Thursday, April 08, 2010

RESEARCH NEWS: Gaps Made By Matriarchial Group Removal Do Not Last in High Deer Density Populations

Commentary on Miller et al. (2010). Tests of localized deer management for reducing deer browsing in forest regeneration areas. Journal of Wildlife Management 74: 370-378.

Managing deer on very small spatial scales has traditionally been problematic, but efforts to remove matriarchal social groups of deer may hold promise for reducing browsing impacts for 10-15 years. This could possibly create a spatial hole in the deer population, thereby allowing a sufficient window-of-opportunity for regeneration. The effectiveness of this approach depends on how accurately the "rose petal hypothesis" actually characterizes population expansion. The rose petal theory suggests that within a group, matriarchal does are located near the center and younger individuals establish home ranges that overlap radiating outward. In other words, removing matriarchal social groups will only work if deer exhibit low female dispersal distances, high female survival rates, and high philopatry.

Miller et al. tested the rose petal hypothesis in Randolph County, West Virginia (eastern North American deciduous forest). Deer densities were considered high (and in excess of sustainable numbers), estimated at 12-20 per square km, with a very skewed ratio typical of traditionally exploited deer populations (6-15 males: 100 females).

The authors first collected movement data (via telemetry) on 224 animals. A social group was identified and targeted for removal in a 1.1 square km area in 2002. A total of 51 deer were removed, 39 were female. This was estimated to be 80% of the animals in the 1.1 square km target area. Vegetation monitoring consisted of examining browsable units and actual browsing on tree regeneration. A second removal was conducted in 2005, with 26 of 31 removals being females.

After the 2002 removal, browsing dropped from 15% to 5% after removal and persisted at this level for 3 years. Telemetry data indicated that deer from surrounding areas did gradually shift their home range and fill in the void. Animals removed in 2005 were not closely related genetically to the 2002 removal group.

The authors were not sanguine about the effectiveness of this approach. It did provide a short-term benefit to the vegetation, but the duration of the benefit was brief and unlikely to translate to increased regeneration.

INDIANA NEWS: City Creates Community Deer Task Force

Involving the community at the earliest stages is smart politically. It fosters civic engagement and shares the burden of responsibility of decisions.

A southern Indiana city is looking for ways to deal with worries over more deer showing up in urban and suburban areas.

The Bloomington City Council on Wednesday unanimously approved creating a community deer task force following complaints from residents that the animals pose a safety risk.

Councilman Dave Rollo says he hopes the group will present its recommendations by September.

In September, a petition with 500 signatures was presented to City Council members and Monroe County commissioners asking them to create the task force.

Source: WTHR

Tuesday, April 06, 2010

UK NEWS: Deer-Vehicle Collsions Number 74,000 Per Year

The soaring numbers of wild deer are causing havoc on Britain's roads, devastating ancient woodlands and ruining gardens, wildlife experts warned yesterday.

Conservationists say the UK's deer population has doubled since the 1970s and is now close to 2million - a level not seen since the time of the Norman Conquest.

According to new figures from the National Deer Collisions Project, the animals cause 74,000 road accidents each year - and kill up to a dozen drivers and passengers.

Yesterday, Dr Jochen Langbein, co-ordinator of the project, warned that the number of accidents would rise unless the creatures were better controlled.

He said 100 people are injured and up to 12 killed each year when deer run into roads.

Last month an inquest heard how a father of two died when a deer crashed through his windscreen. The animal had been hit by another vehicle near Basingstoke, Hampshire, pushing it into the path of his van.

Insurers pay out around £15million a year to repair cars hit by the animals.

The worst accident blackspots are in the Ashdown Forest in East Sussex where more than 300 deer are hit by cars each year.

Accidents involving the animals are often serious because they leap up if they are startled while crossing roads. Some scientists believe they see beams from headlights as solid objects and try to jump over them - ending up crashing into windscreens.

Since the 1970s deer numbers have been rising by three to five per cent a year, and most conservationists agree that 30 per cent of deer have to be shot each year to stop numbers going up.

The muntjac species is a particular nuisance.

Just 20 inches tall, they breed all year round and can be a massive pest for gardeners.

Source: Daily Mail