MONTEREY MAMMALS

FAMILY LEPORIDAE Rabbits & hares

a web page by Don Roberson

Order Lagomorpha includes the families Laporidae (rabbits & hares) and Ochotonidae (pikas). There is a pika in the high Sierra Nevada range in California, but in Monterey County we have but three lagomorphs: two rabbits and a hare. They have 3 pairs of upper incisors at birth but soon lose the outer pair; a second peg-like upper incisor is location directly behind the middle incisors. Lagomorphs eat vegetation, and then produce two types of pellets — dry pellets that are discarded and wet pellets that are reingested. This allows food to pass through the system twice and be further broken down by bacterial action during the second pass (Reid 2006). [People are set up differently and you should not try this at home.]


1 May 2011 Pebble Beach MTY

The three Monterey County (MTY) rabbits are:
Brush Rabbit Sylvilagus bachmani (above),
Desert Cottontail Sylvilagus audubonii (below), and
Black-tailed Jackrabbit Lepus californicus (right)

Although widespread throughout the county, the first two are often confused, and the larger hare is fast and difficult to photograph. We'll look at each separately.


3 June 2012 Vineyard Canyon MTY


3 June 2012 Vineyard Canyon MTY

Brush Rabbit is the small, short-eared, plain gray or gray-brown rabbit found in thick scrub — including maritime chaparral, coastal sage scrub, inland chaparral, montane chaparral, and humid riparian scrub — throughout coastal and western Monterey County (right, photo 21 Mar 2008 Big Sur R. mouth).

For identification purposes, note that the ears are comparatively short, the tips of the ears are rather plain (only a dusky edge at the tip, not a sharply demarcated black tip), and the entire rabbit looks gray, with the back and sides essentially the same color. Dr. James Patton, professor emeritus of mammalogy at U.C. Berkeley, describes the differences as "short ears [equal to or shorter than length of face from nose to base of ear], small tail, [but still white underneath], little or no white hairs along anterior rim of pinna, fore and hind limbs colored as dorsum and sides (not markedly counter-colored ochraceous)."

 

In contrast, Desert Cottontail (left, photo 13 Apr 2006 Borrego Valley, SD) is a more colorful cottontail rabbit of open country, including grasslands, oak and gray pine savanna, and agricultural land. As its scientific name is Sylvilagus audubonii, some books call it "Audubon's Cottontail."

For identification purposes note that the overall color is browner and more 'grizzled;' there is a pale orange patch on the nape; the back is darker than the sides; the ears are comparatively longer and have a more distinct black tip; and the "cotton tail" is usually very apparent.

Dr. Patton notes that "both species have black edging on the ear tips, but this is much more extensive in audubonii and contrasts sharply with the paler inner surface of the ears as well as more extensive white hairs on the anterior edge — i.e., one easily notices the black tips of audubonii, even from a distance, but for bachmani the smaller black tips can be 'hidden' against the dark gray-brown rest of the ear." Also, the whiskers or "vibrissae of audubonii are black, but again, because the face of audubonii is brightly colored, the black whiskers stand out in this species; the vibrissae of bachmani can be variable, but in most specimens are black — they just don't stand out against the dark face."

The range of Brush Rabbit in California pretty much matches that of chaparral habitat, which habitat is shown in the map below (from Fried et al. 2004).

There are 369,345 acres of chaparral habitat in MTY, if one includes maritime, interior, and montane chaparral, and the vast majority is in western MTY. [Maritime chaparral, 17,600 acres, makes up 4.7% of that.]

The MTY range of Brush Rabbit pretty much matches the range of chaparral in the county. The approximate MTY range is shown below in blue; "x" marks a site it has been collected, "v" marks a known observation.

Localities that host Brush Rabbits as residents include the coastal dunes from Zmudowski SP south through the Big Sur coast, including populations at Fort Ord NM (maritime chaparral), Salinas River NWR, Pebble Beach, Carmel R. mouth, Pt. Lobos SR, and Big Sur R. mouth in Andrew Molera SP. It has been collected near Hastings NHR; in chaparral near Pinnacles NM; and in riparian scrub along the Salinas River near San Lucas. It is possible that it occurs in patches of dense chaparral in southeast MTY, but I'm now sure, so put question marks there. I am also unsure whether it reaches the highest elevations in the Santa Lucia Mts. (collected to 2400' at Big Pines), but is recorded to 7000' elev elsewhere in California (Ingles 1965). [Specimens cited from MVZ, U.C. Berkeley on-line data base.]

The MTY range of Desert Cottontail is usually illustrated as the entire county, but I have not found evidence it occurs west of the Santa Lucia Mts crest. The approximate MTY range is shown below in pink; red "x" marks a site it has been collected, "v" marks a known observation.

It has been collected or observed widely eat of the Salinas River, and in southern MTY throughout Ft. Hunter-Liggett/Lake San Antonio area. Here it overlaps widely with Brush Rabbit, with cottontails in the grasslands and savanna, and Brush Rabbits in the patches of chaparral or thick riparian scrub. A mystery series of specimens near the coast is discussed at the bottom of this page; otherwise, I am currently unaware of any coastal records of this widespread rabbit. There are many mislabeled photographs on the web, including several from "Elkhorn Slough" where it may or may not occur. [Specimens cited from MVZ, U.C. Berkeley on-line data base.]

 
A comparison of these two rabbits from behind illustrate their differences again. To the left is Brush Rabbit, very uniform grayish and unicolor, with short ears and inconspicuous tail. Although it has a pale tawny wash to the nape in this view, it is not a conspicuous character. To the right is Desert Cottontail, a more multi-colored rabbit with a prominent orangey nape, a very prominent white "cotton tail," and decidedly longer ears.

Brush Rabbit does have a small "cotton-tail" but this is about as much as one ever sees (left), while in Desert Cottontail the white cotton-tail is very conspicuous, even at a long distance. Note again the very short ears and unicolored gray pelage.

Note again the short ears, very inconspicuous blackish tips to ears, and the very inconspicuous whiskers (vibrissae), which are dull white to grayish in this individual Brush Rabbit.

Our final rabbit in Monterey County is Black-tailed Jackrabbit Lepus californicus (below). It is almost twice as big as a Brush Rabbit, and typically weights 5 lbs. It has very long ears and strong long legs for fast running. The tail is black above (dingy white below) with a black stripe continuing up onto the rump. It is mostly nocturnal, feeding on a variety of grasses and shrubs, and is more often seen sitting in the shade during the day, if seen at all. It has pale yellow eyes as an adult (our other MTY rabbits are dark-eyed).

Black-tailed Jackrabbit is a very common and widespread species of open country, including desert scrubland and Great Basin sage scrub, and is well known throughout western arid landscapes. However, it seems much scarcer in Monterey County, preferring the open grasslands of the southeast. Yet is does range throughout MTY, and is regular along the coast at places like the Salinas River NWR, and there are old specimens for Carmel and Pebble Beach (1908, 1935 respectively). It was at Pt. Lobos in the 1930s before that became a State Reserve and climax Monterey pine forest. There are also specimens up to 3000' elev in the Santa Lucia Mts. Thus, it can be recorded almost anywhere in MTY.


13 Aug 2007 Death Valley NP, INY

3 June 2012 Vineyard Cyn MTY
 

In researching this page, I did come upon a mystery regarding the small Sylvilagus rabbits. Using the on-line data base for the Museum of Vertebrate Zoology (MVZ), U.C. Berkeley, and searching for Sylvilagus in Monterey County, I found only one location which listed both species present and collected. Yes, there were specimens of both near Soledad and near San Lucas, both in the Salinas Valley, but the lat-longs given were difference and using google maps, one could see the habitat was different. But the one location showing both species was listed as "Sandhills, 2 mi S mouth Salinas River." There were 6 specimens of audubonii (Desert Cottontail) and 5 specimens of bachmani (Brush Rabbit) credited to the same spot, all "live trapped" and collected by J.R. Rowley (a well-known mammal collector of that era). between 28-31 Aug 1907.

Today, a location in sandhills two miles south of the Salinas River mouth is almost in Marina State Beach. The only habitat here is coastal sage scrub, and I couldn't imagine both species there — it is classic Brush Rabbit habitat. Dr. Carla Cicero, the ornithologist at MVZ, directed my inquires to Dr. James Patton, retired professor of mammalogy. He graciously examined the rabbit specimens; confirmed the i.d. of each; and examined the specimen tags. The original tags all said "Salinas Valley" but a secondary tag, placed there sometime later, gave the location as "2 mi S of mouth of Salinas River." Why?

Rowley's rabbits were accessioned into the MVZ collection in 1909 among 272 specimens of mammals. Digging deeper, Dr. Patton checked the back of the accession card, and found the following written there: "The 'Salinas Valley' of Rowley's labels he tells me (Oct. 29-1918) refers to a locality in the 'sand hills' within a mile of the ocean and two miles south of the mouth of the Salinas River." This note is signed "J. Grinnell" and is clearly written by him. So Joseph Grinnell himself, the author of Grinnell (1918, 1933) actually talked to Rowley about these specimens in 1918 — 11 years after they were collected — and was given this specific location.

I was explaining all this to my wife Rita Carratello, and she asked a question that became the key to solving this mystery: "Where," she asked, "was the Salinas River mouth in 1907?" Ah, yes. — where, indeed. I had forgotten that part. As explained in detail by Gordon (1977), and mentioned in figure 15, p. 21, of my own work (Roberson & Tenney 1993), the Salinas River mouth's location changed dramatically during the winter of 1909-1910. Before that the river bent northward when it hit the dunes and emptied into the Pacific Ocean north of today's Moss Landing, and just 3 miles from the Pajaro R. mouth. During storms in winter 1909-1910 it broke through the dunes near its current location, and farmers blocked the old channel with flood gates to maintain the river mouth at its current location, some 5.5 miles south of where it used to be. [Later, as everyone knows, Moss Landing harbor was dredged and the current entrance between rock jetties built in 1946].

This meant that in August 1907, the mouth of the Salinas River was north of Moss Landing, and "two miles" south would place the location somewhere near today's Moss Landing Marine Lab — with sandhills to the west (with Brush Rabbits in the coastal scrub) but the Moro Cojo floodplain to the east (with Desert Cottontails in the open grassland). The 'mystery' of the co-occurrence is thus solved. Further, MVZ maintains old hand-drawn "locality cards" for older specimens (a practice given up long ago). Reproduced above is the locality card for the location of these rabbits: it uses an old 15' grid then in use, but the winding northward nature of the Salinas River for 5+ miles northward can only illustrate the "old" river mouth. The "x" on the card marks the location of our mystery rabbits — right about at today's south end of Moss Landing town.

One further point: all specimens of Desert Cottontail in MVZ from Monterey County are attributed to the more southern California race vallicola, except the six from our 'mystery' site near the (then) Salinas R. mouth, which are labeled as nominate audubonii. This, too, is explained by Joseph Grinnell who wrote in Grinnell (1933) of the range of Sylvilagus audubonii audubonii: "Sacramento Valley and San Francisco Bay region; recorded north to vicinity of Red Bluff, Tehama Country, south into northern part of San Joaquin Valley as far as Snelling, Merced Country, on east side, and Los Baños, Merced County, on west side; south from Golden Gate to near mouth of Salinas River in Monterey Country." This latter appears to be a direct reference to Rowley's specimens. As to habitat, Grinnell (1933) says: "Lives mostly in, and within forage radius of, stream-side and river-bottom thickets; also on lowland plains clothed more or less scatteringly with bushes." The Moro Cojo slough would have had lowland plains with scattered bushes in 1907.

 

Acknowledgements: Dr. James L. Patton, curator and professor emeritus, Museum of Vertebrate Zoology, U.C. Berkeley, was extremely helpful in sorting out the distribution and identification of Sylvilagus rabbits.

Literature cited:

Fried, J.S., C.L. Bosinger, and D. Beardsley. 2004. Chaparral in Southern and Central Coastal California in the Mid-1990s: Area, Ownership, Condition, and Change. USFS Resource Bulletin PNW-RB-240.

Gordon, B.L. 1977. Monterey Bay Area: Natural History and Cultural Imprints. 2d ed. Boxwood Press, Pacific Grove.

Grinnell, J. 1913. A distributional list of the mammals of California. Proc. Cal. Acad. Sci., fourth series, vol. 111.

Grinnell, J. 1933. Review of the Recent Mammal Fauna of California. U.Cal.Press, Zoology 40: 71-234.

Ingles, L.G. 1965. Mammals of the Pacific States. Stanford Univ. Press, Stanford, CA.

Reid, F. A. 2006. A Field Guide to Mammals of North America north of Mexico. 4th ed. Peterson Field Guide series. Houghton Mifflin, Boston.

Van Dyke, E., and K. Holl. 2003. Mapping the Distribution of Maritime Chaparral Species in the Monterey Bay Area. Prepared for U.S. Fish & Wild. Serv., Ventura, CA.

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page created 4-16 June 2012

all photos & text © Don Roberson

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