Long‐term wildlife road‐kill counts in New Zealand

Abstract

We compare the number of medium‐sized animals (between rat and dog‐size) killed on repeated counts along the same 1660 km of North Island highways in 1984, 1994 and 2005 with other counts going back to 1949. Elevenmammal and 14 bird species were recorded, but Australian possums (Trichosurus vulpecula), hedgehogs (Erinaceus europaeus) and rabbits (Oryctolagus cuniculus) predominated, and pukekos (Porphyrio porphyrio), mynas (Acridotheres tristis), and Australian magpies (Gymnorhina tibicen) were the most common birds. Counts of possums, hedgehogs and rabbits ranged between 0.7 and 89 corpses/100 km, and changed dramatically over six decades. The possum count rose 80% between 1984 and 1994, but declined 60% by 2005. A possible irruption of hedgehogs is reported in 1988–89, followed by an 82% decline in their numbers between 1994 and 2005. Although rabbit hemorrhagic disease was introduced to New Zealand in 1997, rabbit road‐kill increased 59% between 1994 and 2005. The relationship between road‐kill and traffic volume indicates that roads carrying more than 3000 vehicles per day act as barriers to larger mammals, while vehicles on less busy roads are more dangerous for crossing animals. We suggest that regular counts taken at annual intervals over the same roads is a useful method for gathering information about the changing distribution and relative abundance of certain animals on a provincial or national scale and over long periods of time. Regular counts at seasonal, monthly or weekly intervals are also a rich source of information.     

Mating and immunity in invertebrates

Mating and immunity are intimately linked to fitness. In both vertebrates and invertebrates, recent investigations into mate choice for immunity, tradeoffs between reproduction and immunity, and the relationships between post-mating processes and immune function have revealed that mating and immunity are also intimately linked to each other. Here, we focus on invertebrates and critically examine the evidence that immunity is under sexual selection, both pre- and post-mating, and explore other hypotheses linking mating and immunity. We find little evidence for a consensus regarding which theories best account for the accumulating empirical data. However, we suggest that progress can quickly be made by exploiting the intrinsic strengths of invertebrate model systems.     

A case of co-operative nursing and offspring care by mother and daughter feral horses

Among mammals, non-offspring nursing is the most extreme form of communal parenting. This is because lactation is the most energetically costly part of parental investment (Clutton-Brock, 1991; Packer, Lewis & Pusey, 1992). Non-offspring nursing is most common in species characterized by large litters and small kin groups (Packer et al ., 1992; e.g. lions Panthera leo : Pusey & Packer, 1994). Although non-offspring nursing has also been reported in monotocous species (e.g. water buffalo Bubalus bubalus , Murphey et al ., 1995; African elephant Loxodonta africana : Dublin, 1983; Lee, 1987; Indian elephant Elaphus maximus : MacKay, 1973; Rapaport & Haight, 1987; fallow deer Cervus dama : San José & Braza, 1993) it is almost always associated with reproductive errors (Riedman, 1982) such as milk theft or exclusive adoption (Packer et al ., 1992). However, simultaneous non-offspring nursing in monotocous species has been reported in some bat species (e.g. McCracken, 1984; Eales, Bullock & Slater, 1988), African elephants (Lee, 1987), and captive Indian elephants (Rapaport & Haight, 1987). Recent research, however, suggests that nutritive non-offspring nursing in African elephants is rarer than previously thought as most reported instances were probably non-lactating juveniles allowing infants to suckle (Lee & Moss, 1986; Lee, 1987, 1989).     

The use of guanidinium chloride in the preparation of stable cellular homogenates containing ATP

Rat eye lenses were prepared for ATP determination by homogenization in 8 M guanidinium chloride-0.01 M EDTA. Standards of ATP were made up in the same solution. ATP appears to be quite stable in this solution in both standards and lens homogenates whether storage is at room temperature, 4 degrees C, or -20 degrees C for up to several weeks. ATP was measured using a luciferin-luciferase preparation in Hepes buffer, pH 7.75. The photons of light produced were detected by a bioluminescence counter.     

Evolutionary transfer of ORF-containing group I introns between different subcellular compartments (chloroplast and mitochondrion)

We describe here a case of homologous introns containing homologous open reading frames (ORFs) that are inserted at the same site in the large subunit (LSU) rRNA gene of different organelles in distantly related organisms. We show that the chloroplast LSU rRNA gene of the green alga Chlamydomonas pallidostigmatica contains a group I intron (CpLSU.2) encoding a site-specific endonuclease (I-CpaI). This intron is inserted at the identical site (corresponding to position 1931-1932 of the Escherichia coli 23S rRNA sequence) as a group I intron (AcLSU.m1) in the mitochondrial LSU rRNA gene of the amoeboid protozoon Acanthamoeba castellanii. The CpLSU.2 intron displays a remarkable degree of nucleotide similarity in both primary sequence and secondary structure to the AcLSU.m1 intron; moreover, the Acanthamoeba intron contains an ORF in the same location within its secondary structure as the CpLSU.2 ORF and shares with it a strikingly high level of amino acid similarity (65%; 42% identity). A comprehensive survey of intron distribution at site 1931 of the chloroplast LSU rRNA gene reveals a rather restricted occurrence within the polyphyletic genus Chlamydomonas, with no evidence of this intron among a number of non- Chlamydomonad green algae surveyed, nor in land plants. A parallel survey of homologues of a previously described and similar intron/ORF pair (C. reinhardtii chloroplast CrLSU/A. castellanii mitochondrial AcLSU.m3) also shows a restricted occurrence of this intron (site 2593) among chloroplasts, although the intron distribution is somewhat broader than that observed at site 1931, with site-2593 introns appearing in several green algal branches outside of the Chlamydomonas lineage. The available data, while not definitive, are most consistent with a relatively recent horizontal transfer of both site-1931 and site- 2593 introns (and their contained ORFs) between the chloroplast of a Chlamydomonas-type organism and the mitochondrion of an Acanthamoeba- like organism, probably in the direction chloroplast to mitochondrion. The data also suggest that both introns could have been acquired in a single event.      

A Biochemical Study of Spore Germination in the Blue-green Alga Anabaena doliolum

The spores of Anabaena doliolum formed in light (light spores)and after transfer to darkness (dark spores) are biochemicallydifferent in that the light spores contain chlorophyll a andphycocyanin, while dark spores seem to lack them. The apparentbiosyntheses accompanying dark-spore germination seem to proceedin the following order: RNA, chlorophyll a, phycocyanin andDNA. Results of chloramphenicol treatment indicate that proteinsynthesis precedes RNA synthesis. The biosynthetic events followingRNA synthesis show a requirement for light.     

Limited mitochondrial DNA variation within South Africa's black rhino (Diceros bicornis minor) population and implications for management

The taxonomy of African black rhinoceros (Diceros bicornis) remains unresolved. Maintaining levels of genetic diversity and species rescue by reintroduction and restocking requires its resolution. We compared the sequences of the mitochondrial DNA (mtDNA) control region for a total of 101 D. bicornis from three subspecies: D. b. minor, D. b. michaeli and D. b. bicornis. A single unique haplotype was found within the 65 D. b. minor samples from KwaZulu‐Natal (KZN) Province, South Africa, 55 of which came from Hluhluwe‐iMfolozi Game Park (HiP) and Mkuzi Game Reserve (MGR) source populations. However, six different haplotypes were represented in eleven D. b. minor samples from Zimbabwe. Similarly, published autosomal microsatellite data indicate low levels of diversity within the KZN D. b. minor populations. The low levels of mtDNA diversity within the KZN metapopulation point to the possible need for genetic supplementation. However, there is a need to determine whether the low levels of genetic variation within KZN D. b. minor are a result of the recent bottleneck or whether KZN historically always had low diversity.