoch et al., 2016; Austin &
Ramp, 2019; Jahren et al., 2019).
Especially,
highly residential species with limited migration ability and low
phenotypic plasticity are at the
greatest risk of going locally extinct due to human disturbance whether
they are big or small bodied. For example, the
Yunnan
lake newt (Cynops wolterstorffi )
(Amphibiaweb, 2021), Alpine rock
ptarmigans (Imperio et al., 2013), and
Asiatic lion (Panthera leo
persica ) as well as south China tiger (P. tigris amoyensis ) who
cannot avoid human disturbances in the form of roads or log through
migration (Tilson et al., 2004;
Jhala et al., 2019), the population
decline and local extinctions are common. Nevertheless, some certain
other residential species like some
rodents (Maher, 2009; Harris & Munshi‐South, 2017), primates (Marty et
al., 2019), and some carnivores like some red fox populations (Lambe,
2016; Jahren et al., 2019) are
better able to adapt and survive in human-dominated habitats and gain a
higher population density relative to their rural congeners. To deal
with different human influences suffered, animals have adopted multiple
survival strategies such as adjusting time
rhythm (Poudel et al., 2015a),
allocating more time to vigilance (Griffin et al., 2007; Poudel et al.,
2015b), or using habitats farther away from human activity (Paudel &
Kindlmann, 2011; Macedo et al., 2018; Pita et al., 2020). In terms of
the effect of human activities on habitat utilization for animals that
can survive disturbances that are not directly fatal, certain strategies
were adopted to deal with different disturbances. For example, Vancouver
Island marmot (Marmota vancouverensis ) may build additional
burrows for shelter when threatened
(Blumstein et al. , 2001),
bamboo rat (Rhizomys sinensis ) selectively construct their
burrows away from roads (Yuan et al., 2017), or
some
grassland species like Alpine
marmot (M. marmota ) select regions with large stones to allow
better vigilance (Borgo, 2003). Furthermore, species like Alpine marmot
and some waterbirds can behaviorally reduce flight initiation distance
to optimize their fitness by the accustomed to nonfatal human activities
(Louis & Le Berre, 2000; Thibault et al., 2020;
Feng & Liang, 2020).
Marmots
(Marmota spp.) are large,
residential ground-dwelling and burrowing squirrels with relatively weak
ability to disperse and high philopatry
(Griffin
et al. , 2007; Armitage et al., 2011), forcing them to continue
exploiting habitats disturbed by humans (Neuhaus
& Mainini, 1998). Previous studies
illustrated that Himalayan marmots
(M.himalayana ) deal with grazing
disturbances by adjusting their daily time rhythm
(Poudel et al., 2015a) and changing
the time allocated to feeding and
vigilance behavior (Poudel et al.,
2015b).
In comparison,
some other marmot species like
yellow-bellied marmots (M. flaviventris ) and Olympic marmots
(M. olympus ) also adjust the time spent on feeding and vigilance,
and further, they also adjust their
flight
initiation distance when disturbed by different human activities
(Griffin et al. , 2007, Li et
al., 2011). On the contrary, the flight initiation distance of woodchuck
(M. monax ) did not vary along a rural-urban gradient, but the
home range of the species decreased with the increasing urbanization
(Watson, 2009). Besides, the study
on Alpine marmots indicated that they have learned to tolerate hikers
that pass by (Mainini et al.,
1992).
Himalayan
marmots are mainly distributed across the Qinghai-Tibetan Plateau
(Shrestha, 2016). Some regional populations suffer persistent
disturbance from human activities such as extermination campaigns to
prevent disease, which subsequently has caused them to increase their
reproductive rate in the years following these population reductions
(Huang et al., 1986; Wang et al.,
1986). Other populations are indirectly disturbed by domesticated yaks
and goats, resulting in changes to time spent feeding and greater
feeding efficiency
(Poudel
et al., 2015a; Poudel et al., 2015b). The effects of
persistent, but
not fatal, human disturbances on
the Himalayan marmot requires further investigation. For example, the
impact of motor vehicle activity on their habitat utilization,
population dynamics and behavioral plasticity is still under explored
(Kitchen et al., 1999; Klaassen & Broekhuis, 2018; Edwards et al.,
2019); Whittington et al., 2019).
In
the present study, we recorded and compared the patterns of habitat
utilization of three Himalayan marmot populations sharing the same
habitat type, but suffering different levels of anthropogenic
disturbance around a Tibetan village in the Zoige wetland
(Guo et al., 2020), to explore the
effects of human activity on this species’ behavior and discover changes
that might improve their survival.
Because
reproductive pairs of the marmot will dig some temporary burrows as a
shelter when threatened (Blumstein et al. , 2001) and human did
not alter their habitat selection in the region
(Guo et al., 2020). We predict
that: (1) the distance between burrows of each breeding pair will
decrease with increasing human activity as a consequence of population
growth; (2) more temporary burrow
will be dug and consequently, the distance between burrows will become
shorter with increasing human activity; (3) as a consequence of more
refuge and reduced inter burrow distance, the flight initiation distance
of disturbed populations will become shorter relative to unaffected
population; (4) the distance from reproductive burrows to the nearest
road will become longer with increasing human activity; and (5) due to
the absence of large rocks in the region, marmots impacted by human
disturbance will preferentially build reproductive burrows on sites that
allow for better surveillance of the area, such as big mounds occurring
on the grasslands.