Domestic queens under natural temperate photoperiod do not manifest seasonal anestrus

Domestic cat seasonality between the tropics and the arctic zones is scarcely described and results are inconsistent. The aim of this study was to describe domestic feline seasonal patterns under a natural temperate photoperiod. A total of 372 estrous cycles were studied in 34 post pubertal cats during 900 days. The queens were housed in a cat colony (31°25' South Latitude, 64°11' West Longitude), acclimated under natural photoperiod and daily observed for reproductive behavior. Vaginal cytology was conducted three times a week. For each cat the number of estrous cycles and days in estrus per month for each year were recorded. The months of the year were grouped in four periods of 3 months each according to day length and photoperiod. Comparisons of estrous days among periods were performed by ANOVA for repeated measures. All the cats had estrous cycles throughout the year without intervals of anestrus. Mean number of estrous days differed among the periods (P<0.01), those of long day length and ascending photoperiod being greater (12.5±0.6) to those of descending photoperiod either with long (8.9±0.7) or short (9.3±0.7) days. When the two periods with ascending day lengths were merged and compared to the two periods with descending day lengths merged, the number of estrous days were greater when day length ascended (P<0.01). Nearly 60% of the estrous cycles occurred during the periods of ascending day length. It is concluded, that domestic cats under natural temperate photoperiod have estrous cycles throughout the year showing peak activity the months with increasing photoperiod.     

Predation by domestic cats in an English village

We studied predation by approximately 70 domestic cats ( Felis catus L.) in the Bedfordshire village of Felmersham over a one-year period. All the prey items brought home by virtually all the cats in the village were recorded and, where possible, identified. A total of 1090 prey items (535 mammals, 297 birds and 258 unidentified animals) were taken, an average of about 14 per cat per year. Twenty two species of birds and 15 species of mammals were identified. The most important items were woodmice (17%), house sparrows (16%) and bank voles (14%).
Old cats of both sexes caught fewer prey over the year than young cats. Female cats on the edge of the village also caught more prey than female cats in intermediate or central areas of the village; male cats showed no such effect. The type of prey caught also varied with position in the village; 'core' cats caught proportionately more birds than 'edge' cats. There was some indication in the data that cats caught fewer prey in areas where cat density was highest, but this effect was impossible to disentangle from position in the village. Weather apparently influenced hunting success. Temperature had no direct influence, but fewer prey were caught in winter; cats also caught less on wet days and windy days.
Estimates of the number of house sparrows in the village at the start of the breeding season, and the number of sparrows known to have been caught by the cats, suggest that at least 30% of the sparrow deaths in the village were due to cats. Domestic cats would appear to be major predators in this typical English village.     

Feral cat diet and impact on sooty terns at Juan de Nova Island, Mozambique Channel

Feral cat Felis catus predation on seabirds has been well documented; however, details regarding shifts in feral cat diet in relation to seabird availability, seabird predation rate and impact on seabird population dynamics are scarce. Here, we present data documenting a seasonal shift in feral cat diet at Juan de Nova Island, Mozambique Channel. We also quantify sooty tern Sterna fuscata predation by feral cats and examine the impact on sooty terns over both the short term (by removing individual cats from sub-colonies) and over the longer term by highlighting their influence on population growth rate ( λ ) using a deterministic matrix model. Cat diet shifted dramatically from insects, rats and mice outside the tern breeding season to primarily terns when terns were breeding. The predation rate of sooty terns at Juan de Nova was estimated at 5.94 terns cat⁻¹ day⁻¹, with a proportion of these (22%) being killed without being consumed ('surplus kills'). When only one cat was removed from each sub-colony, tern predation declined tenfold in the short term. From our matrix model, the annual growth rate for sooty terns was 1.01 in the absence of cat predation. It remained above one until a predation impact equivalent to approximately three times the estimated cat density (12.04 per km²) was incorporated. Our results demonstrate that cats preferentially predate and have an impact on breeding sooty terns at Juan de Nova, and that an increase in cat density could lead to negative effects on population growth, despite the large breeding tern population.     

Responses of pet cats to being held by an unfamiliar person,from weaning to three years of age

Abstract

We have determined the extent to which individual responses of domestic cats on being handled by an unfamiliar person are stable between 2 and 33 months of age. Twenty-nine household cats from nine litters were tested at 2, 4, 12, 24 and 33 months of age, by being held for 1 minute by a standard, unfamiliar person. Between 4 and 33 months of age, individual differences in the number of attempts made by the cat to escape, and in whether or not it showed signs of distress, were stable, with the partial exception of the test at 12 months. There was no consistency between tests in whether or not a particular cat purred. At 2 months of age, the number of escape attempts was highest in cats which had been handled the least in the second month of life, but this trend was reversed in the number of escape attempts made at 4 months. The lack of distress exhibited by all cats in the test at 2 months indicated that all had received at least adequate socialization to people, and that none were therefore comparable with the unsocialized cats used in several previous studies. We conclude that under normal domestic conditions, the behavior of a cat when handled by an unfamiliar person reflects a stable character trait, and that extensive handling during the socialization period may be subsequently associated with a reduction in inhibited behavior when interacting with an unfamiliar person.     

Incidence of pyometra in Swedish insured cats

Pyometra is a clinically relevant problem in intact female cats and dogs. The etiology is similar in both animal species, with the disease caused by bacterial infection of a progesterone-sensitized uterus. Here, we studied pyometra in cats with the aim to describe the incidence and probability of developing pyometra based on age and breed. The data used were reimbursed claims for veterinary care insurance or life insurance claims or both in cats insured in a Swedish insurance database from 1999 to 2006. The mean incidence rate (IR) for pyometra was about 17 cats per 10,000 cat years at risk (CYAR). Cats with pyometra were diagnosed at a median age of 4 years and a significant breed effect was observed. The breed with the highest IR (433 cats per 10,000 CYAR) was the Sphynx, and other breeds with IR over 60 cats per 10,000 CYAR were Siberian cat, Ocicat, Korat, Siamese, Ragdoll, Maine coon, and Bengal. Pyometra was more commonly diagnosed with increasing age, with a marked increase in cats older than 7 years. The mean case fatality rate in all cats was 5.7%, which is slightly higher than corresponding reports in dogs of 3% to 4%. Geographical location (urban or rural) did not affect the risk of developing the disease. The present study provides information of incidence and probability of developing pyometra based on age, breed, and urban or rural geographical location. These data may be useful for designing cat breeding programs in high-risk breeds and for future studies of the genetic background of the disease.     

Lynx reproduction – Long-lasting life cycle of corpora lutea in a feline species

A review of lynxes’ reproductive biology and comparison between the reproductive cycles of the domestic cat and lynxes is presented. Three of the four lynx species (the bobcat excluded) express quite similar reproductive pattern (age at sexual maturity, estrus and pregnancy length, litter size). Similarly to the domestic cat, the bobcat is polyestric and can have more than one litter per year. Domestic cats and many other felid species are known to express anovulatory, pregnant and pseudo-pregnant reproductive cycles in dependence on ovulation induction and fertilization. The formation of corpora lutea (CLs) occurs after ovulation. In pregnant animals, luteal function ends with parturition, whereas during pseudo-pregnancy a shorter life span and lower hormone secretion are observed. The life cycle of corpora lutea in Eurasian lynxes is different from the pattern described in domestic cats. Lynx CLs produce progestagens in distinctive amounts permanently for at least two years, regardless of their origin (pregnancy or pseudo-pregnancy). It is suggested that long-lasting CLs induce a negative feedback to inactivate folliculogenesis, turning a normally polyestric cycle observed in most felids into a monoestric cycle in lynxes.     

Survey of zona pellucida antigens for immunocontraception of cats

The purpose of this study was to screen a panel of native zona pellucida (ZP) antigens isolated from five mammalian species for immunocontraceptive activity in the cat (Felis catus). Native soluble-isolated ZP (SIZP) was prepared from the ovaries of cows (bZP), cats (fZP), ferrets (feZP), dogs (cZP), and mink (mZP). Vaccines were constructed using SIZP from each of the above species encapsulated in liposomes suspended in saline and emulsified with Freund's complete adjuvant (SpayVac). Female cats were immunized once (n = 3 cats per group). Serum was collected for determination of antibody titers against SIZP and for binding of antibodies to feline ovaries. All cats responded to immunization by producing anti-SIZP antibodies. The most immunogenic SIZP in cats was from mink, followed by feZP, cZP, and fZP in descending order. Antibodies had low reactivity for fZP, and no reactivity against feline ovaries was detected by immunohistochemistry. A breeding trial was commenced 20 weeks after immunization. All cats became pregnant, averaging 4.1 +/- 0.7 viable kittens per litter. We have previously shown that porcine SIZP is not an effective antigen for immunocontraception of cats. In this study, SIZP from five other mammalian species were immunogenic in the cat, but ZP antibodies failed to bind to fZP in situ, and fertility was not impeded.     

Urban Cats: Their Demography,Population Density,and Owner Characteristics in Baltimore,Maryland

Abstract

A door-to-door questionnaire survey of 430 households in two areas of Baltimore showed significant differences in cat ownership that were attributable to racial composition. Overall, 29.9% of white households owned a mean of 1.9 cats per cat-owning household, compared to 6.8% of black households owning a mean of 1.0 cat per cat-owning household. The mean age of cats was 3.9 yrs and 1.8 yrs in white and black households, respectively. In contrast, dog ownership in the two areas was nearly identical, with 25.6% of white and 29.1% of black households owning a mean of 1.5 and 1.3 dogs per dog-owning household, respectively. Overall, 62.8% of owned cats were spayed/neutered, 51.8% had received a vaccination in the last year, and 34.7% had been wormed during their lifetimes. A total of 31.6% of households allowed their cats to free-range; 42.5% of the 87 owned cats were in this category. The estimated densities of owned free-ranging cats were 7.0 and 2.8 cats per hectare, for the two areas. Driving counts of free-ranging animals in the two areas suggested a larger population of stray or feral cats in the location with lower reported cat ownership.     

BIDIRECTIONAL SHIFTS IN COLONY QUEEN NUMBER IN A SOCIALLY POLYMORPHIC ANT POPULATION

The breeding system of social organisms affects many important aspects of social life. Some species vary greatly in the number of breeders per group, but the mechanisms and selective pressures contributing to the maintenance of this polymorphism in social structure remain poorly understood. Here, we take advantage of a genetic dataset that spans 15 years to investigate the dynamics of colony queen number within a socially polymorphic ant species. Our study population of Formica selysi has single‐ and multiple‐queen colonies. We found that the social structure of this species is somewhat flexible: on average, each year 3.2% of the single‐queen colonies became polygynous, and conversely 1.4% of the multiple‐queen colonies became monogynous. The annualized queen replacement rates were 10.3% and 11.9% for single‐ and multiple‐queen colonies, respectively. New queens were often but not always related to previous colony members. At the population level, the social polymorphism appeared stable. There was no genetic differentiation between single‐ and multiple‐queen colonies at eight microsatellite loci, suggesting ongoing gene flow between social forms. Overall, the regular and bidirectional changes in queen number indicate that social structure is a labile trait in F. selysi, with neither form being favored within a time‐frame of 15 years.     

How can the Yelkouan shearwater survive feral cat predation? A meta-population structure as a solution?

The Yelkouan shearwater, Puffinus yelkouan, is an endangered Mediterranean endemic species of burrowing petrel threatened by feral cats. The life-history parameters of a small population of Yelkouan shearwaters on the Mediterranean island, Port-Cros, were studied in conjunction with the diet of feral cats, to examine the birds’ vulnerability to introduced cats. Yelkouan shearwaters were the birds most frequently found in cat scats, with 431 ± 72 birds killed per year, and predation highest during the pre-laying period. A demographic model was created using data for P. yelkouan and for closely related shearwater species. Without cat predation, only two of four survival rate scenarios led to a mean growth rate (λ) ≥ 1. The model was constrained to have a stable population growth rate and used to predict predation scenarios compatible with the observed population stability, because the population under study has remained stable at around 180 pairs for at least 20 years despite feral cat predation. The results of assuming that the population is closed were inconsistent with the estimated mortalities due to feral cats, while it was possible to reconcile the observed numbers of breeding pairs with the observed mortalities due to cats by assuming that Port-Cros Island is a sink sustained by immigration. This illustrates that small colonies may need to be sustained by larger ones to avoid being driven to extinction. Unfortunately, the absence of a large geographic-scale ringing program makes the precise identification of the origin of the immigrants impossible in this case.     

Maternal-Neonatal Pheromone/Interomone Added to Cat Litter Improves Litter Box Use and Reduces Aggression in Pair-Housed Cats

Introducing a new cat into a household with one or more resident cats can be a significant source of stress for the cats involved. These studies sought to determine if rabbit maternal-neonatal pheromone (2-methyl-2-butenal [2M2B]) in litter impacted cat social behaviors and litter box use. Study 1 determined that cats preferred to eliminate in litter containing 2M2B; other semiochemicals tested did not change litter box use. Cats prone to aggression were identified in an intermediate pilot study, and eight pairs of these cats were selected for Study 2. In Study 2, cat pairs were provided litter containing either vehicle or 2M2B for 24 hours. Cats experiencing control litter displayed more aggression during the first 6 hours (p < .01) and spent more time using the litter box 12 hours and 18 hours after pairing compared with cats experiencing litter with 2M2B (p = .02). These results suggest 2M2B-infused cat litter may act as an interomone in cats housed domestically to prevent initial occurrences of aggression and may improve cat welfare in multicat households.     

Queen recruitment and split sex ratios in polygynous colonies of the ant Formica exsecta

Sex ratios in social insects have become a general model for tests of inclusive fitness theory, sex ratio theory and parent–offspring conflict. In populations of Formica exsecta with multiple queens per colony , sex ratios vary greatly among colonies and the dry-weight sex ratio is extremely male-biased, with 89% of the colonies producing males but no gynes (reproductive females). Here we test the queen-replenishment hypothesis, which was proposed to explain sex ratio specialization in this and other highly polygynous ants (i.e. those with many queens per nest). This hypothesis proposes that, in such ants, colonies produce gynes to recruit them back into the colony when the number of resident queens falls below a given threshold limiting colony productivity or survival. We tested predictions of the queen-replenishment hypothesis by following F. exsecta colonies across two breeding seasons and relating the change in effective queen number with changes in sex ratio, colony size and brood production. As predicted by the queen-replenishment hypothesis, we found that colonies that specialized in producing females increased their effective queen number and were significantly more likely to specialize in male production the following year. The switch to male production also coincided with a drop in productivity per queen as predicted. However, adoption of new queens did not result in a significant increase in total colony productivity the following year. We suggest that this is because queen production comes at the expense of worker production and thus queen production leads to resource limitation the following year, buffering the effect of greater queen number on total productivity.     

Seasonality and reproduction in wild-living cats in Scotland

The definition of the wildcatFelis silvestris Schreber, 1775 in Scotland is contentious, in light of long-term interbreeding with domestic catsF. catus Linnaeus, 1758. Two morphological groupings (Group 1 and Group 2) have previously been proposed to explain the variation found in wild-living cats in Scotland, with Group 1 cats closest to wildcats and Group 2 cats to domestic cats. Data from the reproductive tracts of 185 wild-living cat carcasses and evidence of reproductive activity in 31 live cats were analysed in order to compare reproductive activity between the morphological groups, and in relation to seasonality and existing data on wildcats and domestic cats. For males, Group 2 cats had a greater mean relative testes size than Group 1 cats. Estimated from corpora lutea, there was a suggestion that Group 1 females showed more seasonality in oestrous than Group 2 cats. In all wild-living cats, the mean litter size was 4.3 and estimated birth dates were throughout the year, but least in winter. A high number of pseudopregnancies were recorded. The results were consistent with the hypothesis that Group 2 cats are closer to domestic cats. However, the variation observed in the sample of wild-living cats reported here, suggested that reproduction was neither strictly seasonal nor outside the range observed in some feral cat populations.     

Breeding replacement gilts for organic pig herds

In this study, breeding structures and commercial sow lines were evaluated by economic and genetic simulation studies for their suitability to provide the Dutch organic pig sector with replacement gilts. Sow and litter performance from over 2000 crossbred sows from 2006 to 2007 were collected on 11 to 14 Dutch organic pig herds, respectively, and compared with conventional herds. Results showed that organic herds had lower farrowing rates (3.6% to 7.5%), more live born piglets per litter (0.4% to 1.2%) and higher preweaning mortality rates (7% to 13%) compared to conventional herds. These results were used to simulate economic performance of various combinations of breeding structures and sow lines under organic conditions, under the assumption of absence of genotype-environment interactions. Sow and litter performance data under organic conditions (total piglets born/litter, stillborn piglets/litter, mortality until weaning, lactation length, interval weaning-oestrus and sow culling rate) and the costprice calculation for the Dutch organic pig sector were used as input for the economic simulation studies. The expected genetic progress was simulated for three potential breeding structures of the organic sector: organic breeding herds producing F1 gilts (OrgBS), a flower breeding system (FlowerBS) and a two-line rotation breeding system (RotBS). In FlowerBS, an organic purebred sow line is bred, using on-farm gilt replacement. The OrgBS with a Yorkshire × Landrace cross had the highest margin per sow place (€779), followed by RotBS with Yorkshire × Landrace cross (€706) and FlowerBS with Yorkshire sow line (€677). In case that an organic purebred sow population of 5000 sows would be available, FlowerBS gave the highest genetic progress in terms of cost price reduction (€3.72/slaughter pig per generation), followed by RotBS and OrgBS (€3.60/slaughter pig per generation). For FlowerBS, additional costs will be involved for maintaining a dedicated breeding programme. In conclusion, OrgBS using conventional genetics is economically the most viable option for the organic pig sector. However, this structure has clear disadvantages in terms of risks with regard to disease transmission and market demand. FlowerBS using a dedicated purebred organic line will only be cost-effective if sow population size is sufficiently large. RotBS might be a viable alternative, especially in combination with artificial insemination (AI) boars that are ranked according to an organic selection index. Regardless of breeding structure, the Yorkshire sow line gave the highest prolificacy and the highest economic returns on organic herds.     

Comparison of population numbers of yellow-eyed penguins,

During a comprehensive survey in 1999, 2000 and 2001, we investigated the number of breeding yellow-eyed penguin pairs on Stewart Island, where cats are present, and on adjacent cat-free islands. We found 79 pairs of yellow-eyed penguin breeding in 19 discrete locations on Stewart Island (4.2 pairs per location), and 99 pairs breeding in 10 discrete locations on all cat-free islands (9.9 pairs per location). Large-scale humaninduced habitat modifications have not occurred on Stewart Island, nor on any of its adjacent offshore islands. While the extensive coastline of Stewart Island (673 km) offers potentially large areas of breeding habitat for penguins, the highest number of breeding pairs were found on the smaller, predator-free Codfish Island (25 km coastline), where a total of 61 breeding pairs were recorded. On Stewart Island, where mustelids do not occur, only feral cats can pose a serious threat to penguin offspring. Results from this study suggest that feral cats may prey on yellow-eyed penguins on Stewart Island. Further work is necessary to investigate whether the observed low numbers of yellow-eyed penguins on Stewart Island are caused by feral cat predation. If so, it may be possible to develop appropriate measures to protect this penguin species from a population decline.     

Association between Feline Immunodeficiency Virus Antibodies and Host Characteristics in Finnish Cats

Toward the end of 1989 the largest private veterinary laboratory in Finland (Vet/lab) began using a commercial combined ELISA test for Feline Immunodeficiency Virus (FIV) antibodies and Feline Leukemia Virus (FeLV) antigens (Cite ComboR). The overall proportion of FIV seropositive feline samples was 5% during the 22 month study period. The number of tests performed increased slowly while the positive test results decreased with time (7% in 1990 and 4% in 1991). The decrease in prevalence was assumed to reflect a change in the sample population rather than an actual change in the general cat population. There were more symptomatic and domestic cats tested in 1990 than 1991. The lower-risk groups in the second year of the study may simply be an indication that the cat owners became more aware of FIV and the motivation to send samples switched from the veterinarian’s interest to diagnose the disease in a symptomatic cat to the owner’s interest to survey their cats for possible FIV infection. In a multivariable analysis, breed, symptoms, age and sex were associated with the risk of FIV seropositivity The risk increased faster with age in males than in females (i.e., the age effect was not constant between sexes). The cats with symptoms had a higher risk than those without symptoms and non-purebred cats were at a higher risk than purebred cats. FeLV infection was not associated with FIV.     

Questionnaire-based survey of parturition in the queen

The lack of scientific data concerning whether parturition in the queen proceeds normally or not may prevent veterinarians and cat owners from recognizing parturition problems in time. A questionnaire-based study of parturition in 197 queens was performed to determine several parameters of parturition and their influence on its progress. The mean length of gestation was 65.3 days (range 57 to 72 days) and it decreased with increasing litter size (P = 0.02). The median litter size was 4.5 kittens (range 1 to 9), with more males (53%) than females (46%) (P = 0.05). Sixty-nine percent of the kittens were born in anterior presentation and 31% in posterior presentation, indicating that either can be considered normal in the cat. Males were born in posterior position (34%) more often than females (26%) (P = 0.03). The mean birth weight was 98 g (range of 35 to 167 g) and decreased with increasing litter size (P < 0.01). Mean birth weight was higher in males and kittens born in posterior presentation (P < 0.01). Forty-four (5%) of the 887 kittens were stillborn. This was not correlated with the presentation at expulsion but stillborn kittens were more often female (P = 0.02) and weighed less than those born alive (P = 0.04). The median interkitten time was 30 min (range 2 to 343 min) and 95% were born within 100 min after expulsion of the preceding kitten. The interkitten time as a measure of the progress of parturition was not influenced by the kitten's gender, presentation at expulsion, birth weight, or stillbirth, or by the parity of the queen. The results of this study can be used to develop reference values for parturition parameters in the queen, both to determine whether a given parturition is abnormal and as the basis for a parturition protocol.     

Diet of the feral cat,Felis catus,in central Australian grassland habitats: do cat attributes influence what they eat?

The house cat Felis catus was introduced to Australia as a pet and means of rodent control over 200 years ago, but now has established feral populations and has become a serious threat to native wildlife. Using stomach content analysis of 73 feral cats from semi-arid grassland habitats in Queensland, Australia, we aimed to identify dominant prey groups in the cats' diet and to explore associations between the diversity of prey eaten and attributes of the cats including body size, condition, sex, age and coat colour. We also sought to determine any relationships between cat size and the size of the dominant prey in the diet, the long-haired rat Rattus villosissimus. Mammals and reptiles were the dominant prey, with R. villosissimus occurring in 60 % of samples and comprising more than half of all prey by volume. Birds and terrestrial invertebrates were the next most important contributors to the diet, but fish, frogs and freshwater crustaceans also were surprisingly well represented. The dietary diversity of cats was largely unrelated to any of the cat attributes that we measured, although a positive relationship emerged between cat head width and the range of prey types eaten. Our study was conducted during a population irruption of R. villosissimus and confirms that cats are able to exploit an abundant focal prey resource when the opportunity occurs. Further research now is needed to explore associations between diet and cat attributes during periods when rats are scarce.     

Abundance and detection of feral cats decreases after severe fire on Kangaroo Island,Australia

Predation by feral cats (Felis catus) has caused the extinction of many native species in Australia and globally. There is growing evidence that the impacts of feral cats can be amplified in post-fire environments, as cats are drawn to hunt in or around recently burnt areas and are also more effective hunters in open habitats. In 2018–2019, we established arrays of camera traps to estimate the abundance of feral cats on Kangaroo Island, South Australia. Much of the island (including five of our seven survey sites) was subsequently burnt in a severe wildfire (December 2019–February 2020). We re-sampled the sites 3–8 months post-fire (seven sites) and 11–12 months post-fire (three sites). At two unburnt sites sampled post-fire, it was possible to produce density estimates of cats using a spatially explicit capture–recapture approach. Where estimating density was not possible (due to low detections or individual cats not being distinguishable), the number of individuals and percentage of trap nights with detections was compared between the sampling periods. Some low-level cat control occurred within 2 km of three of the seven arrays (all within the burn scar) within 3 months of the fire. Across the five burnt sites, there was a decline in cat detections post-fire (including those without post-fire cat control). At 3–8 months post-fire, there was, on average, a 57% reduction in the number of individual cats, and a 65% reduction in the number of nights with cat detections, relative to pre-fire levels. Although cat detections declined following the fire, reduced population sizes of prey species and reduced cover as a result of the fire might still mean that cat predation is a threat to some surviving prey species. Management that reduces feral cat predation pressure on wildlife following wildfire should enhance the likelihood of post-fire wildlife persistence and recovery.