#rodent species

[critter-of-the-day]

18th of September 2024: Morgan’s Gerbil Mouse

Today’s critter of the day is Morgan’s Gerbil Mouse (Eligmodontia morgani), a rodent from South America, specifically Southern Argentina and Chile [1].

As all Eligmodontia, they are desert mice, so they are well adapted to dry habitats with little free water, however unlike many other desert species, they do best when they have at least a little rain [2]. Morgan’s Gerbil Mouse in particular prefers wetter and colder areas as compared to E. typus, even though they tend to live within the same region [3]. Morgan’s Gerbil Mouse is found in the Western Patagonia region, and genetic analysis indicates that they are originally from there, rather than having evolved and then immigrated there [4].

They are sometimes also known as the Silky Desert Mouse, having long and silky fur. They are primarily granivores, meaning they eat seeds and grains, though they also eat insects. Their breeding season lasts from spring until autumn, with most of them living a total lifespan of less than a year [5].

They are hunted by a variety of owls, though they try to avoid being caught by running around in a zigzag motion or hopping erratically. Especially in post-burn areas, they take over a large proportion of the owl’s diets. Their populations can increase by a lot after volcanic eruptions, as the ash significantly increases plant growth and cover [5].

Sources: [1] [2] [3] [4] [5] [Image] 

[prolibytherium]

I love that I'm can always still find out about cool animals that I never knew existed. Like today I learned that brush-tailed porcupines exist and straight up look like giant rats with spines

[rebeccathenaturalist]

This is a really exciting development! We've already seen the positive effects of beavers returning to their historic range here in North America, so it's even better to see the same thing underway across the Atlantic. A single pair with their first litter of kits certainly isn't a large-scale reintroduction, but it's proof that these animals have the capacity to get back to work here.

Beavers are often called ecosystem engineers, and for good reason. These keystone species alter waterways by building dams and lodges, creating ponds and other aquatic habitats for species that can't handle faster-moving water. These also often serve as water reservoirs during summer droughts. The dams and lodges themselves may also provide nesting sites for birds and shelter for other animals, plants, and fungi.

Sadly there are still people who want to see beavers trapped and hunted as pests because their dams can sometimes flood fields, to include those that were historically seasonal wetlands. Until we stop seeing animals' value only in terms of whether they're useful to us or not, the beavers are going to face opposition as they reclaim their old territories on both continents.

Nonetheless, I give a hearty cheer to the Mammalian Corps of Engineers!

[synthaphone]

do u have any opinions on the voidling designs from the new plot?

I have opinions on practically everything relating to neopets, lol

I don't hate them, but I definitely have critique for them. I think the main problems I have are that their poses are stiff (the 'neutral' poses in particular), and their faces feel flat in a way that feels unintentional- the line drawn above the bridge of the nose is used to imply depth, but if the mouth and nose are placed on the same plane as the eyes, the illusion of dimension doesn't work. The lines not having much variation in thickness also seriously contributes to the flat feeling.

did some rough sketches to illustrate how i'd personally tweak them- maybe i'll finish these later to take a stab at the line weights.

Conceptually, cat-based imps are a decent enough enemy type, but I do think that they're too close to wraiths visually. Not sure if they're planning on connecting these with those or not in the story, but as of right now they feel a bit redundant. It would maybe be fun to have more of the round shapes from the little floating molecules reflected in the designs, like if they were more liquid than gas? idk

[critter-creature-or-beast]

Submitted for classification by @owlyfisher

"gerbil ❗"

[blujaydoodles]

in all ways except physical I am a six inch tall fuzzy little creature living in a mossy stump (which I've filled with a bunch of random shiny bullshit)

[lizardsaredinosaurs]

Am I hopping for fun? Are you kidding me, I'm just perpetually terrified.

Northern Hopping Mouse (Notomys aquilo)

Northern Territory, Australia, mostly Groote Eylandt

Status: Endangered

Threats: Feral cats, mining, changes in fire regime

[reasonsforhope]

“By day, the shrubby clifftops of North Head, a thriving slice of bushland at the northern entrance of Sydney Harbour, Australia, are a popular walking spot for urban nature enthusiasts. But when night falls, this coastal reserve is ruled by a colony of bush rats, one of the most common native rodent species scampering along the shores of southeast Australia. For anyone lucky enough to spot one of the tennis ball–sized rodents, their endearing appearance sets them apart from their invasive relatives.

“They’re like little dumplings,” says Viyanna Leo, a wildlife ecologist at the Australian Wildlife Conservancy, a nonprofit organization working with the Sydney Harbour Federation Trust to conserve North Head, adding “[they’re] quite round and fluffy.”

pictured: a cutie

The Project

The 250-hectare headland hasn’t always been a bush rat kingdom, though. Following a century of being vilified and exterminated from areas around Sydney Harbour, the bush rat population in North Head was wiped out decades ago by urbanization, habitat fragmentation, and predation by feral cats and foxes. The reserve was overrun by a gang of black rats, an invasive species that’s found on every continent except Antarctica. While bush rats help maintain the ecosystem’s native species, black rats wreak havoc. At North Head, they wasted no time plundering the burrows and tree hollow nests of small mammals and gorging on bird eggs, says Leo. “They were causing a lot of problems.”

But when given the chance, bush rats can be formidable ecological gatekeepers. In 2014, Leo and her team began reintroducing bush rats to North Head to drive out their intrusive counterparts. The rewilding effort is working, with annual wildlife surveys showing that black rat numbers dropped from an estimated 112 in 2019 to 29 by 2020. In May 2021, a mere nine black rats were captured. The project harnesses the bush rat’s innate territorial streak. The native rodents outcompete black rats for habitat and food, and Leo suspects that North Head will one day be a bush rat–only stomping ground. “If they’ve got the fort, they can maintain the territory,” she says.

For the reintroduction effort, Leo and her team captured 180 bush rats over three years from abundant populations in Muogamarra Nature Reserve and Ku-ring-gai Chase National Park, both located roughly 30 kilometers northwest of North Head. The researchers lured the rats into traps with a wholesome meal of oats, honey, and peanut butter, then assessed the animals’ genes to ensure they were diverse enough to build a flourishing new colony at North Head. After inserting a microchip into each rat, the team set the rodents free on the headland...

The Importance of Native Rodents

While most reintroductions focus on giving threatened species a boost, it’s just as important to prioritize common species in conservation efforts and rewilding projects, says Emily Roycroft, an evolutionary biologist specializing in native mammals and population genetics at the Australian National University. For instance, native rodents act as tiny engineers that shape the ecosystems they inhabit, spreading seeds, churning the soil, and keeping insect populations in check.

Native rodents provide fundamental ecosystem services, says Roycroft, who was not involved in Leo’s project. “We know that if [rodents] were once there, they were playing a role.”

Relocating common species like the bush rat can also provide a good dress rehearsal for riskier reintroductions, adds Roycroft. If something goes wrong when reintroducing a common species, there’s often enough time to tweak the approach and try again. But when researchers are dealing with a species that is on the brink of extinction, they only have one shot to get it right. “It might be the last chance for that particular species to establish a new population,” says Roycroft.

Leo suspects the bush rats have reclaimed their territory for good at North Head, which is now free of feral cats and foxes and protected from urban sprawl. “They’re pretty much established now,” she says. “I think they’ll continue to do well.”” -via Hakai Magazine, 1/11/23

[wootusart]

At The Museum Of Ratural Ratstory.

The Squeakerthals were an ancient Ratoose that coexisted with the Wooti many millennia ago. Their disappearance remains a mystery to this day although the dominant theory is that they were simply outcompeted by what became the modern Wootus. There is evidence however that at least in some cases they coexisted peacefully and even bred with the Wooti, but those who speak such blasphemy are soon silenced.

[alliswyattonthewesternfront]

idk how people in my life keep being surprised by the fact i am an environmentalist first and an animal lover second. we should cull the feral cats, dogs, mustangs, declare open season on deer, and reintroduce natural predators to the environment. sorry that y'all love ecological devastation but i'm built different

[critter-of-the-day]

1st of September 2024: Oldfield Mouse

Let’s begin this month with a rodent, shall we? Here’s the Oldfield Mouse (Peromyscus polionotus). They have a total length of 11-15 cm [1], and are spread across the South Eastern US [2].

One of their notable characteristics is their burrowing. They build long tunnels of around 1.8 m long which consist of three parts: an entrance tunnel, a nesting chamber, and an escape tunnel. The latter can be used to flee if a predator such as a snake is blocking the entrance [3]. When compared to the closely related Deer Mice (P. maniculatus) (who also build smaller and simpler tunnels), they begin their construction very early, with Oldfield Mice as young as 17 days building complete burrows. Both of these traits are genetic, as cross-fostering (aka giving Deer Mice children to Oldfield Mice parents and vice versa) did not change anything. Those behaviours are also genetically linked, as cross breeding indicated [4].

Oldfield Mice are firmly monogamous, with both the male and the female providing care to their young. This is also genetic, as this was maintained even when cross-fostering with the promiscuous Deer Mice, who also care less for their children [5]. Oldfield Mice have 1-8 children, averaging 4, at a time [6], but it is suspected they are able to mate year round [2].

Their fur colouration can vary quite a bit, depending on where you look. They have a total of 16 subspecies, and as their habitats vary between disturbed fields and sandy beaches, it isn’t surprising when certain populations have darker backs with stripes, while others don’t [1]. It has also been shown experimentally that blending in helps with survival rates [7]. While they are classified overall as Least Concern, certain subspecies are considered endangered [2].

Sources: [1] [2] [3] [4] [5] [6] [7] [Image]

[dougdimmadodo]

Brown Rat (Rattus norvegicus)

Family: Typical Mouse Family (Muridae)

IUCN Conservation Status: Least Concern

Fossil evidence and historical records suggest that the Brown Rat plausibly originates from somewhere in northern China and southern Mongolia, but after centuries of stowing away on ships and exploiting the resources available in human-altered habitats it is now among the most abundant and widely distributed mammals on earth, being found in large numbers almost anywhere where permanent human settlements exist. Relatively large for a member of its family, it owes its success to its extraordinary adaptability; intelligent and opportunistic, members of this species are able to endure a huge range of different climates by constructing elaborate burrows in which they can regulate the temperature, and (owing to their strong, continually growing teeth and unspecialised digestive system) can feed on almost any form of organic matter - while coarse plant matter, carrion, bird’s eggs and small vertebrates are preferred, the diets of different populations vary enormously depending on what resources are available. Brown Rats are also remarkably fast learners, and seem to teach one another - it has been observed that once a single Brown Rat living in an area has learned a specific skill needed to exploit a specific resource (such as learning to dive for fish,) others within its social group will quickly develop the same skill. Brown Rats live in loosely-structured social groups with a linear dominance hierarchy in which body size determines rank (with larger rats ranking higher,) but when resources are scarce these groups will become smaller or break apart entirely. Like most rodents, Brown Rats breed frequently and mature rapidly - after mating (usually during periods of warm weather, and often with numerous different males in a single breeding period,) females produce litters of up to 14 pups and gather in all-female social groups, with all of the mothers in a group sharing a communal burrow and cooperating to feed and protect their young until they become independent at around 4 weeks old. Although they can benefit ecosystems (serving as seed distributers, sustaining populations of rodent-eating predators and providing soil-dwelling organisms with oxygen by breaking up compacted soil when burrowing), invasive populations of Brown Rats have had devastating effects on many species, destroying the nests of birds, competing with indigenous mammals and transferring diseases between species. While humans generally regard members of this species as pests, a domesticated subspecies of Brown Rat (the Domestic Rat, Rattus norvegicus domesticus) is widely kept in captivity, both for use in research (where they are known as Lab Rats) and as pets (where they are called Fancy Rats.)

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Image Source: https://www.inaturalist.org/taxa/44576-Rattus-norvegicus

[rebeccathenaturalist]

Hey, y'all. Wanna do a quick thing that will make a difference? The Washington Department of Fish and Wildlife is considering uplisting the western gray squirrel (Sciurus griseus) from threatened to endangered. It was listed initially as threatened in 1993, and numbers have continued to decrease due to competition from invasive eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger) as well as turkeys (Meleagris gallopavo), and continued habitat loss and development. Most of the time when you see a squirrel in western Washington, it's an eastern gray. Western grays are still around, but continuing pressure is going to make that less likely in the years to come.

Even if you aren't in Washington, show the WDFW that you care about these little critters by making a public comment; you can find information on how to do that here, to include an email address if you don't want to use the public form. You don't need to write anything super elaborate or long; just a quick note saying you support the uplisting of the western gray squirrel to endangered will work. Then reblog so others can do the same.

The squirrels and I both thank you!

[failsquirrel]

someone name a small- to medium-sized rodent. NOW

[jenlrossman]

[lizardsaredinosaurs]

Is it rat week? No one told me it was rat week?

Silver Rice Rat (Oryzomys palustris natator), subspecies of the marsh rice rat

Lower Florida Keys, USA

Status: Endangered

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Sorry, it's not rat week.