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What the sources say

Black-Tailed JackrabbitLepus californicus

Every figure, record and mechanism on the Black-Tailed Jackrabbit profile was written from a source, and this is the working table behind it: 42 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

Brown, Lorenzo & Álvarez-Castañeda 2019

Brown, Lorenzo & Álvarez-Castañeda (2019). Lepus californicus. The IUCN Red List of Threatened Species 2019: e.T41276A45186309.

The page saysLeast Concern
The source saysLeast ConcernNote: Category read through GBIF's copy of the Red List, taxon id checked against the assessment DOI.

Source
02

Big Bend National Park, National Park Service

Jackrabbits. Big Bend National Park, National Park Service.

The page saysCoyotes, mountain lions, bobcats, foxes, hawks, eagles, owls and snakes all eat hares and rabbits
The source saysHares and rabbits are perhaps nature's ideal prey. Coyotes, mountain lions, bobcats, foxes, hawks, eagles, owls, and snakes will all eat them.Note: 'them' = hares and rabbits
The page saysTo escape, a jackrabbit runs a zigzag course at up to 40 miles per hour (64 km/h)
The source saysrely on running in a zigzag pattern to escape their predators ... They can achieve speeds of up to 40 mph.Note: 64 km/h from 40 mph. ADW (1999) gives 30-35 mph; the park service page (2015) is followed.
The page saysIt can hop up to 20 feet when panicked.
The source saysThe jackrabbit can hop 5'-10' at a time, and up to 20' when panicked.
The page saysevery four to five leaps is an exceptionally high one, to see its surroundings or predators
The source saysWhen at a moderate run, every four to five leaps are exceptionally high to see their surroundings or predators.
The page saysIts eyes sit on the sides of its head, which enables it to see in front, to the side and behind.
The source saysThe eyes are on the sides of the head, which enables jackrabbits to see in front, to the side, and behind them.
The page saysThe park service adds that it has poor endurance and often ends up as some animal's dinner.
The source saysbut they have poor endurance and often end up as some animal's dinner.
The page saysThe jackrabbit is actually a hare.
The source saysThe jackrabbit is actually not a rabbit, but a hare.
The page saysHares are born with hair and open eyes, and can run and hop shortly after birth.
The source saysHares are also precocial, meaning they are born with hair and with their eyes open. They can run and hop shortly after birth.
The page saysRabbits are born hairless, blind and helpless.
The source saysRabbits are altricial, or born hairless, blind, and helpless.
The page saysIt weighs between four and eight pounds (1.8 to 3.6 kg)
The source saysThe black-tailed jackrabbit weighs between four and eight pounds.Note: 1.8 to 3.6 kg from 4 to 8 lb. ADW gives 1.3 to 3.1 kg and AnAge an adult weight of 4,175 g; the park service range is used.
The page saysits total length is between 18 and 26 inches (46 to 66 cm)
The source saysTheir total length is between 18 and 26 inches.Note: 46 to 66 cm from 18 to 26 in; ADW gives 47 to 63 cm nose to rump.
The page saysThe female is larger than the male.
The source saysThe female doe is larger than the male buck.
The page saysA black stripe runs along the top of the tail and onto the rump, which is where the name comes from.
The source saysThe tail has a black stripe that runs along the top onto the rump (hence the name)
The page saysTo help digest tough plants, the jackrabbit's appendix serves as a pre-digesting chamber that starts breaking food down before it reaches the stomach.
The source saysTo help digest this tough vegetation, the jackrabbit's appendix serves as a pre-digesting chamber to start breaking down these food sources before they reach the stomach.
The page saysIt makes two types of droppings. The first is soft, moist and coated in mucus, and the jackrabbit eats it, as it is high in protein and certain B vitamins formed by bacteria in the intestines.
The source saysTwo types of droppings are produced. The first is a soft, moist, mucous-coated sphere. The jackrabbit eats these droppings, as they are high in protein and certain B vitamins that are formed by bacteria in the intestines.
The page saysIts upper front teeth never stop growing, so it must constantly gnaw on vegetation to wear them down.
The source saysThese teeth never stop growing, so the hare must constantly gnaw on vegetation to wear them down.Note: 'These teeth' = the double row of upper incisors and the small secondary teeth behind them.
The page saysFast breeding is an adaptation to being preyed on by so many carnivores.
The source saysThe amazing reproductive rate of hares and rabbits is an adaptation to being preyed upon by so many carnivores.
The page saysA female can have up to six litters a year, with as many as eight young in each, though two to four is more common.
The source sayswill have up to six litters each year with as many as eight young in each litter, although two to four is more common
The page saysThe pregnancy lasts 41 to 47 days.
The source saysAfter a gestation period of 41-47 days
The page saysWithin two weeks the young can forage for themselves, and after one month they live on their own.
The source saysWithin two weeks the young can forage for themselves, and after one month they are living on their own.
The page saysA desert hare that zigzags at up to 40 miles per hour and eats its own droppings for a second pass at its food.
The source saysrely on running in a zigzag pattern to escape their predators ... They can achieve speeds of up to 40 mph ... The jackrabbit eats these droppings, as they are high in protein
The page saysZigzags at up to 40 miles per hour, and at a moderate run makes every fourth or fifth leap a high one to look for predators
The source saysrely on running in a zigzag pattern to escape their predators ... They can achieve speeds of up to 40 mph. When at a moderate run, every four to five leaps are exceptionally high to see their surroundings or predators.
The page saysNo, it is a hare. Hares live in open country and run to escape, while rabbits dig burrows and dash into them. A hare's young arrive furred and with their eyes open, but a rabbit's arrive hairless and blind.
The source saysThe jackrabbit is actually not a rabbit, but a hare. Hares live in open areas and rely on running in a zigzag pattern to escape their predators ... Rabbits, on the other hand, move slower, dig burrows, and scamper into their homes when threatened. Rabbits are altricial, or born hairless, blind, and helpless.
The page saysTwo to four young per litter is typical, though a litter can reach eight, and a female can fit up to six litters into a year. Each pregnancy runs 41 to 47 days.
The source sayswill have up to six litters each year with as many as eight young in each litter, although two to four is more common. After a gestation period of 41-47 days
The page saysEating Everything Twice
The source saysThe jackrabbit eats these droppings, as they are high in protein and certain B vitamins that are formed by bacteria in the intestines. After passing through the digestive system againNote: Heading: it eats the soft droppings, so food passes through twice.
The page saysSecond helping It makes two types of droppings.
The source saysTwo types of droppings are produced.
The page saysAt a moderate run, a black-tailed jackrabbit makes every fourth or fifth leap an exceptionally high one to look for predators
The source saysWhen at a moderate run, every four to five leaps are exceptionally high to see their surroundings or predators.
The page saysweightKg: 2.5
The source saysThe black-tailed jackrabbit weighs between four and eight pounds.Note: task #1261; 2.5 kg also sits inside ADW's 1.3 to 3.1 kg

Source
03

Animal Diversity Web, University of Michigan

Lepus californicus (black-tailed jackrabbit). Animal Diversity Web, University of Michigan.

The page saysIt is found throughout the southwestern United States into Mexico, as far east as Missouri and north into Washington.
The source saysis found throughout the southwestern United States into Mexico, as far east as Missouri, north into Washington
The page saysLook for it in desert scrub, prairies, farmland and dunes, from sea level to about 3,800 m.
The source saysinhabit desert scrubland, prairies, farmlands, and dunes. They favor arid regions and areas of short grass rangeland from sea level to about 3,800 m.
The page saysIn captivity it lives 5 to 6 years
The source saysLifespan in captivity is 5-6 years
The page saysWild jackrabbits often die much sooner.
The source saysrabbits in the wild often die much sooner due to predation, disease or problems associated with overpopulation
The page saysGrasses and herbaceous matter are its preferred foods.
The source saysGrasses and herbaceous matter are the preferred foods of
The page saysWhen other plants are not available, twigs and young bark of woody plants are the staple food.
The source saystwigs and young bark of woody plants are the staple food when other plants are not available
The page saysJackrabbits eat almost constantly: 15 of them eat as much as one large grazing cow in one day.
The source saysJackrabbits eat almost constantly and consume large quantities relative to their size; 15 jackrabbits eat as much as a large grazing cattle in one day.Note: ADW (1999) says 'cattle'; rendered as one cow.
The page saysIt gets nearly all its water from the plants it eats.
The source saysobtain nearly all the water they need from the plant material they consume
The page saysDesert scrub, prairies, farmland and dunes from the southwestern United States into Mexico, north into Washington
The source saysfound throughout the southwestern United States into Mexico, as far east as Missouri, north into Washington ... inhabit desert scrubland, prairies, farmlands, and dunes
The page saysGrasses and other plants, plus twigs and young bark when little else is available
The source saysGrasses and herbaceous matter are the preferred foods ... twigs and young bark of woody plants are the staple food when other plants are not available

Source
04

AnAge: The Animal Ageing and Longevity Database, Build 15, Human Ageing Genomic Resources

AnAge entry for Lepus californicus. AnAge: The Animal Ageing and Longevity Database, Build 15, Human Ageing Genomic Resources.

The page saysone wild-born hare was about 11.8 years old when it died in captivity
The source saysOne wild born specimen was about 11.8 years of age when it died in captivity
The page saysAnAge gives a maximum of about 11.8 years, from a single hare that was born in the wild and died in captivity.
The source saysMaximum longevity 11.8 years (captivity) ... One wild born specimen was about 11.8 years of age when it died in captivityNote: 'a single hare' = 'One wild born specimen'; AnAge rates the sample size Tiny.

Source
05

Young et al. 2014

Young et al. (2014). Limb bone morphology, bone strength, and cursoriality in lagomorphs. Journal of Anatomy.

The page saysA bone study compared it with pikas and a rabbit and found the jackrabbit typically had the longest distal segments, the parts of the limb farthest from the body.
The source sayspikas (Ochotona princeps, non-cursorial), jackrabbits (Lepus californicus, highly cursorial), and rabbits (Sylvilagus bachmani ... highly cursorial jackrabbits are typically marked by the lowest mechanical advantage and the longest distal segmentsNote: 'farthest from the body' glosses 'distal' for readers. The rabbit is Sylvilagus bachmani; 'another rabbit' was cut, since the jackrabbit is a hare.

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.