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Reproductive life history of ocelots Leopardus pardalis in southern Texas

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Abstract

The ocelotLeopardus pardalis Linnaeus, 1758 is an endangered felid in the United States currently restricted to southern Texas. The objectives of our study were to obtain data on ocelot parturition dates, fecundity, sex ratios, den characteristics, and first year survival, all of which are critical in development of population viability models. Sixteen parturition events were recorded ranging from mid-April to late December for 12 wild ocelots. Cumulatively, litters consisted of 1 or 2 kittens (¯ = 1.2 ± 0.44 SD). Cumulative sex ratio was 1∶2.5 (male:female); however, there was no significant difference between the observed sex ratio and a 1∶1 sex ratio. Ten den sites were in close proximity (≤ 10 m) to dense thornshrub. Adult female ocelots used 2 to 4 den sites for each litter with distance between consecutively occupied dens ranging from 110 to 280 m (¯ = 158 m ± 93 SD). An estimated annual survival for ocelots 0 to 1 year of age was 0.68. Evidence suggests that ocelots in the wild may breed more frequently than had been previously hypothesized.
Reproductive life history of ocelots Leopardus pardalis
in southern Texas
Linda L. LAACK, Michael E. TEWES,
Aaron M. HAINES and John H. RAPPOLE
Laack L. L., Tewes M. E., Haines A. M. and Rappole J. H. 2005. Reproductive life
history of ocelots Leopardus pardalis in southern Texas. Acta Theriologica 50:
505–514.
The ocelot Leopardus pardalis Linnaeus, 1758 is an endangered felid in the
United States currently restricted to southern Texas. The objectives of our study were
to obtain data on ocelot parturition dates, fecundity, sex ratios, den characteristics,
and first year survival, all of which are critical in development of population viability
models. Sixteen parturition events were recorded ranging from mid-April to late
December for 12 wild ocelots. Cumulatively, litters consisted of 1 or 2 kittens (
x
= 1.2
± 0.44 SD). Cumulative sex ratio was 1:2.5 (male:female); however, there was no
significant difference between the observed sex ratio and a 1:1 sex ratio. Ten den sites
were in close proximity (£ 10 m) to dense thornshrub. Adult female ocelots used 2 to 4
den sites for each litter with distance between consecutively occupied dens ranging
from 110 to 280 m (
x
= 158 m ± 93 SD). An estimated annual survival for ocelots 0 to 1
year of age was 0.68. Evidence suggests that ocelots in the wild may breed more
frequently than had been previously hypothesized.
Laguna Atascosa Na tional Wild life Ref uge, 22817 Oce lot Rd., Los Fresnos, TX 78566,
USA, e-mail: Linda_Laack@fws.gov (LLL); Fe line Re search Pro gram, Caesar Kleberg
Wild life Re search In sti tute, Texas A&M Uni ver sity-Kingsville, 700 Uni ver sity Bou le -
vard, MSC 218. Kingsville, TX 78363-8202, USA (MET, AMH); Smit hsoni an’s Na tion al
Zoo log ical Park, Con ser vati on & Re sea rch Cen ter 1500 Re mou nt Road, Front Royal,
VA 22630, USA (JHR)
Key words: Leopardus pardalis, den sites, fecundity, ocelot, reproduction, southern
Texas
Introduction
The ocelot Leopardus pardalis (Linnaeus 1758) is listed as an endangered
species in the United States (U.S.) (U.S. Fish and Wildlife Service 1982). Its
population, now restricted to southern Texas, is estimated at 80 to 120 individuals
(Tewes and Everett 1986). Information on reproductive characteristics of North
American ocelots (eg fecundity, kitten survival) is lacking and needed to develop
models of population viability. However, the low density of ocelots, as well as their
nocturnal habits and preference for dense cover (Tewes 1986, Laack 1991)
make reproductive information difficult to obtain. Most information on ocelot
[505]
Acta Theriologica 50 (4): 505–514, 2005.
PL ISSN 0001–7051
reproduction is from captive individuals (Cisin 1967, Eaton 1977, Fagen and
Wiley 1978, Mellen 1989). Captive ocelots have small litters, long gestation
periods, and slow growth rates compared to other felids of similar size. Repro-
ductive information on wild ocelots is based on circumstantial data provided by
Emmons (1988). A review of ocelot reproductive life history is provided by
Sunquist and Sunquist (2002).
The results of our study provide further information about wild ocelot re-
productive life history in the U.S. We report on parturition dates, breeding dates,
fecundity, sex ratios, den characteristics, and first year-survival of ocelots in
southern Texas. These results were part of on-going broader ecological study of
the ocelot in southern Texas that began in the early 1980s (Tewes 1986).
Study area
Laguna Atascosa National Wildlife Refuge (LANWR) in Cameron County is located within the
Lower Rio Grande Valley (LRGV) of southern Texas, U.S. (26°24’–26°09’N, 97°23’–97°17’W). The
subtropical, semiarid climate is characterized by hot summers and mild winters (Thornthwaite 1948,
Lonard and Judd 1985). Mean length of the frost-free period is 330 days with winters frequently
occurring without freezing temperatures. Mean annual temperature and rainfall were 23°C and 68
cm, respectively, although rainfall fluctuates widely during and among years (Norwine and Bingham
1985, Lonard et al. 1991).
The LRGV supports a variety of plants, wildlife, and habitats as part of the Tamaulipan Biotic
Province (Blair 1950, Richardson 1995). Predominant woody plant species that constitute the majority
of thornshrub forest in the LRGV include spiny hackberry Celtis pallida, Texas ebony Pithecellobium
flexicaule, crucita Eupatorium odoratum, Berlandier fiddlewood Citharexylum berlandieri, honey
mesquite Prosopis glandulosa, desert olive Forestiera angustifolia, snake-eyes Phaulothamnus
spinescens, colima Zanthoxylum fagara, and brasil Condalia hookeri (Lonard and Judd 1993).
However, > 95% of the native rangeland in the LRGV has been converted for agricultural and urban
land uses (Jahrsdoerfer and Leslie 1988).
Material and methods
Trapping and monitoring
We captured ocelots with single-door, 108 × 55 × 40 cm wire box traps (Tomahawk Trap Co.,
Tomahawk, WI) from September 1982 to July 1997. We attached a separate compartment containing
a domestic live chicken to the trap as bait. We placed traps in shaded areas and checked each
morning to reduce the risk of hyperthermia.
Ocelots were immobilized with a 9:1 ratio of ketamine hydrochloride and acepromazine maleate.
We injected this mixture with a pole syringe at a dosage of 20 mg/kg body weight. We sexed, weighed,
and classified ocelots as adults or subadults based on maturation of morphological development,
dental wear (sharp dentition for juveniles), canine length (> 15 mm for adults), and weight (female
adults > 6.5 kg, male adults > 8.5 kg) (Tewes 1986, Laack 1991). Ocelots were fitted with a collar-
-mounted radio transmitter having a frequency of 148 to 149 MHz and an activity sensor (Telonics
Inc., Mesa Arizona). We located ocelots 2-3 times each week anytime between 1 hr before sunrise
until 1 hr after sunset. Radio signals were monitored with a directional H-antenna connected to a
model TR-2 receiver (Telonics Inc., Mesa, AZ), and we used ground stations and aerial radio
telemetry to locate ocelots. Trapping and handling of ocelots were performed in a humane manner
506 L. L. Laack et al.
with procedures and research methodology approved by the Texas A&M University-Kingsville
Institutional Animal Care and Use Committee protocol # 1989–5–19.
Identifying breeding females and den sites
Female ocelots handled during captures were suspected of having young if they were lactating or
had brown-stained fur around the teats (signifying post-lactation). In addition, parturition was
suspected if radio-collared adult female ocelots were located at the same site during the daytime for
1–2 weeks. We found this pattern characteristic of denning behavior. We subsequently searched for
suspected dens 2 to 5 weeks after the presumed parturition date. Dens were found by approaching a
radio-collared female until it moved, then searching the area around its last known location. Once
the den was found, kittens were then photographed, weighed in a bag with a scale, and measured in
length with measuring tape from tip of the nose pad to the base of the tail bone. Time spent by
researchers at the den was £ 30 min. An adult female ocelot was monitored until it returned to the
den site. Some dens were not found because of the difficulty of researchers quietly approaching
ocelots in dense vegetation and the concealment of the den. However, if a female displayed denning
behavior for ³ 6 weeks, parturition was presumed to have occurred. Female radio-collared ocelots
with known den sites were suspected of moving den sites when denning behavior was exhibited at a
different location from the initial den site. These new den site locations were estimated with
triangulation. However, we only took measurements at initial den sites to reduce potential stress to
ocelot females and kittens.
Parturition date was determined as the first day a female was found at the presumed site.
Breeding date was determined as 80 days prior to parturition date based on a gestation length of 79
to 82 days for captive ocelots (Cisin 1967, Eaton 1977, Fagen and Wiley 1978).
After den sites were abandoned by ocelots, we recorded general characteristics of the den sites.
These included den site distance to dense thornshrub cover, dimensions of den sites, and identification
of plant species within den chambers. Distance to dense thornshrub cover and dimensions of den
sites were measured with measuring tape.
Statistical analysis
We calculated differences between observed and expected sex ratios using a chi-square analysis.
Survival rates for ocelot kittens aged 0–3 months of age were calculated using number of observation-
-days and number of mortalities (Trent and Rongstad 1974, Heisey and Fuller 1985a) in MICROMORT
(Heisey and Fuller 1985b), a program based on the Mayfield methodology (Mayfield 1961, 1975). We
assumed no ocelots died before den sites were found due to no evidence of kitten mortality at the den
sites. To calculate first year survival for ocelots, we incorporated survival data from Haines et al.
(2005), and extrapolated it with our own data. Haines et al. (2005) defined a resident individual as an
ocelot ³ 6 months of age that inhabited a home range or natal range for ³ 3 months, and calculated
an annual survival rate of S
^
= 0.87 ± 0.02 SE for resident ocelots. Using the same data as Haines et
al. (2005) we calculated an annual survival rate of S
^
= 0.90 ± 0.04 SE for resident ocelots residing on
a natal range (juvenile and subadult ocelots). Both survival rates did not significantly differ
2
1
=
0.45, p = 0.50) from each other when compared using chi-square tests in the program CONTRAST
(Hines and Sauer 1989, Sauer and Williams 1989). Thus, we combined resident ocelot survival rates
with our survival estimate for ocelots 0-3 months of age to calculate an estimate of ocelot first year
survival.
Results
We captured and monitored 15 resident adult females in their established
breeding ranges. Eleven produced young or exhibited denning during this time.
Sixteen parturition events were determined for 12 ocelots (Table 1). Failure to
Reproductive history of Leopardus pardalis 507
record young or denning behavior with the other 4 resident female ocelots may
have been a result of short monitoring periods. One radio-collared female (female
3) was road-killed 5 months following establishment of a breeding range, and was
carrying 2 fetuses. An uncollared female with 1 fetus (female 6) was also a
road-kill. In June 1989, the den site for female 4 was investigated with a kitten
only being heard around the den site. Thus, the kitten was not sexed (Table 1).
Ocelot litters were found from mid-April to late December, indicating a minimum
range of breeding activity from late January to early October (Table 1).
Two ocelots exhibited a 1-year interbirth period following the success of a
previous litter. Litters consisted of 1 or 2 kittens (
x
= 1.2, SD = 0.44, n = 13) at the
time they were found (Table 1). The sex ratio of ocelot kittens found in this study
was 1:2.5 (4 male, 10 female) (Table 1); however, there was no significant
difference
2
1
= 2.57, p > 0.10) between the observed sex ratio and a 1:1 sex ratio.
All but 1 den site either occurred within close proximity (£ 10 m) to thornshrub
cover or were located directly under dense thornshrub cover. Three dens were
located in dense thornshrub brush and 1 den was located along a thornshrub
508 L. L. Laack et al.
Table 1. Breeding dates, birth dates, litter size, and sex ratio of ocelot (Leo-
pardus pardalis) litters found at Laguna Atascosa National Wildlife Refuge in
Cameron County, Texas, USA 1985–1997.
a
Based on gestation of 80 days prior
to date of birth (Cisin 1967, Eaton 1977, Fagen and Wiley 1978).
b
Pregnant
female was killed by a vehicle; date of birth was estimated based on fetal
development.
c
Based on denning patterns observed by females.
d
Heard kitten
in underground den but could not see kitten without destroying the dens site.
e
Observed female crossing road with 2 kittens, sexes not identified.
Adult female
ID number
Date of
breeding
a
Date of
birth
Date litter
observed
Observed litter
size and sex
ratio (M:F)
1 05/06/1985 25/08/1985 11/09/1985 0:1
2 06/09/1985 26/11/1985 19/12/1985 1:1
2 01/10/1987 20/12/1987 12/01/1988 0:1
2 26/08/1988 14/11/1988 02/12/1988 0:1
3
b
25/08/1986 15/11/1986 26/10/1986 1:1
4 23/07/1988 13/10/1988
c
4 01/03/1989 30/05/1989
d
1
5 25/02/1989 15/05/1989 25/05/1989 0:1
6 25/02/1989 15/05/1989 31/05/1989 1:0
7
b
10/04/1989 30/06/1989 25/06/1989 1:0
8 25/01/1991 15/04/1991
c
9 25/01/1991 15/04/1991 11/05/1991 0:1
10 15/06/1992 05/09/1992
c
10 14/03/1997 04/06/1997 18/06/1997 0:1
11 14/03/1997 04/06/1997 10/07/1997 0:1
12 25/02/1997 15/05/1997
c
29/09/1997 2
e
corridor with no vertical cover. Four dens were located in tussocks of alkalai
sacaton grass Sporobolus airoides and 2 in gulf cordgrass Spartina spartinae.
These sites were surrounded on at least 3 sides by thornshrub. Within dens, no
bedding was found and the den chamber usually consisted of grass bases of the
species described previously. Average dimensions of the den sites were 45 ´ 29 ´
30 cm. Thornshrub cover consisted of woody species described within the study
area.
Ten offspring of 7 resident female ocelots were monitored through daily visual
observations until 3 months of age. Eight of the 10 kittens survived until 3 months
of age. One kitten was killed by domestic dogs and the other died of unknown
causes. After 3 months of age, only 2 kittens were monitored until maturity,
whereas the other 6 kittens were not monitored beyond 3 months of age when they
left their den to begin traveling with their mothers.
The estimated survival rate of 3-month old ocelot kittens was 0.785 ± 0.13 SE.
We assumed ocelots over 3 months of age had the same 3-month survival rate as
resident ocelots (0.966). However, we assumed that survival of ocelot kittens
between 3 and 6 months of age was still dependant on their mother. Thus, we
assumed that ocelot kittens between 3 to 6-months of age had a 3-month survival
rate equal to their mothers 3-month survival rate (0.966) multiplied by their own
(0.966). Thus, ocelots aged 3 to 6-months of age had a survival rate of 0.933 (0.933
= 0.966 ´ 0.966). When an ocelot is ³ 6 months of age we assumed its 3-month
survival rate was 0.966, the same as a resident ocelot. Thus, we estimated that
first-year survival of an ocelot was S
^
= 0.68, or the product of S
^
= 0.785 ´ 0.933 ´
0.966 ´ 0.966.
Discussion
Parturition dates
Eaton (1977) found that captive ocelots breed through much of the year. In
addition, Eaton (1977) found that ocelots breed every year. Furthermore, captive
female ocelots have short inter-parturition periods if dependant kittens die at a
young age (Hatfield and Hatfield 1973, Eaton 1977). However, Emmons (1988)
suggested that wild ocelots had 2-year interbirth periods based on circumstantial
evidence. In this study, female 4 produced a litter 7 months following a successful
litter (Table 1), suggesting that wild ocelots have the potential for shorter
interbirth period than suggested by Emmons (1988). In addition, 1 wild Texas
female ocelot (female A) produced 3 litters within 15 months (Tewes 1986).
Unfortunately, female A was not monitored during her denning period and thus
no estimates of date of birth, date of breeding, date litter observed, or observed
litter size or sex ratio were estimated.
In October 1982, female A had a successful litter of at least 1 offspring (Tewes
1986). Eight months later she was recaptured and was lactating. Two months
later female A was captured again with evidence of post lactation with the
Reproductive history of Leopardus pardalis 509
offspring from the previous litter still using the maternal range (which it later
used as its own breeding range). Female A was again recaptured 3 months later
and was again in lactation. We believe the second litter of female A failed to
survive and that estrus occurred soon afterward.
Fecundity and sex ratio
Eaton (1977) found 1 to 3 kittens (
x
= 1.4 kittens) in 168 captive-born litters of
ocelots, with only 3 litters that contained 3 kittens. Previous observations of
free-ranging ocelots included 5 litters with 1 kitten, 3 litters with 2 kittens, and 1
litter with 3 kittens (Enders 1935, Vesey-FitzGerald 1936, Hall and Dalquest
1963, Petrides et al. 1951). Petrides et al. (1951) reported a pregnant female Texas
ocelot with 2 female fetuses, and the Smithsonian’s National Museum of Natural
History in Washington D.C. includes a pair of male kittens from a litter collected
by H. E. Bridgewater in 1956 in Kleberg County, Texas, and a solitary female
kitten collected by F. B. Armstrong in 1892 in Cameron County, Texas. Litters
consisted of 1 to 3 kittens (
x
= 1.4, SD = 0.58, n = 22) when our data was combined
with these historic observations.
When including all known records of litters, the cumulative sex ratio for the
ocelot in southern Texas was 1:2.2 (6 male, 13 female). However, there was no
significant difference
2
1
= 0.33, p > 0.50) from a 1:1 sex ratio. Eaton (1977)
reported a sex ratio of 1:0.7 (n = 168) among captive-born ocelots.
Den ecology
All ocelot dens were devoid of prey remains and scat, much like dens sites of
the Florida panther Puma concolor coryi (Linnaeus 1771) (Maehr et al. 1989).
However, this was unlike bobcat Lynx rufus (Schreber 1777) dens that contained
numerous prey remains, other vegetation, and fecal marking stations (Bailey
1979).
Female ocelots usually used 2 to 4 den sites for each litter, and moved kittens 1
to 5 times. Females occupied den sites from 3 to 64 days (
x
= 27 ± 17 SD days/den
site, n = 16). Distance between consecutively occupied dens ranged from 110 to
280 m (
x
= 158 m ± 93 SD). However, this range excludes 1 female that moved
kittens 990 m. This long movement may have been in response to human
disturbance that consisted of brush clearing 40 m from the den site. Lions
Panthera leo (Linnaeus 1758), cheetahs Acinonyx jubatus (Schreber 1776), and
leopards Panthera pardus (Linnaeus 1758) occasionally relocate cubs to new dens
(Schaller 1972, Seidensticker 1977). Bailey (1979) suggested that female bobcats
may move young up to 6.5 km into areas that contained more prey. Ocelots in our
study relocated dens 0.11 to 0.28 km (excluding the female that responded to
human disturbance), making it unlikely that females moved dens in response to
prey availability. It is more likely that dens were moved because of the changing
needs of maturing kittens, or to move kittens away from a den site with
510 L. L. Laack et al.
accumulated odors and worn trails. Loss of concealment because of worn trails or
odor accumulation may expose litters to threats from other carnivores such as
coyotes Canis latrans (Say 1823), domestic dogs, bobcats, or conspecifics.
Female ocelots did not move kittens £ 3 days after the den was visited by
researchers, and females returned to their kittens £ 2 h after researchers exited
the den. Thus, human disturbance by researchers did not appear to cause den
abandonment or relocation.
Survival of young ocelots
This first year survival rate is comparable to first year survival rates cal-
culated by Hemker et al. (1986) S
^
= 0.67 and Logan and Sweanor (2001) S
^
= 0.64
for 0 to 1 year old mountain lion kittens in an unexploited population within arid
and semi-arid environments. Survival of 3-month old ocelot kittens did not differ
significantly
2
1
= 2.07, p = 0.15) from a 3-month survival rate of resident ocelots.
Logan and Sweanor (2001) found that mountain lion kittens £ 3 months of age had
a higher rate of mortality than older cubs. Logan and Sweanor (2001) attributed
this higher mortality to the ability of predators able to detect trails made by
maternal mountain lions traveling in and out of the den to care for the young.
Ocelot reproductive adaptation and future research
The ocelot is primarily a tropical felid that breeds through the year (Eaton
1977, Mondolfi 1986, Nowell and Jackson 1996). Although the similarly-sized
bobcat residing in the southern portion of its range may breed year-round, it still
exhibits major parturition periods in late winter to early spring (Blankenship and
Swank 1979, Fritts and Sealander 1978, Winegarner and Winegarner 1982,
Wassmer et al. 1988).
Emmons (1988) believed that low fecundity, long gestation, and slow growth
periods in ocelots were adaptations to low expected rates of energy acquisition. In
addition, these characteristics typify other small to medium-sized Neotropical
cats such as the oncilla Leopardus tigrinus (Schreber, 1775) (Fagan and Wiley
1974, Quillen 1981, Widholzer et al. 1981) and margay Leopardus wiedii (Schinz,
1821) (Fagan and Wiley 1974, Eaton 1984, Mellen 1993). However, in southern
Texas, ocelots have the potential for 1- year interbirth periods while evidence
suggests that ocelots in the tropics have 2 year inter-birth periods (Emmons
1988). This may be the result of ocelots within southern Texas having higher rates
of energy acquisition compared to ocelots in the Neotropics. However, this has yet
to be analyzed.
We believe these findings contribute to an understanding of ocelot re-
productive ecology and provide the best available estimates of fecundity and
first-year survival that can be used in population modeling. However, more
research is needed to obtain estimates of ocelot kitten survival, juvenile survival,
and sources of mortality. In addition, we recommend more research on interbirth
Reproductive history of Leopardus pardalis 511
periods and any possible relation to energy acquisition. Furthermore, the majority
of these data are over 10 years old, and the LANWR population is small and
isolated. Thus, current research is needed to analyze potential negative effects of
inbreeding or habitat fragmentation on ocelot reproductive life history.
Acknowledgements: This project was funded by the Rob and Bessie Welder Wildlife Foundation, U.S.
Fish and Wildlife Service, the James R. Dougherty Foundation, the Ben and Rachael Vaughen
Foundation, the Boone and Crocket Club, G. Hixon, and B. Vaughan, III. We thank personnel from
the LANWR for granting permission to use the land. We also thank L. Drawe, D. Everett, M.
Fernandez, E. Haines, J. Janecka, S. Jojola, J. Mays, S. Miller, and B. Tewes for their help in the
field, data collection, and support of the project. Other personnel with the U.S. Fish and Wildlife
Service instrumental in the success of this study were G. Burke, C. Carley, T. Jasikoff, S. Rice, R.
Rauch, and S. Thompson. We thank M. Hornocker and the Wildlife Research Institute of the
University of Idaho for their support facilities, and S. Henke and W. Kuvlesky for reviewing this
manuscript. This is publication #04-119 of the Caesar Kleberg Wildlife Research Institute and
Contribution #637 of the Rob and Bessie Welder Wildlife Foundation.
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Associate Editor was Joseph F. Merritt.
514 L. L. Laack et al.
... Often not only exotic cats are maternal instincts worst with the first litter. Under captive conditions it often happens that the female, being nervous and restless with her litter, kills the kittens or stops care [22].The ocelots are able to reproduce all year [18[.In wild populations [12]observed,15 adult females gave birth from the middle of April to late December. According to [3] ocelots in the Yucatan in Mexico for the most part mated in October and delivered in January, and ocelots in Argentina delivered from October to January in wild. ...
... [3,14], states, that the number of young in a litter is small, usually one rather, than two young and only sporadically three. [7,16] found from one to three kittens in 168 litters of ocelots under captive conditions, of which triplets were born in three of the litters Only one known case of a quadruplet birth has been recorded [12]. ...
... This implies that the birth of two sets of quadruplets is an exceptionally rare event. According to [9,10].According to results of [12] were born more males than females which agree with our conclusions and hypothesis. When was evaluated the age of females at their first litter by [13,15] the females had their first litter at 18 to 45 months of age. ...
... Such shelters can also be important in helping to maintain a stable and adequate thermal environment for the altricial young (Reichman and Smith 1990). Dens of several species of the family Felidae such as Pallas's cat Otocolobus manul, Iberian lynx Lynx pardinus, and ocelot Leopardus pardalis contribute importantly to thermoregulation, as well as providing a refuge from other carnivores, including predatory conspecifics, and from humans (Fernández and Palomares 2000;Laack et al. 2005;Ross et al. 2010). Thermoregulatory factors in den selection were also found to be important in wolverines Gulo gulo (Magoun and Copeland 1998), and the Arctic fox Vulpes lagopus constructs and uses dens with southward-facing entrances to improve microclimate conditions (Smits et al. 1988). ...
... One strategy some species are thought to use to counteract such dangers is to move the nursery site from time to time although this might also be done to accommodate the changing needs of rapidly growing young. Thus, female ocelots are reported to use two to four den sites for each litter and to move kittens one to five times between them (Laack et al. 2005). Domestic cats and bobcats also frequently move their litters, especially if the mother is disturbed by unfamiliar males or humans (Feldman 1993, Nielsen and Woolf 2001, Turner and Bateson 2014. ...
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The mammalian order Carnivora is generally defined as species that feed exclusively or to some degree by eating other animals. The Carnivora comprise around 280 species, divided into 16 families, 13 of which are terrestrial and 3 aquatic. Carnivores are spread across the entire planet, including the two polar regions and on land and sea. Consistent with such diverse ecologies, there is no typical pattern of parental care distinguishing carnivores from other mammals. Using examples from different taxonomic families, our aim is to illustrate the diversity of parental care in Carnivora. Major topics include parental care before and after birth of the young, paternal, and alloparental care and the process of weaning. Given the position of many carnivores at the apex of food chains, a greater understanding of their patterns of parental care as a vital part of reproductive biology is essential to conservation programs.
... Such shelters can also be important in helping to maintain a stable and adequate thermal environment for the altricial young (Reichman and Smith 1990). Dens of several species of the family Felidae such as Pallas's cat Otocolobus manul, Iberian lynx Lynx pardinus, and ocelot Leopardus pardalis contribute importantly to thermoregulation, as well as providing a refuge from other carnivores, including predatory conspecifics, and from humans (Fernández and Palomares 2000;Laack et al. 2005;Ross et al. 2010). Thermoregulatory factors in den selection were also found to be important in wolverines Gulo gulo (Magoun and Copeland 1998), and the Arctic fox Vulpes lagopus constructs and uses dens with southward-facing entrances to improve microclimate conditions (Smits et al. 1988). ...
... One strategy some species are thought to use to counteract such dangers is to move the nursery site from time to time although this might also be done to accommodate the changing needs of rapidly growing young. Thus, female ocelots are reported to use two to four den sites for each litter and to move kittens one to five times between them (Laack et al. 2005). Domestic cats and bobcats also frequently move their litters, especially if the mother is disturbed by unfamiliar males or humans (Feldman 1993, Nielsen and Woolf 2001, Turner and Bateson 2014. ...
Article
Direct care of offspring by the father (sire) is relatively rare in primates. Besides humans, there are a number of species where the male is essential for the survival of offspring: marmosets, tamarins, titis and owl monkeys, some lemurs, and siamangs. All these species show reduced sexual dimorphism, territoriality, and biparental care. However, timing and levels of direct care may vary among these species. Here, relying on both lab and field data, we address the variability found in father's involvement with his infants, the behavioral, neuroendocrine and sensory systems that are a cause and consequence of paternal care, and social bonds between the breeding pair. We integrate studies of laboratory animals (where detailed observations and experimentation are possible) with field studies (which illuminate the ecological and evolutionary functions of paternal care) and discuss the future directions for examining the proximate and ultimate mechanisms of paternal care in nonhuman primates.
... The majority of ocelot habitat studies in Texas to date have occurred on Laguna Atascosa National Wildlife Refuge, an area surrounded by a matrix of agriculture, highspeed roadways, and encroaching urban areas (Harveson et al. 2004;Haines et al. 2005a, b;Laack et al. 2005;Jackson et al. 2005;Horne et al. 2009). Jackson et al. (2005) reported that ocelots in these areas strongly select for areas that have greater shape index values, contain more edge, and are more isolated, indicating a greater degree of fragmentation in these areas. ...
... We were unable to find strong evidence that canopy cover or horizontal cover affected ocelot habitat use. Ocelots have been strongly linked to dense vegetation communities (> 75% canopy cover) possibly for dense screening cover, ample prey, and secure den sites these vegetation communities may provide (Shindle and Tewes 1998;Harveson et al. 2004;Laack et al. 2005;Horne et al. 2009;Booth-Binczik et al. 2013). Heterogeneity in canopy cover (x = 56.7, ...
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About 80% of the known breeding population of ocelots (Leopardus pardalis) in the USA occurs exclusively on private ranches in northern Willacy and Kenedy counties in South Texas. These private ranches support several large contiguous undisturbed patches of thornscrub, which is preferred by ocelots. Past studies have indicated ocelots in South Texas select for woody patches that contain extremely dense thornscrub (i.e., 95% canopy cover and 85% vertical cover) and require large patches of woody cover to survive. Landscape metrics have been used to explain ocelot habitat use in fragmented areas, but their application in less-fragmented rangelands is lacking. From 2011 to 2018, we used camera traps on the East Foundation’s El Sauz Ranch to assess seasonal habitat use of ocelots relative to landscape structure, configuration, and complexity and other site-level factors in South Texas. Seasonal habitat use and detection were positively influenced by larger mean patch area and lower landscape shape index values. We also observed ocelots were less likely to be detected during periods of drought and exhibited a seasonal trend in detection. Ocelots used woody patches that were larger and more regularly shaped, indicating a preference for areas with a lower degree of fragmentation across the study area. As patches become larger, they will coalesce over time and form larger woody aggregates, which will promote ocelot habitat use. Brush management needs to be strategic as patch area and shape index are a limiting factor to promote ocelot habitat use on working rangelands in South Texas. These results demonstrate the ability to use landscape metrics to discern the effects of spatial structure of vegetation communities relative to ocelot occupancy parameters.
... Increased mean patch area, large patch index, and percentage of woody cover are related to increasing forested cover, which has been widely linked to the occurrence of ocelots throughout their range [31,33,45,54,56]. Preference for large areas of forested cover possibly indicates use for specific behaviors such as for reproduction [57], prey [32,[58][59], and may play a key role in facilitating coexistence with competitor species [59][60][61]. In areas of the Atlantic Forest in Brazil, ocelot occurrence has been strongly linked to large patches of undisturbed forest, similar to southern Texas and believed to be rare, particularly in human-modified landscapes [54,[61][62]. ...
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Few ecological studies have explored landscape suitability using the gradient concept of landscape structure for wildlife species. Identification of conditions influencing the landscape ecology of endangered species allows for development of more robust recovery strategies. Our objectives were to (i) identify the range of landscape metrics (i.e., mean patch area; patch and edge densities ; percent land cover; shape, aggregation, and largest patch indices) associated with woody vegetation used by ocelots (Leopardus pardalis), and (ii) quantify the potential distribution of suitable woody cover for ocelots across southern Texas. We used the gradient concept of landscape structure and the theory of slack combined with GPS telemetry data from 10 ocelots. Spatial distribution of high suitable woody cover is comprised of large patches, with low shape-index values (1.07-2.25), patch (27.21-72.50 patches/100 ha), and edge (0-191.50 m/ha) densities. High suitability landscape structure for ocelots occurs in 45.27% of woody cover in southern Texas. Our study demonstrates a new approach for measuring landscape suitability for ocelots in southern Texas. The range of landscape values identified that there are more large woody patches containing the spatial structure used by ocelots than previously suspected, which will aid in evaluating recovery and road planning efforts.
... We used previously collected location data from adult ocelots from the Refuge Population on LANWR from 1982 to 2001 (Tewes, 1986;Shindle and Tewes, 2000;Laack et al., 2005;Horne et al., 2009). Individuals were fitted with very high frequency radio collars with mortality sensors (Advanced Telemetry Systems, Isanti, Minnesota; Telonics, Mesa, Arizona, USA). ...
Article
Full-text available
Encroaching urban development is a leading cause of habitat loss, replacing natural areas with anthropogenic infrastructure and road networks. Roadways can influence the spatial ecology and survival of mammalian carnivores, particularly felids, thereby threatening long-term persistence and conservation of sensitive populations. Ocelots (Leopardus pardalis) are a federally endangered felid in the United States with breeding populations restricted to the Lower Rio Grande Valley of South Texas, an area of extensive anthropogenic expansion. We evaluated the influence of road networks on ocelot survival using a long-term telemetry dataset (1982–2001, n=59) and draw comparisons with a spatially referenced historical dataset of ocelot-vehicle collisions in the same area (1982–2020, n=54). Vehicle collisions accounted for 40% of radio-collared ocelot fatalities. Annual survival rates were 0.90 (95% CI=0.84–0.95) for resident ocelots and 0.66 (95% CI=0.45–0.97) for transient ocelots. We evaluated biological and road-related factors that may influence ocelot survival using Cox proportional hazards regression. The top model included density of unpaved, low-volume, and high-volume roads within home ranges and resident-transient status. Mortality risk increased 16% with every 0.07 km/km² increase of high-volume roads within annual home range, decreased 45% with every 1.12 km/km² increase of unpaved roads, and decreased 276% for residents compared to transients. Further, probability of mortality specifically from vehicle collision increased with greater density of low-volume roads within ocelot home ranges. Within the historical dataset of ocelot-vehicle collisions, 46% occurred on low-volume roads while 39% occurred on high-volume roads. Our results highlight the necessity for mitigation strategies on low-volume roads which cause the most ocelot-vehicle collisions. In addition, continued attention towards high-volume roads is necessary to ocelot conservation. Understanding how road attributes affect the survival of species sensitive to urbanization and habitat fragmentation can aid in their conservation.
... Prior to conducting our analysis we examined all GPS locations for female ocelots and bobcats to look for denning behavior (i.e., repeated returns to the same local vicinity) but found none. The presence of denning behavior could have confounded our analysis, as denning females are likely to show different activity patterns from non-denning individuals [74]. ...
Article
Full-text available
Sympatric ocelots (Leopardus pardalis) and bobcats (Lynx rufus) in South Texas show substantial overlap in body size, food habits, and habitat use. Consequently, we explore whether temporal niche partitioning may explain ocelot and bobcat coexistence. We investigated the influence of sun angle, lunar illumination, and maximum diurnal temperature on temporal movement rates of sympatric ocelots (n = 8) and bobcats (n = 6) using a combination of high-frequency GPS locations and bi-axial accelerometer data. We demonstrated that accelerometer data could be used to predict movement rates, providing a nearly continuous measure of animal activity and supplementing GPS locations. Ocelots showed a strong nocturnal activity pattern with the highest movement rates at night whereas bobcats showed a crepuscular activity pattern with the highest movement rates occurring around sunrise and sunset. Although bobcat activity levels were lower during the day, bobcat diurnal activity was higher than ocelot diurnal activity. During warmer months, bobcats were more active on nights with high levels of lunar illumination. In contrast, ocelots showed the highest nocturnal activity levels during periods of low lunar illumination. Ocelots showed reduced diurnal activity on hotter days. Our results indicate that ocelot and bobcat coexistence in South Texas can be partially explained by temporal niche partitioning, although both felids showed periods of overlapping activity during nocturnal and crepuscular periods.
... We selected the months between January and April as the primary periods to meet the assumption of demographic closure, supported by our field observations as we documented 3 ocelot births that occurred during the summer. Havlanová & Gardiánová (2013) observed that, in captivity, a higher number of litters ocurred during the summer, which was corroborated by Laack et al. (2005), who found that ocelot births in Texas occurred between mid-April and late December. ...
Article
Full-text available
Ocelots (Leopardus pardalis) are legally protected in Mexico as an endangered species. The main threats throughout the species’ range are habitat loss and fragmentation. The ocelot population that inhabits Sonora, Mexico, is at the northern limit of the species’ distribution and knowledge about it is still scarce. We used remote camera data from 2010-2012 and SECR models for density estimation and the Barker Robust Design mark-recapture model to estimate the survival, abundance, and density of ocelots in a arid region in northeastern Sonora, Mexico. Average apparent survival was 0.65 for females and 0.63 for males; abundance estimates ranged from 2.02 ± 0.13 to 7.06 ± 0.24 ocelots. Average density was 0.63 ± 0.06 females 100 km⁻² and 0.95 ± 0.08 males 100 km⁻² using the Barker Robust Design and 0.51 ± 0.26 females 100 km⁻² and 0.77 ± 0.25 males 100 km⁻² using the SECR. Our survival and density estimates are the lowest reported. However, due to the low human population density in our study area, we consider that our findings must be associated with natural processes rather than human-caused disturbance, without dismissing an additive factor by the latter. Arid environmental features could have a negative influence over primary productivity and consequently on prey availability, limiting ocelot survival and density in this region. Large tracts of unpopulated wildlands over a non-fragmented landscape favor ocelots in this area, and it is important to maintain current habitat conditions for this Neotropical species to continue thriving in this region of North America.
Article
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Reliable estimates of population density and size are crucial to wildlife conservation, particularly in the context of the Endangered Species Act. In the United States, ocelots (Leopardus pardalis pardalis) were listed as endangered in 1982, and to date, only one population density estimate has been reported in Texas. In this study, we integrated vegetation metrics derived from LiDAR and spatial capture-recapture models to discern factors of ocelot encounter rates and estimated localized population estimates on private ranchlands in coastal southern Texas. From September 2020 to May 2021, we conducted a camera trap study across 42 camera stations on the East Foundation’s El Sauz Ranch, which was positioned within a larger region of highly suitable woody and herbaceous cover for ocelots. We observed a high density of ocelots (17.6 ocelots/100 km2) and a population size of 36.3 ocelots (95% CI: 26.1–58.6) with the 206.25 km2 state space area of habitat. The encounter probability of ocelots increased with greater canopy cover at 1-2 m height and decreasing proximity to woody cover. These results suggest that the incorporation of LiDAR-derived vegetative canopy metrics allowed us to understand where ocelots are likely to be detected, which may aid in current and future population monitoring efforts. These population estimates reflect the first spatially explicit and most recent estimates in a portion of the northernmost population of ocelots in southern Texas. This study further demonstrates the importance of private working lands for the recovery of ocelots in Texas.
Article
Northeastern México is one of the most diverse regions in the country with high mammal richness. This region also sits on the northern periphery of the geographic distribution of ocelots (Leopardus pardalis), which are listed as endangered in México. Ocelot ecology in northeastern México is poorly known at local and landscape levels, especially in the ecologically rich temperate sierras, a perceived stronghold for ocelots. We used an occupancy approach to estimate ocelot-habitat use in Tamaulipan thornshrub and tropical deciduous forests and a spatially explicit capture–recapture (SECR) framework to estimate density of ocelots in the northern edge of the Sierra Tamaulipas, México. From May to December 2009, we conducted two camera trap surveys (summer: 20 camera stations; fall: 58 camera stations) on Rancho Caracol and Rancho Camotal, north of the Rio Soto de La Marina. We found ocelot detections were higher in areas with increasing patch density of tropical deciduous forest and habitat use was greater in Tamaulipan thornshrub and tropical deciduous forests with lower edge densities. Ocelot densities varied by sex, with females achieving greater densities (7.88 ocelots/100 km2 [95% CI: 4.85–12.81]) than males (3.81 ocelots/100 km2 [95% CI: 1.96–7.43]). Ocelots were averse to areas with high densities of edge cover in each woody community, supporting the notion of a forest patch interior species. Despite the study occurring 11 years ago, population densities were also among the highest reported in México using spatially explicit capture–recapture methods. The high ecological integrity of the habitat within the Sierra de Tamaulipas, recent protection as a Biosphere Reserve, and remote rugged terrain suggest long-term security of the ocelot population in this region.
Article
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A population of ocelots was followed by radio-tracking in a Peruvian rain forest. Two resident adult males, two adult females, and three subadults were radio-collared, as well as two transients. Ocelots were active at any time of day, but usually they rested in the morning, became active in mid — to late — afternoon, and continued activity until after dawn the following morning, with one rest period during the night. They spent an average of 9.6 hours walking per night. Breeding females occupied mutually exclusive territories, but an old female was tolerated on their territories by her former neighbours when the latter had no dependent young. Apparent direct territorial defense by females was recorded four times. Adult males occupied large territories that overlapped three or more female ranges. Circumstantial evidence indicated that females on the study area produced young about every other year. A lactating female increased her daily activity to a maximum of 133 % above normal, to 93 % of the time, before losing her litter. It is conjectured that she was unable to sustain the foraging demands of lactation. An 80 % grown subadult female was already wandering, but two 80 % grown males occupied small ranges within their presumed mother’s territories. The disappearance of an old adult male and establishment of another coincided with changes in the status of all collared residents. Although ocelots hunted, traveled, and usually denned alone, they often met : 37 encounters between collared cats were recorded during radio-tracking. ter. It is conjectured that she was unable to sustain the foraging demands of lactation. An 80 % grown subadult female was already wandering, but two 80 % grown males occupied small ranges within their presumed mother’s territories. The disappearance of an old adult male and establishment of another coincided with changes in the status of all collared residents. Although ocelots hunted, traveled, and usually denned alone, they often met : 37 encounters between collared cats were recorded during radio-tracking.
Article
Records collected principally from 1946 through 1958 in Utah and Nevada have shown that the cougar may have young any month of the year. However, birth months, as determined by reference of juvenile weights from 145 litters to a growth curve, indicated that about 60 per cent of the litters were probably born from June through September with a peak in July. The highest incidence of pregnancy for 199 mature females was noted in June and July. Forty-one per cent of 299 mature females had young at the time of capture. Evidence is presented that some females apparently have young as often as 12–15 months, but a 2-year interval appears the rule. Most young apparently remain with their mothers for at least a year. The average size of 258 postnatal litters was 2.9 (range, 1–5) and of 66 prenatal litters it was 3.4 (range, 1–6).