Keeping an eye on the use of eye-lens weight as a universal indicator of age for European wild rabbits

AbstractAccurate methods for age determination are critical to the knowledge of wildlife populations' age structure and, therefore, to their successful management. The reliability of age estimation may have profound economic and ecological consequences on the management of the European wild rabbits, Oryctolagus cuniculus, in its native and introduced range, where it is a keystone species and a major pest, respectively. As in other mammal species, European rabbits' age is often estimated using the Gompertz relationship between age and lens' weight. The growth rate formula has been developed based on data collected from European rabbits introduced in Australia, where a single subspecies (O. cuniculus cuniculus, Occ) is present. However, this curve has never been validated in the species native range, the Iberian Peninsula, where two subspecies (Occ, and O. c. algirus, Oca) coexist naturally. In this study, we tested the relationship between age and lens' weight using 173 Occ and 112 Oca wild rabbits that were surveyed in two experimental facilities in Spain. Our findings show that, in the native range, the published growth curve formula fits well Occ but not Oca data. Therefore, we recommend using the formula reported in this study to estimate the age of Oca (Lens dry weight = 240 × 10(−64.9/(Age+32))). This study supports Oca rabbits' distinctiveness revealed by previous studies, which suggests that management interventions should be applied to protect this subspecies whose distribution range is very narrow and whose populations seem to be declining. More broadly, our findings point to the importance of testing the suitability of growth curves defined for other species with different genetic forms as occurs in the European wild rabbit case.

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Seedling growth of summer-dormant and non-dormant ryegrasses in relation to temperature

Australian Journal of Agricultural Research ◽

10.1071/ar9690417 ◽

1969 ◽

Vol 20 (3) ◽

pp. 417 ◽

Cited By ~ 2

Author(s):

JH Silsbury

Keyword(s):

Dry Matter ◽

Growth Curves ◽

Dry Weight ◽

Detailed Examination ◽

Dry Matter Production ◽

Controlled Environment ◽

Lolium Rigidum ◽

Relative Growth ◽

Lolium Perenne L ◽

Matter Production

Lolium rigidum Gaud. and a summer-dormant and a non-dormant form of Lolium perenne L. were grown as seedling plants for 32 days in controlled environment cabinets at constant temperatures of either 10, 20, or 30°C and in all cases with a 16-hr photoperiod at a light intensity of 3600 lm ft-2. Sampling at 4-day intervals permitted the detailed examination of dry matter growth curves. Differences in total dry matter production were related to initial differences in seedling dry weight, and the general responses to temperature were similar for each ryegrass. Total dry matter production was greatest at 20°C and lowest at 10°. A temperature of 30° did not induce dormancy in the summer-dormant ryegrass but did depress growth. Relative growth rate fell with time at each temperature.

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Can widespread generalist predators affect keystone prey? A case study with red foxes and European rabbits in their native range

Population Ecology ◽

10.1007/s10144-015-0510-5 ◽

2015 ◽

Vol 57 (4) ◽

pp. 591-599 ◽

Cited By ~ 9

Author(s):

Javier Fernandez-de-Simon ◽

Francisco Díaz-Ruiz ◽

Manuel Rodríguez-de la Cruz ◽

Miguel Delibes-Mateos ◽

Rafael Villafuerte ◽

...

Keyword(s):

Generalist Predators ◽

Native Range ◽

Red Foxes ◽

European Rabbits

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The biogeography of prediction error: why does the introduced range of the fire ant over-predict its native range?

Global Ecology and Biogeography ◽

10.1111/j.1466-8238.2006.00258.x ◽

2007 ◽

Vol 16 (1) ◽

pp. 24-33 ◽

Cited By ~ 232

Author(s):

Matthew C. Fitzpatrick ◽

Jake F. Weltzin ◽

Nathan J. Sanders ◽

Robert R. Dunn

Keyword(s):

Prediction Error ◽

Fire Ant ◽

Native Range ◽

Introduced Range

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Differences in seed properties and germination between native and introduced populations of Triadica sebifera

Journal of Plant Ecology ◽

10.1093/jpe/rtz048 ◽

2019 ◽

Vol 13 (1) ◽

pp. 70-77 ◽

Cited By ~ 1

Author(s):

Jialiang Zhang ◽

Evan Siemann ◽

Baoliang Tian ◽

Wei Huang ◽

Jianqing Ding

Keyword(s):

United States ◽

Seed Germination ◽

Soluble Protein ◽

Native Species ◽

Seed Mass ◽

The United States ◽

Invasion Success ◽

Native Range ◽

Triadica Sebifera ◽

Introduced Range

Abstract Aims Seeds of many invasive plants germinate more quickly than those of native species, likely facilitating invasion success. Assessing the germination traits and seed properties simultaneously for introduced and native populations of an invasive plant is essential to understanding biological invasions. Here, we used Triadica sebifera as a study organism to examine intraspecific differences in seed germination together with seed characteristics. Methods We measured physical (volume, mass, coat hardness and coat thickness of seeds) and chemical (crude fat, soluble protein, sugar, gibberellins [GA] and abscisic acid [ABA] of kernels) properties of T. sebifera seeds collected in 2017 from 12 introduced (United States) populations and 12 native (China) populations and tested their germination rates and timing in a greenhouse experiment in China. Furthermore, we conducted an extra experiment in the United States using seeds collected in 2016 and 2017 to compare the effects of study sites (China vs. United States) and seed collection time (2016 vs. 2017) on seed germination. Important Findings Seeds from the introduced range germinated faster than those from the native range. Physical and chemical measurements showed that seeds from the introduced range were larger, had higher GA concentrations and GA:ABA ratio, but lower crude fat concentrations compared to those from the native range. There were no significant differences in seed mass, coat hardness and coat thickness or kernel ABA, soluble protein or sugar concentrations between seeds from introduced vs. native ranges. Germination rates were correlated between United States and China greenhouses but germination rates for populations varied between collection years. Our results suggest that larger seeds and higher GA likely contribute to faster germination, potentially facilitating T. sebifera invasion in the introduced range.

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Aspergillus tubingensis Is a Pre-Emergent Pathogen of Date Palm Seedlings

Forests ◽

10.3390/f11121327 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1327

Author(s):

Maryam Alomran ◽

Jos Houbraken ◽

George Newcombe

Keyword(s):

Seed Germination ◽

Date Palm ◽

Seedling Emergence ◽

Aspergillus Tubingensis ◽

Native Range ◽

Penicillium Species ◽

Introduced Range ◽

Southwestern Usa ◽

Emergent Pathogen ◽

Positive Effect

Many diseases of date palm are known. However, pathogens that might affect seed germination and seedling emergence from soil are poorly studied, perhaps because date palm cultivars are propagated vegetatively. Here, we first determined the effects of date seed fungi on the germination and emergence of 600 seeds overall (i.e., 200 of each of three cultivars: ‘Thoory’, ‘Halawi’, and ‘Barhi’). In each cultivar, 100 seeds were from Saudi Arabia (part of the native range), and 100 were from the southwestern USA (where the date palm was introduced around 1765). Just four fungal genera (i.e., Alternaria, Aspergillus, Chaetomium, and Penicillium) were isolated from the surface-sterilized date seeds. Aspergillus isolates all belonged to Aspergillus sect. Nigri; collectively they were in the highest relative abundance at 39%, and significantly more common in Saudi Arabian seeds than in American seeds. Aspergillus reduced seed germination and also reduced emergence when germinated and non-germinated seeds were planted in potting mix in a greenhouse. In contrast, Penicillium species were more common in American than in Saudi seeds; Penicillium did not affect germination, although it did have a positive effect on seedling emergence. In a second experiment with 17 seeds of the ‘Halawi’ cultivar, fungus-free seeds were either inoculated with isolates of Aspergillus sect. Nigri or not, and then planted. Controls emerged whereas Aspergillus-inoculated seeds did not. Finally, a third experiment was conducted with Aspergillus tubingensis Mosseray, a sect. Nigri member, as sole inoculum of 100 ‘Halawi’ seeds versus 100 uninoculated controls. Aspergillus tubingensis exerted the same pathogenic effects on germinating and emerging seedlings as the isolates identified only to Aspergillus sect. Nigri. Aspergillus tubingensis is thus a previously unreported, seedborne pathogen affecting date palm seedlings. Our findings also suggest that A. tubingensis may be more common in seeds in the host’s native range than in its introduced range.

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Do YellowhammersEmberiza citrinellaachieve higher breeding productivity in their introduced range than in their native range?

Bird Study ◽

10.1080/00063650509461394 ◽

2005 ◽

Vol 52 (2) ◽

pp. 217-220 ◽

Cited By ~ 2

Author(s):

Catriona J. Macleod ◽

David M.B. Parish ◽

Richard P. Duncan ◽

Stephen D. Wratten ◽

Stephen F. Hubbard

Keyword(s):

Native Range ◽

Introduced Range

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Age Determination in the Dingo and Crossbreeds.

Wildlife Research ◽

10.1071/wr9910075 ◽

1991 ◽

Vol 18 (1) ◽

pp. 75 ◽

Cited By ~ 3

Author(s):

PC Catling ◽

LK Corbett ◽

M Westcott

Keyword(s):

Age Estimation ◽

Canis Familiaris ◽

Age Determination ◽

Growth Curves ◽

Growth Patterns ◽

Birth Date ◽

Eye Lens ◽

Body Measurements ◽

Confidence Limits ◽

Regular Body

Growth curves were derived for captive known-age dingoes, Canis familiaris dingo, and their crosses with similarly sized domestic dogs, C. f. familiaris. Regular body measurements including weight and dried eye-lens weights were used. Age calibration curves and confidence limits were then produced to enable age estimation of animals of unknown birth date. Head length was the better predictor of age up to about 120 days, and eye-lens weight to about 500 days. The only difference in growth patterns in dingoes and crossbreeds from central and southern Australia was between sexes.

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Protected areas in boreal Canada: a baseline and considerations for the continued development of a representative and effective reserve network

Environmental Reviews ◽

10.1139/er-2013-0056 ◽

2014 ◽

Vol 22 (2) ◽

pp. 135-160 ◽

Cited By ~ 29

Author(s):

Margaret E. Andrew ◽

Michael A. Wulder ◽

Jeffrey A. Cardille

Keyword(s):

Protected Areas ◽

Boreal Forests ◽

Management Practices ◽

Sustainable Forest Management ◽

Gap Analysis ◽

Natural Disturbance ◽

Boreal Zone ◽

Mammal Species ◽

Disturbance Regimes ◽

Management Interventions

Boreal forests maintain regionally important biodiversity and globally important ecosystem services, such as carbon storage and freshwater resources. Many boreal systems have limited anthropogenic disturbances and are preserved, in effect, to date largely by their harsh climates and remoteness. As of 2011, almost 10% of Canada is subject to some manner of formal protection, with 4.5% of this protected area found within the boreal zone. The management of existing parks and protected areas (PPAs) is shared amongst many federal, provincial, and territorial jurisdictions. Although there are currently low levels of anthropogenic development in some portions of the boreal zone (especially the north), if expansion of protected areas is of interest, there are challenges to traditional PPA networks that may be more prominent in the boreal zone than elsewhere: (1) the boreal zone is home to charismatic mammal species with area requirements much larger than typical PPAs; (2) the boreal zone is characterized by natural disturbance regimes that impact large areas; and (3) projected changes to climate for the boreal zone are among the greatest in the world, creating temporal considerations for conservation planning exercises. There is currently no PPA assessment specific to boreal Canada. To address this lack of an assessment, we developed a conservation gap analysis of the current PPA system with respect to a variety of environmental surrogates (ecozones, land cover, vegetation productivity, and landscape structure). The amount of formally protected land varied within each surrogate, with few commonly reported features meeting national or international conservation targets. Furthermore, few reserves met the areal requirements that have been previously recommended to protect large mammals or accommodate the disturbance regimes present. We also discuss considerations and implications of area-based versus value-based protection objectives. While recognizing that there are still scientific challenges around understanding and evaluating the effectiveness of PPAs, based upon our review and assessment, the following considerations should inform conservation options for the boreal zone: (1) representation of the distribution of natural features within the PPA network; (2) effective maintenance of habitat requirements and spatial resilience to both cyclical and directional changes in spatial patterns through large, connected reserves; and (3) implementation of sustainable forest management practices (where applicable) throughout the broader landscape, as traditional on-reserve protection is unlikely to be sufficient to meet conservation goals. The Canadian boreal is unique in possessing large tracts of inaccessible forested lands that are not subject to management interventions, thereby offering functions similar to protected lands. The question of how to more formally integrate these lands into the existing PPA network requires further consideration. Further, the important temporal role of landscape dynamics in designing an effective PPA needs to be further studied as well as development of a better understanding of design needs in the context of a changing climate.

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Age determination and growth of Atlantic redfish (Sebastes marinus and S. mentella): bias and precision of age readers and otolith preparation methods

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2005.01.018 ◽

2005 ◽

Vol 62 (4) ◽

pp. 655-670 ◽

Cited By ~ 23

Author(s):

Christoph Stransky ◽

Sif Gudmundsdóttir ◽

Thorsteinn Sigurdsson ◽

Svend Lemvig ◽

Kjell Nedreaas ◽

...

Keyword(s):

Stock Assessment ◽

Age Determination ◽

Growth Curves ◽

Age And Growth ◽

Preparation Methods ◽

Irminger Sea ◽

Coefficients Of Variation ◽

Commercial Species ◽

Almost All

Abstract Age determination of Atlantic redfish (Sebastes spp.) has proven difficult and has led to inconsistent age and growth estimates in the past. Using otoliths of the two major commercial species, golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella), a series of exchange schemes was carried out to assess bias and precision of age readings between four readers and between two preparation methods. Considerable bias between readers and moderate precision were observed for the S. marinus readings, especially for ages >20 years, with coefficients of variation (CV) of 7.7–12.0% and average percent error (APE) of 5.4–8.5%. Agreement between readers increased from 17–28% to 45–61% when allowing deviations of ±1 year, and to 80–92% with ±3 years tolerance. The age of S. marinus determined from broken and burnt otoliths was estimated to be slightly lower than when the age of the same individuals was determined from thin-sectioned otoliths. The bias and precision estimates obtained from the S. mentella material were generally poorer than for S. marinus (CV 8.2–19.1%, APE 5.8–13.5%), but similar to reported values for other long-lived fish species. Better than 50% agreement was only achieved with ±3 years tolerance. Growth rates differed significantly between species, confirming slower growth for S. mentella. For S. marinus, only one reader comparison revealed significantly different growth functions, whereas almost all S. mentella reader pairs showed significant differences in growth curves. Section and break-and-burn readings of S. marinus did not differ significantly. Average ages of around 9–10 years were determined for juvenile S. mentella 24–30 cm long, which were likely to have migrated from East Greenland into the Irminger Sea, based on earlier observations. As some of the error in the age determinations presented could be attributed to interpretation differences between readers, further intercalibration of redfish ageing is urgently needed in order to provide consistent input data for stock assessment.

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Hares and rabbits (Leporidae) in collection of the Šariš Museum, Bardejov (Slovakia)

Theriologia Ukrainica ◽

10.15407/tu1907 ◽

2020 ◽

Vol 2020 (19) ◽

pp. 60-65

Author(s):

Alexander Csanády ◽

Keyword(s):

Oryctolagus Cuniculus ◽

Pannonian Basin ◽

Lepus Europaeus ◽

Wild Rabbit ◽

Brown Hare ◽

Mammal Species ◽

North Eastern ◽

Total Data ◽

Time Capsule ◽

History Department

The Natural History Department of the Šariš Museum, Bardejov, Slovakia, was established in 1956 by PhMr. Tibor Weisz. The mammal collection consists of more than 5 000 specimens of 67 mammal species of the Slovakian fauna. The museum mostly represents the fauna of north-eastern Slovakia, i.e. the transition area between the Eastern and Western Carpathians and adjacent to the northernmost part of the Pannonian Basin. In the paper, data are presented on hare and rabbit specimens deposited in the collection of the Šariš Museum in Bardejov (SMB), Slovakia. In total, data were evaluated on 27 specimens of the brown hare (Lepus europaeus) from twelve sites of Slovakia (n = 19), one site of Czech Silesia (n = 1), and from unknow localities (n = 7). Individuals were acquired in 1958–1971, but mainly in 1965–1966 (n = 19, 70.4 %). Among them, one specimen had signs of „albinism“ and was collected from Zlaté village. The collection also includes a skull of a brown hare with anomalous dentition. Similarly, two skulls of the mountain hare (Lepus timidus) obtained from the Danish preparator N. H. Gustaffson were evaluated. Three rabit specimens were also found in the collection, including two skulls of the wild rabbit (Oryctolagus cuniculus) and a skin-mount and skull of a domestic rabbit (Oryctolagus cuniculus forma domestica). The collection contains 20 adult specimens (15 males and 5 females) with body size values recorded in the protocol cards. Mammalogical collections in the Šariš Museum in Bardejov represent an outstanding scientific time capsule. All stored specimens in this particular and other similar collections, including those in local museums, will largely be needed and used as datasets by ecologists and conservationists in the future. It is necesary to preserve the collections, to computerise and digitise their inventories and the wealth of information they represent. At present, most of these data are not accessible electronically or online. Therefore, such collections, including that in Bardejov, must be sustained for a long term, which will require increased funding for their physical and scientific preservation.

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