The spatial ecology of free-ranging domestic pigs (Sus scrofa) in western Kenya
Thomas LF, de Glanville WA, Cook EA, Fèvre EM
BMC Veterinary Research 2013
In many parts of the developing world, pigs are kept under low-input systems where they roam freely to scavenge food. These systems allow poor farmers the opportunity to enter into livestock keeping without large capital investments. This, combined with a growing demand for pork, especially in urban areas, has led to an increase in the number of small-holder farmers keeping free range pigs as a commercial enterprise. Despite the benefits which pig production can bring to a household, keeping pigs under a free range system increases the risk of the pig acquiring diseases, either production-limiting or zoonotic in nature. This study used Global Positioning System (GPS) technology to track free range domestic pigs in rural western Kenya, in order to understand their movement patterns and interactions with elements of the peri-domestic environment.
We found that these pigs travel an average of 4,340 m in a 12 hr period and had a mean home range of 10,343 m2 (range 2,937–32,759 m2) within which the core utilisation distribution was found to be 964 m2 (range 246–3,289 m2) with pigs spending on average 47% of their time outside their homestead of origin.
These are the first data available on the home range of domestic pigs kept under a free range system: the data show that pigs in these systems spend much of their time scavenging outside their homesteads, suggesting that these pigs may be exposed to infectious agents over a wide area. Control policies for diseases such as Taenia solium, Trypanosomiasis, Trichinellosis, Toxoplasmosis or African Swine Fever therefore require a community-wide focus and pig farmers require education on the inherent risks of keeping pigs under a free range system. The work presented here will enable future research to incorporate movement data into studies of disease transmission, for example for the understanding of transmission of African Swine Fever between individuals, or in relation to the life-cycle of parasites including Taenia solium.
Breeding Biology and Diet of the African Swallow-Tailed Kite (Chelictinia riocourii) in Senegal and Cameroon
Ralph Buij, Simon Cavaillès, and Wim C. Mullié
Journal of Raptor Research 2013 47 (1), 41-53
We studied the breeding biology of the African Swallow-tailed Kite (Chelictinia riocourii) in two study areas located 3400 km apart in the central (Cameroon) and western (Senegal) portions of the species‘ breeding range. With 110 nests in 2.8 km2 of suitable breeding habitat, Kousmar islet (23 km2) in Senegal supports the largest documented colony of African Swallow-tailed Kites known to date. Breeding kites in Senegal nested in a single large colony near a massive winter roost. In Cameroon, breeding colonies averaged seven pairs/colony, with nest densities of 0.3 nests/km2 in protected woodland and 0.9 nests/km2 in cultivated habitat. Egg-laying coincided with the end of the dry season in Cameroon, but eggs were recorded from the middle of the dry season in Senegal. Eggs hatched between April and June in both study sites in 2010, but from March 2012 in Senegal. The incubation period was estimated at 27–31 d based on two nests, and the fledging period was 32–35 d (n = 3 fledglings). Mean clutch size was 2.5 eggs (n = 32) in Cameroon and 2.1 in Senegal (n = 29); one clutch of four eggs was recorded in Cameroon. Nest success estimated with the Mayfield method was low at 17% in Cameroon and exceptionally low at 4% in Senegal, possibly related to a combination of suboptimal food conditions, high predation pressure, intraspecific aggression, and lack of experience among breeding pairs. Prey items at nests were made up primarily of lizards (30–54% of items) and insects (27–49%), notably grasshoppers, whereas the diet at the winter roost in Senegal was predominantly Orthoptera (55%) and Solifugids (43%). Our study suggested that African Swallow-tailed Kites were able to adapt to moderate land transformation near floodplains.
Survival of Juvenile Ferruginous Hawks in Utah
Johanna M. Ward and Michael R. Conover
Journal of Raptor Research 2013 47 (1), 31-40
We examined the reproduction of Ferruginous Hawks (Buteo regalis) in Utah’s West Desert from 1997–99. We found 100 occupied territories during the study; 80 of them contained an active nest (i.e., evidence of eggs laid). Most active nests (91%) were successful in producing at least one hatchling, and 67% of nests with hatchlings produced at least one fledgling. We followed the fate of 202 Ferruginous Hawk hatchlings; 58% survived to fledging. We radio-tagged 46 of these fledglings; 72% survived the fledgling period and dispersed from their natal territories. Most juveniles that died were killed during the late nestling (58%) and fledgling (24%) period; mortality was lowest early in the nestling period (18%). Across all years, 42% of hatchlings did not survive long enough to disperse from their natal territory. Lagomorph abundance increased each year of our study and during 1999 was over 100 times higher than during 1997. Concomitantly, there was a significant difference among years in the proportion of nests that produced a hatchling and in the survival rate of hatchlings and fledglings. For all of these dependent variables, reproduction was lowest during 1997 when lagomorph densities were low and highest during 1999 when lagomorph densities were high. Yet, most juvenile mortalities were from depredation and not starvation. Most depredated juveniles were apparently killed by avian predators. We also found no relationship between the probability of juvenile depredation and either an index of parental nest attendance or an index of intensity of nest defense.
Survival and Home-range Size of Northern Spotted Owls in Southwestern Oregon
Jason W. Schilling, Katie M. Dugger, and Robert G. Anthony
Journal of Raptor Research 2013 47 (1), 1-14
In the Klamath province of southwestern Oregon, Northern Spotted Owls (Strix occidentalis caurina) occur in complex, productive forests that historically supported frequent fires of variable severity. However, little is known about the relationships between Spotted Owl survival and home-range size and the characteristics of fire-prone, mixed-conifer forests of the Klamath province. Thus, the objectives of this study were to estimate monthly survival rates and home-range size in relation to habitat characteristics for Northern Spotted Owls in southwestern Oregon. Home-range size and survival of 15 Northern Spotted Owls was monitored using radiotelemetry in the Ashland Ranger District of the Rogue River–Siskiyou National Forest from September 2006 to October 2008. Habitat classes within Spotted Owl home ranges were characterized using a remote-sensed vegetation map of the study area. Estimates of monthly survival ranged from 0.89 to 1.0 and were positively correlated with the number of late-seral habitat patches and the amount of edge, and negatively correlated with the mean nearest neighbor distance between late-seral habitats. Annual home-range size varied from to 189 to 894 ha ( = 576; SE = 75), with little difference between breeding and nonbreeding home ranges. Breeding-season home-range size increased with the amount of hard edge, and the amount of old and mature forest combined. Core area, annual and nonbreeding season home-range sizes all increased with increased amounts of hard edge, suggesting that increased fragmentation is associated with larger core and home-range sizes. Although no effect of the amount of late-seral stage forest on either survival or home-range size was detected, these results are the first to concurrently demonstrate increased forest fragmentation with decreased survival and increased home-range size of Northern Spotted Owls.
Is the Long-term Decline of Boreal Owls in Sweden Caused by Avoidance of Old Boxes?
Tim Hipkiss, Jonas Gustafsson, Ulf Eklund, and Birger Hörnfeldt
Journal of Raptor Research 2013 47 (1), 15-20
Numbers of Boreal Owls (Aegolius funereus) breeding in nest boxes in northern Sweden have declined since the 1980s. The main cause of this decline is thought to be a similar decline in voles, the owls‘ main prey. However, an alternative reason for the decline might be the aging of nest boxes and the owls‘ avoidance of old nest boxes to reduce the risk of predation. In this study we tested this alternative hypothesis in an experiment during the first two years of a 3-yr vole cycle by comparing predation and the number of breeding owls in old and new nest boxes at their original location, and old and new nest boxes placed at new locations. Predation was lower at relocated nest boxes, but Boreal Owls showed no preference for any of the four nest-box treatments, and breeding parameters did not vary between treatments. We conclude that the decline in the number of Boreal Owls breeding in nest boxes is real, and not caused by aging of nest boxes.
Distinctiveness in the Territorial Calls of Great Horned Owls within and among Years
Karan J. Odom, Jonathan C. Slaght, and R.J. Gutiérrez
Journal of Raptor Research 2013 47 (1), 21-30
Many animals have vocalizations that are individually distinguishable. Researchers can use these differences to facilitate monitoring of individuals. To be an effective monitoring tool, vocalizations must be recognizable throughout a season and preferably throughout an animal’s lifetime. We assessed whether the territorial calls of Great Horned Owls (Bubo virginianus) are individually distinct, both within a season and over several years. Both males and females could be readily identified by their territorial calls. Based on a comparison of within- to between-individual coefficients of variation and a multivariate analysis of variance (MANOVA), nearly all vocal characteristics we measured carried individually distinct information. Using forward stepwise discriminant function analysis (DFA), we found that the internote interval between the last short and first long note of the call was the most useful for identifying both individual males and females. The duration and minimum and maximum frequency of long notes were important for discriminating among individual males whereas the number of notes and total call duration were important characteristics for identifying individual females. Using cross-validation DFA, both male and female Great Horned Owls were accurately assigned to location both throughout a season and among years. Correct assignment of males was reduced across recording sessions and among years compared to within a recording session, but was still greater than expected by chance. Together, our results suggest that individually distinct vocalizations could be an effective tool for identification of Great Horned Owls for long-term monitoring.
Successful Serial Recloning in the Mouse over Multiple Generations
Sayaka Wakayama, Takashi Kohda, Haruko Obokata, Mikiko Tokoro, Chong Li, Yukari Terashita, Eiji Mizutani, Van Thuan Nguyen, Satoshi Kishigami, Fumitoshi Ishino, Teruhiko Wakayama
Cell Stem Cell – 7 March 2013 (Vol. 12, Issue 3, pp. 293-297)
Previous studies of serial cloning in animals showed a decrease in efficiency over repeated iterations and a failure in all species after a few generations. This limitation led to the suggestion that repeated recloning might be inherently impossible because of the accumulation of lethal genetic or epigenetic abnormalities. However, we have now succeeded in carrying out repeated recloning in the mouse through a somatic cell nuclear transfer method that includes a histone deacetylase inhibitor. The cloning efficiency did not decrease over 25 generations, and, to date, we have obtained more than 500 viable offspring from a single original donor mouse. The reprogramming efficiency also did not increase over repeated rounds of nuclear transfer, and we did not see the accumulation of reprogramming errors or clone-specific abnormalities. Therefore, our results show that repeated iterative recloning is possible and suggest that, with adequately efficient techniques, it may be possible to reclone animals indefinitely. Successful recloning of viable mice over 25 generations Cloning efficiency remains consistent over 25 iterations No evidence for the accumulation of reprogramming or genomic errors Serially recloned mice have the same characteristics as standard clones We carried out successful repeated recloning in the mouse over 25 generations, and we found no evidence of the accumulation of reprogramming errors or genetic abnormalities. Our results demonstrate that iterative recloning is possible and suggest that it may be possible to reclone animals indefinitely.
Caffeine in Floral Nectar Enhances a Pollinator’s Memory of Reward
G. A. Wright, D. D. Baker, M. J. Palmer, D. Stabler, J. A. Mustard, E. F. Power, A. M. Borland, and P. C. Stevenson
Science 8 March 2013: 339 (6124), 1202-1204. [DOI:10.1126/science.1228806]
Plant defense compounds occur in floral nectar, but their ecological role is not well understood. We provide evidence that plant compounds pharmacologically alter pollinator behavior by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees‘ bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.
Stephanie L. King, Laela S. Sayigh, Randall S. Wells, Wendi Fellner, and Vincent M. Janik
Vocal copying of individually distinctive signature whistles in bottlenose dolphins
Proc. R. Soc. B April 22, 2013 280 1757 20130053; doi:10.1098/rspb.2013.0053 1471-2954
Vocal learning is relatively common in birds but less so in mammals. Sexual selection and individual or group recognition have been identified as major forces in its evolution. While important in the development of vocal displays, vocal learning also allows signal copying in social interactions. Such
copying can function in addressing or labelling selected conspecifics. Most examples of addressing in non-humans come from bird song, where matching occurs in an aggressive context. However, in other animals, addressing with learned signals is very much an affiliative signal. We studied the function of vocal copying in a mammal that shows vocal learning as well as complex cognitive and social behaviour, the bottlenose dolphin (Tursiops truncatus). Copying occurred almost exclusively between close associates
such as mother–calf pairs and male alliances during separation and was not followed by aggression. All copies were clearly recognizable as such because copiers consistently modified some acoustic parameters of a signal when copying it. We found no evidence for the use of copying in aggression or deception. This use of vocal copying is similar to its use in human language, where the maintenance of social bonds appears to be more important than the immediate defence of resources.
Garofalo, L., Mastrogiacomo, A., Casale, P., Carlini, R., Eleni, C., Freggi, D., Gelli, D., Knittweis, L., Mifsud, C., Mingozzi, T., Novarini, N., Scaravelli, D., Scillitani, G., Oliverio, M. and Novelletto, A. (2013), Genetic characterization of central Mediterranean stocks of the loggerhead turtle (Caretta caretta) using mitochondrial and nuclear markers, and conservation implications. Aquatic Conserv: Mar. Freshw. Ecosyst.. doi: 10.1002/aqc.2338
1. In migratory species female- and male-mediated gene flow are important for defining relevant Management Units, and for evaluating connectivity between these and their respective foraging grounds.
2. The stock composition at five Mediterranean foraging areas was investigated by analysing variation in the mitochondrial D-loop and six microsatellite loci in a sample of 268 loggerhead turtles (Caretta caretta) stranded or accidentally caught by fisheries. This involved a comprehensive Mixed Stock Analysis which considers also recent data from major rookeries in Libya and Turkey, and the generation of a standardized nomenclature of allele sizes at the microsatellite loci.
3. The results indicate:
– that the north Adriatic, the Tunisian continental shelf, the waters around Malta and the Italian Ionian Sea represent important areas for the conservation of rookeries in Greece, Libya and Turkey, respectively;
– that waters off the Italian peninsula and the islands of Lampedusa and Malta are mainly inhabited by individuals of Mediterranean origin, with a major contribution from the nearest and largest colonies, while Atlantic turtles are restricted to the western areas;
– that specific migratory routes exist from rookeries to foraging grounds;
– a poor bi-parental genetic structuring, which suggests a high male-mediated gene flow in the Mediterranean;
– mixing of small turtles in waters distant from natal rookeries, and recovery of structuring for large-sized individuals; and
– that uncommon mtDNA haplotypes are more powerful markers than microsatellite alleles in assessing an individual’s origin, owing to their higher geographic specificity.