Written by Brian Pomfret, Interpretive Naturalist, Ruthven Park NHS, February 2007
Situated in rural Cayuga along the Grand River, Ruthven Park consists of approximately 1500 acres of mixed natural and agricultural lands, the historic estate of the Thompson family, and part of the former village of Indiana. Since 1995 the land has been owned and managed by the Lower Grand River Land Trust (LGRLT), a non-profit, non-governmental, community-based, charitable organization dedicated to the conservation and preservation of the land and historical resources entrusted to its care.
Ruthven Park is located within the Carolinian Life Zone. In Canada this is found only in southern Ontario within a relatively small band of territory along the northern shore of Lake Erie. It contains many species and communities of plants and animals found nowhere else in Canada.
Ontario represents the northernmost edge of the Carolinian Life Zone and many of the species found within this zone in Canada are consequently at the extreme northern end of their range. This extremity of range and the small size of the Carolinian Life Zone in Canada means that many of the Carolinian species found in Canada are considered to be nationally uncommon or rare. In many cases they are more abundantly represented in the heart of their range further south in the United States.
The forested areas of Ruthven Park represent one of the largest remaining forestland complexes in Haldimand County, and in the Carolinian Life Zone of Ontario. As a consequence Ruthven Park has been designated provincially as an Area of Natural and Scientific Interest and regionally as an Environmentally Sensitive Area. The wetland areas found within the park are also significant and have been designated provincially as Class 1 Wetlands.
_______________Sidenote: Carolinian Life Zones_______________
The “Life Zone” concept was developed in 1889 by C. Hart Merriam, an American zoologist and a founder of the US National Geographic Society, as a means of describing areas with similar plant and animal communities.
The Carolinian Life Zone is centred in the Carolinas in the United States and is found in Canada only in the southwestern section of Ontario. Carolinian forest is characterized by a predominance of deciduous, or broad-leafed, tree species.
Although only approximately 1% of Canada falls within the Carolinian Life Zone, more species of plants and animals are found here than anywhere else in Canada. Over 2200 species of plants are found within the Carolinian zone in Canada.
If You Go into the Woods Today
The largest forested section of Ruthven Park is located east of Haldimand Highway #54 and north of Indiana Road. The topography, soils, and vegetation of this forest block are fairly uniform except for the presence of wetland sloughs and vernal pools that are interspersed throughout the area. Variations in vegetation community types are minor and are generally due to differences in historical land usage and small changes in topography. The extant forest is mainly deciduous with Sugar Maple (Acer saccharum) being a consistent and significant component. Other common species include White Oak (Quercus alba), Bur Oak (Q. macrocarpa), Red Oak (Q. rubra), Shagbark Hickory (Carya ovata), Red Ash (Fraxinus pennsylvanica) Red Maple (A. rubrum), and White Ash (F. americana).
Portions of the tree communities within Ruthven Park range in age and maturity from young stands to mature closed forests. Some sections have been extensively logged in the last 50 years, but other areas appear to have been relatively untouched. A number of the forest stands contain large individual trees, mostly White Oak or Bur Oak, that are thought to predate the creation of the Ruthven Park Estate and European colonisation.
_________________Species note: Bur Oak____________________
Bur Oak is so named for the burr-like bristles found around the edge of the cap of Bur Oak acorns. The Bur Oak can be found in a variety of habitats but prefers clay soils with neutral or higher pH. It is tolerant of seasonal flooding and drought.
The acorns of the Bur Oak were a common part of the diet of the aboriginal peoples that once inhabited the area and are significant to many wildlife species such as deer, Racoon (Procyon lotor), woodpeckers, and Wood Duck (Aix sponsa). The Bur Oak produces a large crop of acorns every two or three years.
The Bur Oak can grow to 18-20m in height and 60-120cm in diameter and live for 200-300 years.
A Plethora of Plants
A wide variety of plant species can be found at Ruthven Park. An inventory conducted in 1997 identified 569 species of vascular plants. This diversity, at least in part, is encouraged by the area’s location in the Lake Erie Basin climatic region of Ontario. This is the warmest region of Ontario and provides a long growing season with moderate rainfall.
A total of 118 of the plant species recorded at Ruthven Park are not considered native to Haldimand County. While this total, approximately 20%, seems high, it is considered to be average for southern Ontario given the region’s history of human disturbances and land usage. The non-native plant of most concern is Garlic Mustard (Allaria petiolaris), which originates in Europe and colonises disturbed habitats. Garlic Mustard forms dense masses that choke out native under-storey species by the weight of their numbers. It also gives off allelopathic compounds that inhibit the growth of other plant species and are thought to kill salamanders and ants that pollinate some native plants.
Thirteen of the plant species recorded are provincially rare and 95 are uncommon and/or have restricted ranges in Ontario.
______________Species note: Shagbark Hickory_______________
The shaggy appearance of older Shagbark Hickory comes from the 30-90cm plates of bark that curl away from the trunk at one or both ends. Shagbark Hickory can be found growing in many different substrates from sand and gravel to clay, in wet or dry conditions.
Shagbark Hickory nuts have very thick husks but the kernel inside is sweet; consequently they are a favoured food source for squirrels and other rodents that can penetrate the thick shells. Aboriginal communities and early European colonists also widely used the nuts as a source of food.
Shagbark Hickory can grow to 18-22m in height, with a diameter of 30-80cm, and can live for more than 250 years.
________________Species note: Black Walnut_________________
Black Walnut (Juglans nigra) can be found in a wide variety of soil types. In the heavier soils of Ruthven Park it prefers to grow in elevated locations. Much prized for its durable wood and the high protein content of the walnuts, the Black Walnut was widely planted by aboriginal communities and early European colonists. Compounds from the seeds were also used as a brown dye.
The Black Walnut exudes a toxic substance called juglone that inhibits the growth of other plants, including other Black Walnuts. This allelopathy is thought to reduce competition.
The nuts of the Black Walnut are valuable food sources for squirrels and other rodent species, deer, and Red-Bellied Woodpeckers (Melanerpes carolinus). Its foliage is the preferred food source of the Luna Moth (Actias luna).
Black Walnut can reach heights of 20 to 30m and live for more than 150 years
Here’s the Dirt on Sloughs
Ruthven Park is located on the Haldimand Clay Plain, a region of mostly heavy-textured soils with poor drainage. The soils of Ruthven Park tend to be saturated in the spring due to snowmelt and dry out very slowly as the year progresses. Surface water collects in lowland areas and form vernal pools and sloughs. Most of these vernal pools and sloughs have standing water in the spring and early summer but are dry by late summer. The vegetation found in these areas tend to be wetland varieties or species that are tolerant of periodic inundation.
Sloughs and vernal pools provide valuable breeding sites for insects with aquatic larval stages, such as mosquitoes, and amphibians such as Wood Frog (Rana sylvatica) and Yellow-Spotted Salamander (Ambystoma maculatum). Since these bodies of water dry up during the year large predators such as fish are not present to depredate the developing insect and amphibian larvae, although insect predators such as aquatic beetles and Odonate larvae can be present.
_____________Species note: Ebony Jewelwing______________
The Ebony Jewelwing (Calopteryx maculata) is a common and widespread species of damselfly found near running water, particularly around shaded forest streams. Both the aquatic larval stage and the widely roaming adult are predacious. Adults have iridescent green bodies, with males having black wings and females brown with dark wing tips.
You’re Not Bugging Me
The huge numbers of insects that emerge from Ruthven Park’s vernal pools and wetland sloughs are a valuable food source for many species of birds. Neotropical migrants–birds that spend the winter in the tropics and nest in North America–travel to the northern hemisphere to nest because of the plentiful supply of insects. Long periods of cold weather shorten the amount of time insects can be active in North America. As a consequence most insects are active at the same time, providing an abundant and varied food supply for adult and young birds. In the warmer regions of Central and South America insect activity is less concentrated and feeding opportunities for birds as a result are less plentiful.
_____________Species note: Giant Swallowtail______________
The Giant Swallowtail (Papilio cresphontes), with its wingspan of between 83-113mm, is the largest butterfly found in Canada. It can be recognized by its large size and its dark brown wings crossed on the upper side by a diagonal band of bright yellow spots.
Larvae of the Giant Swallowtail resemble large bird droppings, which disguises them from predators. They feed upon Northern Prickly-Ash (Xanthoxylum americanum) which is found resident at Ruthven Park.
The Giant Swallowtail is uncommon in Ontario and may be at risk.
Birds of a Feather
Ruthven Park has been a centre for bird study in Canada since 1995. Research activities include migration monitoring at the Ruthven Park Bird Banding Station–part of the Haldimand Bird Observatory–during spring and fall; and nest box monitoring and breeding bird surveys during the summer months. A total of 188 species of birds and two hybrids have been encountered at Ruthven Park since monitoring began. This includes year-round residents such as Red-Bellied Woodpecker and Black-Capped Chickadee (Poecile atricapillus), through migrants such as Cape May Warbler (Dendroica tigrina) and Hermit Thrush (Catharus guttatus), nesting species such as Blue-Winged Warbler (Vermivora pinus) and Grey Catbird (Dumetella carolinensis), and winter residents such as American Tree Sparrow (Spizella arborea) and Slate-Coloured Junco (Junco hyemalis).
The forested habitats of Ruthven Park provide ample nesting sites for a wide variety of breeding species. Forked branches in the forest canopy and cavities within dead tree limbs or trunks are favoured spots. One of the largest birds found nesting at Ruthven Park is the Great Blue Heron (Ardea herodias) A small heronry (heron nesting colony) can be found near Indiana Road.
Populations of migrant birds benefit from the shelter and food resources found within the forests of Ruthven Park. Insects and seeds provide energy that the birds utilize during their northward and southward journeys, while the physical structure of the woods provide cover from predators and harsh weather conditions. The loss of such habitat greatly disrupts bird nesting and migration and the loss of forested habitat has played a major part in the worldwide decline of migratory songbird populations.
____________Species note: Red-bellied Woodpecker_____________
The Red-Bellied Woodpecker gets its name from the subtle stripe of red feathers that runs longitudinally down their bellies. This feature is very difficult to see in the field.
Found year round at Ruthven Park the Red-Bellied Woodpecker prefers to nest in cavities in dead limbs located on live trees. Oaks are favoured foraging locations to find insects burrowed into the wood or on the surface of the bark.
The Red-Bellied Woodpecker is listed as secure in Ontario and has become regionally more numerous in recent years.
____________Species note: Blue-gray Gnatcatcher_____________
The Blue-Grey Gnatcatcher (Polioptila caerulea) is a small vociferous bird that can be recognized by the white feathers lining its long tail. Resident during the breeding season at Ruthven Park the Blue-Grey Gnatcatcher builds nests of spider silk and moss on branches found in open deciduous sloughs and creek valleys.
The Blue-Grey Gnatcatcher is listed as secure in Ontario.
____________Species note: Blue-winged Warbler_____________
The Blue-Winged Warbler is a fairly recent addition to Ruthven Park, with the first one being recorded locally in Caledonia in 1955. Residing in shrubby clearings and woodland edges, the Blue-Winged Warbler has begun to supplant the similar Golden-Winged Warbler (Vermivora chrysoptera) over much of the latter’s range. Two hybrids are produced: the more common Brewster’s Warbler and the Lawrence’s Warbler, both of which can be found in Ruthven Park.
Crawl Out from Under a Log
Several species of terrestrial amphibians are found in the forests of Ruthven Park. Many of them spawn within the standing water of the vernal pools and wetland sloughs. When the eggs hatch and the larvae have finished their transformation into adults, they then disperse to upland sites in the forest to reside and forage for food. They generally return to water to breed. One species, the Redback Salamander (Plethodon cinereus), does not require standing water for any stage of its life cycle. Adults can be found under damp woody debris and stones on the forest floor, and eggs are laid in or under decaying logs. The Redback Salamander is also unusual in that the adults, usually the female, exhibit parental care for their eggs. Most species abandon their eggs to develop on their own. The female Redback Salamander guards her eggs against predators and secretes an antimicrobial substance from her skin that is then rubbed over the eggs to protect them from fungal growths.
Forest amphibians feed on a variety of small invertebrates and are in turn depredated by birds and mammals.
It’s a Jungle Out There
With its warm climate it should be no surprise that the Carolinian Life Zone in Canada contains the largest human population in Ontario. As a consequence, over 80% of the Carolinian Forest habitat found prior to European settlement has been destroyed. The remaining habitat faces a variety of threats such as forest fragmentation and isolation, pollution, and invasive non-native species.
Much of the forested land in Carolinian Canada was cleared to make way for fields, buildings, and roadways, leaving only small, generally isolated fragments of forest behind. These surviving segments can not support as large a population of birds and other wildlife as intact contiguous woodlands. In addition their small size limits the amount of shelter for residents, which are consequently more prone to depredation. In the case of nesting birds this means that nest predators such as Racoons and nest parasites such as Brown-Headed Cowbirds (Molothrus atar) have an easier time finding nests to depredate since there is a smaller area in which they have to search. This has had a severe negative impact on the reproductive success of many species of forest bird.
The intricate and extensive web of roadways that blanket the Carolinian Life Zone in Ontario has a significant detrimental effect upon terrestrial creatures, particularly herpetiles and small mammals. With only isolated pockets of habitat remaining, roadways generally act as barriers between fragments of extant habitat. This can isolate wildlife populations from important feeding, breeding, and over-wintering sites. Small, slow-moving creatures such as salamanders, snakes, and rodents are frequently struck and killed by vehicles as they attempt to cross busy roadways. This can lead to the extirpation (local extinction) of some residents of the remaining forest fragments, and reduce the chances of re-colonisation should surviving populations reside nearby.
Pollution from industry, residences, vehicle emissions, agriculture, even excess light and noise, all have negative impacts on the habitat quality of the remaining pockets of Carolinian forest. They affect resident species in a variety of detrimental ways, including reducing life spans and reproductive success.
______________Species note: Wood Frog_______________
Although found in many habitats in addition to the Carolinian Life Zone, the Wood Frog is a common resident in the forested habitats of Ruthven Park. Wood Frogs, recognisable by their black masks, spawn in the vernal pools and wetland sloughs that dot the area during early spring. Adults feed upon invertebrates found along the forest floor and can be found at great distances from water.
The Wood Frog is listed as secure in Ontario.
So Whatcha Gonna Do About It?
The Carolinian Forests of Ruthven Park are protected and preserved under the mandate of the LGRLT. In order to improve the ecosystem health of these natural lands, the Land Trust is gradually decommissioning active farmland surrounding the forests and re-establishing forest habitat. This forest expansion will have many positive effects, including increasing the available habitat and survival rate for resident wildlife species, secluding and sheltering the inner forest core from negative human impacts, and improving the robustness of the forest community as a whole.
You can become directly involved in the preservation and enhancement of the forests at Ruthven Park by joining the LGRLT. As a volunteer, you can assist with the planting and maintenance of native species, and in the removal of detrimental invasive non-native species such as Garlic Mustard. You can help indirectly by reducing your energy consumption and consequent negative footprint. Living more efficiently, with less waste, ultimately helps to protect natural habitats.
The lush Carolinian Life Zone in Ontario is the most unique in Canada. Despite centuries of destruction more species of plants and animals are found here than in any other Life Zone represented in Canada. As the regional human population increases, the threat to the surviving Carolinian habitat becomes more severe. In a country that prides itself on its diversity, the loss of the abundance represented by the Carolinian Life Zone would be a monumental shame.
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Waldron, Gerry. 2003. Trees of the Carolinian Forest: A Guide to Species, Their Ecology and Uses. The Boston Mill Press, Erin, Ontario.
Ruthven Park Fact Sheet No. 1: Ruthven Park Carolinian Forest was produced with the generous financial support of the Ontario Trillium Foundation