Survival, age estimation and sexual maturity of pouch young of the brush-tailed bettong (Bettongia penicillata) in captivity

2015 ◽  
Vol 37 (1) ◽  
pp. 29 ◽  
Author(s):  
Craig K. Thompson ◽  
Adrian F. Wayne ◽  
Stephanie S. Godfrey ◽  
R. C. Andrew Thompson

The brush-tailed bettong or woylie (Bettongia penicillata) is a continuous and rapid breeder. However, research investigating the monthly survival and development of young woylies from parturition to parental independence is incomplete. The reproductive biology of eight female woylies was observed for 22 consecutive months within a purpose-built enclosure. Adult female woylies bred continuously and were observed caring for a dependant young 96% of the time. Pouch life of the young was ~102 days, with sexual maturity of female offspring reached as early as 122 days post partum. Crown–rump measurement was an accurate predictor of age for young restricted to the pouch, while skeletal morphometrics were a better predictor of age for ejected pouch young, young-at-foot and subadults. A four-month period between May and August of each study year accounted for 85% of pouch young mortality and 61% of pouch young births where the neonate went on to survive to subadult age. Here we discuss the possibility that pouch young born during the cooler, wetter months of May to August may have an increased chance of survival in the wild, resulting from an increased maternal investment being directed towards the rearing of ‘fitter’ progeny.

1994 ◽  
Vol 21 (5) ◽  
pp. 553 ◽  
Author(s):  
PM Johnson ◽  
K Vernes

The reproduction of Thylogale stigmatica in captivity was studied and a predictive growth equation for age determination of the pouch young was developed. The general pattern of reproduction involved an oestrous cycle of 29-32 days, a gestation period of 28-30 days and a mean pouch life of 184 days. A post-partum oestrus and mating generally followed birth. Births were observed in all months in captivity, and from October to June in the wild. Mean age of weaning of young was 66 days following permanent pouch emergence, and the mean ages at maturity for females and males was 341 and 466 days, respectively.


1998 ◽  
Vol 25 (6) ◽  
pp. 635 ◽  
Author(s):  
P. M. Johnson

Reproduction of the whiptail wallaby, Macropus parryi, was studied in captivity. The mean length of the oestrous cycle was 41.8 days while the mean length of the gestation period was 38.0 days. M. parryi bred throughout the year and post-partum oestrus was not recorded although mating did occur during the pouch life when the pouch-young was 118–168 days of age. The length of the pouch-life was 256–267 days and weaning occurred 104–215 days after emergence from the pouch. Sexual maturity for females occurred at 509–647 days of age. An age-determination table was produced and found useful for predicting age of pouch-young using body measurements.


1995 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
R.T. Gemmell

The brushtail possum is a common arboreal marsupial that is well adapted to the Australian urban environment and to rearing in captivity. Data obtained from 100 female possums housed in a semi-captive colony over a 7 year period demonstrate the reproductive capability of this marsupial. The main breeding season is from March to June with a declining number of births occurring from July to October. The possums gave birth to 259 single young and one set of twins. The range of the lactation period was from 177 to 200 days with the birth of the subsequent young occurring at 188.4 ± 4.1 days post partum (SD, n = 5). The growth rate of the young female possum varied greatly after day 100 post partum, the mean body weight of possums at day 172, being 753.0 ± 76.2g (SD, n = 5) with a range of 685 to 851 g. Female possums, with a mean body weight of 2171 ± 388g, gave birth to their first litter on day 345.9 ± 69.3 days postpartum (mean, SD, n = 7). Although two female possums trapped in the wild were held in captivity for 64 and 63.4 months and one possum bred in captivity had a life span of 51.5 months, the mean life span was 21.0 ± 12.5 months (SD, n =3D 8), with a range of 14.3 to 51.5 months. This life span is very variable and it is of interest to determine if this is an artefact of captivity or is also observed in the wild.


1976 ◽  
Vol 3 (2) ◽  
pp. 93 ◽  
Author(s):  
JC Merchant

Female agile wallabies in captivity reached sexual maturity at about 12 months old and males produced mature spermatozoa by 14 months. Breeding was continuous throughout the year and birth and oestrus were recorded in every month. The mean length of the oestrous cycle was 32.4 days, and the mean gestation period 29.4 days. Females exhibited post-partum oestrus, usually mating within 1 day of birth. Sixty-four young born in captivity comprised 24 males, 30 females and 10 of unknown sex. If a pouch young were removed or lost, the quiescent blastocyst resumed its development, to birth about 26.5 days later. Failure or absence of the blastocyst was followed by an oestrus at about the time of the corresponding post-partum oestrus. Both the oestrous cycle and the interval between removal of a pouch young and oestrus were significantly longer than when a pregnancy intervened. The oestrous cycle was characterized by changes in the proportions of the main cell types in the vaginal smear, and by changes in the appearance of the urogenital opening and the pouch and teats. The approach of oestrus could not be predicted from vaginal smears but the post-oestrous condition was always recognizable even without mating. Young animals first left the pouch for short periods between the ages of 176 and 211 days, and left permanently between 207 and 237 days. Animals of known age were measured and the development of various morphological characters noted at weekly intervals from about birth until 12 months old.


2000 ◽  
Vol 22 (1) ◽  
pp. 35 ◽  
Author(s):  
RE Woods ◽  
FD Ford

This study examined aspects of behaviour in a captive colony of smoky mice, Pseudomys fumeus, over a two year period. Wherever possible behaviours observed in the captive population are compared to data collected in a study of a wild population in south-eastern New South Wales. This paper provides the first recorded observations of behavior in this species. Both captive and wild populations of P. fumeus display strictly nocturnal circadian activity rhythms. In the captive study, P. fumeus were found to exhibit social interactions similar to some previously studied Pseudomys species. However, in the wild, the species was found to communally nest during the breeding season, behaviour not observed in other Pseudomys from similar habitats. P. fumeus in captivity can have more than two litters in one breeding season which suggests that their reproductive parameters are more flexible than previous studies of wild populations have shown. Field data indicate that post-partum oestrus can occur in this species, and that gestation lasts for approximately 30 days, although these observations are based on a small sample.


1973 ◽  
Vol 21 (3) ◽  
pp. 331 ◽  
Author(s):  
GM Maynes

Female M. parma in captivity reach sexual maturity at 11 1/2-16 months of age. Scrota1 size indicates that sexual maturity is attained in males at about 22 months. One male had spermatozoa at 19-20 months and another had a first fertile mating at 24-25 months. Mating behaviour is described and resembles that of other small macropodids. M. parma is monovular and polyoestrous. The oestrous cycle has a mean length of 4197810.72 days (n = 58; range 36-59 days) while the gestation period is 34.54*0.13 days (n = 28; range 33-36 days). Post-partum oestrus and mating occurred from 4 to 13 days after birth in a small proportion (16.7%) of those animals examined. However, most animals had an oestrus, while carrying a pouch young, between 45 and 105 days after birth. A few animals did not come into oestrus at all while carrying a pouch young. Removal of pouch young typically resulted in return to oestrus between 6 and 15 days later, in females that had not had a post-partum oestrus or an oestrus while carrying a pouch young. Females which mated at some stage during lactation prior to removal of pouch young gave birth 31.16 days later (n = 3; range 30.5-32.0 days). Three females at the Melbourne Zoo had estimated delayed gestation periods of 31, 31, and 32 days. The earliest observation of a young with its head out of the pouch was at 146 days of pouch life. Most young had left the pouch for short intervals by 175 days with the youngest observed out at 160 days. Young permanently leave the pouch at 211.9+-1.0 days (n = 10; range 207-218 days). Permanent exchange of pouch young has been observed in two cases, both at approximately the time young were first leaving the pouch for short intervals. Some females that mated while carrying a young in the pouch gave birth 6-11 days after permanent pouch exit of the primary young. Unmated females returned to oestrus 12-24 days after permanent pouch exit of their young. Young were weaned at 2 5 3 ) months after pouch exit. Most females entered anoestrus in 1968 following transfer of the animals into small holding pens. In 1969 only 5 of 24 matings resulted in young in the pouch, while in 1970 the corresponding figure was 21 of 44 matings. In both years there was evidence of young being born but apparently being lost during the climb from the urogenital opening to the pouch, probably because of overcrowding of the mothers. Evolution of embryonic diapause is discussed in relation to the reproductive pattern established for M. pavma. It is postulated that embryonic diapause first arose at the end of pouch life and has come to occupy the entire length of pouch life in most macropodids.


1987 ◽  
Vol 14 (3) ◽  
pp. 225 ◽  
Author(s):  
WE Poole ◽  
JC Merchant

Wallaroos were bred in captivity during almost 20 years. Individual males attained sexual maturity at between 18 and 20 months old and females at between 14 and 24 months old; both sexes were capable of breeding throughout the year. Gestation was 30-38 d and extended almost the full length of the oestrous cycle, 31-46 d. Post-partum mating usually produced a blastocyst subject to lactational quiescence. Removal or loss of a pouch young usually resulted in birth 28-32 d later but up to 41 d later in the presence of an actively suckled young-at-foot. Pouch life ranged between 231 and 270 d, with vacation of the pouch usually followed by another birth 1-14 d later. Lactation exceeded 12-14 months but suckling had waned by 15-17 months. Reproductive patterns for M. r. robustus and M. r. erubescens were similar although significant differences between the subspecies were recorded in length of oestrous cycle, the interval from loss of pouch young to birth and post-partum oestrus, the length of pouch life and the time between vacation of the pouch and birth. In addition, the reproductive activity of hybrids produced by matings between the subspecies was observed, as was that of a limited number of M. antilopinus.


1979 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
PM Johnson

'Reproduction in the plain rock-wallaby was studied in captivity. The oestrous cycle ranged from 30.2 to 32.0 days and the gestation period from 30.0 to 32.0 days. A post-partum mating usually followed birth; the resultant quiescent embryo developed and was born 28-30 days after premature removal of pouch young. The pouch life of the young ranged from 189 to 227 days, males and females maturing sexually at approximately 590 and 540 days respectively. Tail and hind foot lengths were found to be useful indicators of age of young up to the end of pouch life.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marina B. Blanco ◽  
Lydia K. Greene ◽  
Robert Schopler ◽  
Cathy V. Williams ◽  
Danielle Lynch ◽  
...  

AbstractIn nature, photoperiod signals environmental seasonality and is a strong selective “zeitgeber” that synchronizes biological rhythms. For animals facing seasonal environmental challenges and energetic bottlenecks, daily torpor and hibernation are two metabolic strategies that can save energy. In the wild, the dwarf lemurs of Madagascar are obligate hibernators, hibernating between 3 and 7 months a year. In captivity, however, dwarf lemurs generally express torpor for periods far shorter than the hibernation season in Madagascar. We investigated whether fat-tailed dwarf lemurs (Cheirogaleus medius) housed at the Duke Lemur Center (DLC) could hibernate, by subjecting 8 individuals to husbandry conditions more in accord with those in Madagascar, including alternating photoperiods, low ambient temperatures, and food restriction. All dwarf lemurs displayed daily and multiday torpor bouts, including bouts lasting ~ 11 days. Ambient temperature was the greatest predictor of torpor bout duration, and food ingestion and night length also played a role. Unlike their wild counterparts, who rarely leave their hibernacula and do not feed during hibernation, DLC dwarf lemurs sporadically moved and ate. While demonstrating that captive dwarf lemurs are physiologically capable of hibernation, we argue that facilitating their hibernation serves both husbandry and research goals: first, it enables lemurs to express the biphasic phenotypes (fattening and fat depletion) that are characteristic of their wild conspecifics; second, by “renaturalizing” dwarf lemurs in captivity, they will emerge a better model for understanding both metabolic extremes in primates generally and metabolic disorders in humans specifically.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Swetlana G. Meshcheryagina ◽  
Alexey Opaev

Abstract Background In the last decade, enigmatic male-like cuckoo calls have been reported several times in East Asia. These calls exhibited a combination of vocal traits of both Oriental Cuckoo (Cuculus optatus) and Common Cuckoo (Cuculus canorus) advertising calls, and some authors therefore suggested that the enigmatic calls were produced by either Common × Oriental Cuckoo male hybrids or Common Cuckoo males having a gene mutation. However, the exact identity of calling birds are still unknown. Methods We recorded previously unknown male-like calls from three captive Oriental Cuckoo females, and compared these calls with enigmatic vocalizations recorded in the wild as well as with advertising vocalizations of Common and Oriental Cuckoo males. To achieve this, we measured calls automatically. Besides, we video-recorded captive female emitting male-like calls, and compared these recordings with the YouTube recordings of calling males of both Common and Oriental Cuckoos to get insight into the mechanism of call production. Results The analysis showed that female male-like calls recorded in captivity were similar to enigmatic calls recorded in the wild. Therefore, Oriental Cuckoo females might produce the latter calls. Two features of these female calls appeared to be unusual among birds. First, females produced male-like calls at the time of spring and autumn migratory activity and on migration in the wild. Because of this, functional significance of this call remained puzzling. Secondly, the male-like female call unexpectedly combined features of both closed-mouth (closed beak and simultaneous inflation of the ‘throat sac’) and open-mouth (prominent harmonic spectrum and the maximum neck extension observed at the beginning of a sound) vocal behaviors. Conclusions The Cuculus vocalizations outside the reproductive season remain poorly understood. Here, we found for the first time that Oriental Cuckoo females can produce male-like calls in that time. Because of its rarity, this call might be an atavism. Indeed, female male-like vocalizations are still known in non-parasitic tropical and apparently more basal cuckoos only. Therefore, our findings may shed light on the evolution of vocal communication in avian brood parasites.


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