Juan F. Beltrán

Rates and causes of mortality in a fragmented population of Iberian lynx Felis pardina Temminck, 1824

Abstract Data are presented on mortality rates of the Iberian lynx Felis pardina in Donana National Park and the surrounding area in southwestern Spain, collected from 1983 to 1989. Data from radio-tagged lynxes and records of lynx mortality were used to assess causes of death. Annual mortality rate, estimated by using the Heisey and Fuller methodology, was 0·37. Human activities were the main cause of lynx mortality in this mainly fully protected area, either directly (illegal trapping: 41·7%; road traffic: 16·7%; hunting with dogs: 8·3%) or indirectly (artesian wells: 8·3%). Only 8·3% of the annual mortality can be related unequivocally to natural causes. Sex, age, social status, year, and home range situation influenced mortality rates. The trend of this lynx population during the seven years of study revealed serious threats to its survival. This case study exemplified how a small population can approach extinction because of increased mortality due to habitat fragmentation, despite full protection of the main portion of its range.

Environmental determinants of circadian activity of free-ranging Iberian lynxes

From February 1983 to May 1985, 12 Iberian lynxes ( Lynx pardinus ) (six adults and six juveniles) were radiotracked at hourly intervals for 114 24-h periods at Donana National Park, southwestern Spain. Nine environmental factors were related, by season and age class, to 12 indices of daily activity of lynxes derived from movement rates and pulses of the motion sensor in the transmitters. Coefficients of determination were higher in winter and summer than in spring. Juvenile lynxes appeared more sensitive to environmental factors than adults. Photoperiod had a major influence ( R 2 = 29%) on circadian activity pattern throughout the year. Environmental factors significantly related to activity of lynxes during winter were maximum temperature, pressure changes, evaporation, and moonphase. In summer, important variables were maximum temperature, moonphase, hours with moonlight, and high pressures. In spring, only rainfall and temperature (minimum and maximum) showed a slight but significant influence on activity of lynxes. Although some climatological factors may have a direct effect on the circadian activity of Iberian lynx, others (e.g., moonlight) may act indirectly by influencing the activity of the Mediterranean rabbit, the lynxs main prey.

Physical characteristics of Iberian lynxes (Lynx pardinus) from Doñana, southwestern Spain

External and cranial measurements were determined for live-trapped Iberian lynxes and lynx skulls from Donana National Park, Spain, and its surroundings. Skins of Iberian lynxes from the same population collected between 1895 and 1986 were examined to determine pelage-pattern characteristics. Adult (≥2 years old) males were larger and heavier (27.3%) than adult females. Age-classes were statistically different for most skull measurements. Considerable variation was found between juveniles (0.5–1 year old) and subadults (1–2 years old). In 10 of the 19 skull measurements, adult males were significantly larger than adult females, including length of ml, mandibular fossa—length of P4, height of mandible, length of skull, and condylobasal length. Iberian lynxes were similar in size to the Nearctic bobcat ( L. rufus ) and the Canadian lynx ( L. canadensis ). Three main pelage patterns were present in the Donana population until 1960. Genetic variation of this population may have decreased during the past 3 decades as exemplified by the loss of the two rarest pelage patterns.

Energy expenditure and prey requirements of free-ranging Iberian lynx in southwestern Spain

We developed an additive model to estimate seasonal energy expenditure of nonreproductive, free-ranging Iberian lynx (Felis pardina) at Donana National Park in southwestern Spain. We considered only resting, locomotion, hunting, and eating costs. Data for the model were provided by radiomonitoring an adult male (15.4 kg) and an adult female (9.95 kg) in 24-hour samples (n=53) between 1983 and 1985. Average daily energy expenditure was 912 kcal for the male and 673 kcal for the female, with greater seasonal variation in the male. Based on the energy content of the lynxs staple prey, the European rabbit (Oryctolagus coniculus), we estimated the prey requirements of this endangered felid as about 1 rabbit per day

IMMOBILIZATION OF OCELOTS AND BOBCATS WITH KETAMINE HYDROCHLORIDE AND XYLAZINE HYDROCHLORIDE

We immobilized 10 ocelots (Felis pardalis), and 21 bobcats (F. rufus) in south Texas (USA) during March to November 1991 with a mixture of ketamine hydrochloride (KH) and xylazine hydrochloride (XH); two ocelots were immobilized twice. Species were immobilized with (mean ± SE) 14.7 ± 1.6 mg KH/kg body mass for ocelots, 13.3 ± 1.8 mg KH/kg for bobcats, and 1.1 ± 0.1 mg XH/kg and 1.2 ± 0.1 mg XH/kg for ocelots and bobcats, respectively. Immobilization times in bobcats were longer (P = 0.08) than in ocelots. Adult female ocelots (18.5 ± 2.6 mg/kg) needed larger (P < 0.05) doses of KH than adult males (12.0 ± 1.7 mg/kg). Bobcats were immobilized during summer with lower initial (8.6 ± 0.9 mg/kg, P < 0.001) and total (10.1 ±1.3 mg/kg, P = 0.02) doses of KH than bobcats immobilized in winter (14.5 ± 1.0 mg/kg, and 18.5 ± 3.8 mg/kg, respectively); summer immobilization times (44.3 ± 3.8 min) were also shorter (P = 0.03) than during winter (59.1 ± 5.2 min). Bobcats immobilized during summer had lower (P < 0.01) initial rectal temperatures (39.4 ± 0.2 C) than bobcats trapped in winter (41.1 ± 0.4 C). Overall, we observed no effects of KH-XH dose on body temperature.

Sex and age-class differences in calls of Iberian red deer during the rut: reversed sex dimorphism of pitch and contrasting roars from farmed and wild stags

Stag rutting calls differ among subspecies of red deer Cervus elaphus. Studying sex-, age-, and subspecies-related vocal variation may highlight the forces driving this evolution. This study presents the first bioacoustical comparison of oral calls produced during the rut by Iberian red deer Cervus elaphus hispanicus stags, hinds and calves and compares the acoustics of nasal and oral calls of hinds and calves. Also, it provides the first comparison of rutting roars between farmed and wild stags. Call maximum and mean fundamental frequencies (f0max and f0mean) were higher in farmed than in wild stags. Moreover, hinds had lower f0max and f0mean compared with both farmed and wild stags. The call minimum fundamental frequency (f0min) was indistinguishable between all groups of adults, irrespective of sex, farming and nasal versus oral vocal emission. In calves, but not in hinds, oral calls had higher f0max and f0mean compared with nasal calls. The higher fundamental frequencies in farmed as compared with wild stags may have resulted from emotional arousal due to human presence at recordings or from the higher body conditions of stags reared under a farm. The comparison of our results with previously published data on various subspecies of red deer suggests that there are different pathways of vocal ontogeny in eastern and western branches of Cervus elaphus and that the acoustics of stag and hind calls are more similar within the various subspecies than they are among the subspecies.

IMMOBILIZATION OF THE ENDANGERED IBERIAN LYNX WITH XYLAZINE- AND KETAMINE-HYDROCHLORIDE

A combination of the dissociative anesthetic ketamine hydrochloride (KH) and the sedative xylazine hydrochloride (XH) was used to immobilize 31 wild Iberian lynx (Felis pardina) 45 times at Doñana National Park, Spain. A mean (±SE) dose of 4.6 (±0.2) mg/kg KH and 4.0 (±0.2) mg/kg XH resulted in mean (±SE) induction time of 5.6 (±0.3) min and mean (±SE) first reaction time of 59.3 (±6.5) min. Convulsions occurred four times (9%), but with no noteworthy consequences.

Tolerância e sensibilidade térmica em anfíbios.

We are currently living in a scenario of climate change in which the rise of the average environmental temperatures and the increase of events of extreme temperature peaks is forecasted, among others. The study of the thermal tolerance and sensitivity is very important, particularly in amphibians, when forecasting the impact of rising temperatures on both the fauna and flora of the world. Knowing that amphibians are an essential part of the world’s terrestrial and aquatic biodiversity, and that they possess a series of ecophysiological characteristics and life history traits, which makes them very susceptible to environmental changes, it is essential to identify the species/communities that are more vulnerable to global warming.

Immobilization of Coypus (Myocastor coypus) with Ketamine Hydrochloride and Xylazine Hydrochloride

A combination of 100 mg/ml of ketamine hydrochloride (Ket) and 20 mg/ml of xylazine hydrochloride (Xyl) was used to immobilize coypus (Myocastor coypus). Eight mature coypus (four males and four females) were injected intramuscularly with doses ranging from 2.33 to 6.25 mg/kg of KET and 0.25 to 0.86 mg/kg of Xyl. The mean (±SE) time for induction, arousal, and recovery were 7.3 ± 2 min, 23.5 ± 0.3 min and 46 ± 2.5 min, respectively. The mean ± SE doses injected were 4.07 ± 0.52 mg/kg Ket (range, 2.33 to 6.25 mg/kg) and 0.5 ± 0.08 mg/kg Xyl (range, 0.25 to 0.86 mg/kg). No adverse responses were observed in any of the animals treated.

Effects of temperature on the song parameters of the Moroccan bushcricket Eugaster spinulosa (Orthoptera, Tettigoniidae)

Acoustic signals are important for inter- and intraspecific interactions in many species. Their information potential depends largely on species characteristics. Here we describe quantitatively the song of Eugaster spinulosa (Johannson 1763), (Orthoptera, Tettigoniidae) and analyse the relationships of song parameters with temperature. To the best of our knowledge there are no previous descriptions available of the song of any species in the genus. Songs of seven males from the mountains of Jebilet, Marrakech (Morocco), were recorded in a semi-anechoic chamber for 105 days. Using automated thermal tables, individuals were exposed to a daily cycle of temperatures between 17.5 and 41.5°C. The calling song of Eugaster spinulosa is broader in frequency (2–28 kHz) than the song of other tettigoniids. It consists of extended series of separately audible echemes, which are polysyllabic and comprise a variable number of broadband syllables, usually between 5 and 10. The stridulatory activity of Eugaster spinulosa showed a wide thermal plasticity (ranging over 24°C between thermal thresholds). In addition to changes in temporal features, we found that an increase in temperature reduced the number of syllables per echeme.